What set up do you use far the .300? I’ve heard the springco white/extractor spring with a carbine buffer works best from JSOC experience. Also what 147-150 gr handloads do you use for training?
Setup depends on barrel length and gas system length - and barrel manufacturer as well.
Using AAC as the reference-
16" bbl, Carbine gas - GI Spring and Carbine buffer
9" bbl, Pistol gas - GI Spring and H2 buffer
You should go to the manuf of your particular setup for their recommendations.
DDM4V5 with carbine gas system. Yea I kow it depends on the weapon design. Just asking what others are using/loading.
300:
I can offer a limited data point on the buffer issue. I recently received a PSA upper in .300 Blackout. Temporarily, I am shooting it atop a Bravo Company lower with a Cavalry Arms A1 buttstock with the rifle spring, buffer and tube.
The PSA upper is 16", carbine gas. I have fired 200 rounds of Remington UMC 115 grain ammo through it with no problems. I ordered one box (twenty rounds) of the Gunn Ammo 130 grain load. The first two rounds of Gunn fired short stroked. The other eighteen fed, fired and extracted normally.
220 rounds is, of course, not enough to draw any real conclusions, but it does constitute data.
Got less than two weeks before I get home from working. I did the 1,2,3 round test with mags on my 300 blk 9" AAC barrel two days before I left. So, belive me I’m going to wring it out a little.
The function test went flawless with carbine spring and h2 buffer. I think I’m going to play a little, bought all the springco springs and have C through H3 buffers so I will see what I like best.
Talked to springco the other day and they recommended the following:
16" BBL w/carbine gas system use the white spring and a carbine buffer.
I run a 9" 300 AAC barrel on a DD SBR with DD BCG. Used the carbine spring and carbine and H buffers. Several FTE’s.
Put a black o-ring on the extractor spring, no more problems with any buffer.
On a rig with a barrel shorter than 16" the designers recommend using a pistol length gas set up. Carbine for 16 and up.
I’ve got a mgi rate reducing buffer and like it a lot.
My 300 runs supers (including Gunn 130 gr, UMC 115 gr, and 110 gr V-max handloads) 100% with a standard carbine spring and carbine buffer. Cycling is a little iffy w/subs if it doesn’t have a can.
It is a Wilson Combat 16" barrel, carbine gas, and DD BCG. Also, it is fairly accurate as well, 1-1.5" @ 50 yds with UMC 115 gr.
9" Delta Company Arms barrel & Colt bcg
I’m using an VLTOR A5 system with the standard A5 buffer and stock spring. Fired and locked back on subs, supers, and weak handloaded subs (just barely on the handloads). No issues. I’m going to start experimenting with heavier buffers and different action springs to see if I can notice any affect on perceived recoil.
No surprise there since that is exactly what AAC suggests. The white spring is a standard GI spring, not an extra power or anything. That and a C buffer.
Well, yes and no. It is a GI strength spring. However, if you notice, the length is almost an inch shorter than a GI spring. Springco has made the White spring more linear than a std GI spring (better). This also means reduced stress on the spring (longer life).
So, in short, it was designed to behave more like a Vltor A5 or a rifle spring (though not exactly like it). Pannone had a hand in designing the White spring as well according to springco.
Gents, I want to bring this back up so I wont have to start a new thread. I am building an upper. Id like to chamber it in 300aac. Ive found the bbl and rail already. (16"bbl carbine gas). My question is: would I be GTG throwing this on my DDM4 lower? ( H buffer, carbine spring im assuming, Milspec DD BCG) ?? id love to not have to modify the lower everytime i switch uppers. Thanks!
Yes, you should be fine.
FWIW, since this thread was revived, I run a 16", carbine gas DD S2W 300BLK barrel w/ a Vltor A5 system & A5 buffer. Has run 100% ever since. I highly suggest it!
id love to get the dd bbl, i found a wilson combat bbl which is slightly cheaper. i own a factory ddm4v4 so i know dd quality. that wilson barrel has a nice stainless finish too! heres my deal: im not going to run suppressed or sbr so is the .300 right for me? my primary use for it will be deer hunting. i read the round lacks power and accuracy past 100-200 yards ish. If that is the case, i might just build a .223 wylde “3 gun style” upper instead. :help:
Mine is not suppressed, which is why I got carbine gas as opposed to pistol. I think the 300BLK is perfect for hunting personally and will just fine out to 300-350yds. With the accuracy potential of this cartridge, you can do more than most believe. See below.
FWIW, it was toss up for me between the Wilson and the DD barrel. You really can’t go wrong with either one. The Wilson barrel is a stainless match grade while the DD is non-chrome lined melonite treated.
I did this a while back @100yds so the 300BLK definitely has some potential for accuracy. I haven’t had a chance to test is out to longer distances yet, but this really impressed me when I saw what it did.
Ideally you would use a C buffer. That being said, I have mine on a rifle lower which has the weight of an H2 buffer, and I have no trouble as long as I don’t use subsonic unsuppressed - so in practice you will be fine - but if the brass is not throwing as far as you expect, it is because an H buffer is a tad heavier than ideal.
I’m running a Vltor a5 with my 9" AAC upper and it locks back on all ammo and feels a little smoother all around.
sweet thanks! you have helped alot!!
id really not like to mess with the lower. i just want to be able to swap uppers without an issue