Lee 310-430-RF and Ruger NM Blackhawk Flattop .44 Magnum...Will that work?

[Southern Shooter]

Recently, I was told that the Lee 310-430-RF boolit would not fit in a Ruger NM Blackhawk Flattop .44 Magnum. That the boolit would stick out the front of the cylinder and bind the gun. Is that true? I like the design but want to make sure it works before buying the mold.

Also, which crimp groove, the top or bottom groove, should I use?

Thanks
90991

[C. Latch]

What is the cylinder length on a flattop? Should be the same as any other NMB.

[Southern Shooter]

Don't know the numbers...but, it is the same as the NMB.

[Doc_Stihl]

There's 2 crimp grooves for a reason.
If you crimp in the bottom crimp groove and it's too long. Crimp in the top crimp groove. Make sure that you check your OAL vs your powder charge to ensure you aren't compressing when changing the internal volume.

[Southern Shooter]

If I crimp in the top groove, then the pressures rise, correct? So, the maximum powder charge would be lower than what the reloading manuals may call for?

[AlaskanGuy]

I think it will fit just fine...... Crimp in the top ring, and load about 16 grains of Enforcer, or 10 grains of unique.... That boolit is a favorite around here... Just slug the gun and size .001 larger and make sure you crimp good... If you dont have a good crimp, the boolit will walk on ya a bit, causing the cylinder to bind up.

AG

[Doc_Stihl]

I load the Lee 310 with 18gr of H110 and a CCI mag pistol and crimped in the bottom groove.
Some manuals will list a similar bullet with similar seating depth. But if you find load data for a 300 or 310 and it's seated out a quarter inch farther than that load should be slightly reduced.