I have a DPMS 16" upper I just put together. Its carbine length with dpms low profile gas block. It will not feed, it always ejects the spent round and ussually either doesnt pick up the next round or stove pipes. I have had the gas block and tube off twice to check for alingment and blockage and have tried different ammos. The rifle feeds manually fine so I dont think its the mag. Should I try a different buffer spring or magazine.
-
Having trouble using the site?
Contact support
Short Stroking AR 15
- Thread starter bschneiderheinze
- Start date
Re: Short Stroking AR 15
Check gas key first to ensure it is torqued down properly (do not overtorque it though, you will shear the bolt). Next check the condition of the gas rings. Then, make sure you have the right type/size of buffer and spring for the type of stock you have.
Check gas key first to ensure it is torqued down properly (do not overtorque it though, you will shear the bolt). Next check the condition of the gas rings. Then, make sure you have the right type/size of buffer and spring for the type of stock you have.
Re: Short Stroking AR 15
The carrier and lower were used on my 6.8 and worked well. I just swapped out the gas tube with another and it cycled for a couple rounds and then started stove piping. I would bu another mag, but functions perfect manually I dissambled the bolt and carrer to check the gas rings and made sure they were staggered.
The carrier and lower were used on my 6.8 and worked well. I just swapped out the gas tube with another and it cycled for a couple rounds and then started stove piping. I would bu another mag, but functions perfect manually I dissambled the bolt and carrer to check the gas rings and made sure they were staggered.
Re: Short Stroking AR 15
A very slight problem with the gas rings, (either too tight, or gaps, excessive wear, or anything that prevents normal function), can cause short stroking.
A very slight problem with the gas rings, (either too tight, or gaps, excessive wear, or anything that prevents normal function), can cause short stroking.
Re: Short Stroking AR 15
Gas rings, dpms had some weird stuff going on w/them. We built 11 10.5" for a deal. 8 of them needed new gas rings less than 500rds. Haven't had a problem since we switched them out. Does the bolt slide in and out of the carrier too easy? Its rings.
If not rings it will the buffer /spring issue.
Gas rings, dpms had some weird stuff going on w/them. We built 11 10.5" for a deal. 8 of them needed new gas rings less than 500rds. Haven't had a problem since we switched them out. Does the bolt slide in and out of the carrier too easy? Its rings.
If not rings it will the buffer /spring issue.
Re: Short Stroking AR 15
The bolts brand new and feels tight. I took apart the buffer toady and it had three steel inserts , which I would assum means it is the lighest. Should I get a heavier buffer h or h2. I just down understand how slowing the cycle rate is going to help it pick up ammo. There is also several impact marks on the buffer is this normal or does this mean its cycling to hard. It looks like some took a punch and hit it along the edge in a couple spots.
The bolts brand new and feels tight. I took apart the buffer toady and it had three steel inserts , which I would assum means it is the lighest. Should I get a heavier buffer h or h2. I just down understand how slowing the cycle rate is going to help it pick up ammo. There is also several impact marks on the buffer is this normal or does this mean its cycling to hard. It looks like some took a punch and hit it along the edge in a couple spots.
Re: Short Stroking AR 15
My knowledge on buffer weights is very limited. But I would think that if the rings are good, meaning when the bolt is extended in the carrier you can stand it on end(bolt side down) and it will stay there and not slide down. Then the buffer spring combo is too much/too heavy or too light. Either the buffer or the spring or the combo of each.
My guess is it is too light, again not an expert, but if you can find someone near by that has another buffer spring combo try it. Id find out what's wrong before you buy new stuff. That way you know what to buy.
I'll, buffer too light.
My knowledge on buffer weights is very limited. But I would think that if the rings are good, meaning when the bolt is extended in the carrier you can stand it on end(bolt side down) and it will stay there and not slide down. Then the buffer spring combo is too much/too heavy or too light. Either the buffer or the spring or the combo of each.
