This winter I want to load some for my 450 Marlin. The rifle is the BLR. I'm noticing the magazine has an intentional block to limit OAL for the factory ammo or commercial ammo. This has me wondering if I could use the WSM mags so I could get that bullet out of the case more and have more usable powder space? I know this shortened magazine is done to accommodate commercial loads but why not take advantage of more magazine space and be able to use any profile of bullet? I'm just cu4ious if the wsm mags would do this reliably.

I’d wonder if the chamber had enough throat to take advantage of any increase in OAL.
My Ruger #1 .45-70 has a near zero throat. It works fine with the crimp groove (or bump on Remington 405’s), but runs into issues with other (like LBT) designs.

I took the aluminum block out of the magazine by tapping out the 2 roll pins that hold it in .I loaded Barnes 300 grain TTSX .050 off the lands and it was very accurate.This load used up most of the available mag box length