S&W 625 .45 Colt....Throats and Boolit Diameter...Bad For The Gun??

[Southern Shooter]

I have a S&W 625 in .45 Colt with chamber throats measuring .452. The boolits I have been shooting are of recycled bullets/boolits...so, not very hard. They are cast from a Lee 452-255-RF mold and are dropping at around .455 (it was Beagled) then sized down .454 (the smallest .45 caliber sizer I currently own). They will not push through the cylinder throats with finger pressure. Loading them on top of 12.5 grains of HS-6 the velocities are averaging 925 FPS and the groupings are looking like this at 20 yards:
106934

My concern is, the boolits being the size they are, are they causing damage to the gun? Should I size them down closer to .452 ?

Thanks

[Char-Gar]

You are not going to damage the gun, but you will be better accuracy if the bullets are sized .452.

[DougGuy]

It raises pressures for sure. It's not going to hurt the cylinder but as already said, it will shoot better with them sized .0005" under throat diameter. Lee push through dies are cheap, and easy to hone them out to size to a specific amount of "drag fit" in the throats which is what you want them to do.

[RobS]

I would say that if you are shooting scrap lead that is "softer" alloy and you size to .454 and don't use an expander die then you are likely fine as it will probably only be the front drive band at .454. I've used soft lead without an expander die to the depth of the boolit before (planned for it actually) and a once sized boolit at such diameter is not at the same diameter after seated/crimped and is why I sized to a larger diameter. My advise, check a pulled boolit from a seated/crimped round before you go to sizing to a smaller sized diameter. Many individuals know here that correct diameter, "size is king" is what matters but often some do not pull a loaded round to see what the brass and reloading process is doing to the boolit.

[Outpost75]

You will reduce group size about 20% by sizing bullets to fit the throats, and about 30% by changing to a mold which drops bullets of correct diameter to shoot them as-is, not requiring any sizing.

[9.3X62AL]

No argument with anything stated above.......but that target isn't a bad grouping, in the big scheme of things. I'm wondering......what diameter will the mould cast at in an un-Beagled condition?