300 AAC Blackout (Medium Length Gas Tube)

SierraAACBlackoutTest Specifications/Components

Firearm Used: CMMG

Barrel Length: 16″

Twist: 1 x 8″

Case: Remington

Trim-to Length: 1.363″

Primer: Rem 7 1/2


The 300 AAC Blackout (300 BLK, or 7.62x35mm) was created by Advanced Armament Corp. and Remington in order to provide the military with a way to shoot .30 caliber bullets from the M4 platform with only a barrel change. It has since become popular for a wide range of uses including hunting and home defense.

The cartridge shares case-head dimensions and body taper with the .223 Remington. Not only does this allow for compatibility with existing magazines and bolts, but it allows reloaders to form their own brass from cut-down 5.56mm or .223 cases – ensuring brass supply even in the event of a shortage of factory brass.

The 300 AAC Blackout is a similar concept to previous wildcats, such as the 30-221 and 300 Fireball, as well as the proprietary 300 Whisper®, except that 300 BLK was the first to be a SAAMI approved cartridge and any company is free to make firearms or ammunition.

300 AAC Blackout is also finding use with hunters, who may not have been able to legally hunt with .223 in their state, and who prefer .30 caliber bullets for medium-sized game. It provides similar effectiveness to the 7.62×39 or the slightly more powerful 30-30 cartridges except works in the more up-to-date AR15 platform. Effective range for hunting is about 100-150 yards.

Click here to download Sierra Bullet’s 300 AAC Blackout Load Data

This entry was posted in Reloading and tagged , , , , , , , . Bookmark the permalink.

105 Responses to 300 AAC Blackout (Medium Length Gas Tube)

  1. Ron says:

    Sounds like an interesting cartridge. What about headspace issues with the barrel change?

  2. Austin says:

    What length system is being used? You say medium length but the majority of guns are all pistol or carbine, no mid length really available from anyone except for a few custom barrel makers.

    • Austin – This would be considered the “carbine” length gas tube.

    • Lweatherby73@yahoo.com says:

      My dpms mini sass barrel uses a mid length gas tube not rifle, pistol, or carbine length. They are are little harder to come by but not impossible brownells sells them. I use the rifle buffer wich makes for a real light recoil light enough my eight year old shoots it with no complaints.

  3. Nick Staudenmyer says:

    Do you have load data for pistol length gas tube? I have one, and not a clue how to adjust charges for my trial loads. Thanks!

    • Nick – We have only the medium length tube data at this time. Thanks.

      • Nick Staudenmyer says:

        Do you have any suggestions on if this load data will work o.k. with pistol length? I’m afraid of over pressure. Using Lil’ Gun and want one good supersonic, and one good subsonic accurate loads.

      • We did not test these loads in a pistol length gas tube gun. I would not recommend that. Thanks – Duane Siercks, Sierra Bullets Ballistic Technician

      • Carlbo says:

        I’m one of several people I know that are waiting the pistol length data. Would greatly appreciate your efforts in this area.

  4. I downloaded the PDF, but you dont list the 220 gr subsonic loads. Your bullet was and is the most popular bullet for this cartridge. 10.8 – 11.2 grains of A1680 behind the 220 SMK is the best load this cartridge has for suppressor owners.

    • Adam – We are not releasing any sub-sonic data at this time. Thanks

      • Bob Bowers says:

        That is a shame as that is the real data I need to complete the information on loading sub-sonic with a suppressor. I bought 4 boxes of 220 Match King HPBT just for this and would love to know what loads you all recommend. I have a Daniels Defense M4 300AAC.

  5. Stan Martin says:

    Thanks for this information. I have begun reloading, including cutting .223/5.56 brass, and your company adds to my information database. Do you actually have the reloading information printed already as inserts to my Sierra Manual. Also, is this the only data produced so far or is there any other data sheets for the 300 BLK or 300 Whisper?

    • Stan – There are no update pages for the manual. You can print out the data from the pdf (above) and size it to fit the manual. This is all of the 300 AAC data. I do not know of any intentions of doing more data for the Blackout. Thanks – Duane Siercks, Sierra Bullets Ballistic Technician

  6. Steve says:

    I see you loaded the 110 gr bullets with AA 4100 but not the 125 gr bullets, was there a reason for this ?

  7. Doug says:

    I have some of your 125gr. Pro hunter bullets that I have yet to load. My question is concerning expansion. I was wondering about the speed range for proper expansion and does the blackout exceed min. specs in that regard?

