loose gas checks

[calsite]

Had my first experience with gas checks over the weekend. Crimped them on with a lee lubrisizer, and then pan lubed them. Of course I had to get all of that gooky stuff off the outside of my boolit, noticed that several I resizedthe second time, the gas check popped off with a little thumb pressure. I don't recall any of them popping off like that when I initially crimped them on. Talked with osage today and he said I might have to anneal my gas checks. Looking for further guidance on my problem........

[44man]

lap the back portion of the mold to make it larger.
I have had good luck using a Lee factory crimp die to crimp gas checks. Figure it out, it works. Just catch the top edge by using a rod to run the boolit up to the crimp edge. Gas check up.

[odoh]

Would a loose chk result in any performance issue? Its only real need is during bore travel right?

[hyoder]

What brand gas check? What size bullet, what size gas check?
If the base is a little small the Hornady checks should still crimp on.

[NVcurmudgeon]

I read here that loose gas checks can spring back after crimping. I can't say for sure, but if I anneal the same gas checks that were loose, the problem goes away, so it stands to reason. Annealing also helps make it easier to expand GC that are too small to go on. Opposite problems, same cure.

[454PB]

If the boolits are seated so they are contained by the case, don't worry about it. If the boolit is used in a bottle necked case and protrudes inwards far enough that the GC could get loose, it could create a hazard. Back before Hornady started selling their crimp-on checks, I used thousands of Lyman checks that were actually designed to fall off at firing.

[calsite]

I haven't done any measurement as far as boolit base and ID of gas check. I've also been told about annealing and flaring the gas checks. Currently the gas check will not fit over the base of the boolit. They are Hornady gas checks and I'm casting 50/50 WW - Lead out of a new RCBS 429421 mould. Like I said this is my first experience with gas checks. Probably my biggest concern is that one of the gas checks possibly come of and remaining in my bore. I'll probably anneal and flare my checks and try again. Osage told me that I outta be able to push the check onto the base of the boolit prior to sizing it. Is this generally an expectation from everyboby?

[454PB]

Yes, but sometimes it takes more than finger power to seat a tight check. When I'm using a Lyman 450, I place the die nut wrench on the top of the sizing die and use the nose punch to push the check (which is positioned cup up on the wrench) onto the boolit base. For the Lee sizers, I place the check loosely on the base, place the nose in the die enough for it to stay positioned, then raise the ram and give the check a quick "tap". This always seats it fully and squarely, and then I push it on through the die. The same method works for the Star sizer, only upside down.

[floodgate]

odoh:

The original patent by John Barlow - proprietor of the Ideal Manufacturing Co. - (#847149, issued March 12, 1907), states*, and contemporary references in the Ideal Handbooks imply, that the gas check is supposed to separate from the base of the bullet after it exits the muzzle. Practical experience has shown that this separation is not reliable or consistent, and that the best accuracy results when the checks remain firmly attached throughout the bullet's flight.

floodgate

* "...and the gas-check means will leave the bullet after the same has been ejected fromthe barrel..."

[Lloyd Smale]

like floodgate said the biggest problem will be flyers at the range. You cant expect a bullet to fly the same everytime if its shedding its check at different times each shot.

[454PB]

True, if the check falls off at random, it should cause accuracy problems. However, I've never seen any evidence of that.....maybe I'm just really lucky.

[odoh]

True, if the check falls off at random, it should cause accuracy problems. However, I've never seen any evidence of that.....maybe I'm just really lucky.

I know that was the common thot 50yrs ago ~ in all that time, I've not seen evidence of performance issues. I gotta 250gr bullet sprinting out at 1400fps or so and how much does a gas chk weight? Just how much influence can a caboose have on a train? I know my bro accused me of not putting them on tightly but he's just a lousy shooter at best.

Hornady is the only crimp-on available for the avg handloader? Lymans are still stick-ons right? Whats holding them on after they leave the muzzle? If there were an inflite issue, Lyman wouldn't be still making them as nobody would be buying them. I wonder if the crimp-ons were just a marketing ploy ~

[MT Gianni]

Hornady is the only crimp-on available for the avg handloader? Lymans are still stick-ons right? Whats holding them on after they leave the muzzle? If there were an inflite issue, Lyman wouldn't be still making them as nobody would be buying them. I wonder if the crimp-ons were just a marketing ploy ~

Current LY are crimp on. General opinion is that they are made by Hornady. Gianni

[Lloyd Smale]

It doesnt show much at 25 yards but groups at a 100 yards will show flyers. At least they have in my testing.

[odoh]

Current LY are crimp on. General opinion is that they are made by Hornady. Gianni

Gianni ~ thanks, haven't used them for decades as the hornadys have been more affordable.


It doesnt show much at 25 yards but groups at a 100 yards will show flyers. At least they have in my testing.

Lloyd ~ thanks, I respect your experience. Personally, the bulk of my concern has been w/while the bullet is moving thru the barrel. Things like lead vapor/dust coming out the cylinder gap/ports from the BB/PB bullets I'm trying to use up. At my age, its probably too late to worry about it but I know it can't be good for a person. I had thot that what w/the intense pressures of discharge together w/engraving of the lands would make a loose chk tight. I'm just now starting to stretch out at the longer handgun ranges and will gain experience.

[floodgate]

odoh:

"Hornady is the only crimp-on available for the avg handloader? Lymans are still stick-ons right? "

Ackshully, Lyman stopped making their own several years ago, and are now selling Hornady's - at a higher price....

floodgate

[anachronism]

They are Hornady gas checks and I'm casting 50/50 WW - Lead out of a new RCBS 429421 mould.


Two things. First of all 429421 is not designed to accept gas checks. It is a plain base bullet. Second, Lyman makes the 429421, not RCBS (a minor point). Which mould do you really have?

[Lloyd Smale]

like he said if your truely using the lyman 429421 its not designed for gas checks and there not going to work anyway anyhow! As to gas checks falling off in a barrel. Ive shots 100s of 1000s of loads with lyman press on checks and have never had that happen. I dont think its even possible. If the check is on the base of the bullet the gas pressure is going to hold it there till it leaves the barrel. Only problem i could possibly see is if the gas check falls off the bullet in the case before firing. If a guy is really conserend about that a dab of superglue or silicone or any adheisive would no doubt hold it good enough to get it out of the barrel.
Two things. First of all 429421 is not designed to accept gas checks. It is a plain base bullet. Second, Lyman makes the 429421, not RCBS (a minor point). Which mould do you really have?

[calsite]

I had the same thoughts about the lands and grooves futher crimping the gas check on and realize that with alot of gas pressure behind the check it will probably come out with the boolit. I just thought it was unusual that about a third of my checks popped right off with a bit of thumb pressure. Being my first time atbat with gas checks I was pretty uncertain. Thanks for all of the replies......... I think I'm going to anneal and flare and see what happens.

[calsite]

Well, I know it's a RCBS mold because lyman handles won't fit it and RCBS handles will. The box it came it was an RCBS box and was labled .429421, other than that that's all I know about the mould, other than it has the gas check ring. Moukd came out of the back room of an old gun shop, where I always do my hunting before I buy new, I guess it could've been place in the wrong box.