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+--- Thread: buffer weight issue (/showthread.php?tid=15295)
buffer weight issue - LRRPF52 - 02-14-2018
For 18" RLGS, I wouldn't use anything more than a carbine 2.9oz buffer, if the port is .094" or smaller, shooting 120gr.
buffer weight issue - blackholegun - 02-14-2018
After the first grendel build I did with the Faxon barrel mid length gas and with the little time invested in getting it running correctly.
I think I am going to cut my losses and order another Faxon barrel.
Either it works or it does not, and this combination does not work.
buffer weight issue - blackholegun - 02-14-2018
LRRPF52 Wrote:For 18" RLGS, I wouldn't use anything more than a carbine 2.9oz buffer, if the port is .094" or smaller, shooting 120gr.
The issues are the same as running the 2.9 oz buffer
Again, I am not sure of the port on the barrel as I did not measure it.
I would hope I would not have to though.
All AP and BA parts, should work, right
buffer weight issue - Tex Nomex - 02-14-2018
Is the bolt locking all the way back on the bolt catch on single shot, or does it let go when you drop a mag? If it lets go, it's not enough gas.
Running a rifle length gas system on an 18" barrel means both gas pressure and dwell are diminished. I'd try a very wide open non-adjustable block on that rifle. And standard carbine buffer or, at max, a +1. Maybe even a lightened buffer spring.
Added:
Just a Q to clear up one possibility:
How much free space do you have between the bolt lugs and the bolt catch when you pull your charging handle all the way back?
buffer weight issue - blackholegun - 02-14-2018
There is about 1/4-3/8" free space from all the way pulled back to locking on the bolt catch when releasing forward.
With the adjustable gas block wide open, it would also not feed reliably.
buffer weight issue - Tex Nomex - 02-14-2018
blackholegun Wrote:There is about 1/4-3/8" free space from all the way pulled back to locking on the bolt catch when releasing forward.
With the adjustable gas block wide open, it would also not feed reliably.
So we know it's not a tube issue, at least.
With a marginal gas system:
Any kind or resistance is bad - rough chamber, dry BCG, new/dry rings, mag spring too stiff (new mags)...
Any kind of gas leak is bad - rough chamber, worn gas rings, loose gas block, misaligned gas block, worn gas tube, bad key seal...
You might have a weak extractor not keeping its grip on the case head when pressured by the compressed mag spring, especially with new mags.
I'd brush the chamber, check my gas key and tube end and shoot it with a non-adjustable gas block with a HUGE hole and some not-new magazines next. Sometimes these issues work themselves out after some shooting.
buffer weight issue - Dcommoncents - 02-14-2018
Maybe this is implied in your post, but have you tried running it with the gas block opened more? If not, I'd try opening it all the way to help eliminate undergassing as the culprit (or at least mostly eliminate, as I'm currently dealing with undergassing on a fully open block but that's on a 12" barrel). And if your still restricting gas flow through the gas block, you don't need to worry about your gas port diameter just yet.
buffer weight issue - blackholegun - 02-15-2018
I am going to chalk this one up as a "Lesson learned" thing.
It is only my third build, so I am by no means fully experienced with the AR platform.
I was kind of leary about the rifle length gas barrel and the carbine buffer system.
I am now to the point of how can I fix this correctly and have a reliable gun.
At this point, I think the only logical answer is to purchase a Faxon 18" barrel with mid length gas system as I have a 223 Wylde upper to run on the lower also.
Will just have to sell the BA barrel to adjust some costs I guess
buffer weight issue - Tex Nomex - 02-15-2018
Remember this for future builds: It's got nothing to do with the carbine buffer tube or carbine buffer. It is the long rifle gas system in a shorter-than-rifle barrel. It seems to need a larger gas port.
Try a different non-adjustable gas block.
-or-
Drill out the gas port. Easy with a drill press or for a shop to do.
-or-
Run a suppressor.
-or-
Try a Krink-style muzzle device.
You give up too easily. I truly believe this rig would be buttery smooth and accurate with a little more gas. Have you contacted BA and asked them how to make their barrel work? Could be out of spec.
buffer weight issue - blackholegun - 02-15-2018
Tex Nomex Wrote:Remember this for future builds: It's got nothing to do with the carbine buffer tube or carbine buffer. It is the long rifle gas system in a shorter-than-rifle barrel. It seems to need a larger gas port.
