Intermittent loading issues...bolt issue?

[rogerg12]

I have a Begara B-14 HMR 6.5CM. Almost never used to have loading issues after cycling the bolt. I'm getting ready for my first PRS match and so I switched from the default 5-rd plastic magazine that comes with the rifle to 3rd party 10-rd magazines for matches. I've bought two different types...one plastic (MDT Polymer AICS) and two metal magazines (described by Brownells as 'Short Action Double Stack Single Fire Mag 10-rd 3.050 OAL'). All three of the new 10-rd magazines will have occasional, but not uncommon, loading issues...where it can't seem to pull the cartridge out of the magazine. It seems hard jammed instead. Sometimes I just try to recycle the bolt again a little harder and it works. Sometimes I have to eject and reseat the magazine, and sometimes I have to pull the magazine out, mess around with the bullets, and then re-seat. It does seem that when I have loading problems that the problematic cartridges didn't have their rim fully seated against the back of the magazine, although I'm speculating. Just thinking now, I need to re-try my original 5-rd magazine and see if I have issues, but I haven't tried that yet (but I will).

But I'm guessing this is not an uncommon problem. Is this likely to be more of an issue with the magazines where I might need to make some small physical modification or is it more likely to be a bolt starting to have issues? Where should I look and what should I look for?

I just know for sure I can't be having magazine issues going into a PRS match.

 

[stanley_white]

If you have calipers, measure the width of the front and rear of the feed lips on the magazine that works.

Measure the same on the other magazines that don’t work, modify them as necessary for uniformity across all magazines.

This video might help:



This too:



-Stan

 

[rogerg12]

If you have calipers, measure the width of the front and rear of the feed lips on the magazine that works.

Measure the same on the other magazines that don’t work, modify them as necessary for uniformity across all magazines.

This video might help:



This too:



-Stan

Thank you. Yes, I have calipers. Thanks for the videos.

 

[wade2big]

Do the 10 rounders allow the nose of the bullet to slide under the feed ramp? Some actions don’t play well with magazines that allow for an extended length. Put an empty magazine in the action with the bolt open. If any part of the action over hangs the magazine then that could very well be your problem.

 

[spife7980]

You need to figure out what’s actually happening so we can try and offer suggestions. “It doesn’t work” gives us nothing to go on.

It’s pushed out of the mag and hard jam of what? I don’t care what your hand is doing, we need to know what’s happening in the action.

 

[rogerg12]

Yep, I think the feeding lips were far too tight. Without modification, maybe only, at most, top 1/6th of the bullet was protruding into the action. I've modified the lips to be what the videos show it should be. Now to go shoot and confirm.

Thanks for your help.

 

[rogerg12]

You need to figure out what’s actually happening so we can try and offer suggestions. “It doesn’t work” gives us nothing to go on.

It’s pushed out of the mag and hard jam of what? I don’t care what your hand is doing, we need to know what’s happening in the action.

Great point. Fired cartridge was ejecting, but new cartridge was not getting fed into chamber or I would find cartridge pointing up or down in action like it got jammed. Based on the videos above I think the magazine lips were far too tight. Very little (1/6th or less) was showing up in the action for the bolt to capture and push. I've got to test.

 

[spife7980]

If you got it working then great. Just make sure they aren’t spread sooo far now that rounds slide out loosely and spray everywhere or present too high and jam into the breech face vs riding the feed ramp into the chamber.
A lot of this is just trial and error with what’s basically stamped metal

 

[rogerg12]

If you got it working then great. Just make sure they aren’t spread sooo far now that rounds slide out loosely and spray everywhere or present too high and jam into the breech face vs riding the feed ramp into the chamber.
A lot of this is just trial and error with what’s basically stamped metal

Agree. I opened very conservatively. I'm all about little changes. Test. Then decide what to do.

Thanks again to everyone for your help.

 

[tucaz]

i had a bergara b14 308 that would not feed well with the MDT metal 10 rd mags. pmags were fine.

i have intermittent issues with the same MDT’s in my ruger american too but not nearly as bad. that rifle really likes fast cycling.

it happens more when slow cycling but i also think the springs are strong enough in the MDT’s

just my rookie experience with bolt guns AICS mags but i will definitely be checking the feed lips on my metal mags.