41 mag sizing

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mhblaw

Blackhawk
Joined
Jan 15, 2009
Messages
890
Location
North Dakota
Reloaded with some 215 gr. SWC's sized .412. Difficulty chambering in my two Ruger NMBH's. Measured throats at .411. I do not cast or size but order commercially. Should I go for bullets sized .411? or .410? Had trimmed cases to same length so crimp should be uniform. Suggestions?
 

Sharp Shooter

Single-Sixer
Joined
Nov 24, 2005
Messages
110
Location
MCCammon,Idaho,USA
Truthfully, I've never measured either the barrel or cylinder throat diameters of my two .41 Magnums, a Taurus and a Freedom Arms. But .410" diameter bullets, both jacketed and cast, work great for me in either gun.
I guess it depends on the bore diameters, as well as the cylinder throat diameters, of your two Rugers, what diameter bullets will work for you. Concidering the fact your cylinder throat diameters are only .411, it sure doesn't sound like .412" diameter bullets are going to be all that easy to chamber.
How do they shoot though? Accurate? Leading? I ask because if they're accurate and you're not having leading issues, you COULD have your cylinder throats reamed a little. Or, who knows - maybe reaming the cylinder throats would solve the accuracy and/or leading issues if you're having any. I myself wouldn't have them reamed. I'd try some .410" or .411" diameter bullets first. But they're not my guns. :)
 

Cherokee

Single-Sixer
Joined
May 21, 2003
Messages
472
Location
Medina, Ohio, USA
I use 412 size cast bullets because my barrel slugs at 411 and my cylinder throats are 412. Try some 411 bullets to see how they work, then 410 if you need to.
 

jforwel

Bearcat
Joined
May 19, 2006
Messages
74
Location
Montana
At one time my throats measured .409 and I was still able to chamber .412 bullets. I did have CAS open the throats a bit and accuracy is very good. You may have dirty chambers or slightly undesized chambers (not throats) for the round not to chamber.

You also might consider the cheapest fix first. That would be a Lee factory crimp die if available in .41 mag. That die tends to size the whole round down as the final loading step.
 

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