Loading 44 magnum MBW 255 grain GC bullets

[ciwsguy]

Posted this in another loading forum. Posting here for more exposure.

Wondering if anyone has tried hand-loading Montana Bullet Works 44 Magnum 255 grain Keith style gas check bullets. I’m using IMR 4227 powder. No loading manual I have seen cite this particular bullet. There is data for 240 grain and 265 grain jacketed bullets, but nothing on 255 grain Keith style GC semi-wad cutters. The bullets are significantly longer than the 240 grain semi-wadcutters I normally use. Has anyone else loaded these MBW bullets?
I’m starting at 19 grains of 4227 and loading to 1.65 inches COL. putting more powder into the case than that may be compressing the powder.
Wondering.....

Follow up: I’m using this in a Marlin 1894 lever gun. The bullets load into the tube and cycle well.

 

[Blue68f100]

You can use the heavier bullet weight for a starting point. Start low and workup.

 

[243winxb]

The Lyman 45 edition has this data. Not your exact bullet, but close. I dont shoot gas checked bullets. Adds to the cost & the check can come off in flight.
* Designates a compressed powder charge. EDIT. Buy a Lyman cast bullet manual. @Soonerpesek.

 

[Bazoo]

RCBS manual lists the 44-250-KT with 19.5-21.5 grains 4227. My example measures .365 from the base to the top of the crimp groove.

 

[.38 Special]

I have not used that exact bullet but would be perfectly comfortable with any of the published data for 250 grain cast bullets. As @243winxb has illustrated, 19 grains of 4227 should be a fine starting load.

 

[Bronco72]

In the Marlin you may not be able to stabilize the bullet, unless pushed hard. I was developing loads for my Marlin, wanting cat sneeze loads as well, and anything 240 grs. , or over, had to be pushed hard to stabilizes. Eventually had a 1-16 twist put on and now even 300 cast gc work well at about 750 fps.

Good luck on your endeavors

 

[243winxb]

RCBS manual lists the 44-250-KT with 19.5-21.5 grains 4227

This more modern data is safer then the old Lyman i posted. Work up always. Starting loads will be dirty.

 

[Soonerpesek]

https://www.thehighroad.org/index.php?pages/code-of-conduct/

Weren't you one of those who opposed this kind of thing on the copyright thread.......

 

[MatrixReality]

+1 on hot loads to stabilize the bullets. Near max loads according to load manual will give you the best accuracy. The 1:36 twist barrels won’t stabilize the bullet once you get to bullet weights of about 270gr or more

 

[black mamba]

I load a 265 gr SWC GC bullet to an OAL of 1.68". With more of the 10 gr heavier bullet out of the case, the seating depth must be very close to the same as your 255 @ 1.65 inches. 22.5 gr. of 4227 in my S&W 629 Classic 6½" bbl. is very accurate and hard hitting. I tried 23.0 gr. but it was slightly less accurate.

 

[ciwsguy]

I load a 265 gr SWC GC bullet to an OAL of 1.68". With more of the 10 gr heavier bullet out of the case, the seating depth must be very close to the same as your 255 @ 1.65 inches. 22.5 gr. of 4227 in my S&W 629 Classic 6½" bbl. is very accurate and hard hitting. I tried 23.0 gr. but it was slightly less accurate.

Thanks much. I started to load with 22 grains of IMR 4227 and heard “the voice” say this might become a compressed load with such a long bullet, so I stepped it down to 19. Did not feel any compression when you loaded 22.5 grains? Haven’t shot these yet, so I’m expecting a dirty cleanup

 

[black mamba]

The 22.5 gr load has 99.8% load density, basically touching the bottom of the bullet with no compression. Many published loads show 107-108% density and still OK.

 

[Soonerpesek]

EDIT. Buy a Lyman cast bullet manual.

Haha…I was just messin’ with ya….
I’m all for posting any data that will assist a fellow loader…