    • The velocity parameters for expansion on the 125 ProHunter are stated as being 2700 fps up to 3600 fps. So, no the Blackout does not provide enough velocity to produce reliable expansion. I would recommend the 125 FNHP 30-30 bullet. – Duane Siercks, Sierra Bullets Ballistic Technician

      • Mike says:

        Sierra’s 2700 FPS minimum expansion velocity for the 125 grain Pro Hunter bullet given above is not consistent with calibrated ballistic gel testing of the 300 Blackout performed by Brassfetcher.com. Their testing of the 125 grain Sierra Pro Hunter at 2100 FPS exhibited expansion of .47, .69, and .71 inches with an average penetration of over 18 inches. In addition there are other gel tests and dozens of reports from hunters using the 300 Blackout/125 SPH on deer and hogs all reporting significant expansion.
        The 125 FNHP is un-suitable for the AR platform. It is too short and the meplat is too wide for reliable feeding from a magazine.

    • Mike says:

      Several members at 300blktalk.com have stated Sierra techs have told them the Sierra 125 Grain Pro Hunter will expand down to 1700 feet per second. So is the minimum expansion threshold 2700 feet per second as stated here or 1700 feet per second?

  8. Doug says:

    I’m not sure I’d recommend a bullet that does not provide enough velocity to produce reliable expansion for hunting. I’ll load them to hit POI as my other reliable 125gr. bullets. Thanks for the load data.

    • The 300 Blackout wasn’t necessarily designed as a hunting cartridge. It really has sparked interest as a plinking/target and maybe varmint round. The velocity potential is a bit less than the 30-30 and therefore the 30-30 bullets will give better expansion than will bullets designed to expand at higher velocity. We listed the bullets you asked about because they will work fine for the plinking/target applications that the Blackout is normally used for. Duane Siercks, Sierra Bullets Ballistic Technician

  9. Jon says:

    The 300 Blackout does very well with bullets designed for its velocity window in the role of hunting hogs and deer out to short/medium distances. Remington as well as Barnes branded ammunition exist as such, and are sold as such (Remington “Hoghammer” 130gr and Barnes VorTx 110gr).

    • Jon says:

      I look forward to Sierra’s excellent R&D coming up with competing products specifically designed for the 300 Blackout. There is definitely a market-vacuum to be filled in this caliber, currently.

  10. Doug says:

    I’ve taken deer with the 125gr. Nosler bullet in the 300 Blackout. Was hoping the 125gr. Pro Hunter would be an alternative. What can I say, I like Sierra bullets. I’ve used Pro Hunters with success at higher grain weights and got excellent accuracy and penetration in both .308 and 30-06. I’ll shoot up the 125gr. spritzers I have and then see how the 125gr. RN/HP 30-30 bullets perform. I just hope I can get enough of them before deer season to test.

  11. Patrick says:

    I do not think that hunters are the primary loaders of 300 BLK. It’s a PDW cartridge like 5.7 FN and 4.6 HK. I realize that the caliber is very versatile and to list all the good loads for all applications would require you to have 4 test guns of different types and using a range of bullets from 110-240gr would take a chapter of a reloading manual. Good luck.

  12. how about info on using Alliant 300MP?

  13. Kevin says:

    The most popular bullet for .300 blackout is your Sierra .220 gr. HPBT match, and you don’t even list a load for it in your manual? I’m sorry, but that makes no sense at all.

    • The 220 gr. was not mentioned because the loads were sub-sonic. It was decided that we were not publishing sub-sonic loads at this time. Sorry!

      • Matt says:

        I was excited to see you had load data for the 300 AAC advertised on your home page only to find out it was a hoax. I am extremely disappointed to see a company as great as Sierra cop out on its load data for the 300 AAC. You tested your ammo on a cheap 300 platform that is rarely used. It is as if you bought the cheapest platform possible so that you could put 300AAC in your load book. Testing on the supersonic rounds should have been an afterthought to the Subs as it most commonly used with your 220gr bullet. I hope you plan to make this right because your customers are calling you out.

    • Bob Bowers says:

      Can you tell us why you all decided not to publish them at this time?

      • As with all sub-sonic load data, you do experience some risk of bullets lodging in the barrel. Management’s decision was to avoid any sub-sonic loads.

