Cartridge to Magazine Fit Issues

ArTeeKay

Not last, but certainly, the least.
Full Member
Minuteman
Feb 8, 2019
270
358
Montana
I've got a rifle that I'm struggling to get to feed properly from it's magazine. The issue I think is the cartridge geometries compared to the feed lip/magazine length.

To get specific, and what is likely the root of the issue, is that I am trying to feed both 6.5x55 AI and .338 RUM cartridges out of MDT CIP length magazines into a Defiance action bolted into a KRG W-3 chassis. The .338 feeds ok, not quite as smooth as I'd expect, but I can't get the 6.5 rounds to feed at all, they hang up all over the place, sometimes inside the mag, sometimes getting jammed into the feed ramp, sometimes nose into the chamber.

I know KRG offers a mag well insert for their chassis that allows the use of the shorter mags intended for 30-06 size cartridges, but I believe it's installation involves taking the rifle apart, which I'd like to avoid when switching between cartridges. I also know I'll already have the barrel off, but it's a shouldered affair that I screw on hand tight plus an extra ugga-dugga, so it's basically a no tools job, and if possible, I'd like to keep it that way.

Basically, what I want is to make one size magazine feed both rounds. Not one magazine for both, one size for both.

I don't have preference as to manufacturer, and I'm not averse to sending the rifle off to a smith for magazine adjustments. I just would like to know if what I'm looking for is reasonable, or if I should suck it up, buy the insert, and deal with the 20 minute process that comes along with that.
 
You’re asking a lot of a magazine to feed a 6.5x55 and 338rum.
I use the same 308 mag for 2 rifles, 260 and 7 saum.
one magazine is obviously 260 is no issue but I had to tune up 2 mags dedicated for the magnum.
You can try the same, just tune up a magazine for the 6.5.
A couple searches here will get you a ton of information on how to tune up and modify mags.
 
I've done a little bit of touching with a feed lip tool, to no great success. It appears that the distance between the feed lips is great enough that when the round is held in the right place to feed smoothly, it is too low and doesn't get picked up by the bolt. As soon as I adjust high enough to have the bolt peel a round out of the mag, the funny stuff starts happening. Is there a CIP length magazine available designed for smaller diameter cartridges, that might have a range of adjustment closer to what the rifle needs?