Gunsmithing Feed issue - Bolt not picking up round

[Habituallinestepper]

Having trouble getting my rifle to feed rounds from the magazine. The bolt starts to push the round forward, but the round's base dives as the tip rises into the chamber and the bolt slides over the top.

Savage 12FV 6.5CM
MDT LSS-XL
Magpul AICS 10rd mags (2)

A few posts suggests removing material from the feed lips. Curious if folks have had success doing this (lots of suggestions, little follow-up). If so, are you taking material off the front of the lips closest to the barrel or on the underside where the mag contacts the case? Is there something else I'm missing?

I'm new to the bolt game, so if this is a case of operator error, I'll gladly take my lumps.

 

[Hoyt7mm]

Tagging in. I have a similar issue with 10 rd PMAGs. Only happens when I'm down to the last couple rounds in the mag. Going to play with the Accurate Mag and ARC mags to see if that helps.

 

[FUNCTIONAL]

Have you tried pushing up on the back of the mag while cycling the bolt?

You could also bend the lips open on the mag a little at a time to make the round protrude up more.

 

[Apnea]

Tagged...

 

[Bandaid]

My Magpul 10rnd did the same thing. I took it apart and cleaned it up and thought it was ok but during my club match this weekend it did the same thing. Looks like the follower isnt sliding up in the back as fast as the front causing the cartridge to sit a little too low. I have never had a problem with my 5 rnd magpul mag. I am going to try and tweek the spring and see if there is anything to deburr on the follower... and probably buy a ARC or AICS mag that I can trust.

 

[Mordamer]

Sounds like your mag I'd not being held high enough into the action buy your chassis.

 

[supercorndogs]

Have you tried pushing up on the back of the mag while cycling the bolt?

You could also bend the lips open on the mag a little at a time to make the round protrude up more.

You have bent lips on magpul mags?

 

[pedalpower]

This was my solution to the problem of 10 round Accurate Mag magazines that have the 2nd or 3rd remaining rounds not feeding because of the bullet angle: Take apart the magazine (you see that the follower is actually angled up) and adjust the bend that is closest to the follower (so that the follower lays flatter to the spring). It doesn't take much. I didn't need to adjust the lips. I didn't need to grind the follower. I now can sleep at night!

 

[FUNCTIONAL]

You have bent lips on magpul mags?

Wow thats a big mistake on my part...missed the part where he named magpul. I wonder if you could take some smooth needle nose pliers and try and bend it as you apply heat with a good heat gun? Not sure if it would just start melting first or get a little flex in it.

In any case Id ask to borrow someones AICS or Accurate mag just to see what happens.

The first post sounds like the lips are too long though and doesn't release the back of the case soon enough. Id try filing the front of the lips to make them shorter. Really the lips are only there to hold the bullet in, slowly star chambering a round and watch to where the back end dives and the bolt overrides tbe case and STOP. Mark the mag with a marker 1/8" before it overrode the case and trim the lips back to that point.

 

[LRI]

Having trouble getting my rifle to feed rounds from the magazine. The bolt starts to push the round forward, but the round's base dives as the tip rises into the chamber and the bolt slides over the top.

Savage 12FV 6.5CM
MDT LSS-XL
Magpul AICS 10rd mags (2)

A few posts suggests removing material from the feed lips. Curious if folks have had success doing this (lots of suggestions, little follow-up). If so, are you taking material off the front of the lips closest to the barrel or on the underside where the mag contacts the case? Is there something else I'm missing?

I'm new to the bolt game, so if this is a case of operator error, I'll gladly take my lumps.

"Booger hooking" the feed lips is the last resort. The problem is insufficient case overlap with the bolt face. Simply to mean not enough of one in contact with the other. You fix this one of two ways. Either make the action sit lower in the stock or make the floor metal present the magazine further into the receiver bore.