      • Bob Bowers says:

        Okay. I guess in this day and age you can’t be too careful.

      • Kevin says:

        Some experimentation and a disclaimer would have sufficed. I mean this cartridge was developed to be subsonic with your specific bullet By AAC and they have published load data for it. In any case, I would encourage you to develop a less expensive non-match heavy .30 bullet specifically for subsonic .300 blackout, preferably with a very thin jacket, flat base, and with a shorter ogive. It would be wildly popular with those of us who choose to “risk” subsonic blackout loads.

      • Bob Bowers says:

        I heartily agree with Kevin. Keep the weight in the 220 grain scale, but a thin jacket and flat base with a wider 45-50% meplat with shorter ogive would be awesome! That would be a “Thumper” for sure!

  14. Bob Bowers says:

    As long as it would feed reliably.

  15. Adam Culpepper says:

    I have used Sierra bullets and manuals for years now and I find the 300 Blackout information to be indicative of a larger problem at Sierra. You guys really need to hire some younger R&D folks. The knowledge of your current staff is very impressive, but there seems to be a gigantic segment of the industry that you know very little about. Simply using the term “Medium Length Gas Tube” tells me that you guys are slightly out of touch. AR gas lengths primarily come in four sizes, Pistol, Carbine, Mid Length, and Rifle. These are industry accepted lengths and designations. I can only assume that you mean Mid Length when you say “Medium Length”. If you have a true Mid Length gas tube, you have one of the rarest and least reliable 300 Blackout combinations. Mid Length 300 BLK barrels make up less than a tenth of one percent of all the 300 BLK barrels ever sold, if that much. I seriously doubt you can even buy one with a mid length gas tube today, from any of the top manufacturers.

    On top of that, YOUR 220 gr. SMK is the industry standard for subsonic 300 BLK ammo. With 10.8-11.2 gr. of A1680 being the most common loading, you can still drop as low as 8.0 gr. and NEVER stick a bullet in the bore, at any barrel length. I understand liability concerns, and Im sure youre all familiar with it too (considering your line of work), but this cartridge is not one thats prone to squibs. As mentioned above, a few asterisks and warnings would go a long way here.

    AR’s are the most popular rifles in America, and 300 BLK is a popular enough round (especially amongst reloaders) that I believe you owe your customers a little more effort than youre currently putting out. Your bullets are second to none in this caliber and your literature is literally among the worst. I dont mean to hammer on you guys, but I grew up loading Sierra bullets with excellent Sierra load manuals.

    • Jon Henshey says:

      Very well said! It would seem that Sierra does not care about the subsonic crowd, which is the group this cartridge was literally designed for. Although I disagree with Sierra’s “excuse” and position on the load data, we have other sources for the load data.

      If Sierra is too afraid (totally bogus reason, all reloading comes with risk i.e. max load) or doesn’t think people should be allowed to own suppressors (more likely answer), that is their prerogative. However, they are sending a very clear and offending message to a significant group of their customers (we don’t just load .300 Blackout).

      The short answer is, get your subsonic load data from AAC, Hogdon or some other source and hope that someone else starts making the 220 grain bullet we’d like to have for this great gun and then we can take our business elsewhere.

      Sierra management, we welcome your non-BS response…

    • Finding subsonic loads for .300 Blackout has been a chore — frustrating is more accurate. I’ve been hand loading since ’72 and used Sierra bullets and their data more than anyone else’s. I have to wonder if part of the reluctance to provide a load for subsonic is the understood but unwritten narrative that this a cartridge for defense and therefore for killing people. (Disclaimer: I don’t keep firearms primarily for sport or hunting but self-protection) I got into .300 Blackout for protection from window varmints and have discovered many are using it for feral pig hunts which I’m interested in planning on loading a 200 grain soft point. It would be nice to have at least that load data. (Another disclaimer: Remington is loading 220 grain subsonic apparently without too many concerns of squib issues.) Look forward to when you do decide to provide subsonic data.

  16. james says:

    I have been shooting and reloading the 300 whisper / blackout since 2000. I have 2 ar’s, 5 bolt guns( 4 customs built on savage actions and a rem 700 factory gun) plus a 10″ thompson contender. I have had excellent accuracy with the 125 pro hunter and the 125 open tip match out to 200 yards. and the hornady 130 spire point. The only bullets I cannot get any groups with is the noslers. I have expermented with 100’s of loads. I hunt deer in pennsylvania and use the 125 pro hunter and barnes 130’s with great sucess. 99% of my shooting is supersonic loads.

