AR Sponsor
Posted: 12/29/2015 10:49:39 AM EDT
|
Seekins billet upper / lower receiver set White Oak Armament 16in Krieger 1:7 twist fluted barrel with 0.086 gas port hole 0.759 under the gas block 223 wylde chamber Noveske Intermediate length gas system and gas tube SLR Sentry 7 set screw adj gas block Young Manufacturing National Match Lite chrome plated BCG and bolt Vltor A5 buffer tube and Spring Hiperfire 24c trigger BCM KMR 15in handguard Assorted stocks and grips I am having some sort of dwell time issue. I can get the rifle to cycle XM193 properly but only when shooting SUPPRESSED. If I take my suppressor off, the rifle appears to short stroke. I started to tune the gun with the gas block closed. And opened it 1 click at a time. 1-3 clicks open = FTE. 4-8 clicks open the bolt would cycle to the rear, but get locked back on the magazine follower. 8-15 clicks open and the bolt would go into battery after the last shot in the magaine. I am not able to get the bolt to lock back on the last shot. All of this was with the standard A5 spring and an H2 buffer. I tried a JP flatwire spring + H0 buffer, but still couldnt get lock back. Next I tried a JP lightweight BCG with no luck I finally tried a LMT enhanced BCG, and it started to function properly unsuppresseed. And I was able to dial the gas down more at the block when shooting suppressed and had proper functioning. I dont understand why I cant get the gun to lock back with my YM lite BCG. The rifle shouldnt be that undergassed. Is the YM BCG is moving too fast? It seems that betwen 5-7 clicks open the gun is really close to working. But just going from 5 to 6 clicks open the bolt will go from locking back on the follower to going into battery. Its almost like I need to be at 5.5 clicks open to get the right amount of gas??? Should I try an H1 buffer? Anybody else running an intermediate gassed 16in barrel? If so, what BCG, buffer, and spring are you running? |
| I have an SLR. They are designed to be resting fully forward against the shoulder where the hand guard stop usually rests. When I found this out, I checked both rifles I use a SLR on. One was right on the edge, and one was compromising about 1/4 of the barrel gas hole. That might be a place to check. |
| Take it loose and slide it forward, and you will be able to see the alignment from the gas residue. It was just a thought. Mine seemed to be working properly, but when a SLR rep posted in a thread where a fellow was having a problem, I took mine loose and found the misalignment. Tolerance stacking and all that. |
|
I didn't rip the gun down just now, but from looking around the gas block I don't see any obvious signs of leaking gas. It strange that the enhanced LMT BCG cycles the gun fine, both suppressed and unsuppressed. But if I put my light weight JP or YM BCG into the gun, it will only function properly SUPPRESSED. Im really starting to think that the intermediate gas length doesn't like light weight bolt carriers for some reason. I think with the H0 buffer and flat wire spring that the BCG is maybe moving too fast and not allowing the bolt catch to raise quick enough to lock the bolt back. I can try an H1 buffer I guess. I know the H2 and H0 don't work.
This is super frustrating. It happens with Pmags and USGI mags. So i don't think its a magazine issue. When the bolt locks back when shooting suppressed, its getting good purchase on the bolt stop. The bolt stop appears to be moving all the way up appropriately. 
|
|
You have a 16" barrel with an Intermediate gas system?!?!
Intermediate is somewhat too long of a gas system for 16" barrels, it's intended and best suited for (223/5.56) barrels in the 17.5 to 18" range. .086 would be too small of a gas port on a 16" Intermediate with a .750 gas block journal. .086 was (IIRC) barely functional on an Intermediate 17 1/2" barrel with .625 journal. |
|
Quoted:
You have a 16" barrel with an Intermediate gas system?!?! Intermediate is somewhat too long of a gas system for 16" barrels, it's intended and best suited for (223/5.56) barrels in the 17.5 to 18" range. .086 would be too small of a gas port on a 16" Intermediate with a .750 gas block journal. .086 was (IIRC) barely functional on an Intermediate 17 1/2" barrel with .625 journal. I thought intermediate was between carbine and midlength? Eta; huh, guess not, well that makes sense then. |
|
Quoted:
I thought intermediate was between carbine and midlength? Eta; huh, guess not, well that makes sense then. Quoted:
Quoted:
You have a 16" barrel with an Intermediate gas system?!?! Intermediate is somewhat too long of a gas system for 16" barrels, it's intended and best suited for (223/5.56) barrels in the 17.5 to 18" range. .086 would be too small of a gas port on a 16" Intermediate with a .750 gas block journal. .086 was (IIRC) barely functional on an Intermediate 17 1/2" barrel with .625 journal. I thought intermediate was between carbine and midlength? Eta; huh, guess not, well that makes sense then. Intermediate is something like 1 7/8" longer than midlength. It's between midlength and rifle. |
|
Correct. The Noveske intermediate length gas system is longer than mid length, but shorter than rifle length. It was originally designed for 18in SPR barrels. However it has trickled down to 16in tubes. Even the KAC SR15 is using a version of the intermediate system. And Im fairly certain that they are running a .086 port hole, or dam near that. My rifle shoots stupid soft with the suppressor on. And even with the LMT enhanced carrier unsuppressed its like butter. But dam i can't get the thing tuned with my YM light weight carrier.
I think most guys running 16in intermediate sticks are using an H1 buffer and normal weight carrier. That is the only combo I haven't tried yet. Surely there has to be someone on this site with a 16in Recce style rifle rocking an intermediate gas system. |
AR Sponsor