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Posted: 3/7/2007 4:18:52 PM EDT
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alright i have a 16 carbine upper from del-ton, 6 position collapsible stock and car grips. been having short stroke issues with federal american eagle amongst other brands. just started happening after 900-1000 rounds. short stroking and not picking up a round but rather wedging it in the middle. i clipped two coils off the buffer spring and took out one of the three wieghts in the buffer. where else should i be looking? will clipping the spring and decreasing wieght in the buffer aid in fixxing my short stroke issues??? |
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First big assumption: You don't have a tracable gas leak, like a loose carrier key? Second, on the assumption that the carbine was running properly before the spring and buffer modifications: Removing the weight from the buffer and reducing the weight could cause the carrier/bolt to open prematurely which should be hard on the brass rims. The brass however is resistant to leave the chamber because there is still too much pressure holding it against the chamber walls. That in turn holds back the carrier and O'lay short stroke. You may wish to call a Priest as there is nothing all AR15.comdom can do to help this! |
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no gas leaks checked from gas port on barrel down to the carrier. i snipped the spring and took a wieght out last night. was built and then after about 1000 rounds started short stroking. no modifications were done. before i go blow a bunch of money on ammo to see if this cures it , i wanted to see what you guys thought. gas rings are alright as well as the rifle is clean and lubed. bolt carrier slides freely in upper. so removing wieght will cause premature ejection, in turn causing a short stroke? what about just reduced spring tension? should i just open the gas port a little? and use a new spring? |
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1. Put the all the weights back in the buffer. 2. Find a deep lake and throw the clipped spring into it, then install a new unclipped spring. 3. Flood CLP down the gas tube from inside the receiver (it should flow into the bore through the gas port), and flood the chamber with BreakfreeCLP. Now using a butt stock cleaning kit, scrub the chamber by hand with the chamber brush. Once brush scrubbed, flush the chamber again (flowing the CLP downward out the muzzle), then attach a 30 cal mop soaked in CLP on two cleaning rod sections. Now using a drill to spin the mopped rods (don't use the drill to every spin the wire brush) make passes deep into the chamber and back out about 6 times. The chamber brush will get most of the chamber fouling, but you need the mop to get the last of the chamber cut clean. Once everything has been scrubbed, add one more blast of CLP down the chamber, and then using Q-tips and dry patches, get the barrel extension, chamber, and bore dry (again everything pushed out to the muzzle from the breach. Once you have the upper clean, then pull the B/C apart and clean it as well with CLP. With the B/C clean, before you put it back in the rifle, spray a thin coat of CLP on the entire B/C, including the gas section (through the key and making sure that you are getting flow into the carrier gas section), the cam section, and even on the bolt lugs as well. At this point, you can install the B/C back in the rifle. And if you where wondering, Yes the Buffer and recoil spring should have a thin coat of CLP on them as well. 4. Go shoot the rifle!!!! |
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dano i would love to shoot it. damn thing shortstrokes every few rounds. last two or three trips to the range. the rifle is cleaned after each trip. lubed as well. this rifle is as clean as any and lubed properly as well. yet still shortstrokes. damn ive blown through 1000 rounds of ammo and still am working out bugs. first finding a magazine worth a damn. now it shortstrokes wtf. what is the best way to overcome a shortstroke with .223 ammo. cut the spring? reduce wieght in buffer? open the gas port? |
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At 1k or rounds, the rifle should have teethed out any problems out on it's own, and not found new ones. At this point, confirm that the key bolts are 37 inch lbs tight, the bolt will stay in the carrier when the ringed bolt is face down without the cam installed, you have flow through both the gas tube to the barrel bore, and through the key to the carrier gas chamber (read didn't blow a primer and have a piece of it stuck in the key). Lastly, please in Gods name don't tell me that you changed ammo brands, and it alone is the problem at hand (read trying to run some off/third-world surplus never designed to run in the rifle platform). |
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carrier bolts tight and staked. rings seal and bolt stays in carrier. bought a case of federal american eagle 55grain fmj. put the weight back in the buffer going to order a new spring, any recomendations??? damn thing will short stroke again i am sure. any other places to look? open up gas tube and keep springs and wieght stock, is my best guess/ |
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If the rifle ran for 1k rounds clean, then started having problems, either its a chamber condition problem, or you have a gas system problem (not the barrel gas port size). Again, check to make sure that you have full flow through the gas system, and not something either clogged, or leaking like a sive. Worst case, the upper needs to be sent back if you can not find the new fault with the system. |
| I'm not an armorer, but maybe it's not short stroking. I put together a 11.5" rifle and mine did the same thing. I thought mine was SS also. However thanks to this site I put a HD extractor spring with an o-ring over that and she ran like a raped ape. Shorter barrels have pressure bonding problems. Just a thought. |
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ordered new buffer spring and put the wieght back in. took the gas block off and drilled the hole to .078". looks to be on the high end of spec for this rifle. polished the chamber and detail cleaned and lubed. will post again with results. going to get some different ammo types and run it through the mill. |
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