.399 in a 40 S&W

[BT Sniper]

My CH 40 cal die is spiting them out @ .399 will this work in a 40 S&W? I suppose I could take some fine sandpaper to it and polish it a little if need be. What is your thoughts?

Thanks

BT

[Leadsmith]

I'd give them a trial before enlarging the die. Messing with the die is inviting trouble if you don't do it carefully.

Bob

[GBertolet]

Slug the bore of your gun first. In 40 cal .400 is the standard. If you elect to go with the .399 die and you gun is .400 or better, don't cast the bullets too hard, as they must upset to seal the bore, to avoid leading and give acceptable accuracy. Too soft and you may have feeding problems. Try wheel weights. Another possibility that sometimes works for me, is to tumble lube the bullets in Lee Liquid Alox. This will add to the diameter of the bullet which will help during it's trip down the bore, often giving satisfactory results with no leading whatsoever. You can even tumble lube the bullets unsized, also giving good results. All the bullet sizer dies I have purchased lately from Magma Engineering for my Star sizer, were undersized by a thousandth, verified by several different micrometers. Even the test cast bullet included with the die was undersized. I lapped them all out using a dowel with a slot across the end, using a piece of emery cloth inserted across as a flapper. I chucked it in a variable speed drill. Go slow, it works. Try the liquid alox first, it's the easiest fix.

[bohica2xo]

BT:

They will shoot just fine. Are these the brass case "jackets"? If so, you are just seeing the springback in the jacket material.

When that 30,000 pound hammer hits the bullet in the base it will seal up just fine...

B.

[BT Sniper]

Yep brass jackets from 9mms. I just took a core and ran it into the final swage die skipping the core seating step. I'll try the core seating as it is supposed to be done first see if this makes a difference.

I ran a lead slug into the swage die and it came out at .399 as well. Can't imagine lead has much spring back though. I have been learning all about brass spring back though and it makes sense as the case was allready smaller it is going to shrink back just a bit after leaving the die.

Been quite the challenge making .410 jackets from the 40 S&W case. I attempted to make a sizing die but it did not turn out as good as I would like it to be. Still working on it though.

Don't actually have a 40 pistol. Making bullets for friends here and need the advice from those of you that know. I'll have them give it a try before I mess with the die. Suppose I'll get alot of ware out of it before it gets to big.

Thanks

BT


B, sent you a PM a while back. I'm working on the .308 from a 5.7x28 now. I recall you said there might be some lying around out there in the desert. Let me know if you come across any extra. TNX for the feed back. Helpfull as always.