Gas Check Shank Question

[LEADHOPPER]

Alright, I have a LBT 45 Cal 340 grain WFN mold that I got here on a group buy. Haven't had much time till now to cast with it. The problem that I am running in to, is that the gas check shank appears to be small. The gas checks on my RCBS 45-255-SWC have to be pressed on and you can tell that it is there. With the LBT mold the gas check just kinda floats around a little. It doesn't have that snap when you put it on. I was water quenching when I cast with the LBT mold, but don't think I was with the RCBS mold. Could this be causing the gas check shank to come out undersize? I am getting great cavity fill out so i don't think that is the problem. I have not emailed Veral yet, figured I would try here first. I am using Hornady gas checks. I am using Lyamn #2 alloy on both molds. This is my first aluminum mold, so don't know if I need to cast in a different manner then I would with a steel mold.

[Ben]

Once the bullets & the g/c go through the sizer , are the g/cs loose and can they be rotated on the shank base ?

Take a mic and measure the g/c shank on Mold A( RCBS ) and do the same for Mold B ( The LBT ) and report back here with your findings.

[cbrick]

Ben is right. If they are snug after sizing and crimping them on simply count your blessing.

I have many molds where I would have bloody fingers after putting on a couple hundred checks they are so tight. Did this for many years until I took my head out of my hieny and made gas check sizers for each caliber. Now the most boring thing in my loading room is sizing GC's but by golly they go on straight and go fully on and flat against bullet base & crimp snug.

After a few years of sizing the checks I read on this forum about annealing the checks, haven't tried that yet, sizing them works so well I've just stuck with it.

All that has given me an ever growing love of the plain base though. As long as they crimp snug consider yourself a lucky man, if they don't crimp snug contact Veral & tell him you have an undersized shank.

Rick

[Ben]

Rick :

All that has given me an ever growing love of the plain base though

See if you can tell why I'm liking my plain based .30 cals. so much ?

If you take out the " 2 O'clock round " from the group below( and that round is most likely me..not the rifle ) ....it is basically shooting in 1 hole at 50 yards.

http://img.photobucket.com/albums/v494/haysb/SAECO%20%20315%20Plain%20Base/021.jpg

[LEADHOPPER]

Haven' t had a chance to run them thru the lube sizer yet, still waiting on the die to show up. So as long as they crimp on the gas check shank when I size them I should be good? Just thought it was kinda strange how good the gas check fit on the RCBS boolits, kinda with a snap, to not even having to push the gas check on. The RCBS checked .421 and the LBT checked .419

[rockrat]

You might try some "Gator" gas checks. I have been told that they are slightly thicker and a more snug fit. Maybe some Gator Rifle checks. Thats what I use for boolits for my 450Bushmaster. Could send you some of the rifle checks if you want to try them.

[Doc Highwall]

Annealing the gas checks will help the grip on the base of the bullet better after sizing.

[Bret4207]

Yes, as long as they seem fairly secure on the base after sizing you are okay. The older style checks didn't even crimp on and I've shpt many thousands of those with no issue. As long as they don't fall off you should be good to go.

Annealing can help by lessening the "spring back" of the check if they are little loose for you.

[PacMan]

As much as i like LBT molds the only problem i have had with any of them was two that the GC shank was not large enough on. Like the guys said above for the most part if after you run them thru the sizer if they are tight you are good to go,
But if the shank is so amall that the check bulges out away from the base of the bullet when crimped on than you may have a problem. If so contact Veral and send it back.He does have a snap on garantee fit. I sent one back and it was corrected.

If it fits tight and flat to the base after sizing and you do not like trying to hold it on while runing it thur the sizer you can rough the base slightly. I have my sizer c-clamped to the bench with small threaded clamps and what i do is with nose up lightly run the base of the bullet downward across the threads of the clamp and that is enough to hold the check in place.

One other thing i have done if the check does not fit flat to the base is size nose first without lubing using a punch smaller than bullet dia. which tends to push the check flat in the center but still allows it to crimp on tightly. That is what i was doing with the .411 bullet using a .358 punch before i returned it to Veral for correction.
Dwight

[Blammer]

leadhopper, as long as after you crimp them on they stay put and are tight, I don't really see a problem. I have several GC moulds that the GC won't stay on at all until you size them, then they are on very nicely and won't come off.

[LEADHOPPER]

Thanks for all the advice I will run some thru the sizer when it shows up and post the results here.

LH

[PacMan]

LH-I may be the only person in the world that some of the things i mentioned matters to.I do know that i have less experience with cast bullets and GC's than most of the guys that replied here but i firmly beleive that improperly fitting GC's negate their use.

On the .411 bullet i refered to i fired some reduced loads into a stop and i was less than pleased with the way the checks looked. They were distorted really bad.Now if you like most others think that the base of the bullet is more important than the nose you would not like the results.

One other thing that i forgot to mention is that if the check has to roll in very much to crimp it has a tendecy to spring back right at the corner of the shank. I measured some that was as much as
.005 larger at that point than the sized bullet. When you seat the bullet in the case the gc cant help but expand the case larger than bullet dia. resulting in loss of case tension.

I really doubt that your shank is small enough to cause some of these problems but they are things i think people should be aware of. I have other molds that have small shanks that the GC's seat on just fine with none of those problems. I like someone above hate one that is sturbon to put on and that is where my Saeco sizer shines.
Dwight

[Doc Highwall]

One other thing that i forgot to mention is that if the check has to roll in very much to crimp it has a tendecy to spring back right at the corner of the shank. I measured some that was as much as
.005 larger at that point than the sized bullet. When you seat the bullet in the case the gc cant help but expand the case larger than bullet dia. resulting in loss of case tension.

This is why annealing the gas checks is important, it eliminates the spring back after sizing.

[PacMan]

Thanks Doc i wish i had of know that before. I have learned a lot here along with a bunch of trial and error.

[LEADHOPPER]

Doc,

How do I anneal gas checks, kinda new to the gas check game? Up till now most of my cast loads have been plain, or bevel base. But due to the fact that I am workin with my .454 Casull I am starting to work with gas checks. I understand the concept of the gas check spring back, it is the same when forming aluminum aircraft parts. The harder the metal the farther you have to bend it so that when it springs back it is to the right form. But when you have "O" condition(softest state) which you can bend with your hand you don't have to bend it quite so far before it retains the proper shape. Does annealing the gas checks change how much pressure it can withstand? Or does it not affect this.

LH

[Doc Highwall]

LEADHOPPER, annealing gas checks is easy. I spread them out in a pan and use a propane torch to heat them till they glow red. They will turn black and I have shot them that way. Now I drop them into my Lemi Shine that I use for cleaning my brass cartridge cases while they are still hot and they come out a nice pink/rose color. The annealing does not affect the pressure they can take but it takes less force to size and lube the bullets and the gas checks stay on very well. I have a small wire basket that the gas checks cannot fall through that I place the gas checks into when I place them in the Lemi Shine. There is a long thread on citric acid for cleaning cartridge cases that has a lot of information in it and about the Lemi Shine being found at Wall Mart in the dishwasher soap section.