  17. Tom says:

    That was a big Hammer (To Shay)

  18. Steven says:

    Well said Adam. I will add that the “pistol” length gas system is very popular for the subsonic and suppressed crowd, as are the SBR length barrels. This round makes a great substitute for AR platform weapons in 9MM and 45 ACP as it uses common AR parts rather than specialized magazines and bolts. Management should reconsider testing subsonic as well as pistol length gas.

    P.S. – I have 700 of the 220SMK and I’m using AAC load data with great success. I also have 500 of the 125SMK (2121C) that I will load using your load data (Lil’Gun). I use your products and appreciate your support.

  19. Chad says:

    I started using a 16 inch 300 Blackout rifle in June 2013 and due to unavailability of factory ammunition I started to load my own. I have had great accurate success with Sierras load data for #2121 125 gr and #2130 150 gr at supersonic velocity. I have purchased over a thousand of each bullet to load. As of last week I am excited to have a 10.5 inch barreled 300 Blackout to add to my collection. As most people probably are, I was very excited to start hand loading subsonic cartridges but have come to find out sierra provides no load data for subs. Because of this current situation I would have to agree with Adam Culpepper in his statement and include this quote.

    ” AR’s are the most popular rifles in America, and 300 BLK is a popular enough round (especially among re-loaders) that I believe you owe your customers a little more effort than you are currently putting out.”

    I hope the good people at Sierra can help its current and future costumers by providing some data on this cartridge on the other side of the spectrum (subsonic loads). Thank you Sierra for providing a great product I do appreciate it very much.

  20. Davis says:

    I am on the Sierra side. Just because 300AAA Blackout buyers are using short(pistol) and/or NFA barrels for subsonic or other use does not predicate Sierra to supply load data that is available elsewhere for non standard uses. AAC will not do it either. Just way scary product liability guys.
    Sierra, thank you for the excellent scientific based data.

    • Kevin says:

      Except AAC did do it.

      • Davis says:

        AAC does NOT supply load data. Powder and bullet companies do.
        AAC recommends commercial ammunition only per their manuals.

      • Kevin says:

        No load data, huh. Why don’t you just scroll down to the bottom of the page, and quit posting from complete ignorance.

      • Davis says:

        kev.. one bullet, one load is NOT a data sheet- it is a recommendation

      • Kevin says:

        Uh, you said that the was no load data there, which is wrong. I have used their load, and it is a good one. I have chronographed it, and, with a 10.3″ barrel, it yields about 1050fps at 1500 foot elevation.

      • Davis says:

        PER the AAC black rifle manual.
        “Use only quality factory ammunition
        suitable for your firearm.”

        Handloading is dangerous and please use caution and care

      • Kevin says:

        Find me a rifle without that disclaimer. .300 blackout is a low pressure cartridge. Handloading is only dangerous when practiced by morons.

    • Adam Culpepper says:

      Davis, the pistol length gas and carbine length gas are not “non standard” uses. They ARE the standard. Mid length gas systems are not used with this cartridge as the timing cannot work with the powders that 300 Blackout is loaded with. The 16 inch barrels use pistol length gas systems on a regular basis. While carbine length systems are popular with 16 inch barrels, they are not the sole choice, by a long shot.

      Sierra’s excellent 220 gr SMK will work with both gas systems (with A1680). The lighter bullets will work with both gas systems (with a variety of powders like H110 and Lil Gun). The NFA barrels require pistol length systems, regardless of bullet speed. None of this is non-standard. Its simply tailoring gas tube length and port diameter to the cartridge you intend to fire.

      Honestly, if Sierra is going to concentrate their data towards what cycles an AR15, they should also consider showing OAL’s that are suited to the AR mag. By this, I mean lining up the .250 O.D. point of the bullet ogive with the forward rib in a GI mag.

      • Davis says:

        Sir, I am saying SIerra, as they stated, will not list loads that may cause liability. Sierra listed a CMMG AR with a 16″ barrel. Granted, most will wildcat barrels/loads/ bullets/ reloading method but it is not Sierras responsibility to accept that liability.

      • Adam Culpepper says:

        Davis, I dont think you own a 300 BLK rifle. Youre talking about “wildcatted” barrels and loads as if subsonic loads and pistol gas lengths are unusual. All this round ever was is a SAAMI approved version of 300 Whisper. This cartridge is and always will be a suppressor round. Maybe the fact that AAC brought it to market might be a clue?

