Marlin 45/70 Bore size

[wv109323]

I want to start casting for this caliber.(45-70) What is the "nominal " mold size needed? The rifle is a Marlin lever with the Micro-groove barrel. I thought it should be .458 or .459 (.001 over bore). But I see Molds at .457 for the 45-70.
If you had one mold for the 45-70 what would it be ,as to weight and configuration?
I am leaning toward a 300-325 grain mold due to the recoil of the rifle but what is accuracy like with the shorter bullets vs the longer heavier ones?

[Wayne Smith]

Remember that barrels for the 45-70 have been made for over 100 years. There is huge variation in them. Thus you will find variation in the size of boolit molds available. A boolit that fits a Trapdoor that may run .460" or larger vs. one that fits my Katadin Encore barrel that runs .4575" grove will be different.

You need to slug your barrel and choose a boolet size .001"-.002 over groove, not bore. It really does not matter what size that is as long as it fits your barrel. "Nominal" doesn't matter, your barrel does. Marlin Micro-groove tend to be a little large, but you need to measure yours and see what it is.

As to boolit, my 457122 Gould HP will do most of what I would want. You can see my post in Single Shot area to see what I mean. I'm waiting on a Group Buy mold in .405 that will do the rest. While I have a 457125 I don't plan on using it much as I don't plan to shoot long range. The 457122 is a 330gr HP, the 457125 is a 520 RN.

[Dan Cash]

+1 for the 320-350 Gould bullet. Next up would be a 405 grain. Longer bullets will give feeding problems in the Marlin. Besides that they really kick, even with black powder. Using smokeless and achieving the level of velocity possible in a Marlin can be painful.
Dan

[high standard 40]

I asked a question along the same line as you last week. I did get an answer from a member who has the mold you refer to marked .457. He assured me it drops bullets closer to .460 so you should be able to size to .459. At least that is with his mold. I'm hoping for the same results.

[jack19512]

If you had one mold for the 45-70 what would it be ,as to weight and configuration?







I have the Lee 340 gr. mold, the Lee 405 gr. mold, and the Lee 500 gr. mold and if I had to choose just one it would be the 340 gr. mold. My Marlin 1895 CB shoots all of them very accurate but the 340 gr. takes less lead to make and should be good for anything I plan on using it for. I haven't found the need for gas checks either.

[Slow Elk 45/70]

Hullo WV, welcome, IMHO Ranch Dog has a very good 350gr boolit for the marlin 45/70 and a
425ger. These boolit molds are made by Lee for RD on special order, they are CHEAP @ $26

These molds are made up for the Marlin 47/70 lever action with crimp grove in the proper place for max length feeding in this rifle. They are gas check boolits, but shoot well with or with out the GC.

As for the proper size for the boolit, he also sells the Lee sizer in .460 , this is the size that works best with these BBL's. You don't want an undersized boolit for these BBL's. This makes the finished boolit about .002 over size and works best for accuracy.

There are lots of molds out there, 292gr-585gr for this caliber, I have a lot of them , but since I got the RD molds, those are what I use in my Marlins. For someone starting out, you can't beat the price and if you have any issues with the molds, there are lots of folks here that can help you.

Also, take a little time and read the threads for the forum, lots of information there, I think you will enjoy having access to all the information at hand.

Good casting and good luck.

[Wayne Smith]

Actually, Slow Elk, I have the NEI version of the 120gr Collar Button mold for the 45-70. Originally a Lyman design, I think.

[wv109323]

Thanks to all that replied. I cast for .357 and .45 acp. I have found very good information on this board.