Leading about 10 inches from the muzzle

[oldracer]

I did some searching and could not find why I would get some lead buildup during shooting yesterday on both my Sharps 45-70 rifles. Since it was both guns I am suspecting it was the bullets I was shooting as one box was about 3 months old so that may have done it? I blew 4 breaths through the blow tube since it was hot and dry at the range near San Diego and was drinking plenty of water and when I wiped the barrel it looked clean after just one or two patches. I could not see any build up just looking when at the range.

At home the patches kept coming out black so I got out the Chore Boy and ran some down the barrel. I checked the bore with my bore scope and found some buildup in the lands still so I made a bunch more passes and it finally cleaned out. I checked the other gun and it was the same so I did a thorough cleaning with it also?

Both guns are Sharps replicas by Uberti, 34 inch barrels, both slugged to the same size bullet after measuring. I use Doug Knoel's lube, 68 gn FFG Goex powder and Winchester large rifle primers and the bullets are Lee 500gn flat nose which gives me great accuracy at 100 and 200 yds. At the end of the shooting I did see that the shots were not as close as when I started so I think the leading caused this? I am also thinking the lube may have burned out before the bullet got all the way down the barrel so the leading started?

Anyone have this happen and figure what caused it?

[Don McDowell]

Either your lube isn't holding up or your bullet isn't carrying enough lube, or both.Also you may not of been getting enough moisture in with the blowtube, in hot dry conditions wiping is about all that will work.

[oldracer]

Thanks for the reply Don, those are what I was thinking. As I noted the loads had been sitting for several months so the lube may have dried out a bit too much. I think I'll start carrying some extra with me and checking the bullets before and during shooting a set of 20. I don't crimp so I can check them easily enough.

[Boz330]

Lee boolits don't carry much lube. I have gotten to the point that I don't load much ahead of my immediate needs so that the lube doesn't dry out.
You didn't mention your boolit alloy. I have gotten great groups with wheel weights for short strings, but they always lead up on me after long strings.

Bob

[John Boy]

... both slugged to the same size bullet after measuring. Racer, are you saying that the base diameter of your bullets are the same as your rifle's groove diameters? If yes ... the bullets are not properly obturating in the grooves and creating lube starvation. Next Q - what wads are you using?

[Black Prince]

What Don said. If you are not blowing a lube star at the end of your barrel, you have run out of lube before the bullet got there.

All the best.

[kokomokid]

My snover bullet shoots very well under ideal conditions (40/65) because of the small lube grooves in my opinion but when things turn hot and dry it really falls apart. I cant blow tube enough under 20% humidity.

[SharpsShooter]

Lube shortage is a prime suspect. I had a 75 C Sharps that would lead a bit until changed over to BullShops Nasa lube. I think Don had a similar problem with leading but don't recall what rifle / boolit combo. Like me his leading issue disappeared with that product.

Still you need a boolit that carries enough lube or you need to use a lube cookie under it.

SS

[oldracer]

Thanks for the replies everyone. It is looking more like a Lack of Lube issue (LoL ?). The bullet alloy is 20:1 and what I means about the slugging was the diameter of the bullets after slugging on all 3 of my BPCR guns are the same so there is no difference in the need for different bullet sizes.

I am leaning towards keeping less bullets cast and make them more often which allows the lube to be fresher. I think these are the oldest ones I had and in thinking about how many I have loaded and ready to shoot I have 300 total in those 20 round plastic cases. I usually shoot 40 each week when I go to the range, maybe a few more but that is average. So they sit for a maximum of about 7 or 8 weeks. My garage is nice and cool so they don't get much heat to help the drying out issue I thought.

I checked after shooting 10 or so shots and I did see a nice lube cookie but I think that was with the first box of loads. I plan to start wiping the muzzle after I wipe the barrel as I had not been doing that and checking the cooking periodically.

Thanks again everybody, happy 4th of July!

[martinibelgian]

4 breaths is just about enough when it is humid, and not too hot - barely. If your barrel is perfect. If you blowtube in hot,dry condtions, you'll need to give it about double, or more. And long, slow, full breaths - not just a bit of puffing down the tube.