        As to liability concerns, do you really want to go down that road? Every loading in the Sierra book can potentially cause harm to a shooter if the directions are not closely followed. The subsonic loadings (which the cartridge was originally designed for) are perfectly safe and practical in any AR with any length barrel. You are aware that several companies produce over-the-counter subsonic ammo with the 220 SMK, correct? Or is Remington a bunch of “wildcatters” loading on the ragged edge of safety?

        Sierra has probably sold more 220gr SMK’s in the last two years than all of the other 200+ gr. bullets in 30 cal combined. They are bright folks with good equipment, and all we are asking for is a little bit of product support.

        You sir, have some serious misconceptions about this round, the rifles it fires, and its uses.

      • Mike says:

        Sierra already has subsonic carbine loads listed in their manual so I have a hard time believing it is a liability issue when one of the 300 Blackouts main features is it’s sub-sonic capabilities.

        My guess is they they couldn’t get a single subsonic load to cycle through that non standard out of spec. CMMG mid length gas system upper. Why on earth they chose that platform for the test makes no sense. The industry standard is a pistol length gas system if your primary use is sub-sonic, SBR, or cold climates. Carbine gas for primarly supersonic with 16 inch barrels. AAC has stated mid length and rifle length gas systems do not provide enough pressure to cycle reliably. So why use it when 99% of your targeted audience is using something else?

        My Drill Instructor had a saying,”Recruit,if you are doing one thing and everyone else is doing something different you are probably wrong!”.

  21. Davis says:

    Note fellas that we are using a military designed cartridge for civilian use..in so many ways it’s prideful to say we are inventive.

    • Ragged Hole says:

      NO, the 300 Whisper was a Military designed cartridge, and that is the only reason that J.D. Jones is out there. The 300 BLK was civilian from inception to market, which is why they got it SAAMI accepted…so any manufacturer can load it. the Whisper was proprietary (military), not SAAMI accepted, so you have to pay J.D. Jones his money. This cartridge, and the Whisper, are from start to finish designed around sub-sonic loads. It feeds through an AR, just as the whisper did, but it was the reduced case capacity for a fuller case when loaded sub-sonic that they were also after. Anyone who shoots benchrest or F-class knows the most accurate loads are ones where the case is close to full or full. That is THE problem with using .308 for sub-sonic–you have to use fillers. What was the very first load Cor-Bon came out with with the Whisper, and Rem. came out with with the BLK? The sub-sonic. IF you don’t want the sub-sonic, why wouldn’t you use an AR in 6.8? Still 30 rd. mags, on an AR platform, and remarkably better performance for hunting.
      As for Sierra, this talk of liability is ridiculous, sincerely. It is the equivalent of saying “I make 3000 HP race engines, BUT, I won’t give you the information on how to install it because you might wreck your car.” Well, then why the hell are you making it? You think there are a lot of benchrest shooters shooting a 220 gr 30 cal? The only cartridges that can push that heavy of a bullet at long-range velocities are magnum cartridges, which you don’t see in benchrest. The FEW people shooting F-class with .30 cal are damn sure shooting a Berger VLD or Hybrid or other bullet. Any way you look at it, Sierra is selling something they KNOW is being used for a sub-sonic load, but refuse to post data about it. That is nonsense. If it is really a liability, then quit making the bullet. You are more likely to get sued becasue there are FACTORY cartridges being loaded with it, so it is clear that it is acceptable, so if I blow my gun up loading the same bullet that I see in a factory cartridge, I could say I had to guess at the charge because Sierra wouldn’t post load information for a bullet that is accepted as a standard for the cartridge. It is more dangerous NOT to post the data, because I am GOING to load it, and Sierra has become an impediment to my doing that safely!

      • Jake says:

        Not according to Robert Silvers at AAC R&D and Remington Defense. The Blackout was developed for Supersonic AND subsonic use with a high mass projectile capable flash suppression and against barricade. Another attempt at a military contract to make the M-4 AR a more effective package with just a upper change.

      • Jake says:

        This statement is a hoot- – “I make 3000 HP race engines, BUT, I won’t give you the information on how to install it because you might wreck your car.” Just a FYI.. I do make race engines and I have almost those same words in my disclaimer.

