Recent acquisition. 43,500 psi factory ammo per SAAMI/ANSI Z299.4-2015 suited for lever action Marlin and Winchester rifles. Appears to be same front locking multi-lug action as 7mm RM and 300 WM BLR's.

450 Marlin has same belted magnum case head dimensions so 450 Marlin BLR should operate safely at higher than standard pressure. Hornady standard pressure 450 Marlin 350gr ammo claimed 2100 fps mv (24" barrel) for example.

Chronographed near maximum handloads (20" barrel): 300gr Sierra HP 2500 fps, 350gr RN Woodleigh 2250 fps and 400gr Barnes Buster 2000 fps mv. Deep seating depth because of short magazine/throat limits 400gr Buster performance. Good accuracy.

Very nice post, Thank you for the photos.

Should be a hammer. 300gr Sierra at almost 2,500 is some nice horsepower

Not a recommendation however 325 WSM BLR mag fits 450 Marlin BLR. No fixed spacer/ramp so increased OAL possible can load 300/350gr TSX and 350gr MT. Only difference action has to be opened to install 325 WSM mag filled with 3 450 Marlin rounds. It will do.

That's a very capable levergun for just about anything, anywhere. Hope you get to hunt with it soon.

The WSM magazine provides the option of additional performance using pointed bullets and you have the stock mag for FN bullets. Nice set up.

Did you have to do much to make the WSM mag fit the rifle?

Your landscape photos are simply brilliant.

Thanks! 325 WSM BLR mag plug'n play no alterations needed to fit my 450 Marlin BLR. And can now load 325gr FTX without using 450 Marlin shorty brass.

500gr Hornady DGX and 500gr Woodleigh PP rounds as shown fit 325 WSM BLR mag and chamber no issues in my BLR. Pretty sure 1900~2000 fps muzzle speed near max pressure possible. 500gr PP more downrange wallop compared to current 400gr Buster hunting load. Excellent results on big Moose with 500gr DGX at about 1700 fps impact.

quote:

Originally posted by 4sixteen:
500gr Hornady DGX and 500gr Woodleigh PP rounds as shown fit 325 WSM BLR mag and chamber no issues in my BLR. Pretty sure 1900~2000 fps muzzle speed near max pressure possible. 500gr PP more downrange wallop compared to current 400gr Buster hunting load. Excellent results on big Moose with 500gr DGX at about 1700 fps impact.

What is the safe max pressure in your gun you think? I load for some win 71's & am close to 2000 fps with the 500's,woodleigh RN's,I flatten the nose down.I think I am in the low 40,000's psi in my guns.

BLR 81's available in belted magnum rounds 7mm RM/300 WSM/270 WSM/7mm WSM/300 WM so 450 Marlin BLR max pressure probably approaching those levels.

For the kind of game you’ll likely encounter Woodleigh’s 480grRN or 400grPP might be more appropriate choices.

The extra length in the WSM mag really opens up the bullet options.

Also excellent results with TSX bullets 300gr or 350gr possible with 325 WSM mag. My 450 Marlin Ruger No.1-S loaded with 350gr TSX at 2300 fps could go with this load in my BLR. Or 300gr TSX at 2500 fps.