What is gascheck?

mdlowry · May 13, 2002, 09:54 PM

I've seen the term around, and I was wondering what it is. What is the purpose of it?

swifter... · May 13, 2002, 10:43 PM

Think of it as a very short jacket. Covers the base of a cast bullet, extends maybe 1/10" up the sides.
Some folks fondly believe they prevent hot gases from cutting up the sides/base of a lead bullet. Sometimes they work, too.

Tom

labgrade · May 14, 2002, 10:24 AM

Too, the cast bullet must be designed to accept a gas check. The bullet base is slightly less in diameter than the rest of the bullet. You can't realistically stick a gas check on a bullet with a full-caliber base (although I'm sure someone will prove me wrong - lots of "home-gardening" with reloaders).

Coupla kinds: Hornady's got one (I've never used it) that is similar in use/different in stickin' in on (?), but different than Lyman's which gets crimped onto the bullet base during the sizing operation.

Steve Smith · May 14, 2002, 11:19 AM

The Hornady is a press fit onto the bottom of a GC bullet. When yourun the bullet through the sizer, you put the bullet in position, and press the GC onto the bullet base a little. Then you run the ram and it presses the GC onto the base. If you're pushing lead really fast you'll usually need them.

Contender · May 14, 2002, 05:56 PM

All very good responses:

A gas check is, in effect, an increase in bullet base hardness to prevent the bullet base area from deforming and overcoming the film strength of the bullet lube with the heavier loads.

It also can be thought of as a "wrench" to engage the barrel rifling and prevent stripping in the bore with heavy loads.

Regards

May 13, 2002, 09:54 PM	#1
mdlowry Senior Member Join Date: December 15, 2001 Location: New Hampshire Posts: 417	What is gascheck? I've seen the term around, and I was wondering what it is. What is the purpose of it?

May 13, 2002, 10:43 PM	#2
swifter... Senior Member Join Date: March 16, 1999 Location: So. CA Mountains Posts: 540	Think of it as a very short jacket. Covers the base of a cast bullet, extends maybe 1/10" up the sides. Some folks fondly believe they prevent hot gases from cutting up the sides/base of a lead bullet. Sometimes they work, too. Tom

May 14, 2002, 10:24 AM	#3
labgrade Member In Memoriam Join Date: November 29, 1999 Location: west of a small town, CO Posts: 4,346	Too, the cast bullet must be designed to accept a gas check. The bullet base is slightly less in diameter than the rest of the bullet. You can't realistically stick a gas check on a bullet with a full-caliber base (although I'm sure someone will prove me wrong - lots of "home-gardening" with reloaders). Coupla kinds: Hornady's got one (I've never used it) that is similar in use/different in stickin' in on (?), but different than Lyman's which gets crimped onto the bullet base during the sizing operation.

May 14, 2002, 11:19 AM	#4
Steve Smith Senior Member Join Date: December 9, 1999 Posts: 4,131	The Hornady is a press fit onto the bottom of a GC bullet. When yourun the bullet through the sizer, you put the bullet in position, and press the GC onto the bullet base a little. Then you run the ram and it presses the GC onto the base. If you're pushing lead really fast you'll usually need them.

May 14, 2002, 05:56 PM	#5
Contender Senior Member Join Date: December 10, 1998 Location: NY Posts: 680	All very good responses: A gas check is, in effect, an increase in bullet base hardness to prevent the bullet base area from deforming and overcoming the film strength of the bullet lube with the heavier loads. It also can be thought of as a "wrench" to engage the barrel rifling and prevent stripping in the bore with heavy loads. Regards