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Posted: 3/19/2024 8:31:11 AM EDT
[Last Edit: DemoknotRooster]
I have a Windham Weaponry .308 20" made mostly from the original Bushmaster. I have have more and more malfunctions since getting closer to the 100 round breaking and now probably have 140 rounds through it. I have been shooting 7.62X51 NATO FMJ through it and a couple of mags of other ammo. No reloads! I have changed the Gas block to Superlative Arms Adjustable and added 2 grams more of weight to the buffer. On time before last before I did the upgrades I had 15 malfunctions out of 17 rounds. After I did the upgrades I had 4 malfunctions out of 35 rounds 3 were failure t feed and one failure to eject (the failure to eject probably due to tuning the gas block) . I took it home tore it down and discovered a burr on the feed ramps and a little sharpness on the end of each ramp I did a little Dremel filing on the burr and sharp ends as i noticed on the defective rounds gauging and scratches on the unspent ejected rounds. I also polished the feed ramp. Is there anything I might have missed? I know Windham Weaponry (formally the old Bushmaster is a decent rifle. Everything is torqued to spec. Magpul Magazines 20 round.
But I am more than just a little frustrated. And the Mrs. is tarting to ask "How Much Did you put into it again!!!!???" |
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Now you’re going to spend a little more lol. Buy some ammo and test your dremel work.
Those burrs could have been the only problem. What mags and ammo are you using? |
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"The true soldier fights not because he hates what is in front of him, but because he loves what is behind him."
G. K. Chesterton |
Magpul 20 round and NATO standard issue FMJ 7.62X51
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What kind of malfunctions are you getting.
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Failure to feed mostly
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What type of stock system (rifle length or carbine length), buffer spring and buffer being used, as you state you upgraded the buffer to one that is 2oz more? Any chance you could post pics of the feed ramps or damage on the ammunition? If it's a feeding issue, have you tried to go to a heavier buffer spring to give the feed more push forward, and if so did this give different results? Also have you tried different magazines, specifically labeling them so you can see if the problem on feeding is with one particular magazine for with all the magazines?
CY6 Greg Sullivan "Sully" SLR15 Rifles DefensiveEdge.com (763) 712-0123 |
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The Butt Stock is a FAB Defense RAPS, A2 Rifle length, a vast majority of the issues occurred with a 5.4 oz buffer, I traded out 3 steel weights for 3 tungsten weights making it 7.4 oz. Not gram. The buffer Spring is the same as before the additional weight as I cannot find a a rifle A2 tube spring that is harder.
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Photo of the when the rig fails to feed, and where the bolt face is stopping at the jam, tells me a lot about the problem.
If bolt stopping on top of back of case, then either B/C is not coming far enough back to get behind the ammo rear rim*, or mag is not retained high enough in the mag well, or not recover fast enough to get top round tight against the entire bottom of mag lip before the bolt start to move forward again. * the fact that you changed the buffer mass, and even the gas block, could be the problem at hand. Here, the simple test to tell if all is correct, load a single round in to the mag, fire the round while leaving the empty mag in the well, and make sure that bolt is locking back on the bolt catch (bolt face in front of the catch). With an adjustable gas block in play, make sure once you have it set, adjust it to allow slightly more gas through the system, as the rifle starts to foul and will need that slight more gas. As for this being a civilian rifle, really need to check the chamber and leade, to see if tight 308 reamed to promote accuricy with shorter leade for longer ogive bullets, or is looser side wall dimension and slightly longer leade for FMJ ogive bullet to promote reliablilty instead. Hence tight chamber, with short ogive to give shorter jump to land with longer ogive bullets, is going to end up with 150fmj ammo pretty much embedding into the rifling at loading, which cause a spike in the working pressure of the round as well. The easy to to see if this is the problem, remove upper off lower, remove B/C, drop a loaded round into the chamber and tap the back of the round with a wooden dowel to make sure case shoulders are tight against chamber shoulders to get with. Then tilt muzzle up, and live round should free fall out of chamber. Next, need to know if this is a long action with long stroke, or if short action with long stroke isntead in 308. The difference, is pull the charging handle all the way back, and tell me the distance that the face of the bolt retracts behind the bolt catch, that the last inch of pull is no greater then the center of pull, and where the bolt face is stopping against the back of the receiver ejection port window. If bolt face stops in front of back of ejection port window by 1/8"~1/4" and behind bolt catch, the long action, long stroke. If bolt face stops behind the back of ejection port (to get behind the bolt catch), then short action and long stroke, and need to see a photo of the bolt face. The reasons behind this, is at end of buffer rear stall, where the spent case is starting to be pivoted off the bolt face and ejection, inside of ejection port back is in the way, and the bolt face has to have twin ejectors, to control the spent case ejection off the bolt until is moving forward in front of the ejection port window and the case be ejected cleanly, and at the same time, the spent case not being let loose to possible knock the top of back of the rim down in the mag, to cause a bolt over problem isntead. As for bur on feed ramps, may allow for a cleaner feed up the ramps, but in most cases, should not be a problem with the rifle jamming. Hence if getting bullet tip strikes below the feed ramps, then problem is the mag itself, with either the mag catch not installed with its inner threaded section flush to face of button, or mags themselves not recovering correctly to get the entire live top of round tight against the bottom of feed lip for a clean strip isntead. As for other jams, could be that hammer top of contact pad is catching the firing pin stop collar to slow the forward stroke down, assist paw catching the side of carrier slots to slow the carrier down on the forward stroke, or something stupid, like O ring on the extractor spring adding so much tension, that extractor can not spring open at last of the way forward, to allow the live round rim to shape into bolt face, so extractor lug can clear the barrel extension lugs to allow the cam over to lock