When the DBM is sitting where it "should" (presenting well on the bottom of the stock) its cosmetically painful to sink it. Just looks like poo afterward. What I do in this instance is pull the release lever and either make a new one (slightly longer) or put a stitch of TIG weld on the original to grow it some. Then machine/fit to make it run again.

The ideal arrangement is the "upside down figure 8". The receiver bore is one of the arcs in the 8. The primer pocket is the other. When those two circles are tangent to one another, things work as they should. You verify this by pulling the bolt, gassing up a magazine, and inserting it. Now look down the ass of the receiver. If you can see a trace edge of the primer pocket just starting to invade the receiver bore, your golden. That gun should run like a scalded dog.

The one exception to this is ARC magazines. On occasion they'll hang up the last round. We've adopted a little alteration to the follower to help mitigate this.

Happy to help. Good luck.

 

[isofahunter]

First I would take mag apart and make sure it is clean. If that does not work I have always made adjustments to the follower and not the lips of the mag. Running Magpul in a Gas Gun and would not lock open the bolt by trimming the follower ever so slightly it would ride higher in the mag and catch the bolt stop. Can buy replacement followers if you over cut. I have a mag that does exactly what you describe and for me is is always a dirty mag that causes it, clean it and back to 100% feeding.

 

[Bandaid]

When I have the problem with my magpul AICS mags I can take them out and visually see that the case head is not all the way up against the feed lips of the magazine. It is like the follower is hanging up. It usually does it in the last couple rounds of the 10rnd magazine only.

 

[tomcatfan]

I had this same issue with my savage 6.5x47 in an HS stock with factory bottom metal and savage 10 rd mags. So I bought cdi bottom metal and magpul mags and I had the same issue. I put epoxy at the bottom of the latch on the magpul mags to push the mag further up in the action and it didn’t help. I emailed cdi and they recommend I use a longer latch which they sent me for free. I threw that in and it worked like a charm. I feed now from both magpul mags and accurate mags. I don’t have the issue anymore.

 

[CharlieNC]

Proper lip adjustment is surprisingly critical. I tried filing off the top, sanding lip interior smooth, adjusting with pliers, etc. Feed continued to suck. Finally bought the proper tool from Brownell, and it also includes specs for the distance between the lips. Adjusting the front and rear gap a few 100ths to spec and feeding is much improved.

 

[Apnea]

I recently put together a rifle with a KRG X-ray chassis and experienced a similar problem on my first trip to the range. The mag appeared to be sitting too low and the bolt would just go right over the top of the next cartridge. This happened with MDT and Magpul AICS pattern polymer mags. The fix was pretty simple: all I had to do was move the forearm cover on the chassis slightly rearward and retighten. On this chassis, moving the forearm rearward pushes the rear of the magazine upward, and positions the case of the next cartridge high enough for the bolt to pick up. The amount of adjustment needed to achieve correct feeding was surprisingly small.

 

[ptm121]

The height issues above are the typical problem. However, if that doesn’t resolve it, check bolt travel. I’ve seen this happen when the bolt doesn’t go rearward quite far enough to always get full engagement of the rounds in the mag. Ensure there’s a gap between the case head and bolt when the bolt is fully open.

 

[Habituallinestepper]

Realized I never posted a follow-up on this. I contacted MDT - they were extremely helpful and responded very quickly. From them:

The Magpul mags are a known issue and they do state that problem on their website - https://www.magpul.com/products/pmag-10-762-ac

Their feed lip shape is different so the front of the feed lips are going to be touching your action, if you look down into the ejection port with the bolt open, as you insert the mag, you should be able to see where the mag is touching, if you file those areas down, it should allow the mags to seat to a proper height.

The Magpul mags are designed for their Hunter stock for a Remington. The opening in the bottom of a Remington action is different than everything else so most Savages have an issue and every single Tikka does.

I did exactly what they said - filed down just slightly on front of the feedlips. Took a tiny bit off at a time, testing as I went. Fixed it, 100% reliable now. Ran one PMAG AICS exclusively at Guardian, no issues.

Hope that helps others that stumble onto this thread going forward.