Mausingfield / Accurate Mags / MPA. won't pick up 9th round

[b6graham]

I picked up a mausingfield a few weeks ago. shooting a 6xc using accurate mags without the binder plate. MPA comp chassis

on the 9th round in the mag it fails to be picked up by the bolt. bolt glides over it. not nose up or anything. i poke the round down and let it return up into the feed lips with my finger and run the bolt and it works fine. all 3 mags do it every time. the mags didn't do this with a tikka or another action they were ran with i just forget what he was running.

anyone else had this issue with either the mausingfield or accurate mags or chassis?

 

[Ledzep]

Pull your bolt from the action, and get it so you can look down the receiver bore straight from behind (may need to move/remove the cheek piece).

Load a round in the magazine (or two) to replicate the lowest point the ass-end sits in the magazine-- i.e. the most likely scenario to cause what's happening. Insert the magazine into the rifle and look from behind down the receiver bore and see how much of the rim you see.

Do the same thing with the rounds looking "normal". You should be able to see the primer or at least the bevel that goes into the primer pocket. If you don't you don't have enough case exposure and can either play with the feed lips, extend the magazine catch (weld, file, grind or talk to the chassis maker), or try different magazines.

Don't look at magazine issues as absolutes. There are at least 10 popular magazine makers with multiple variants, endless stock/chassis makers, endless DBM's, and quite a few different actions out there being put together by an array of thousands of individuals ranging from morons to the best smiths in the world..... It's amazing to me that they all go together and work as well as they do just from a tolerance stacking perspective. Nonetheless, a little massage work may be necessary to get height and angle set up so that everything runs reliably.