Gas check terminal retention, How important?

[BrushBuster]

I've done some searching to get this pinned down, but don't seem much further ahead. I would be interested to know how seriously many of you take this aspect of boolit preparation.

Does shooting tighten the check, or does it tend to loosen them further? I've got varying opinions so far. Then there's those half filled cases, where you wonder whether the check might have come off during handling and storage. Maybe that's where those darn flyers come from!

I've also read about chronograph damage due to loose checks, and always try for a snug fit on my boolits to avoid this, but some molds leave me with moderately tight checks and I end up trying various methods to further tighten them (I'm also a fan of non-sizing). I know I could try lapping my mold to improve the situation, but wonder if any of this is necessary especially in relation to accuracy? Not talking about sloppy loose checks here, just one's that will rotate a little too easily for my liking.

[beagle]

I like gas check retention and try and rework the mould rings to attain it whenever possible.

Lyman says that gas checks have done their job when they exit the barrel. I can't help but think that they disturb the bullets flight when they come off. I attribute this to some of the flyers we experience.

Gas checks tighten upon firing. I've recovered checks from 30-150-SPs used on railroad plates at 100 yards. They spread out about the diameter of a nickel and clearly showed the micro groove rifling of the Marlin .30/30 I was using. The corner area showed blacking where gas leaked by before it sealed.

If the gas check takes the complete ride, I can't help but think that accuracy will be improved./beagle

[44man]

Since I make my own moulds I can make the checks fit tight. I have to tap the boolits on the bench a lot of times to get them on. Then I run the base into a size die that is the same size as the boolit is from the mould. I can't pry them off with a screwdriver! I have never found a lost check except after hitting steel downrange when the boolit blows into shrapnel.
If they are too loose, I would lap the mould a little.

[shooter2]

I am all for retaining the gas check. I lost one of the screens on my Oehler because of one that came off. It was a Lyman check. No surprise there I guess. It's got to affect the bullet when it comes off. JMHO...

[arkypete]

Many years ago in the Cast Bullet Assoc. news letter 'The Fouling Shot' there was a discussion on this topic. The old masters agreed that keeping the gas check on is preferrable. One of the suggestions for insuring the retention was to anneal your gas checks to remove most if not all spring back after seating and sizing.
Sounded good to me so every box of checks I get gets annealed before it goes to the loading shed.
Jim

[Bass Ackward]

Does shooting tighten the check, or does it tend to loosen them further? I know I could try lapping my mold to improve the situation, but wonder if any of this is necessary especially in relation to accuracy?

Brushy,

Fenatical is the term I would use on rifles. Handguns? ehhhhhh. You can't rotate mine on rifle bullets with a pair of pliars without destroying the check / bullet.

Does a check tighten or loosen under pressure? Well, it depends mostly on the anneal. Your barrel is a nose first sizer. In addition to sizing it indents into the shaft rifling grooves for drive grip .... that keeps bullet integrity and maintains the pressure seal. If you have a tight fitting check and tall rifling, you get maximum bite (strength) against stripping and thus gas cutting. Anything in between those conditions is a compromise and results in a lower velocity ceiling IMO.

If you can anneal and seat your checks correctly for strength, and you have tall enough rifling to get a good bite, then you can shoot closer to bore diameter bullets. If you can't, then you need to choke and let the barrel do this for you under pressure. This is why a lot of people get better results from filling the throat or choking. Especially with lower rifling heights like micro grooves.

[Lloyd Smale]

it definatley effects the accuarcy of handguns if some fall and some dont. Im sure it would be even more of a factor in long range rifle shooting.

[BrushBuster]

It's great to have this level of concencus, and sure helps make one feel a little less anal. I think I'll accept annealing my checks as standard procedure and tighten them all up.

Now if I can expand on this thread a little more, I would like to find the best way of annealing a box (1000) of checks. My understanding is that a pipe nipple sealed with caps on both ends and containing a small amount of paper along with the checks can be placed in the melt and left until heat soaked. Have I got this right? Is there a better method, and should the checks be degreased beforehand?

[Lloyd Smale]

before you go through the bother. What kind of checks are you using? IF there lymans throw them away and by some hornadys. That alone will probably cure your problem.

[Bass Ackward]

Strangely enough, my last box of 44 caliber checks were Lyman because of cost difference. But there was no difference in the checks in any measurement that I could tell and the same lip was inside the rim.

Are they now just saving manufacturing costs and repackaging Hornady's in their boxes?

Remember, GCs will get hard and brittle just sitting around on the shelf.


Brushy,

I am generally lazy and try to combine steps to save time and effort. I normally anneal my checks now when casting. I just leave some space in the pot, clean off the dross after fluxing, lay a cut out steel can lid down on top the mix and poor in the checks. When I am done, I either remove the checks with a spoon so I can refil the pot or just shut it off and remove the checks by hand when it cools.

[BrushBuster]

Lloyd Smale, all we seem to get up north are Hornady, so whenever I ask about checks I'm talking Hornady. I had heard a rumour that Lyman was out of the gas-check business?

Bass, thanks for that simple and lazy solution!

[Halfbreed]

hello fellas, I only shoot gc's on a 458 winnie. Hornady only, I have never found a bullet without a gc on it. wether I was reclaiming lead from a burm or steel plate silhouetts. From what I understand Lyman gc's are now made by Hornady.
John

[Lloyd Smale]

I dont know whos making them now but the old ones were not crimp on checks and tended to fall off.

[PerversPépère]

Writer Ross Seifreid said he use to spill a bunch of gas-checks in a small cast iron skillet and heat them until they turn a yellow-green tinge then he let them cool slowly.
This anneals them and make them dead soft so they don't spring back when crimped in place.
Sounds right to me.
PP.

[arkypete]

Writer Ross Seifreid said he use to spill a bunch of gas-checks in a small cast iron skillet and heat them until they turn a yellow-green tinge then he let them cool slowly.
This anneals them and make them dead soft so they don't spring back when crimped in place.
Sounds right to me.
PP.

I don't try for finesse, I throw the checks in a skillet and when the protective coating turns black I'm done. looks like I got them at a fire sale.
Jim