AR 15 issue
- Thread starter hornetguy
- Start date
I'd never head that most Ar's are over gassed, good information, would that explain why my guns get incredibly dirty when running a suppressor compared to a suppressed bolt gun in 223 using the same ammunition?
I believe I have 3 different lengths of buffers in my pile of extra parts, one rifle has a standard AR stock the other a MFT adjustable length stock, both are 16" barrels, what buffers should they have for 60gr v-max bullets loaded to the max.
BTW they both function perfectly until they are to dirty to which is around 50 rds.
I believe I have 3 different lengths of buffers in my pile of extra parts, one rifle has a standard AR stock the other a MFT adjustable length stock, both are 16" barrels, what buffers should they have for 60gr v-max bullets loaded to the max.
BTW they both function perfectly until they are to dirty to which is around 50 rds.
stagpanther
New member
No, I was not suggesting that. You have an unknown lower matched to a manufactured upper--so occasionally tolerance issues do come up. I generally work my way up from "easy fix scenarios" in a process of elimination before I venture into "gas system/buffer musical chairs."
But that's just me, I'm not a professional armorerIf you have an over-gassed AR and then suppress it, yes, you amplify the over-gassing.
But the bolt gun pushes almost all of the gas out the bore, instead of recycling some through the action like a DI system.
Most people don't want to adjust a load...but when you adjust the DI system to a load, you really should pick whatever your lowest powered load is, and tune to that. The load "gas generated" has more to do with charge weight than energy level or bullet weight.
So, given load, you can adjust the system to that load by 1. reducing gas volume into the gas tube with an adjustable gas block or 2. increasing buffer mass/spring weight.
My suppressed ARs have a carbine spring and buffer, usually gutted or low mass, low mass carrier and a standard gas block. But I use premium 16" barrels that are optimized to not need adjustable gas. When the suppressor goes on, the buffer and or spring get changed.
I am working on tuning Jerry Miculek's magnetic buffer for one of my guns. It is adjustable and tunable, so great hope it is another good solution in this area.
Sweet Shooter
New member
I wouldn't bother with an H buffer. Go straight to a H2/S2. Also consider a flat wire buffer spring, like a Strike Industries, or Tubbs, that will give you a little more lock time and slow things down.
I keep meaning to try a flat wire buffer spring. but they are spendy. I ended up getting a JP Tuned/polished buffer spring. It was a good improvement over the mil-spec.
I really want to try the JP captured buffer system.... but I cant justify it at the moment.
Obviously, I'm not either. I believe in working easiest fix to hardest. This is why I polished the feed ramps and looked at the barrel/receiver junction to make sure all of that was as close to correct as I can get it. I think I've eliminated (in my mind, at least) the magazines as the issue.
The overgassing is something I wasn't aware of, so I'm going to approach that by putting in an H2 buffer, picked up this afternoon on the way home. I'm also going to see if I can find anything suspicious about the magazine lock up in the lower. (too low?)
I have not mentioned that this rifle also does not pick up a round, if the magazine is inserted against a closed bolt. I have to lock back the bolt, insert the mag and release the bolt. This makes me think about magazine lock up height.
I don't think I'm quite to the point of getting a new lower with known quality parts... yet.
I finally made it to the range... bottom line, it's way better, but not quite "there" yet.
I had installed the H2 buffer, and a flat wire recoil spring.
I had only one jam, second to the last cartridge. It appears the cartridge was partially stripped out, then slipped off the bolt lug, allowing the bolt to slam into the side of it.
I did several mag changes, loading anywhere from 5 to 20 rounds, and emptying the magazines. This was the only jam.
It still won't strip off a round when the magazine is loaded under a closed bolt, unless I manually push upward on the mag, and let the bolt go forward.
It appears that the magazine just doesn't sit high enough in the receiver for the bolt lugs to make a good "grab" on the cartridge head.... which would also explain the jam... if the lug is just barely pushing against the case head, any downward movement at all of the cartridge would allow the bolt to slip off, and over the cartridge.
I had installed the H2 buffer, and a flat wire recoil spring.
I had only one jam, second to the last cartridge. It appears the cartridge was partially stripped out, then slipped off the bolt lug, allowing the bolt to slam into the side of it.
