Show off your 300 AAC rifles!
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Death
Was that group at 100y with 220gn?
My reloads eject the brass with 220gn smk and 11.8gr of h4198, but will not pick up the next round. I am going to range now to try 12.2gn H4198
Update: 12.2gn of H4198 will not cycle either
Some one give me A1680
Was that group at 100y with 220gn?
My reloads eject the brass with 220gn smk and 11.8gr of h4198, but will not pick up the next round. I am going to range now to try 12.2gn H4198
Update: 12.2gn of H4198 will not cycle either
Some one give me A1680
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I was out a couple days ago and did testing with 208gr Hornady match and the rifle would not cycle any loads with H110 or LiL'gun, AA1680 did cycle all loads over 12gr and locked back after last round. The loads lower than 12gr cycled but would either lock on the carrier or not at all.
Looks like AA1680 is my powder for 200+gr.
I also got 155gr Amax to cycle on LiL'gun with 15gr and hotter but not with H110 up to 17.2gr, they just started to cycle but didn't lock back after last shot. No pressure signs.
Looks like H110 for 110-125gr LiL'gun for 140-165gr and AA1680 for anything heavier.
PWS Mk109 upper, 9.75" barrel, pistol length piston system.
Looks like AA1680 is my powder for 200+gr.
I also got 155gr Amax to cycle on LiL'gun with 15gr and hotter but not with H110 up to 17.2gr, they just started to cycle but didn't lock back after last shot. No pressure signs.
Looks like H110 for 110-125gr LiL'gun for 140-165gr and AA1680 for anything heavier.
PWS Mk109 upper, 9.75" barrel, pistol length piston system.
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50yard range with 125gr Accupoints
Im gonna play with a lighter buffer here in the next couple weekends. But will probably stick with 110gr-125gr supersonics. Subs are a waste of time because of the BS no Silencer rules our government has set up
Im gonna play with a lighter buffer here in the next couple weekends. But will probably stick with 110gr-125gr supersonics. Subs are a waste of time because of the BS no Silencer rules our government has set up
I dont think you can get lighter than carbine buffer, i can get 150gn btfmj to cycle in my core15 with 16+ gn of H110 and decent accuracy at 50 yards. The 150gn btfmj are about as cheap as you can get at $25/100. I paid $50 for the 220gn smk and $30 for the 110vamx.
Those prices are for the projectile not the loaded bullet.
Instead of changing buffers try using a better powder. I posted my results to help people do this the easy way. H110 is not a good powder for heavier bullets. Try lil'gun or AA1680 instead and save yourself some trouble.
Even though the cartridge is very versatile in the weight of bullets you can use no one said it did it with one powder. There is load data for it but that doesn't mean it can be made to work in a semi, some people use bolt guns with this cartridge and it could be used in those.
I thought subs were a waste of time till I got them to cycle. Now I think they would be better suppressed but they do have some pluses, I did find that they are quieter, they are going to be easier on your brass, and they don't use much powder making a pound go further. Now I just need to find some cheap 200+gr projectiles.
My goal is to have rounds built for sub and supersonic that will cycle perfectly without modifying my rifle and that are accurate. I now have the first part done and just need some more time at the range to find accuracy.
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I was out yesterday with 110gr Vmax and 150gr FMJBT with mixed results.
Vmax with 19.6gr H110 at 2.065 were multiple 3 shot groups in about an inch at 100 yards out of a 7.2" barrel with the 5x scope I had on it for testing. Went from 18.8gr to 20.0gr and I didn't like beating my gun with 20gr. I'm going to focus on 19.4-19.8 now and play with coal and see how tight I can get them. I'm impressed and see some sub moa potential here.
