Help needed with a leading issue

[Lumpy Grits]

Could gas cutting be the issue

[Lone_Star]

I would like to recover bullets from my testing, but only have a dirt backstop at 200y. It is way too overgrown right now to even get to. I will shoot a match this weekend and see what the results are.

[Lone_Star]

Match update;
I shot the local match this past Sunday, using the flat nosed, .460 dia bullet with poor results in accuracy, and still had leading issues starting at the chamber and running about 8" up the barrel. The leading was not as heavy, but was still difficult to remove.

[JonnyV]

Seems like a mystery…something doesn’t add up…

[bryany]

What is the bullet alloy and source of alloy?

Bryan

[steveu834]

Seems like a mystery…something doesn’t add up…

I don’t think it’s a mystery at all, it’s a GM barrel.

[JonnyV]

Seems like a mystery…something doesn’t add up…

I don’t think it’s a mystery at all, it’s a GM barrel.

Well, there is that….

[buffalocannon]

FWIW, and it may have nothing to do with it, I fought occasional leading in my 100 with 34” barrel for 20 years, and a couple of years ago I sent it back to Shiloh and had it cut down to 30”, and guess what, no more occasional leading with my GG bullets.

[Tomklinger]

Doesn’t green mountain barrels have a specific break in procedure shooting copper bullets and cleaning the copper between each shot for 10 rounds or so?

Tom Klinger

[ian45662]

Doesn’t green mountain barrels have a specific break in procedure shooting copper bullets and cleaning the copper between each shot for 10 rounds or so?

Tom Klinger

I did their procedure on my GM barrel and it leads. It shoots really well but I just have to be sure to get the lead out between relays. If I do that then it’s not a problem at all. If I don’t then it starts becoming a problem. A couple tightish fitting patches soaked in the bore solvent that Shiloh makes takes it right out.

[desert deuce]

I feel compelled to confess, I feel very much discriminated against. Because, we have been shooting Green Mountain Barrels for years in 44-70 (32"), 45-70 (30") and 45-90 (34") with no leading, or other, problems of any kind. Using mostly 16-1 alloy but also have used 1-20, 1-25 and 1-30 on occasion. Guess we are doing something wrong because we simply can't get them to lead. Oh, woe are we?

It is a lonely state to be in you know, having no leading to complain about?

3 rifles, no leading. Must be an anomaly

Oh, I know. May I complain about not having any leading?

[Aviator]

My Shiloh barrel always leads more than my Green Mountain, Douglas, Kreiger, and Badger barrels.

My Shiloh has been known to shoot pretty darn well despite that ....

Perhaps there is some variation barrel to barrel, not just brand to brand........

[mike herth]

DD must be shooting PP bullets! Sorry, couldn't let that pass, I'll see myself out.
Mike

[desert deuce]

No diapers here. All Grease Groove, mostly sized to groove or slightly below.

Thinking about what I might have to do to get one of these GM's to lead? I am stumped.

[kwilliams]

I bought a GM 45 cal no. 4 barrel blank during the COVID and it was pathetic. Rough grooves and bore per the bore camera. It was a continual battle to get the lead out. It had to use turpentine between every relay, but oddly it did shoot 6-8 shots pretty good. Tried fired lapping and then lapping to no avail. One season was enough and I re barrelled it with a Mcgowan.
kw