Author Topic: Gas check bullets (Read 1038 times)

Bounty Hunter · « **on:** March 18, 2006, 01:38:26 PM »

Can someone please tell me what the term "gas check" means when referenced to a bullet? Many thanks
BH

LAH · « **Reply #1 on:** March 18, 2006, 02:57:21 PM »

A gas check is a small copper or gliding metal cup that's placed on the base of the bullet. This cup covers only a small part the driving band area of the bullet. It's used to help seal the gas of the burning powder and to protect the base of the bullet from such.

Some say a gas check is worthless in a sixgun, others say contrary.

Creeker

Dusty Miller · « **Reply #2 on:** March 18, 2006, 04:02:25 PM »

The version I'm getting is that gas checks don't "check gas" at all but do scrape lead out of the barrel and seem to give a slight edge in the accuracy dept. My experience seems to bear this out but I can't give you any definite reasons why.

Chuck White · « **Reply #3 on:** March 19, 2006, 05:09:11 AM »

Gas Checks are supposed to prevent gas (pressure) from going between the bullet and the side of the barrel and therefore cutting small grooves lengthwise in the sides of the bullet!

They also help control leading in the bore!

Bounty Hunter · « **Reply #4 on:** March 19, 2006, 11:53:39 AM »

Many thanks to all of you for your reply. I have only shot jacketed bullets before. Sounds like if I buy some lead bullets that the gas checks are good things to have. Thanks again,
BH

Chuck White · « **Reply #5 on:** March 19, 2006, 01:22:30 PM »

Bounty Hunter

Keep in mind that the cast bullet needs to be designed for gas checks!
The base of the bullet will be smaller diameter if the bullet is designed for them!

quickdtoo · « **Reply #6 on:** March 19, 2006, 01:53:48 PM »

To illustrate Chuck's reply, the bullet on the left is designed for a gas check...

Dusty Miller · « **Reply #7 on:** March 19, 2006, 09:02:56 PM »

You also want to keep in mind that the price of copper has been going thru the roof lately and that a box of 1,000 45 caliber gas checks will run you somewhere in the neighborhood of $30. :cry:

flash-in-the-pan · « **Reply #8 on:** March 20, 2006, 03:45:44 PM »

Quote from: Dusty Miller

The version I'm getting is that gas checks don't "check gas" at all but do scrape lead out of the barrel and seem to give a slight edge in the accuracy dept. My experience seems to bear this out but I can't give you any definite reasons why.

Dusty, perhaps you have heard of the "zinc-base" or "zinc-washer based" bullets, which were in fact, designed to remove (powder) fouling. They are not very common in smokeless powder usage. More used in black powder, was my experience.

Gas checks do upset (deform) into the rifling with firing, and the purpose and function is to create a seal. That they might remove some fouling is a possibility, but not their designed function - just a small side-benefit, if any is removed.

The gas-check usually parts company with the lead slug within a few feet of the muzzle in my experience. I've used them on 180gr hard-cast in a 30-30Win., as well as 158gr SWC in .357 Mag., and I have found a number of them 3 to 20 feet from the firing point.

Flash

quickdtoo · « **Reply #9 on:** March 20, 2006, 04:28:42 PM »

I gotta share this....a fella at the range wondered why his chrono wasn't working, he took a close look at it and a gas check had gone thru his chrono, left a nice gas check sized slot right thru it like a frisbee!! :eek:

Tim

Dusty Miller · « **Reply #10 on:** March 20, 2006, 09:29:13 PM »

Flash, I'm suprised to hear that you've found them laying on the ground 2-20 feet from the muzzle. I've NEVER seen them on the ground but I'll admit that I've never really taken the time to look closely for them. Next time out I'll do that.

LAH · « **Reply #11 on:** March 21, 2006, 02:46:43 AM »

Gas checks can become detached should they be improperly installed or if the thickness of the check and/or the bullet shank aren't proper in size. This said I've no problems personally..........Creeker

lovedogs · « **Reply #12 on:** March 21, 2006, 04:48:22 AM »

A gas check shouldn't come off the base of the bullet. This is why Saeco has designed the base of their bullets the way they have. They do have a slight taper so that when you apply a gas check properly they crimp on tightly. Upon firing they upset and fill out to match the riflings, which further crimps them on even tighter all the way around the bullet. If you can retrieve a bullet that has a properly fitting and properly installed gas check you'll note that the check is still on the base. Quite often when they come off it's because the base of that bullet isn't a good design or it isn't filling out as it should to have the right dimension to allow the check to crimp on tightly enough.

flash-in-the-pan · « **Reply #13 on:** March 21, 2006, 09:14:29 AM »

ld,

Perhaps I should have noted that my experiments and experiences with gaschecks were late'60's - early '70's. I think they were Hornady, (in a tin can), and they were of uniform thickness, base and rim. They were the press-fit type. Bullets hard-cast, Lyman and Lachmiller molds, had a reduced heel diameter which was not tapered. Seems they held onto the projectile about as well as a shotgun wad holds the shot charge.

But their reason for existence was all within the barrel of the firearm, and they served that purpose well.

Rifling marks were evident, though I never actually miked one to see if it upset to the *full* groove diameter. Memory holds the result to look about the same as the base of a recovered JHP.

Chuck White · « **Reply #14 on:** March 21, 2006, 12:19:16 PM »

There are/were two types of gas checks!

Hornady makes a crimp-on type that actually swages onto the base of the bullet when it runs into the Luber-Sizer!

Lyman make a gas check that the bullet just sits in! Not swaged at all!

I use Hornady gas checks and I have never had a check separate from the base of the bullet (that I know of)! I have dug them out of sand burms, just to see if they were still attached! They were!
The Lyman brand is another story!

lovedogs · « **Reply #15 on:** March 21, 2006, 02:52:31 PM »

I've always used the Hornady's because of that crimp-on feature. Don't know if it's true or not but have heard that the newer Lyman's are now crimp-on's, also. Looks like they're all getting pretty high-priced.