150gr FMJBT at 2.065: were another story. Would eject but not grab a new round under 16.0gr of H110. 16.0gr would work with most of my mags, but not all. Everything above cycled and locked back no prob, went up to 17.0gr and couldn't get under 2" at 100yd. I have loads all the way up to 18gr to test but ran out of time. Didn't see any signs of pressure up to 17.0gr. I'm going to try 16.6gr-16.8gr again at the start of my day and see if I can do better, then play with coal and maybe switch over to Lil Gun which I have standing by. Failing that I have some W296 too.
I put a very light crimp on all loads.
How accurate do I expect a 7.2" barrel be at 100yd? Well it's an ATRS custom job from a Rock Creek blank so I'm thinking pretty darn accurate, would like to see sub-moa if I really do my part and load properly.
Spikes T2 buffer (equivalent to heavy) is what I'm running.
I'm after a cheap, accurate, reliable load as well and would really like the 150gr bullets to work.
Vmax with 19.6gr H110 at 2.065 were multiple 3 shot groups in about an inch at 100 yards out of a 7.2" barrel with the 5x scope I had on it for testing. Went from 18.8gr to 20.0gr and I didn't like beating my gun with 20gr. I'm going to focus on 19.4-19.8 now and play with coal and see how tight I can get them. I'm impressed and see some sub moa potential here.
150gr FMJBT at 2.065: were another story. Would eject but not grab a new round under 16.0gr of H110. 16.0gr would work with most of my mags, but not all. Everything above cycled and locked back no prob, went up to 17.0gr and couldn't get under 2" at 100yd. I have loads all the way up to 18gr to test but ran out of time. Didn't see any signs of pressure up to 17.0gr. I'm going to try 16.6gr-16.8gr again at the start of my day and see if I can do better, then play with coal and maybe switch over to Lil Gun which I have standing by. Failing that I have some W296 too.
I put a very light crimp on all loads.
How accurate do I expect a 7.2" barrel be at 100yd? Well it's an ATRS custom job from a Rock Creek blank so I'm thinking pretty darn accurate, would like to see sub-moa if I really do my part and load properly.
Spikes T2 buffer (equivalent to heavy) is what I'm running.
I'm after a cheap, accurate, reliable load as well and would really like the 150gr bullets to work.
Suputin,
I've been pondering it. Everything I've read says AAC recommends a H buffer for barrel lengths under 9" but I can't for the life of me figure out why, must have something to do with running a can. The H buffer seemed to slow down the bcg significantly on my loads with lighter powder charges. Lighter buffer means I can run less powder and that means I can load for less, and I'm cheap, so that's good, lol.
As an aside, I had the opportunity to shoot three different PDW's in a row yesterday...
1. 7.5" custom 556 build with a HERA Linear Comp and the muzzle blast almost gave me a concussion. 5 shots and I handed it back, lol. And I'm not recoil sensitive, I've never really understood the muzzle blast complaint from shorties until I shot this gun!
2. 7.5" PWS 556. Was a lot of fun, nice little brake on it too. If I were going to own a 556 PDW that would probably be a strong contender.
3. My 7.2" 300Blk. Obviously I'm obsessed, and biased, and I can't get enough of this cartridge. Zero muzzle blast (I'm sure the Eliminator helped) and minimal recoil. It was loud for sure, but not a high pitched rifle crack, much much lower. I compare it to shooting a 45acp 1911 vs. a 40S&W polymer gun.
I've been pondering it. Everything I've read says AAC recommends a H buffer for barrel lengths under 9" but I can't for the life of me figure out why, must have something to do with running a can. The H buffer seemed to slow down the bcg significantly on my loads with lighter powder charges. Lighter buffer means I can run less powder and that means I can load for less, and I'm cheap, so that's good, lol.
As an aside, I had the opportunity to shoot three different PDW's in a row yesterday...
1. 7.5" custom 556 build with a HERA Linear Comp and the muzzle blast almost gave me a concussion. 5 shots and I handed it back, lol. And I'm not recoil sensitive, I've never really understood the muzzle blast complaint from shorties until I shot this gun!
2. 7.5" PWS 556. Was a lot of fun, nice little brake on it too. If I were going to own a 556 PDW that would probably be a strong contender.