Try a different non-adjustable gas block.
-or-
Drill out the gas port. Easy with a drill press or for a shop to do.
-or-
Run a suppressor.
-or-
Try a Krink-style muzzle device.
You give up too easily. I truly believe this rig would be buttery smooth and accurate with a little more gas. Have you contacted BA and asked them how to make their barrel work? Could be out of spec.
I appreciate your suggestions, but in the end, they are not as cost effective or guaranteed to work.
The Faxon barrel build I did worked as good as I could expect as far as function and reliability.
I am not bashing BA as my Creedmoor is shooting fine with one of their barrels.
buffer weight issue - grayfox - 02-15-2018
Now that I think about it, I had an 18" rlg once upon a time... 264/6.5 "whatevah" - barrel was decent but it just didn't suit me.
Wound up selling it and going with a couple of faxon's.
Much more at peace now.
Everyone has 1 or 2 "lessons learned" in their closet, not to worry.
buffer weight issue - Tex Nomex - 02-15-2018
blackholegun Wrote:I appreciate your suggestions, but in the end, they are not as cost effective or guaranteed to work.
The Faxon barrel build I did worked as good as I could expect as far as function and reliability.
I am not bashing BA as my Creedmoor is shooting fine with one of their barrels.
I completely understand. Had a car do me like that once...
I purchased one of the group-buy 18" Faxons and it's a beauty for the money.
Have yet to get to the range, though, so I can't offer you a range report.
buffer weight issue - LRRPF52 - 02-16-2018
Open the port.
buffer weight issue - Kswhitetails - 02-16-2018
LRRPF52 Wrote:Open the port.
This. Why spend money for another barrel, ($150+) - when you could strip things down, find a local machine shop, and pay much less to have a competent drill press user to step up the port a little? You've already got an adjustable gas block.
I don't want to push you, but it seems to me that you're giving up right before the finish line. If you're dead set on going with another barrel anyway, and a shop is too inconvenient, why not try to do it yourself before you do? Could pay off, might not, but even if it doesn't you're not any worse off than your current plan?
My advice - here, it comes with a free grain of salt.
buffer weight issue - Dcommoncents - 02-16-2018
I didn't want to chime in because I also don't want to push you, but I have to say I agree with LRRPF and Ksw. After the effort and $ you've already put into this, why not spend a half hour opening the gas port. Even if you don't have a drill press you could easily do it with a hand drill. Just determine the maximum drill depth you can go without marring the bore opposite the gas port and put a stop on the drill bit or some electrical tape to tell you when to stop.
To each his own brother -- I'd just hate to see you abandon the barrel prematurely when an easy fix is in reach.
buffer weight issue - blackholegun - 02-17-2018
I appreciate both of your guys advise, that is what is great about this sight.
You will have to forgive me, but I already ordered the Faxon barrel for the sake of knowing in the end, I will have a reliable gun.
Like I said, this only my third build, still learning.
Someone will benefit from this as I am going to be selling the BA barrel.
I do thank you guys and appreciate your input though.
buffer weight issue - Dcommoncents - 02-17-2018
I have an 18" grendel mid length gas system and it's awesome. I'm sure you'll love your faxon. Just be sure to let me know if you're down to selling that ba barrel at a "defective" price. I have an 18" .223 wylde Hanson profile barrel from ba and it's an outstanding barrel.
buffer weight issue - blackholegun - 02-17-2018
I put an upper together in 223 wylde with the same barrel and it is a shooter no doubt.
My Faxon barrel will be here today, going to switch them out and then put the BA barrel up for sale
buffer weight issue - Greyling - 02-25-2018
for whatver it's worth, I had a blackout that was short stroking with my low powered 150grn cast lead bullets, even with a .125 gas port and carbine length gas system. I pulled 1 of the 3 weights out of the buffer. better, but still not good enough. So I cut 2 coils off the buffer spring and it has worked great ever since. Maybe the gas block was leaking, maybe my ammo was just too low powered, but remember, the AR was designed around the 223 round generating some 50K+ pressures. other calibers may need tweaking.
buffer weight issue - blackholegun - 02-25-2018
I tweaked it by putting the Faxon barrel on it, all is good now.