up. Also, if you screwed around with gas block, the make sure that gas tube is correctly aligned with carrier key as well. To test, remove bolt from carrier insert carrier with finger in the back to push it until it face touches the barrel extension face, then tilt muzzle upwards to make sure carrier can free fall back. The gas tube enters the carrier key when front of carrier is about an 1" from touching the barrel extension face, and if not aligned, can cause the B/C last of forward movement as well. If gas tube needs to be tweaked to align with key, then its tweaked over center of barrel, not the back side that is protruding out into the receiver tweaked isntead. Bottom line, welcome to the site, and just need more information if the problem is just break in that should self resolve with a bit of live fire and cleanings (including the mags pulled down and CLP cleaned as well), or something that you induced with the parts changes instead (and the ammo its being feed). Also, going to add, if rifle shoots fine for a mag, then starts to have problems, either something causing a gas leak, or your using the wrong solvents to clean and lube the rifle; with it just fouling choking out too soon. |
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Posted By PlaymoreMinds:
'Twas not the <cough> sweet and innocent <cough> PlaymoreMinds... <---skips away in frilly skirts to Candyland, leaving gutters and snorkels FAR behind. |
Originally Posted By DemoknotRooster: Magpul 20 round and NATO standard issue FMJ 7.62X51 View Quote What specific brand NATO FMJ ? ( ZQI sucks... ) No offense intended... make sure the chamber and bore is clean of any storage / OEM oil... then relube properly the BCG, and recoil assm. Plan on giving ample lube for "break-in " ( you might wear some of it upon firing , Lol ) Do the "one mag fed round , fire, bolt locks back 100% test" first. Adjust the gas block as needed. Then focus on / look at feeding issues... then look at extraction / ejection issues. No offense, but baby stepping will narrow down the issues. Post clear pics of fired cases as need be. We will be looking for rough chamber marks. |
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*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man. ________________________________ TOGC,IADC |
When i reload my mags I will check the origin of the ammunition.
Concerning the spent brass, will do as soon as I get the chance to shoot again we got a nor'easter coming in tonight and below zero tomorrow. As for the hold open it holds open after last round in mag is spent so I assume its not under gassed. Brass ejects to the 4:30-5:00 position. There was a burr and some really sharp areas on the feed ramp that looked like it had been there from the machining and fitting from production. The gas block is aligned perfectly and spaced were it is supposed to be and is torqued and Loctited. To your point about lubricating I applied Hopps elite gun oil to the top and bottom of the bolt carrier. I cleaned to GI inspection when I got home. This time when I shoot I will use CLP instead of the Hopps Elite. For polishing and removing the burr I removed the barrel and extension from the upper and reinstalled after polishing and cleaning with the proper torque for the Midwest Industries free float hand guard. |
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*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man. ________________________________ TOGC,IADC |
Absolutely love this diagram. Outstanding HOOAH! lots of things I have forgotten since 1992 and receiving my DD214 and graduating to civilian from a former US Army 12B Combat Engineer.
Next time ill give her lots of loving and make sure she is well lubed LOL. |
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Originally Posted By DemoknotRooster: The Butt Stock is a FAB Defense RAPS, A2 Rifle length, a vast majority of the issues occurred with a 5.4 oz buffer, I traded out 3 steel weights for 3 tungsten weights making it 7.4 oz. Not gram. The buffer Spring is the same as before the additional weight as I cannot find a a rifle A2 tube spring that is harder. View Quote Are you using an AR-10 spring or an AR-15 rifle spring? |
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Slash at Heavy buffers can help with correct buffer and spring. I went with the heaviest full length buffer and his spring. My 20” runs smooth with slow push recoil.
Try taking your bolt and soaking overnight in mobile one synthetic oil. Shake off the excess and install wet. This tip has been shared and proven. |
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WOW! Isn't that a little overkill? I'm not runnin Full Auto...
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AR .308
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Originally Posted By DemoknotRooster: WOW! Isn't that a little overkill? I'm not runnin Full Auto... View Quote I had a box stock dpms lr308 that was exhibiting the same issue as yours, and it was amazing how much oil I had to put on that BCG to get it through a full mag trouble free, but it really worked. After a few hundred rounds it seemed to break in and ran with just a normal lubing. You have done a lot of changes on yours, so I’ll defer to our experts. |
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"The true soldier fights not because he hates what is in front of him, but because he loves what is behind him."
G. K. Chesterton |
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So, I went polished the receiver and shaved down a burr and some very sharp points. I went to the range and shot 60 rounds through it NATO 7.62X51 standard. Before I shot I lubed it with CLP liberally. Fired 3 rounds to adjust the Gas Block. The rest shot without any malfunctions. Shot 2" groups at 100 yards. So I guess that's good since it wasn't match grade. But then again I wasn't there for marksmanship but to test for malfunctions.
Thank You everyone for your advice and tips. i used a lot of them. i didn't soak the bolt carrier in 10W40 though LOL. Just CLP in the points in the manual of arms. |
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Originally Posted By DemoknotRooster: So, I went polished the receiver and shaved down a burr and some very sharp points. I went to the range and shot 60 rounds through it NATO 7.62X51 standard. Before I shot I lubed it with CLP liberally. Fired 3 rounds to adjust the Gas Block. The rest shot without any malfunctions. Shot 2" groups at 100 yards. So I guess that's good since it wasn't match grade. But then again I wasn't there for marksmanship but to test for malfunctions. Thank You everyone for your advice and tips. i used a lot of them. i didn't soak the bolt carrier in 10W40 though LOL. Just CLP in the points in the manual of arms. View Quote Thank you for the update. Glad it worked out ! |
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*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man. ________________________________ TOGC,IADC |
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