How much slump is acceptable?

[BK7saum]

I loaded some range lead for my 10mm with a moderate load of HP-38. Boolits were powder coated. Shot some this morning and accuracy was acceptable. Palm sized group at 95 yards. When I recovered the boolits from the berm, they looked almost like a full wadcutter. The lube groove was nonexistent and the ogivery was smaller/shorter, also. Boolit was a NOE 403-200 WFN.

Anyway, I will shoot these up and go harder for the next batch. Just wondered how much slump was acceptable as long as accuracy was maintained.

[RED333]

Palm sized group at 95 yards, sounds very good to me, accuracy is good.
No expansion "The lube groove was nonexistent and the ogivery was smaller/shorter, also." might not be a good hunting boolit, but read the first line in my post. If no leading "aint PC great" I would leave the mix alone.
Is yours a gas check mold, was the check still there?

[BK7saum]

Yep, this is my first go at PC. This is the plain based mold, and you are right, no leading. I had just a little haze in front of the chamber that disappeared with one pass of a bore snake.

Velocity should be about 900-950 fps and with 231, I'm sure pressures are beyond the limits of the alloy, obviously.

I was just surprised to see that the boolit collapsed/slumped enough to make the lube groove disappear.

Lol, who needs a slicked sided PC boolit anyway.

[Walter Laich]

not unusual if the bullets hits square with the backstop.

glancing hits should still have some of the lube groove showing

Mine are all cast and PC for cowboy shooting so not worried about hunting with them.

Good groups and no leading are great. You can add mushrooming if these are hunting bullets--course shattering isn't great for hunting either

[popper]

I'd say its not slump but expansion. Using almost pure in 40 (185gr) about same fps, I got keyhole on the target and LG & nose profile (TC) still there.

[pls1911]

as Pepper said, perhaps the more appropriate term for post firing lead displacement is expansion, or perhaps deformation, or bumping up.
Slumping could reference a long, unsupported, non bore riding nose in softer alloy under higher pressure "slumping " in the bore as well.


HAHAHHAHAHhahahaaa.. foolish me....in disbelief, I had visions of someone loading slumped bullets and looking for accuracy.
Mine usually slump in the oven heat treating... like they're really disappointed they have to go back into the pot. MY screw up.

Eliminated the self induced problem by NOT trying to go the ragged limit years ago by just going to a preset and verified 450 degrees as "close enough". Bullets still harden up to 25+ after a few days.

[OS OK]

If I could shoot 'palm sized' groups @ 95 yards with a mild load and no leading...are you kidding? Heck, I'd be tickled if they were palm sized for BigFoot !

I'd be doing backflips of joy! Would I worry about the expanded rounds? NOPE !