The widely unknown and forgotten marlin mr-7 - building a mountain rifle in .270 sherman

[elkaholic]

Well my cousin managed to connect!

610 yards, high lung hit, buck hit the dirt so hard he bounced ha ha. That 170 did excellent, zero meat damage on entrance just under the spine, quarter sized exit with a soft ball sized section of bloodshot, and lungs were jelly. Absolutely fantastic View attachment 149887

Well done Cody! That unique build is gettin it done!!

 

[IanCo]

Did the 270 Win brass fire-form easily to 270 Sherman?

 

[codyadams]

Did the 270 Win brass fire-form easily to 270 Sherman?

Once we found the proper procedure to create the false shoulder, it was extremely simple. Neck up to 30 cal using an expander ball in a 30-06 die we had on hand, then we simply ran them all the way up into a standard non bushing 7mm rem mag die without the expander ball, dump powder and seat bullet.

Since the 7mm die is a non bushing die, it necks down to .275 and relies on the expander ball to bring it up to .282 when you pull the brass out, but without the 7mm expander ball it leaves it at the perfect diameter to hold a .277 bullet, and a 7mm rem mag die also just happens to place the neck/shoulder junction perfectly to create a false shoulder for a nice snug crush fit with the .270 sherman, as pictured below.

 

[IanCo]

Gotcha. Gotta neck up to be able to neck down to start the shoulder.

Thanks

 

[searlock]

i read this post on the 270 sherman from a marlin mr 7. i own a mr 7 and would like to rebarrel. what is the thread and pitch size?

 

[codyadams]

i read this post on the 270 sherman from a marlin mr 7. i own a mr 7 and would like to rebarrel. what is the thread and pitch size?

I'm actually not sure of the thread, the gunsmith that installed the barrel didn't say. The action is essentially a copy of a winchester model 70 with a couple other changes, that would be my guess but I wouldn't ride on it?

And thanks for bumping, this threD, I got some updates!!

 

[searlock]

Thanks for the information. If any one else knows rhe answer I'd be grateful

 

[xsn10s]

I've read that it's small shank savage pitch. I don't know for sure.

 

[codyadams]

Yearling calf at 910

Lots of friends and family have used it as well! It now wears a YHM resinator as well.

Blake's biggest deer!!

This build has beena fantastic rifle, thanks for all that followed along!