I did several mag changes, loading anywhere from 5 to 20 rounds, and emptying the magazines. This was the only jam.
It still won't strip off a round when the magazine is loaded under a closed bolt, unless I manually push upward on the mag, and let the bolt go forward.
It appears that the magazine just doesn't sit high enough in the receiver for the bolt lugs to make a good "grab" on the cartridge head.... which would also explain the jam... if the lug is just barely pushing against the case head, any downward movement at all of the cartridge would allow the bolt to slip off, and over the cartridge.
well, at least you know what the issues are. over gassed and an out of spec mag well from the sounds of it. the H2 buffer is a quick fix but an adjustable gas block is probably a good idea.
For the mag well, that is an issue that is one that I have no idea on. maybe a pic with the upper off and a mag in the mag well to see how far up it protrudes when locked in?
For the mag well, that is an issue that is one that I have no idea on. maybe a pic with the upper off and a mag in the mag well to see how far up it protrudes when locked in?
I measured down from the top of the receiver with calibers, comparing it to my DPMS Panther... The "troubled" receiver is made by SOTA, and it measures .681 to the top of the slot for the catch.
The DPMS measures .692 in the same space.
I then measured down into the mag well to the top of the mag catch, and got .696 and .706
I think I'm going to swap the mag catches between the two, and see if that is the issue.
I tried swapping the BCG's, and the Sota still would not strip a round out of the mag.
When I pulled the bolt back on the DPMS slowly, I saw the top cartridge "jump" as the bolt passed over it. Doing that on the Sota, all I see is the cartridge tip slightly downward at the back of the cartridge.
Either way, the mag sits higher in the DPMS... the bolt lugs catch the cartridge positively, no problems at all.
I tried swapping the BCG's, and the Sota still would not strip a round out of the mag.
When I pulled the bolt back on the DPMS slowly, I saw the top cartridge "jump" as the bolt passed over it. Doing that on the Sota, all I see is the cartridge tip slightly downward at the back of the cartridge.
Either way, the mag sits higher in the DPMS... the bolt lugs catch the cartridge positively, no problems at all.
imashooter
New member
Thinking the lower is out of spec considering everything. I'd contact Mr. PSA (Josiah) over at ar15.com (great guy) https://www.ar15.com/member/user.html?id=158425
or
Palmetto State Armory
200 Business Park Blvd
Columbia, SC 29203
Web Sales: 1-803-724-6950
customer.service@palmettostatearmory.com
They'll square it away. If not offered make sure and ask for a prepaid shipping label.
or
Palmetto State Armory
200 Business Park Blvd
Columbia, SC 29203
Web Sales: 1-803-724-6950
customer.service@palmettostatearmory.com
They'll square it away. If not offered make sure and ask for a prepaid shipping label.
Thanks, but I didn't get the stripped lower from them. I bought it on a whim at a gun show for about $45. I guess you get what you pay for.
I'm looking at lowers now...one is a Primary Arms 7075 billet, for not quite 3 times what I paid for my "budget" lower. Lesson learned. I still might get a PSA one, but I need to research it more before I decide.
I'm going to put my new upper on my DPMS lower in a few minutes, to see if it feeds the same way the DPMS upper does. That should help narrow down if it is indeed the lower.
I'm looking at lowers now...one is a Primary Arms 7075 billet, for not quite 3 times what I paid for my "budget" lower. Lesson learned. I still might get a PSA one, but I need to research it more before I decide.
I'm going to put my new upper on my DPMS lower in a few minutes, to see if it feeds the same way the DPMS upper does. That should help narrow down if it is indeed the lower.
switch those uppers, that will for sure narrow it down to a lower issue. thumbs up
Yep.... it's the lower.
I swapped them, and the new upper fed perfectly off the DPMS lower.
The upside is that I now have an H2 buffer and flat wire spring....
My "budget" AR is going to end up costing about $800-900.... lol
I put a free float handguard on it, and love it. It just feels WAY better.... I imagine I'll do my other AR and the AR-10 the same way.
I swapped them, and the new upper fed perfectly off the DPMS lower.
The upside is that I now have an H2 buffer and flat wire spring....
My "budget" AR is going to end up costing about $800-900.... lol
I put a free float handguard on it, and love it. It just feels WAY better.... I imagine I'll do my other AR and the AR-10 the same way.