Odd Observation

[Gohon]

Asked this same question on another site but thought I'd also post it here for additional opinions.

"Yesterday while playing around with a new scope I put about 30 rounds of 250 grain casts down range with a 45 Colt H&R Buffalo Classic. The reloads were from a batch I put together a couple months ago, lubed with LLA and shot through the same gun on several occasions. Upon inspection after the shooting I noticed some very minor leading the first 4-5 inches into the bore. This has never happened before and a couple passes with a bore brush wrapped with chore girl cleared it right out. The only difference between previous shooting and yesterdays shooting was temperature. Previous shooting was with about 70+ degrees ambient temperature and yesterdays temperature was in the low 30's. So I'm wondering if temperature can affect the characteristics of the bullet or lube which could lead to possible leading. Doesn't make sense to me but I can't come up with any other solution as to why. Any thoughts from anyone?

Oh, the cast bullets were WW/AC at 1371 fps as registered by my chrony from the long gun if that helps."

[HeavyMetal]

"Minor Leading the first 4-5 inches into the bore"?

4-5 inches from the chamber or from the muzzle?

To different issues, if measured from the chamber the boolits are a bit soft and "skidded" just a touch before "grabbing" the rifling.

If measured from the muzzle the lube just gave out.

Temperature extremes can affect how ammunition performs, ask anyone thats shot WW296 in temps below 20 degrees or so.

Next time out try keeping the ammo either on your person ( to keep it warm) or in the heated cab of your truck or car and see if the issue goes away.

[Dean D.]

Could the cold weather have tightened up your barrel just enough to cause the leading? I dont know how much cold effects bore diameter but it sure does for pressing two tight fitting metal parts together.

[waksupi]

I would go to a softer alloy. It isn't bumping up fast enough. If you aren't using black powder, there may not be enough boost at ignition. Boolit may need to be a thou or so larger.

[Gohon]

Leading was from the chamber. What got me to thinking was because the same batch of bullets and reloads hadn't done this before. I'll try getting things up to in house room temperature and try again to see if there is a difference.

[hyoder]

A guess - you may be borderline on having the boolits small, the cooler temp may have caused the boolits to cross that thin line and were indeed too small. Small boolits allow gas blow by and causes leading.

[jdgabbard]

There was a thread a while back that talked about boolits beginning to "normalize" After a few months. A point at which they begin to reach their final BHN. You think it is possible that maybe that batch just got a little soft, and/or shrank a little over time due to this "normalizing"