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Posted: 2/16/2009 1:06:31 PM EDT
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Took my 261 kit out this past Friday, Kit has a couple thousand rounds through it already, It was a total Jam-o-matic. Was getting FTF's and it was pushing the rounds up too high it appeared with known reliable mags and some newer BDM mags I was trying to break in. Here's the wierd part last trip I went through almost 1K of rounds flawlessly. I even had 3 mags loaded up out of the same box of ammo that had the problem. I had it lubed like I always do, switched to sopping wet to see if that would help, no dice. Stripped it down although i thoroughly cleaned it after the last trip, and still FTF's. Kit has so far been super reliable with just a few FTF's and a dud round here and there. This is an Oly kit, with BDM mags, 2 25 rounders, and 2 24 rounders with the bolt hold open(which were brand new). Using Federal value packs. All mags did the same thing. I even tried the kit in my buddys AR and it did the same thing. Thanks in advance for any suggestions.
JestersHK |
Usually if ever thing worked before I tend to believe it might be ammo related. I've noticed my conversion kits were sometimes unreliable in colder weather. I'd suggest down loading the BDM mags to around 10 to 15 rounds and see if this improves functioning. When my BDM's were new they needed a little break in. During the break in period I put drop of CLP lube on the follower. The lube seemed to help the mag function better. On my AKT 98 I was having feeding issues. I filed the follower on the BDM mags to change the angle the cartridge was pushed into the chamber. My cartridges were hitting the base of the chamber then bouncing up and hitting the top of the chamber causing a stoppage. A stronger recoil spring helps solve this feeding problem sometimes to. Also look at the extractor and make sure there is clearance for the rim of a case to sit on the bolt face. Check the extractor for free movement and make sure there are no burrs. Also look at the bolt face and make sure it is smooth with no burrs. On some guns the round has to slide under the extractor while feeding. On other guns the extractor snaps over the case rim as the bolt goes closed. I don't have a M-261 kit so I'm not sure if the case slides under the extractor while feeding or snaps over as the bolt closes. If either type of feeding is not smooth it can cause the round to hit the top of the chamber. You might read in the M261 BDM mag thread above for some other ideas. I also have polished the feed ramp and chamber inserts on my kits to improve functioning. Good luck some times it takes a lot of patience to figure out what is going on.
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If it ran good before, Did You change ammo brand? Get a bad lot of ammo? Or, it's temperature related. Or Physically, something changed within the Magazine or the Conversion Unit since your last trip shooting.
I had feed problems with the 2 units I had for testing but that was cleared up with a minor feed ramp mod and never showed itself again. I also replaced the Firing pin Retainers with Roll Pins because they backed out and got caught on the Ejector Port |
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Quoted:
If it ran good before, Did You change ammo brand? Get a bad lot of ammo? Or, it's temperature related. Or Physically, something changed within the Magazine or the Conversion Unit since your last trip shooting. I had feed problems with the 2 units I had for testing but that was cleared up with a minor feed ramp mod and never showed itself again. I also replaced the Firing pin Retainers with Roll Pins because they backed out and got caught on the Ejector Port can you post pics of the new pins? I lost my pins and need to fix it somehow |
| I don't even have the M261 Conversion Units any More. I have gone to strictly Ceiner Style Conversions as I currently have 7 of them. The Roll Pin just needs to be big enough to fit into the hole somewhat snuggly, so it can be tapped into place and long enough to retain the Firing pin. I seem to remember that it was similar in size to the Trigger Guard Pin But you should verify that. I'm guessing at anything beyond that. |
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Thanks for the replies all,
I will check that back tab, kit fits super tight in the upper. Ammo was also my first guess, but I loaded 3 mags with the leftovers from the range trip when it worked flawlessly and they all did the same thing. Guide rod was lubed. Looked at the mags the other night and may try cleaning up the feed ramps just a teeny little bit. Will try again this weekend to get her running again. Thanks, JestersHK |
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