How to choose size

[twidpa]

If I have a 45 colt rifle that slugs 449, to what should I size the lyman 452664 boolit? Is it trial and error or is it a nominal 3 or 4 thousandth over?
T

[Buckshot]

If I have a 45 colt rifle that slugs 449, to what should I size the lyman 452664 boolit? Is it trial and error or is it a nominal 3 or 4 thousandth over?
T

.................I'll assume that .449" is the groove. What's the bore? Naturally you want the slug to seal the grooves, so .452" would be fine @ .003" over groove. Others try to fit the throat (within reason) but with a barrel that tight I dunno, even if the chamber and throat allowed a larger slug. If the bore is .441" for .004" deep grooves, even at .452" those lands will be plowing considerable lead out of the way, so I really can't say shooting a larger boolit then .451"/.452" would be better. Something you're going to have to experiment with. What rifle is it?

.............Buckshot

[Bass Ackward]

If I have a 45 colt rifle that slugs 449, to what should I size the lyman 452664 boolit? Is it trial and error or is it a nominal 3 or 4 thousandth over?
T


Yep. Exact size required compensates for weaknesses. That can be weakness of design, or hardness, or the gun itself. This is defined by you, based upon what you are asking from the load, and how the gun reacts in trying to do that for you.

And sizing is not uniform either so you have to check. I forgot this last week and sized several bullets of one of my designs and several 429215s through the same die. Bullets were the same exact hardness. My design was coming out .4315 and the 429215s were .4305.

The larger a bullet is molded in relation to the final (groove) dimension, the wider (stronger) the bands will become when sized. In essence, we may quote that we are all using a 452664, but really we aren't, at least using it the same way.

Measure, don't trust what's stamped on the die. then test for "this" gun.

[Bret4207]

Might want to measure that slug with a different micrometer or check the mic against a standard to make sure of the measurement. That's a pretty tight barrel.

[MT Gianni]

When you slugged it was it uniform or one tight constriction?