      • Adam Culpepper says:

        Jake, with all respect to Mr. Silvers, AAC didnt design anything. The JDJ cartridge has had a 220 gr. / A1680 load since Sierra released the 220 SMK. Opening the leade of the chamber a small bit doesnt equate to anything particularly special. Its the same old 300 Whisper with the same old loads as it has always had, except for the safety margin of the extended rifling leade.

        Just like the list of “design goals” that came out with the original sales ads with the 300 BLK was released, its all marketing hype. The implication has been made that Mr. Silvers and bunch of white-lab-coated R&D guys worked tireless hours trying to design a cartridge from scratch that would suppress well and fit in the AR rifle with no loss of capacity. They just standardized a JDJ cartridge and wrote up its benefits after-the-fact as “design goals.”

        As for wild race car analogies, lets leave that to race cars. I was into Top Sportsman and Top Alcohol for awhile, and never heard of any sort of disclaimer by any major engine builder.

        The bottom line is that liability does not lie with Sierra for something like this. In the Sierra #5, they already list a few subsonic 300 Whisper loads, so no one here is really buying the “subsonic liability” argument. That boat has already sailed.

      • Jake says:

        I may have sold you an engine..Chicago area?
        Regardless. Keep shooting ..

  22. randy rucker says:

    I would like to see a SMK 110gr bullet for the Black Out. Any chance you guys will be producing one?

  23. Fred says:

    I appreciate the data and will try some supersonic loads one of these days but am disappointed that the 220SMKs aren’t listed. I’ve purchased thousands of them in the last few years and they are the only Sierra bullet that I’ve ever loaded. They are fantastic for subsonic 300BLK. Too bad I have to go to other sources for the data. If I was new to the cartridge and couldn’t find subsonic loads in Sierra’s data but Hornady published loads for the 208 AMAX, I’d never even try the 220 SMKs.

  24. I would like to load sierra 155 HPBT with Win 296 powder but I didn’t see any load data on that. Why not?

    • Adam Culpepper says:

      Charles, Im sure Sierra will chime in as well, but the heavier bullets (130+) start to build pressure very quickly with H110/W296. You can go from zero signs of pressure to flat primers and extractor swipes in 0.3 grains. Lil Gun seems to be better suited to the heavy supersonic bullets.

      • Jacy Messer. says:

        I have loaded a lot of other brand 125 grain bullets. Such as nosler, hornady and Barnes. The Nosler recommends max of 18 grain of lil gun. Hornady goes up to 20 grains of lil gun. Sierra has the max at 17.2? Seems a little bit low me. I was wondering your thoughts of going higher to get the velocity up around 2300

    • That would have been because Win 296 did not sufficiently cycle the action of our specific rifle. It was tested but did not perform well in our gun.

      • Charles says:

        THANK YOU.

        Charles Saucier

        Inside Sales Engineer

        Ward Mechanical Equipment, Inc.

        P.O. Box 4233

        Jackson, MS 39296

        Cell 601-624-8914

        PH. 601-956-3002

        Fax 601-956-6212

        email: charless@wardmech.com

        Description: WARD_Mech_CorporateID-3

  25. Mike says:

    The problem with Lil gun is that it is temperature sensitive and pressure increases during cold weather. If H110/W296 is not cycling the gun used in the test that is solely due to the issue I brought up before. Sierra used a mid length gas system rifle to develop load data. The 300 Blackout is not designed for a mid length gas system. It is designed for pistol and carbine length gas systems.

  26. steve says:

    Any load data for IMR 4227 ?

    • Hodgdon states that the H4227 and IMR-4227 are exactly the same. They have now discontinued the H4227 version because the two powders were made at the same plant and are the same. So, use the H4427 data starting at the minimum and working up carefully.

  27. Clifton Williams says:

    Considering a small, legal pdw in a small 338 cartridge. Can you suggest weapon and caliber. Readily available ammo supplies both now and future. Can your crystal ball tell us which will be the eventual winner. And, I am getting older. No more hand loading. Weight is a factor. Thanks in advance.

    • I am not sure what type of firearm you are searching for. Usually a personal defense weapon would be a handgun. I am not aware of any handgun cartridges using .338″ diameter bullets. In a rifle platform, there are not any small cartridges. If we can be of further assistance on this, give us a call at 800-223-8799. Thanks, Duane Siercks, Ballistic Technician

  28. John Drudge says:

    For the whisper, you listed the 135 gr SSP bullet and not for the BLK out. Is there a reason for not listing this bullt?

