OAL & Crimp Groove for 45-70

[cigg52]

I have a Marlin 45-70 loaded with 405 gr meisters bullets. When crimping the bullet in the crimp groove the OAL is 2.540. Which feeds and shoots fine. But I have some RCBS 300gr fn that if loaded using the crimp groove they are about .060 OAL shorter than the 405,s.

My question is should I use the crimp groove in the 300 gr bullet, which there would be at least .060 jump into the rifling, or seat it out farther and not use the crimp groove ?
Thanks

[peerlesscowboy]

Use the crimp groove.

John C. Saubak

[mpmarty]

I try to make my 45/70 loads 2.570 oal. I don't worry about crimp grooves as I use a collet type crimp die and it "makes its own groove" so to speak. I load both 350 and 425 gr RD boolist in the 45/70 and use both 3031 and RL7 for hunting type loads and 2400 for target and plinking.

[cigg52]

John, using the crimp groove seem like the logical thing to do, but a .060 jump to the rifling, won,t that negative affect on accuracy?

[btroj]

So they jump. Whoopee. Big deal. many great loads jump the bullet into the rifling.
Try them in the crimp groove and see. You will most likely find that they work out just fine.

[peerlesscowboy]

John, using the crimp groove seem like the logical thing to do, but a .060 jump to the rifling, won,t that negative affect on accuracy?
Run 'em thru' a nominal (459) sizing die they'll come out miking .458", crimp 'em in the crimp groove and they'll shoot just fine in your Marlin, trust me. I have the magazine of my Marlin '95 Cowboy stuffed full of 'em now, carry it in my feeding pickup for coyote medicine when I'm out feeding cows every morning.

John C. Saubak

[cigg52]

I wanted a bullet in that weight range and ordered 50 from Montana Bullet Works to try before I bought the mold. If you are looking for store bought bullets these are top notch. I also ordered some for a my 40-70ss, RCBS 300 fn and Hoch 430 gr. to try.

[josper]

cigg52: I know this is an old thread but hope you see this.as far as I know the RCBS boolits ,the 300,405 and the 500 are made with the same nose profile.I have tried this and that but I keep going back to the RCBS 45- 405-fn. The mold produces my best boolits and groups grate at 100yds.[2" or under"] My OAL is 2.530 ,right on the crimp groove.My rifle is a Marlin 1895G.