PMAG Mods for 300wsm

TexSavage

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I am getting ready to buy a CDI or PTG bottom metal for my Savage Model 12 in 300WSM. Will have my smith do the inletting on my McMillian A5-ADJ which is a blind mag on the model 12. My question is has anyone done mods to a Magpul short action mag for bolt rifles to accommodate the 300wsm? I had seen in another forum the VP at Magpul saying he had done it, but no information or details and I have an email into Magpul. I know Accurate Mag has magazines for 300WSM, a 3 and a 7 round variety. I like messing around with things and wondered if anyone had attempted this.

I have my Berger 215's adjusted to an overall of 2.950" so I'm sure the mod would include something to accommodate the length I need.

Tried the search tool here on the LRH forum, but really never found a thread on this. If you know of one or info I would be real excited to see it. Of course your input would be well respected and a good time will be had by all!

Your mileage may vary.
 

tim_w

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Mar 25, 2008
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I did not think the SA pmags had that much internal length to fit your coal regardless of feed lip mods. IIRC max is 2.86 in the ac7.62 pmag.

Accurate mags are very nice and the wsm/rsaum version has the blocker plate rmoved and feedlips adjusted already. Their coal should just clear your coal but you are maxing out for any detable mag at that length. Alpha might get you a bit more but quailty is not as good from what I have read from others but not personally had experience with them.
 

livetohunt

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I could adjust feed lips on a p mag to accommodate a 6.5SS, which is based off of a 7 SAUM. My main concern would be the length your able to achieve. My measuring comes up with approx 2.9” for OAL, you will need less than that for the rounds to feed. I’m Right at 2.95 with the dummy round I have for the 6.5ss. I can sneak the case in under the feed lips, so it’s technically wide enough. You will have fun filing the plastic out to get that .05”, but it’s possible.

I’m intrigued by this as my next build will be a 300 WSM.
 

TexSavage

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Amarillo, Texas
I appreciate both of the replies. I have seen someone using a dowel rod with emery cloth on it and did a little sanding on the front thickened portion of the magazine to get just a few more thousands to accommodate a minutely longer COAL. I have tested my load and dropped it down to 2.950 from 3.015 and saw no change in group size, pressure or velocity. So I think I have a little wiggle room in my coal if need be. The 215 Berger Hybrid has not been finicky one bit as far as being off the lands at a precise point.

I'll keep you posted once I get the magazine modified, which I will then get my bottom metal and have the stock insetted and bottom metal installed.
 
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tim_w

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Mar 25, 2008
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It seems all the hybrid bullets are very tolerant of chnages in jump Imhave seen .2s and .3s 5 shot from 0.015 to 0.087 IIRC bet some have jumped them 0.100 and done well. If the chamber is cut deadnuts straight line with bore it really helps.
 

tim_w

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Mar 25, 2008
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Why not just sell or use the pmags on a different gun and get and use unmolested mags designed for your case? If its all you had for choice thats one thing but pmags are popular and easily sold, where once you chew up the lips and thin the front wall, not so much. Its obviously up to you but I would just pick up an wsm accurate mag in the capacity you want.
 

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