1909 45LC & accuracy issues

[simmer.down]

I have a 1909 New Service, 4.5" barrel with 45 Colt, all matching numbers. Its was re-blued waaaay back. The Pony has the Big C around it. I opened it up for some oiling and it looks nearly new. No clear wear and no rust patches.

I loaded some light 45s, cowboy loads, about 750fps, with 240g RN lead.

I cocked it for SA and thought it had some safety on because the pull was so stiff. DA is is double stiff.

Accuracy was all over the paper. I know this could be the 85# trigger. I mostly shot SA to see how much I could zero in but I the paper looked like it was shot by a nervous first-timer.

I slugged the the barrel and its .455 on the lands & .450 on the grooves. I assume these old guns were closer to .454

So, open to the panel; what the heck is going on here? Hunches, knowledge, half-A guesses?

[WIL TERRY]

THAT IS exactly how they were made. I will make a minor wager on the back 180,000 acres that pistol will shoot just fine with .454" lead bullets moving faster than you are pushing them. An excellent test bullet is the R-P 250gr LFN .455-456" OD. The standard factory W-W and R-P 250/255GR loads also shoot up a storm in the old guns as well as the modern 45COLT sixguns.

[simmer.down]

Thanks. I don't have handy access at the moment to .454 lead. I'll try loading to 850fps and see if that narrows the wobble. Hard to believe .001-.002 will make that much difference.

[porsche]

Bullet fit is king for cast bullets and low amounts of leading as well as accuracy.