My guess is it is too light, again not an expert, but if you can find someone near by that has another buffer spring combo try it. Id find out what's wrong before you buy new stuff. That way you know what to buy.
I'll, buffer too light.
Re: Short Stroking AR 15
I didn't read any of the responses but make sure you have a buffer spring with the right amount of coils/length and the proper size buffer for the buffer tube/type of stock you have. Example: running a rifle length buffer or spring or both in a carbine length buffer tube will cause problems.
Without a mag seated in the gun, pull back the charging handle and hold the catch to grab the BCG. Does it keep the BCG back by itself or does it not catch and let the carrier slide forward? If you have too long of a buffer or a spring with too many coils or both, it will cause problems. The BCG won't lock open on an empty mag either. Good luck, sorry if that's the third time its been mentioned.
I didn't read any of the responses but make sure you have a buffer spring with the right amount of coils/length and the proper size buffer for the buffer tube/type of stock you have. Example: running a rifle length buffer or spring or both in a carbine length buffer tube will cause problems.
Without a mag seated in the gun, pull back the charging handle and hold the catch to grab the BCG. Does it keep the BCG back by itself or does it not catch and let the carrier slide forward? If you have too long of a buffer or a spring with too many coils or both, it will cause problems. The BCG won't lock open on an empty mag either. Good luck, sorry if that's the third time its been mentioned.
Re: Short Stroking AR 15
If you are running a UBR or PRS stock with the screw that goes into the end of the buffer tube to hold the stock on... Then that screw could aslo be too long and stopping the buffer short and causing the marks on the buffer's tip. If you are running a UBR or PRS then that screw needs to be the factory slotted/vented screw. You also need a rifle length AR15 buffer and spring with the UBR/PRS
If you are running a UBR or PRS stock with the screw that goes into the end of the buffer tube to hold the stock on... Then that screw could aslo be too long and stopping the buffer short and causing the marks on the buffer's tip. If you are running a UBR or PRS then that screw needs to be the factory slotted/vented screw. You also need a rifle length AR15 buffer and spring with the UBR/PRS
Re: Short Stroking AR 15
I would look into mags as well. However, if it the carrier doesn't hold open on an empty mag after firing one round loaded in the mag, then it isn't going back far enough to grab the next round and I would listen to the people mentioning buffer/buffer spring. hope you figure it out
I would look into mags as well. However, if it the carrier doesn't hold open on an empty mag after firing one round loaded in the mag, then it isn't going back far enough to grab the next round and I would listen to the people mentioning buffer/buffer spring. hope you figure it out
Re: Short Stroking AR 15
New heavier buffer and a new carbine spring and it seems to function flawless. I am guessing the bolt was coming back forward to fast to pick up a new shell.
New heavier buffer and a new carbine spring and it seems to function flawless. I am guessing the bolt was coming back forward to fast to pick up a new shell.
Re: Short Stroking AR 15
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: redirt78</div><div class="ubbcode-body">If you are running a UBR or PRS stock with the screw that goes into the end of the buffer tube to hold the stock on... Then that screw could aslo be too long and stopping the buffer short and causing the marks on the buffer's tip. If you are running a UBR or PRS then that screw needs to be the factory slotted/vented screw. You also need a rifle length AR15 buffer and spring with the UBR/PRS </div></div>
Actually the UBR requires a carbine buffer and spring. You are correct on the PRS.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: redirt78</div><div class="ubbcode-body">If you are running a UBR or PRS stock with the screw that goes into the end of the buffer tube to hold the stock on... Then that screw could aslo be too long and stopping the buffer short and causing the marks on the buffer's tip. If you are running a UBR or PRS then that screw needs to be the factory slotted/vented screw. You also need a rifle length AR15 buffer and spring with the UBR/PRS </div></div>
Actually the UBR requires a carbine buffer and spring. You are correct on the PRS.
Similar threads