  29. Pingback: With A Tube Length

  30. Gary Anderson says:

    I am looking for load data for a .300 blackout using H4895 and the sierra 125 grain bullet. Any suggestions.

  31. Mitch says:

    I have been using the 300 blackout for about 2 years now its a great round for 200 yards or less I have loaded everything from 110 grain bullets to 220 grain for rounds; Hodgdon gun powder data is the best for load information, great on deer and hogs; big fan of the 110grain Hornady V-max 2388 FPS at muzzle

  32. John Drudge says:

    Is there another bullet that can do the same as the 135 SSP that I can use that will do the same as the afore mentioned bullet. I primarily use these in the whisper and herrett.

    • John – We do offer our #2120 125gr SPT Pro-Hunter that will work well in this application. It was designed to be a little tougher than the 135 gr was so it will give a little less expansion with all other things being equal, but you shouldn’t have any problems getting it to function in your firearm. We have load data supporting our 125 gr and you can still find this on our website. Thanks for the interest.

  33. Joshua Mendoza says:

    On page 5 of 6, with the 165gr HPBT #2140 it says a COL of 2.005? Is that a typo? I’m trying to get to this measurement and kind of seems like I’m about to push the primer out with 17.5gr of Accurate 1680 powder? Some “Googling” and saw a guy loading to 2.175″? Could you clarify/verify 2.005″ COL Please?

    • Joshua – This isn’t a typo, but let’s look at this a bit more. I did some calculations and found that the max OAL with this bullet would be approx. 2.240. But you have to be careful when seating this bullet out due to the bluntness of the ogive. This allows the bullet to touch the rifling much sooner than when comparing a Spitzer style bullet. You can try seating longer, just be certain that the rounds will chamber without the bullet being jammed into the rifling. Thanks – Duane Siercks, Ballistic Technician

  34. Jim Marker says:

    Same question as Joshua Mendoza, but I am loading a 2190 bullet with IMR4227. At a OAL of 2.105 I can only get 15.5 grains in without compressing the powder which is below what is on the table by 0.5 grains. Can I go out to 2.205 or more for the over all length? Even with 100/1000 more I won’t have much room in the case. This is my first time reloading 300 blackout but not my first reloads and I am never anywhere near full with any other reloads I’ve done rifle or pistol.

  35. Pingback: Firearm Safety: Always Double Check Your Ammunition | Sierra Bullets

  36. Doug says:

    i havent head anything on using 2400 as a powder

  37. Jacy Messer. says:

    I have loaded a lot of other brand 125 grain bullets. Such as nosler, hornady and Barnes. The Nosler recommends max of 18 grain of lil gun. Hornady goes up to 20 grains of lil gun. Sierra has the max at 17.2? Seems a little bit low me. I was wondering your thoughts of going higher to get the velocity up around 2300

    • james says:

      I have been loading 300 whisper/ blackout for 20+ years and load the 125 grain to 20 gr h-110. My most accurate in my ar and several bolt guns is 19.5 gr h-110 with the serria 125 pro hunter and 125 gr open tip match king. measured 2330+ velocity with cronny

    • We were not able to go any higher due to pressure. In another gun with different cases, bullets, primers, etc., you might be able to get a bit higher, BUT watch pressures and work loads up carefully. It is also possible that you may not be able to get to any listed max loads safely with your combination of components and firearm. Safety is more important than velocity. – Duane Siercks, Ballistic Technician

  38. M Renteria says:

    Any data , on 147 grain fmj grain regarding 300 blk reloading

  39. Jason says:

    Do you have any load data for the new #7725 TMK 125gr bullet for 300 blackout?

  40. Adriaan Pieterse says:

    hi i am looking for the starting and ending data with S365 powder in a Pmp case with pmp primer and a 85gr varminter sierra spitzer bullet please

  41. phillip says:

    I have a questipn i have a 16in 300 blackout with a pistol length gas system can i shoot 220gr subsonic i have shot a couple of rpunds of it but was told i couldnt

    • chad says:

      Pistol length gas on a 16″ barreled 300 Blackout is very user friendly. It is my personal preference and what I’m using now.

    • I don’t know of any reason that you can’t. In fact, I think that is what is most commonly used to get best function with Sub-sonic loads. – Duane Siercks, Ballistic Technician

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s