Help fixing this jam, slow motion video inside (Axor MF3, MKA 1919 type shotgun)

[Grods]

Noticed many people here have experience with MKA 1919 type semiauto shotguns. Mine is Axor MF3, as far as i can tell it uses same mags and is pretty much a cheap turkish clone of the 1919.

 

Most of the time it works fine, but this one type of jam has plagued the gun since new and it happens with all magazines, i usually get something between 50 to 200 rounds between jams and thats kind of bad for competition. Heres the slowmo of my friend shooting the gun before i got it showing whats happening:

https://drive.google.com/file/d/1uKmD7n8aK8UT4YTfMMWNBvUr7_GkDNUE/view?usp=sharing

 

As far as i can tell its recoil of the gun stripping the next round from magazine too early causing it to fly around the upper receiver slightly before the bolt would strip it. I tried bending the mag lips inwards to make it less likely for a round to strip by itself due to recoil, it reduced this jam (earlier it did this almost every 10 rounds) but didnt completely fix it.

 

Any ideas? Its not only costing time in competition, but im worried about that ejector hitting a primer on that jammed shell with bad luck.

Edited April 13, 2021 by Grods

[gerritm]

I have shot an MKA 1919 for many years. Not knowing what parts are in that or how it is set up, hard to tell. Does it happen with all ammo? Depending on what recoil spring is in it it can be that with hotter/lighter FPS ammo the bolt is cycling too fast/slow and not having time to go far enough back to strip the next round off correctly. Mine will do this with hotter ammo 1300 FPS and up. Over runs the bolt. Or you are not running hot enough ammo and again it is not cycling completely. Try different FPS ammo to see what it likes. Key is it happens with all mags. 

 

I run Win AA 1145 fps to 1250 fps only in competition because the shell case is smooth, feeds well,  and is hard and are way more reliable than other brands. Yours may need hotter FPS to cycle properly. Not sure where you live, but here in Texas on a hot summer day the cheap brands will actually deform from the heat.

 

gerritm

[Grods]

55 minutes ago, gerritm said:

I have shot an MKA 1919 for many years. Not knowing what parts are in that or how it is set up, hard to tell. Does it happen with all ammo? Depending on what recoil spring is in it it can be that with hotter/lighter FPS ammo the bolt is cycling too fast/slow and not having time to go far enough back to strip the next round off correctly. Mine will do this with hotter ammo 1300 FPS and up. Over runs the bolt. Or you are not running hot enough ammo and again it is not cycling completely. Try different FPS ammo to see what it likes. Key is it happens with all mags. 

 

I run Win AA 1145 fps to 1250 fps only in competition because the shell case is smooth, feeds well,  and is hard and are way more reliable than other brands. Yours may need hotter FPS to cycle properly. Not sure where you live, but here in Texas on a hot summer day the cheap brands will actually deform from the heat.

 

gerritm

 

Usually it happens with hotter ammunition like slugs. I seem to have less (but still happens from time to time) trouble running skeet/trap birdshots. More frequent when using slugs like some competitions here require. To my eye it looks like on the video that the bolt has quite a bit of excess velocity when it cycles, but that next round pops out from the magazine before bolt even starts to close.  12/70 rounds actually have enough room to pop out from the magazine even when the bolt is closed if they are bumped forward enough so that could be another reason.

[gerritm]

My gun is very temperamental with slugs. It only likes certain ones including Wolf & Xtreme. They are slightly shorter and will feed & eject. Most others are just a hair longer and catch or are too hot and over run the bolt. Will not run Fiocchi slugs consistently. Same with longer & hotter birdshot. 

 

You have to find what the gun likes, goes with the territory. We shoot a VR80 also and it also likes certain ammo and slugs. I have mine set up to run light loads with a lighter recoil spring from Tooth & Nail. Once you figure this out it will run consistently. Cannot run cheap soft shell ammo like Win white box. Need a smooth hard shell. 

 

My MKA & her Vr80 run 99.9% with the same ammo & slugs in competition. Can run whatever in practice when it doesn't matter.

 

gerritm

[Chillywig]

I don't have one of these guns but watching the video it look like the bolt ejects the empty, the next round seem to jump straight up out of the mag before the bolt has a chance to push it forward. The bolt and extractor never hook up with that round and instead stop on the second live round in the mag. How far does a round need to move forward to be released from the mag? If it is recoil induced is it happening with the mag completely full, nearly empty or any round count? I think your onto the right thing bending the feed lips and I too would be concerned about an extractor primer detonation. If softer recoiling ammo does the trick is there some sort of mag spacer you could put in there to keep the rounds from moving forward in recoil in the mag? Good video! 

[mpom]

I wonder if the bolt is actually pushing the new shell forward, only to have that shell not chamber, but stop dead, causing the bolt to bounce back and then get hung up

on the next shell coming up from magazine. Suspect if the shell that stopped cold would have been chambered the bolt would have followed and locked. 

Can you reproduce this issue with dummy rounds? Have you checked for any sharp edges at chamber mouth that could catch the shell as it attempts to enter chamber?

 

Mark