45 long colt bullet diameter

piper394

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I've just ordered a Pietta SAA in 45 lc from Marstar and have a bullet mold in .454. Some loading specs say the correct diameter for 45lc is .451. Anyone know which these revolvers prefer?
 
My Uberti's (rifle and sixgun) both shoot better with the .454 bullets. There is less soot blown back on the cases. Just make sure you get an expander for .454. I just ordered a new plug from RCBS. Rugers seem to do fine with the .452 bullets. YMMV
 
Generally, pre WW2 guns in .45 Colt have .454" bores while post-war guns have .451" or .452" barrels. However, regardless of the bore diameter best accuracy will be obtained by matching the bullet size to the cylinder throat. If .452" bullets will fall through the chamber throats with the barrel pointed down then go with the .454" bullets. If you have to push the bullet through then go with .451" or .452" bullets. It's not uncommon to find revolvers with .452" barrels that have .454" (or greater) cylinder throats.

-Zimms
 
Your Pieta will likely have a bore diameter of .451. Provided a bullet sized to .452 will not fall through the cylinder I would and do size my cast bullets to .452 for my Beretta Stampede. I have found that with commercial lead bullets the box may say .451 but you will find the bullets are actually sized .452. When shooting cast bullets you want the bullet to be at least 1/1000 over the size of your bore or you will get leading problems at least and very poor accuracy. In the 9MM I size my bullets to .357 and have excellent results both in accuracy and tight velocities over my Chronograph.

Take Care
 
Thanks for the input guys. So, if 1/1000 over bore size is right for accuracy and leading is 3/1000 over (.454) too tight with a cast bullet? and will it cause any harm or just affect accuracy? I suppose it would increase pressure somewhat.
 
With any revolver and cast bullets, you want the bullet to be slightly larger then each stage of its trip down the bore.

First off is the forcing cone, the bullet should be 1 to 2 thou larger then that. The forcing cone will swage the bullet down easily to the bore diameter. Hopefully, the forcing cone is larger then the barrel or else accuracy will be lousy.

From there, the bullets are sized for the bore and away they go. The standard 45LC bore is 451 but that is not the important dimension.

If you size specifically for the bore and that is sig smaller then the forcing cone, you will get blow by which leads to leading which causes all sort of grief.

It would be ideal if the bore was a .451 and the forcing cone exit was a .452/451 with an entrance of 0.452 to 454. That way you start with a 454/453 and have at it.

That is why your mold is a 454 diameter. If you use wheel weights, the finished size will likely be 453.

Jerry
 
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