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Help me solve a cycling problem please. (UPDATE Fixed)

wareagle700

wareagle700

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Full Member
Minuteman
Jan 5, 2010
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SE Georgia
My new MA-10 build has been having a strange issue that I can't figure out. Please help.

The Rifle:
MEGA MA-10 Receivers
Lilja 20" barrel (.308 match chamber)
Rainier Match NiB BCG w/ additional JP Enhanced Bolt
DPMS .308 buffer
Syrac Ord. Adjustable gas block.

Problem:
Factory match ammo = functions 100%.

Reloads = dribbles out/jams/sometimes ejects fine (178 HPBT, 44.5gr Varget, 2.810")

My Findings:
I have adjusted the gas block to try and slow the bolt down but the problem is still there. The rounds always extract fcrom the chamber but don't eject 50% of the time. Many times the round stays in the chamber and causes a jam, or sits on top of the magazine feed lips. I do not believe this is an extractor issue as I have tried 2 different extractors and springs. I do not believe it is a gas issue as I have adjusted the gas block both ways and the problem still exist. Keep in mind all factory ammo works fine so this is leading me to believe something is wrong with my reloads.

Any ideas?
 
Last edited:
I found out when I got home my die was only bumping the shoulder back around .001".
Could that be causing a tight chamber and the extractor to slip off and the round just popping out of the chamber?
 
Any issue(s) can arrise if your brass is binding or "oversize or tight" in the chamber esp when you are using the gas (limited) force to cycle the action/bolt. May be a good start...
 
testing at home your spent brass:mandatory a caliper and Sinclair/Hornady bump gauges
try to see if the (un)-ejected brass has some dimensional difference from the others handloaded but correctly ejected brass_
try to chambering and extracting again the faulty brass, to see if it has macroscopic problems about that_
about brass dimensions, can happen that the brass grows in lenght as in width, and not everytime some full res.dies can manage to take it again to the best dimensions suited to your rifle chamber_that can depend from the die and/or from some brass springin'back _
compare the commercial ammo dimensions (fired and unfired)with headspace and width dimensions of your ejected and not-ejected handloads_
write all:workin'on that, you could identify and/or eliminate some factors about the possible cause of this problem_
 
If the shoulder bump does not work, I would measure some new, reloaded, and fired cases near the base to see if the base dimension is the issue first.
 
the FIRST STEP is MEASURING and comparing everything with the proper instruments_
AFTER THAT BUY whatever you want and/or discover to need_
Doin'that in the reverse order will drive you mad_ and unhappily confused_
 
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wareagle700 said:
I can shut the gas off completely with the Syrac.
Click to expand...

Shutting the gas off doesnt fix the problem. You are having issues with FTE/FTF which deals with the gas. I dont think you are sticking brass, I think the BCG is moving way to fast. Try some of those 178's over 42.5 Varget at 2.80 OAL and see what happens. That should be close to the pressures you need.
 
sic65stang said:
Shutting the gas off doesnt fix the problem. You are having issues with FTE/FTF which deals with the gas. I dont think you are sticking brass, I think the BCG is moving way to fast. Try some of those 178's over 42.5 Varget at 2.80 OAL and see what happens. That should be close to the pressures you need.
Click to expand...

I was implying that I can control the gas flow with my Syrac gas block. I can open up all the way or close it off completely and anywhere between. I don't think its a gas issue as I get the same ejection problems when the gas system is tuned specifically for those loads.

I resized some more cases .005" back with a Hornady FL die (which is said to be basically a small base die). I will test tomorrow if the weather lets me.

Thanks again yall.
 
Went out and put 20 more rounds though it today. Had 1 stove pipe and one weak ejection just dribble out. This was with cases that were resized about .004"-.005" using the Hornady die. Again, accuracy is great and still only get problems with the reloaded Hornady Cases.

My loads:

155 Lapua
46.6gr Varget
Hornady Brass
CCI-200
2.810"
2700 fps

178 HPBT
Hornady Brass
44.5gr Varget
CCI-200
2.810"
2500fps

I ordered some extractor spring inserts and o-rings to see if increasing the tension on the extractor helps.
 
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I've got the same mega upper/lower, barrel and bolt carrier group and had very similar problems. I chased it and spend a lot of money over a year trying to fix it. I bought a full length small base sizing die, JP case gauge, adjusted my gas block, bought a tubbs weight to slow down the bolt carrier movement, added heavier buffer spring, replaced extractor and added a heavy duty extractor spring, and added the rubber d ring around the extractor spring. Finally, I bought new brass. It now runs, thank God. I think the actual fix was the new extractor with Wolf heavy extractor spring and d ring along with the new brass that fixed it..
Hope you find your cure before you waste as much money and time as I did.
 
While replacing extractor springs today I noticed a difference between my two bolts. I replaced each sping with dual springs with o-rings. My JP Enhanced bolt has noticeably less extractor tension than the 7.62 Industries bolt. Even with the extractors swapped, the JP has much less tension. I can work the extractor with my fingernail while I can not do the same to the 7.62 Ind. I will try the other bolt today and see if that makes a difference.
 
If your extractor has too much tension, it pushes the case onto the opposite side of the bolt with so much force that the ejector lacks enough power to push the case out in time during the bolt's cycling rearward and back forward. Often an extractor with less force solves the problem. It solved all my ejection issues.
 
Unknown said:
If your extractor has too much tension, it pushes the case onto the opposite side of the bolt with so much force that the ejector lacks enough power to push the case out in time during the bolt's cycling rearward and back forward. Often an extractor with less force solves the problem. It solved all my ejection issues.
Click to expand...

This seems like a possible answer. With the lighter extractor springs, empty cases seem to move more freely out of the bolt than the stronger springs. The stronger springs would actually hold the empty case in at an angle. That might casue the stovepiping I experienced.

More testing wil be done tomorrow. (missing a match because of this, not happy)
 
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Put in a new extractor and extractor spring and that seems to have fixed the issues. The DPMS extractor that came with my JP bolt would hold a empty case in the bolt. It would also leave two sharp dents on the inside of the case rim which I think is why it would not release the case. I installed the 7.62 Ind. extractor and Sprinco springs and had no issues at all today through 35 rounds of reloads and 10 factory. All perfect ejection.
Loaded up the same loads as before as well as some different loads using different brass, bullets, and powder. All functioned fine.

Thanks for the help.
 
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