3. My 7.2" 300Blk. Obviously I'm obsessed, and biased, and I can't get enough of this cartridge. Zero muzzle blast (I'm sure the Eliminator helped) and minimal recoil. It was loud for sure, but not a high pitched rifle crack, much much lower. I compare it to shooting a 45acp 1911 vs. a 40S&W polymer gun.
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Mind if I ask what brand of 150's you're using? Hornady's are generally one of the more accurate 150 gr. FMJ-BT bullets out there but of course it all depends on what your rifle likes.
FWIW, I've been using 16.5 gr. H110 with the Hornady bullet in a bolt gun and I'm getting (5) round accuracy +/- 1.5" @ 100 yds. so I don't think your results are too far out of line. Then again, those bullets are what they are and I personally don't expect match grade accuracy from them.
Ever consider any of the 155 gr. Match bullets out there? I'm thinking the Sierra MK would be a better choice for feeding in AR's over the A-MAX or Lapua bullets.
A Lee Factory Crimp Die might be of benefit for you as well. Promotes a more consistent crimp on your hand loads.
150gr Hornady FMJBT
No the results aren't terrible, and I could live with 2" groups for 35 cents per round (loaded) if that's all they can do, but I'm just starting out with them and hope they have more potential, especially now that the Vmax have my hopes up.
I have an arms length list of bullets I want to try out but my first priority is developing a cheap, reliable, and accurate practice round, and that rules out anything with the word "match" in the title for now, lol
No the results aren't terrible, and I could live with 2" groups for 35 cents per round (loaded) if that's all they can do, but I'm just starting out with them and hope they have more potential, especially now that the Vmax have my hopes up.
I have an arms length list of bullets I want to try out but my first priority is developing a cheap, reliable, and accurate practice round, and that rules out anything with the word "match" in the title for now, lol
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I crimp,not so much for the feeding issue (change of OAL)due to feed ramp contact, but for a better more consistent burn on the powder.
You have to keep in mind that the spec to which AAC is adhering to is much more focused on supersonic operation than subsonic. Robert Silvers was obsessed with bolt carrier velocities in supersonic operation so they went with a smaller gas port and the heavier buffer. Personally I dont see the issue with a bit if extra BCG velocity if it means the rifle cycles subsonics reliably. We know many 556 guns are overgassed and they seem to last fine.
I am not a good example because I am using non-conventional recoil systems in my guns. One is bufferless md the other is a captive silent spring setup much like the JP Ent system. Both these systems allow me to vary spring weight to my ammo. I also run adjustable gas blocks but to be honest I tend to leave those on a middle ground setting that works for both subs and supers. I mostly shoot subs so my guns are set up for that ammo.
And does that work? How do you know?
I don't crimp. For a long time the rule was to never crimp subsonics so I got into the habit of not crimping. Besides it is just extra work.
Without crimping I seem to get pretty decent accuracy and velocity.
My crimping is simply using my lee dies and with a trimmed case in the press and the ram at the top I thread the seater die in till it touches the case then lower the ram and turn the die in another 1/16 or so of a turn. I'm not worried about it enough to get a factory crimp die and add another step to the reloading process. Maybe if it was a high recoil round but this is pretty gentle. I do the same for the 308 loads I feed my RFB and pretty much all my reloads. The 460 S&W gets a stronger crimp but that's about it. Even my 338 Lapua gets a similar light crimp.
Sure, just up your powder charge, watch for high pressure though.
However I was just conversing with Suputin at the top of this page about taking the H buffer out of my 7.5" gun and replacing it with a standard buffer so it would cycle with lighter loads.
I personally would not go with anything heavier than an H buffer...
As for crimping I do a very light crimp with a Lee Crimp die only on bullets that have a cannelure. Without a crimp I was able to push one of the 150gr FMJBT deeper into the shell by hand so I figured it couldn't hurt.
