Which mold for a Marlin 336 30-30 micro groove?

[MarkP]

RCBS 30-150 Cowboy. Its a plain base design thaylt shoots well in my 30-30's both Winchesters and Marlins (micro grooves)

[smkummer]

I got him talked into Lee’s C309-170-F with Sage gas checks.

[smkummer]

So the above Lee 170 grain gas check mold seated where the crimping groove is located won’t chamber as the micro groove rifling is engaging the forward ogive of the bullet. Sure seems odd that a design for the 30-30 can’t be seated in the crimping groove where intended? Out of spec mold? I’ll tell him to call Lee and see what they say.

[Jeff Michel]

if you can find one, 311440.

https://www.accuratemolds.com/bullet...bullet=31-150L

[imashooter2]

My C309-150-F engraves rifling too. The lever closes just fine and the boolits don’t pull if I want to unload it without firing.

[RickinTN]

Engaging the rifling is a good thing if it doesn't interfere with the bolt closing or removing a loaded round. It contributes to accuracy.
Good Luck,
Rick

[Griff]

So the above Lee 170 grain gas check mold seated where the crimping groove is located won’t chamber as the micro groove rifling is engaging the forward ogive of the bullet. Sure seems odd that a design for the 30-30 can’t be seated in the crimping groove where intended? Out of spec mold? I’ll tell him to call Lee and see what they say.

My C309-150-F engraves rifling too. The lever closes just fine and the boolits don’t pull if I want to unload it without firing.

What length are you trimming your brass to? I trim all mine to 2.028" and have no issues feeding & chambering in multiple rifles. I even trim new brass as it is often inconsistent in length.