Gas Check Seating [Archive]

BABore

07-15-2005, 09:09 AM

Is there any way to seat/crimp a Hornady 30 cal. gas check onto a boolit (Lyman #311041) without using a sizer? I just got the mold and a Lee 0.309 sizer. The boolits are dropping at 0.3095 with WW's, just about right. Going thru the Lee sizer they come out at 0.3085 to 0.3090, acceptable, just. I know I can lap the sizer if necessary, but does anybody make a tool for a standard reloading press that just crimps checks? I have machining abilities, so I could make what I need if required.

sundog

07-15-2005, 09:30 AM

BABore, Lyman, and maybe others, make a gas check seater which is nothing more than a length of pipe, open along one side to fit around the depth adjusting screw on either the Ly or RCBS press. When it is in place you can use your .309 die and the boolit will go only deep enough to seat and crimp the check.

Now the best part of this is you can make it yourself from about any tube like material that will hold up to the little bit of pressure put on it. I made for the SIL a few years ago from an 06 [I think] case. I have a store bought Ly, and it doesn't work any better - it just works. Maybe someone on during the day can post the length as I'm at work, or I'll try to remember tonight and measure it and let you know.

Why not just a .310 sizer? sundog

BABore

07-15-2005, 10:09 AM

Like I said in my first post, the mold is dropping the boolits at the correct diameter. Rather than having to apply liquid Alox first, then size and seat the checks, I thought I could just seat the checks, lube once or thrice, and shoot. Also, I don't have any type of lube/sizer, just the Lee sizing die. I was talking about using my stock RCBS Rockchucker.

StarMetal

07-15-2005, 10:14 AM

BABORE

Make a device that fits into the shellholder slot of your press and make it so that it has a hole in it to seat your gascheck. Make the with a bottom that has enough depth to seat the entire check and made the diameter of the hole for the size you want the check sized to. Then made a die for the top of the press that either had the shape of the nose punch or make it to hold a nose punch. All this should be easy and fast to make on a lathe.

Joe

Junior1942

07-15-2005, 10:26 AM

Do it the easy way and buy a Lee .311" sizing die. It will crimp your gaschecks and not touch your .3095" bullets. Alas, Lee doesn't make a .310" die.

45 2.1

07-15-2005, 10:30 AM

Simply lap your LEE sizer out to where it just touches your bullet.

Magnum Mike

07-15-2005, 11:42 AM

I think lapping out your existing lee sizer is your best answer. If you open it up to .310" as suggested if wont touch the bullet but will crimp the chek on. Most anything else that you would make is going to require of bunch of handling of the boolits as opposed to just pushing them thru that sizer...

The Saeco sizer allows you to "just crimp" the checks on but since ya dont have one, thats not an option.

sundog

07-15-2005, 03:02 PM

BABore, sorry 'bout all that "GREAT" free advise you got from me. On second thought..., what them udder fellers said, get a .310 or .311 Lee push thru and y'all be in fat city. I have 5 lubrisizers (that's a lot of lube sitting in reservoirs) and still find the Lee push thrus pretty handy sometimes. sundog

buck1

07-15-2005, 03:45 PM

slughammer

07-17-2005, 08:48 PM

I actually had a problem using a .311 die to seat checks and fill the lube grooves. Works great for boolits that drop at .312 from the mold, but the boolits I was sizing were also 311041 and about the same diameter as yours.

What happens is the gas check is not sized down enough and when the boolit is seated the case neck is streched by the gas check. Might not be noticeable for some boolits and case necks, but with 311041 and 30-06 cases it is. End result was loose boolits.

Starmetals idea is quite good. Another would be the use of a Lee FCD. Search on the "Free check" over at accurate reloading and there is a picture of a modified FCD used for crimpimg checks on. (There may be a link to the thread somewhere on this board also, try searching "free check" here first.)

Easiest idea would be to make a nose puch to fit the shellholder slot of your press. Then just run the boolits check first up into the Lee die about 1/8 inch to only crimp and resize the check. A 1/4" hex bolt of appropriate length could be dropped into the top of the die to work as an ejector.

Iron River Red

07-19-2005, 12:31 PM

I have several molds now that the shank the gas check crimps on seems too long. The gas check once run thru the sizing die seems to be on good and tight but there is a groove created by the length of the shank being too long. Now I have tried using it as an additional grease groove and they look fine, but I'm concerned that the grease may unseat the check and allow it to seperate from the bullet.

Have any of you had to deal with this before?

I can seat with out the grease in that area and have done no testing as of yet. The bullet design is a SWC with a single groove and I am putting additional grease in that area making it a double grease groove. Whether or not it is practical or necessary is unknown to me. It just so happens it came out that way from the beginning.

Please advise...

Red

Willbird

07-19-2005, 12:37 PM

This is not my personal experience, I sort of got it from a book, and I may get wacked with a 2x4 for saying it, but here goes.

Mr. V. S. who makes custom boolit molds insists that such an area ahead of the check is good because the check scrapes lead from the bore and that extra room there lets the system work better.

Bill

45 2.1

07-19-2005, 01:10 PM

Allot of different gas check shank lengths from all manufactures. What seems to work the best is the RCBS shanks. The shank should be about 1.5 to 1.9 times as long as the height of the gas check. This leaves room for lube and to collect minor lead slivers. I have seen no advantage to longer shanks and I have dug up thousands of bullets that were test fired for various purposes. Shorter shanks DO cause problems.