Bigger is Better?

[ChristopherO]

In my 1895 Cowboy I've been shooting 405 grain cast sized to .459. the barrel slugs at .458. It will lead a little near the chamber but can easily be pushed out with T-shirt patches doubled up over the jag with cleaner lubricating them. These make for a tight push but within 3 swipes any lead fragments are cleared out. I believe the barrel lapping I did before ever shooting this rifle helps it to clean up quicker. The first shots with .458 sized lead FN boolits a friend gave me originally leaded terribly. Enough so that I had to use patches of scotch brite pads to clean the bore near the chamber. The .459 sized rounds were much, much better.

This said, earlier this week the .460 sizing die came in so I promptly lubed some slightly larger diameter boolits up to see if this will tighten up the groups and eliminate any lead fouling. It was getting late by the time I got to the range so there is still some work to determine group sizes. The lead fouling issue, upon cleaning last night, after 13 shots showed more lead particles with the .460 than I had with the .459. This was interesting. The barrel still cleaned up with three swiped of doubled T shirt patches and cleaner just fine. The fourth patch showed the carbon and lead was clear.
I truly though a slightly larger diameter would show less leading, not more. I am using 26 grains of 2400 and the slug is lubed with X-Lox 2500. Both proven components. Is this common?

[5Shot]

Some of Elmer's articles that I have been reading lately mention exact groove diameter (or even slightly under). He states that the rifling displaces enough lead to seal the bore and that oversized bullets are not accurate for him.

I plan to try it on several of my guns and see if smaller is actually better.

[paul h]

There are no absolutes. The right size is the right size for a given gun and only testing will show what the right size is for your gun.

[44man]

If your boolit is on the soft side, the load of 2400 is really thumping it so it will skid until rifling can take over. That also opens gaps at the rifling for gas to cut lead.
I never found over size is needed for the grooves either. A little is OK but I have shot .430" boolits for 36 years from my .430" SBH and all the other .44's I have had. The difference between .430" and up to .432" can't be measured at the target.

[Mal Paso]

Some of Elmer's articles that I have been reading lately mention exact groove diameter (or even slightly under). He states that the rifling displaces enough lead to seal the bore and that oversized bullets are not accurate for him.

I plan to try it on several of my guns and see if smaller is actually better.

I have wondered about that. I think I remember him saying the grooves were important to give the displaced lead somewhere to go without distorting the bullet.

It is also true that the large front drive band on his bullet Designs was inside the throat of many revolvers and would not chamber if larger. (Lyman's alterations) I think front band inside the throat is key to top accuracy and why many have abandoned "Keiths" in favor of more self aligning designs.

I am happy .001-.002" over groove.

It would be nice to ask Elmer wouldn't it?

[ChristopherO]

Was Elmer writing about revolvers only with those comments or was he including rifles in this idea?

[prs]

ChristopherO; the leading you describe seems to be more like scraped-off lead rather than traditional melted on, jetted-off leading. Perhaps the large lead boolits are being scraped on the chamber end or abrupt initial rifling onset. Maybe a throating reamer for cast boolits if casting to slug size does not git'r done?

prs

[paul h]

Was Elmer writing about revolvers only with those comments or was he including rifles in this idea?

I'm pretty sure it was revolvers only. All the rifles I recall him using and writing about were shooting jacketed bullets.