Did some testing today with prvi 5.56 and older black follower Pmags
lower is a Mega with A5 extension, buffer and spring from kit form.
A T-1 was used on both also.
1st upper was BCM 16" midlength with BCM BCG and A2 FH
function was fine, bolt did not lock back, several attempts were made
2nd upper was a complete Colt 6920 upper cut to 14.5" with pinned Vortex function was fine, bolt DID lock back everytime.
I found the Colt carbine gas /A5 to be noticeably softer shooting and less muzzle rise than the mid. Follow up shot groups were also much tighter with the carbine.
What is the reason for the Carbine shooting softer? The Vortex?
Why is the bolt not locking back on the Mid? Buffer to heavy?
Thanks
I’m currently running the Vltor A5 RE on my SR15E3, and it’s done an exemplary job of mitigating felt recoil, (in conjunction with the BC 1.0), and this is with LC / IMI M855 ammo.
The A5 definitely softened recoil coming from a car ext. with H buffer on the mid length but, the carbine/A5 setup was softer than all the setups i tried.
I’ve been seeing a lot about the A5 and I’m very curious as to whether it may be a useful mod to my gun. Do you guys think it be a good addition to my BCM 11.5" w/BC 1.0?
I am thinking long and hard on one of these for my 14.5 middy. What is the general consensus on buffer weight and spring type? I am currently running an H-buffer with stock Colt 6920 spring and, I’m having the occasional failure to lock open using PPU 62gr .223 loads.
I’ve found that the A5 has been a useful addition to all of my rifles. I’ve run it on a 10.5" for a few mags and I noticed quite an improvement. I have a LMT mk18 type upper coming this week and am glad that I can use a flah hider but still have a little muzzle flip control by using the A5 though I’ll need to determine which buffer is correct to make it the most reliable.
Now, hearing people say their 16" middy is rough and everyone stating the 14.5" middy is the softest shooting, etc., has me wondering a few things. Looking at the pressure differences alone, it would appear the 16" mid length would be one of the softest shooting and the 14.5" being a little rough in comparison. But, we hear the exact opposite.
So, how much does gas port size play into this? Is it the speed of the carrier that makes one harsher than another? Looking at the 10.5" port sizes recently, it varies widely even within the same company. A while back there was a thread about Colt port sizes on 10.5" barrels. Colt had once told me personally when I talked to a “tech” that it was something like .093, but I believe this is their commercial offering, but we know their contracted 10.5" barrel is closer to .068, or similar. I could be off, but you guys get the point.
So, if we have a 14.5" and 16" that are both mid length from the same company, should we then expect the 16" to be softer due to pressure or the 14.5" due to dwell time?
I’m just thinking out loud here and it seems every time one thing finally makes sense, more questions pop up… Anyway, I just want reliable guns that shoot my choice of ammo regardless of gas system. All else is just curiosity and means little in the big picture… But still interesting.
yep, surprised me too. but it’s not just a whim, every one who has shot my BCM middy says it shoots noticeably harsher than my DDM4 V1 (that’s lighter to boot!).
that’s why I am adding the A5 to it this this afternoon. if it is of interest to anyone, I’ll report back my results…
don’t get too worried about this - my experience is only a sample of one. too many variables to consider it anything other than an anomaly against the trend.
but yes, all things considered, a gun with less dwell (midlength over car length gas, 14.5" over a 16") should shoot “softer”.
Yeah, I’m not really worried, just find it interesting. If you go by chamber pressure alone, the 14.5" middy (or comparing carbine gas systems as well) will have more pressure than the 16". So, that would lead one to believe the 16" middy will be softer shooting. But, it seems to be pretty common knowledge that the 14.5" mid length is softer shooting than the 16".
Again, it’s not a big deal to me as I’m most interested in reliability, but it is an added bonus if I can stay on target a little better as well without having to use a brake. I recently sold one of my two Triple Taps and I’m selling the other today or tomorrow.
Right now, I have two SR15’s that are very reliable and I’m shipping one of those uppers out today for a trade I did on a 10.5" with a DD mk18 rail. I have an 8" PSD also that is collecting dust plus my SCARs. I also recently sold my 16" Noveske upper that would have soon needed re-barreling and a 14.5" carbine gassed BCM bare upper. I’m looking to pick up another 14.5" with a DD RIS II 12" rail and I’m debating on whether to get the mid length or carbine. Every one of these was different and each had it’s own feel.
Friend and I both have N4 light rifles, his 14.5" mine a 16".
With the A5 mine shoots as soft as his with an AAC can.
Can definitely say my 16" in recoil feels better with the A5 as compared to carbine spring and H2, or Sprinco blue and H1 (my former setup).
Of course the BC comp has a lot to do with muzzle rise, but that has been there all along. Done experimenting with springs/buffers. Now just go and shoot from various positions, try to do fast mag changes…
Next range day will swap his upper for mine and see if it shoots softer, as described above. Would be surprised if it does, but will report back.
Mark
Interesting that some of you seem to find your 16" middy’s are more harsh-shooting than other rifles- mine shoots WAY softer than the only other AR15 I’ve ever shot- which was a pretty standard carbine frankenbuild with mostly Del-Ton parts.
I wanted to add my experience last weekend to this thread. A few of us went out to a friend’s ranch this past weekend for three days. Most of my shooting and hunting was done with the SR15 with the Vltor A5 and standard buffer.
I recently got an LMT mk18 upper. Both had standard flash hiders. I just switched back on the SR15’s from Triple Taps and will most likely go to Blackouts for all once the suppressor thing is figured out.
Anyway, my MK18 (10.5") upper shot just as soft, if not softer than the SR15 when both used the Vltor A5 and standard buffer. This was not my experience before with a borrowed Noveske 10.5" but I believe I had the brakes on the longer guns at the time.
So, my guess is that the Vltor A5 system is going to be most effective with a carbine gas gun over a middy, though both will definitely benefit. My bought is that you can only get so soft for the caliber and a 16" middy is already nearing that point, as is the 14.5". When we start running the shorter guns or carbine gassed longer guns, the A5 system has more to work with and it becomes more noticeable.
Seeing it on a wider range in barrel length and a wider range in gas system length as well, I have a feeling this is what the OP is experiencing here. I would say that on almost any upper we’ll see some sort of benefit in feel amd reliability though we may need to use a lighter buffer for 14.5" middies, but we’ll actually feel more of a difference on carbine gassed guns, whether 16" or 10.5".
I ran both the SR15 and MK18 on the A5 this weekend back to back as well as suppressed and I can say that it would be very hard to tell a difference between any of them using the same buffer with the A5. I couldn’t say that if all I had was a carbine re and a carbine or H buffer. I like this set up more and more each time I’m out.