FTF help

[67camaro 0]

So I've been having constant FTF's only growing worse the more I shoot. I think I have finally narrowed it down. At first I thought it had something to do with the R&R magwell or the mags themselves, but it seems like when feeding the rim of the shell is binding against the side of the receiver and the bolt seems to be pushing it that way. Has anyone ever experienced this and if so do you have any ideas on how to fix it? This is my competition open gun and if I can't fix it soon I'm gonna end up scrapping it for a new Wright 12 or KL-12 but would prefer not to drop 4k if I don't need to. This is a video showing of what it's doing. Any help would be greatly appreciated. Thanks.

 

https://youtu.be/CsI_XWpn140

[evlblkwpnz 3,418]

Tell me about your recoil assembly. Factory or do you have something else going on there?

[67camaro 0]

The entire recoil assembly is factory. Only thing ever changed is recoil springs. Other than polishing bolt surfaces the entire top end is factory. The weapon was converted by me in late 2007. I honestly can not give an accurate round count but I'm guessing between around 5000 - 7000 on the high end. Which I don't think is that much. I can't seem to figure out why the bolt is pushing the shell to the side of the receiver.

 

ETA: It only does this when stripping the shell from the magazine. If I drop a shell into chamber and manually drop bolt onto it it pulls back and forth freely from the chamber back past the spot where it is binding and then back to the chamber fine. This has only started happening within the last 1500 rounds or so. I initially thought it was mags then chamber issues. I've ground/polished feed ramps of the chamber and also filed the top part of the hood of the chamber to stop shells from binding on the top and this has worked to keep shells from grabbing up top.

Edited May 8, 2018 by 67camaro

[evlblkwpnz 3,418]

How is extractor spring tension?

 

Yes, 5-7k isn't all that much for these weapons. I stopped keeping track on my SBS at around 11k or so. I have been through 2 extractor springs. One extractor spring failure was because I got carried away experimenting with tension. These take standard AK rifle extractor springs, by the way.

 

 

How do things work when the bolt is allowed to fly forward on its own with factory springs?

 

When you are behind the weapon at least about 4 feet or so looking slightly down on the weapon, viewing from a little higher than the sights with the receiver cover off and the carrier removed (put it in a vise or whatever), how drastically does your receiver bend just behind the trunnion? A good pic might be helpful.

 

What are the strongest loads you have fired with non-factory recoil springs?

[67camaro 0]

How is extractor spring tension?

 

Yes, 5-7k isn't all that much for these weapons. I stopped keeping track on my SBS at around 11k or so. I have been through 2 extractor springs. One extractor spring failure was because I got carried away experimenting with tension. These take standard AK rifle extractor springs, by the way. Never replaced an extractor spring, never have any FTE just FTF

 

 

How do things work when the bolt is allowed to fly forward on its own with factory springs?  I have onyl replaced with factory power spings. Its a lot better dropping quickly but still 2-4 FTF per 20rd mag 1-2 per 12rd

 

When you are behind the weapon at least about 4 feet or so looking slightly down on the weapon, viewing from a little higher than the sights with the receiver cover off and the carrier removed (put it in a vise or whatever), how drastically does your receiver bend just behind the trunnion? A good pic might be helpful. Pic below.

 

What are the strongest loads you have fired with non-factory recoil springs? Probably less than 200 full power 2 3/4 slugs on factory strength recoil springs.

 

Thank you for taking the time to give me some help.

 

 

 

[evlblkwpnz 3,418]

That wrap/decal/dip is making it realty hard to tell exactly what I am looking at, but there is some fairly significant bend to the right in the receiver. No clue if it is directly contributing to your issues, but it certainly could be. Also, the hammer is way off of center. I've never seen one that far to the left.

 

Have you checked the receiver rails to ensure no spot welds are broken?

 

Looks like the feed foot of the bolt is hitting the feedramp to the right pretty hard as well.