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Posted: 6/19/2005 5:32:07 PM EDT
| My Beowulf jams once in a while: instead of pushing a new cartridge into the chamber, the bolt hits the cartridge in the middle and tries to push it in almost sideways. What might cause this feed problem? I have Rock River lower with MGI buffer and an extra-power Wolf spring. |
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I will say I'm not really fond of the factory mags. they work ok I guess. Definitely try some differnt mags to see if that eliminates the problem. But try both ways with the extra power spring and with out. I have a feeling it will work fine with different mags and the normal buffer spring. |
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i have never had any problems with the 20rd mag that comes with the wulf i would try removing the extra pwr spring first and seeing if that helps since thats a freebie and then go at the mags if that doesnt help. also make sure that the spring your using is the correct length, if your running a2 or similar length stock make sure your using rifle length spring and shorter collapsable stock use the shorter carbine length spring. could also be a problem since you have a new spring you might have gotten the wrong length, if your running a car stock and have a rifle spring it would never have enough pwr to compress the spring. |
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The gun definetely short cycles. I've been to the gun range almost every day (my shoulder is about to fall off after this week...) and this is what I've tried so far: * Replaced the extra-power spring with the original spring * Tried various different magazines * Polished all sliding surfaces on the bolt carrier * Replaced the carrier key I have run out of things to try. I guess that the next step would be to send the upper back to Alexander Arms that they could check whether there is something wrong with the gas port. |
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Have you tried firing loading one round in the mag firing it and seeing if it locks the bolt open ? What stock are you running on it? Are you running a stock (factory) trigger ? I had a adjustable trigger that would catch on the head of the firing because the disconnect wasn't catching.(screw had come loose on disconnector) Look at the top of you trigger and head of the firing pin to see if it's been draggin or catching on anything. ETA: Do you have another complete lower you can swap the upper on to ? |
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car or rifle stock??? i had problems when i installed a ace m4socom stock with something similar to short stroking, would close on the round before chambering. reinstalled the a2 that was on there and problems went away, i guessing the car setup has too fast of a bounce back. |
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Guys, thanks for your continuing help in debugging this! I have A1 stock, which (I believe) has the same lenght buffer tube as A2 has. When I load only one round, the bolt catch engages intermittently - most of the time it fails to catch. The thought on the bounce-back effect is interesting. I've experienced it even with .223 and certain stocks. I just did a quick comparison between my wulf (MGI buffer & the delrin spacer for rifle stocks), a carbine (telestock & CAR buffer), and a rifle (A2 stock & rifle buffer). The gap between the fully retracted bolt and the bolt catch is about the same with wulf and the carbine. The rifle has almost twice as wide a gap. Maybe the next thing to I try is to shorten the delrin spacer that the bolt would retract as far as it does with the rifle (I bought MGI buffer for my carbine, too, so I have an extra spacer to play with). Though if this were the root cause I'd expect that other MGI buffer owners would experience the same problem... |
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Two things to try: 1 - Really suck the stock into your shoulder. When shooting my 1911, if I limp wrist it too much, it stove pipes. Similarly, I have had some .458 uppers that as long as I really shoulder it, it runs fine 2 - take out the MGI buffer. The extra weight can be too much some times. I ran one for a while and then stopped because a) I am used to the recoil and b) it did not like the Lil Gun loads..... Just use the extra power spring. Nothing bad about the MGI buffer (I am an MGI dealer) but sometimes it is just too much of a good thing. Don't ask, sometimes rifles are finicky |
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1. try adjusting feed lips 2. and adjusting magazine catch. Give the magazine catch screw a couple of turns. 3. buy a thermold mag The mag catch trick worked for this guy ar15.com/forums/topic.html?b=3&f=121&t=235999 |
| I did some more debugging yesterday and this is what I found: this problem seems a classic textbook example of an effect that combined tolerances can cause. The MGI buffer & spacer combination is about 3/64" longer than a regular rifle buffer. This alone wouldn't probably cause any problems, but then I found that the buffer tube that I have on wulf is about 1/16" shorter than the tube on my .223 rifle. When you combine these two tolerances the wulf cycle becomes nearly 1/8" shorter than what it should be! It is a miracle that the bolt catch has been able to work at all, even intermittently. So yesterday I milled the MGI spacer 7/64" shorter and now the wulf bolt retracts as far as my .223 rifle bolt does. Unfortunately I won't be able to go to test this on the range today, but I'd be very, very surprised if this doesn't fix the problem. |
YIKES!! i think i would have tried every suggestion before i milled/machined an expensive MGI buffer. you sir are a braver man than I. |
Heh, I am not that brave either. I didn't machine the buffer itself, I machined the delrin rifle-stock spacer that comes with MGI buffer.
Is your buffer tube too long? Would an extra spacer (like a thin disk) help? If that is the case, let me know the thickness of the spacer that you'd need and I'll machine you one out of delrin (at no cost, just for the fun of it). |
| I won't be able to test it until this Saturday. I sure hope that this would fix the problem. So far the too short travel distance seems the most likely candidate. The bolt was stopping so close to the bolt catch that it is amazing that the catch ever worked (even very intermittently). But I won't find out for sure until Saturday. |
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