Of those two - do both use the special long buffer and standard rifle spring?
How much, if any, additional travel is there in the buffer from full recoil to the bolt being closed?
From these photos, it would appear that the A5 has the same amount of travel as a standard carbine stock, but is designed to work with a rifle spring. Is that the case?
They are the same length, the one designed for the Emod stock has an extra locking position.
Both use the A5 buffer and standard rifle spring. The A5 RE and buffer are extended the same length, so bolt travel remains the same as carbine.
Looking to get an upper that can shoot super w/a 13" barrel. What gas port and length should I use? Thanks
Is anyone following this thread anymore???
Who knows?
13" bbl - pistol-length gas
May I ask why? What are the benefits, etc? Why not mid or carbine length? Thanks
16" carbine gas 300BLK here. I have not had a single hiccup in this rifle. Vltor A5 kit should be here Friday, it should be just about perfect then.
I wouldn’t go Pistol gas unless it is to be suppressed or a SBR/Pistol.
I am hearing great thing about the 12.5" barrel and the longer suppressors, shortcoming is no IR LASER with the dual BDC ability.
Sounds like 200 yards with subs and 500 yards with supers.
With carbine length buffers.
If you go back and read the thread from the beginning, you’ll see why not a middy
This.
The 5.56 has a longer pressure curve than 6.8, which is longer than 300BLK.
The faster the pressure drops off, the larger the gas port needs to be.
If the gas port needs to be bigger than the max (.125), the gas system needs to be shortened to get enough gas drive.
I’ve read it from the beginning but man you guys really get into the details. Just tell something around the lines of, “small boom go short, big boom go long” or something like that.
So guessing mid is too long due to the bullet taking up most of the brass’ room. Say I want to shoot up to but not limited to 500-600 yds with super, is carbine length capable?
Judging from Onyx Z:
…seems like the way to go. And Onyx what is the gas port size you have for your upper?
No idea on the gas port size, but I can check when I get home. It’s a 16" DD 300BLK S2W barrel.
Generally, gas length has nothing to do with effective range of a rifle. It only has to do with the action, which you feel as recoil.
If you are looking for 500+ yds with a .30 cal bullet, I would definitely turn my attention to a larger caliber cartridge, not a 300BLK. There just isn’t enough room in the case for the powder to get the bullet travelling at proper the velocity.
Thanks, I’ll hold you to that. I’m planning on getting an upper from Arsenal Democracy, and when I get it, want to zero in at 300 yds; 500-600 yds is just for kicks in case I feel like or have to shoot that far with 300blk. Also, a barrel change and maybe buffer group will do fine if I want to go back to 556.
If you roll your own ammo and want to shoot subsonic rounds there are some powders that will cycle in a pistol length gas system but not a longer system.
My experience so far has been good with a carbine length gas system though- there is a decent array of powders that are reliable in a carbine for subsonics.
This is nice to know, if I get into 300blk, I would definitely want to roll my own.
My gas port is .118. I’m willing to bet DD tuned it to this size for the carbine gas.
In terms of gas port for carbine gas, bigger is better. In fact, running a gas port at .125 seems to have no detrimental effect in terms of overgassing even with super ammo, and seems to significantly help reliability with subs. It is good to hear that DD made the gas port fairly large on their 16" barrel.
Personally, given the 300 BLK’s intended use, I would personally always choose a pistol gas even if I was going with a 16" barrel. This is for maximum reliability with subs and more latitude to play with powders. Also, if you are zeroing at 300 yds, you are missing the point of this cartridge. From my calcs, a 300 yd zero puts you nearly a foot over POA at 150 yds.
I have a LMT MRP barrel in 300BLK from LMT and it has a pistol length gas system. Works just fine so far.