300 RUM vs. Accuracy International Magazines

[Eastbay]

I'm stripping down and rebuilding my Rem 700 SPS in 300 RUM, the only part I'm reusing is the action (thinking about getting a Stiller Tac 300 though). I ordered a Manners T2A and their DBM mini chassis, and understand they use Accuracy Internationals magazines. They are supplying me with a mag for a 338 Lapua for my 300 RUM. My problem is while researching, I'm finding out that these magazines wont work. How can I make these work? Does anyone have the experience and the equipment to fix this problem? Did I choose the right caliber magazine (338) to base my 300 RUM off of? Thanks in advance.

 

[338RUM runner]

Get the AI 300 Win Mag mags. They are the ones I use it my 338 Ultra. You have to cut the shoulder stop rib away with a mill or a Dremel but they work great. The Rum case is about the same Dia. as the belt on the WM. The 338 LM has to big of a base and you need to cut the rib also. Just get the WM mag. If you need more help just ask.

 

[Eastbay]

Get the AI 300 Win Mag mags. They are the ones I use it my 338 Ultra. You have to cut the shoulder stop rib away with a mill or a Dremel but they work great. The Rum case is about the same Dia. as the belt on the WM. The 338 LM has to big of a base and you need to cut the rib also. Just get the WM mag. If you need more help just ask.

Those worked for the length? 300 RUM and 338 RUM is 3.600, while the 300 WM is only 3.340 in length. I"ll take your word!
Thanks!

 

[338RUM runner]

The WM mag loaded length is 3.625 and mag length is 3.725. 338 LM has the same Dim.

 

[Eastbay]

The WM mag loaded length is 3.625 and mag length is 3.725. 338 LM has the same Dim.

This is what's confusing me:

 

[338RUM runner]

The Max load length for the AI Mag is 3.625 for the WM and the LM

 

[Eastbay]

The Max load length for the AI Mag is 3.625 for the WM and the LM

Ah! I see, thanks for the help bud.

 

[Eastbay]

The Max load length for the AI Mag is 3.625 for the WM and the LM

Leaning more towards the 338 Edge now. Think they will fit in the 300WM AI mags?

 

[338RUM runner]

The Edge is just a little longer at the shoulder than my 338 Ultra. I'm sure it will be OK.

 

[Eastbay]

Got it. Thanks