View Full Version : gas check cutter?
05-14-2006, 06:57 PM
I just acquired a well machined tool which mounts in a press, the punch slides into shell holder slot, slides through body of tool, and brass or aluminum sheet in slot is punched 0.462 approx., pushed up thru tool. Would this make .338 gas checks? I assume sides of gas checks to be about 1/16". I don't have check forming tool so I'll probably sell or trade after it's identified. Did Freechec make this?
05-14-2006, 07:18 PM
You take the diameter you want the gascheck to be. Lets take that 338 so you would have .338 (and you want the walls to be 1/16th high which doubled is .125) and add double the wall height of .125 and that gives you .463 which sounds very close to what you measured the disk you cut.
08-23-2006, 04:36 PM
Time to ressurrect this thread - has anyone actually done this - make their own gas checks? Would love to hear details and successes/failures.
08-23-2006, 06:53 PM
I have never made checks but I'm interested in all get out on a freecheck tool or something like it. IIRC Paco Kelly used to make them but doesnt anymore. With the price of checks skyrocketing I'm in need of one bad for the 357Mag, 44Mag, and the 30/30. If ANYONE out there makes these I want some. What say you???:castmine:
09-21-2006, 04:53 AM
Currently I don't do any GC'ing of any of my cast bullets (.44mag revolver and .45acp), but I think this would be a pretty cool project and wouldn't mind devoting some time and effort to turning out a die set. Could someone tell me how thick GC's normally are? and what caliber would you want? .308-.309?
I found this forum scouring the net for info on turning .22LR brass into jackets for .224 bullets. So far it's been a frustrating journey, and I've found some neat ways to obliterate .22 brass. I'll get around to posting some pictures as time permits.
09-21-2006, 10:26 AM
Welcome to the asylum....
Check out Corbins site if you haven't already, or PM Swagerman on this forum - there are other swagers here, but he is the first one that comes to mind. I have heard of using .22lr cases for jackets of .22-.243 bullets, but I do no swaging, I have enough different projects going right now :-D .
Hornady GC's are about .020-.022" thick, but I measured them with the depth rod on my vernier - I know where the mic is, but it might take an hour or more to dig it out.... I can send you samples of .30, .32, & .35. PM me a mailing address.
If you came out with such a tool, you would have a ready market here in just about any caliber you could come up with, from .22 on up to .50. (My personal wish list would have .30 & .35 right on top.) There has been discussion here about it in the past, and several members do make their own GC's of one style or another, but no one has gotten it together yet to make the punch and the cup former as a marketable item. Produce the tool, and like the Munchkins said: "You'll be a bust/Be a bust/Be a bust/In the Hall of Fame"!
09-21-2006, 10:37 AM
There have been previous discussions here on the stamping out of GCs.
Couple of the members here. as best I can recall, make their own production machinery. ie punches and etc.
Some of them may chime in.
Looking back in life a few years, I wish I'd kept a big Herters bullet swaging press I had.
Think it would possibly be useful in this arena.
Then, I'm already up to my navel in projects already.
09-21-2006, 11:17 AM
I have made my own gas check tools on my lathe. No I would not make them for the group. They are tetious to make, you need a wide selection of reamers and alot of time. Not worth the time to make them, that's why you will notice that Corbin doesn't exactly give his gascheck makers away, they cost in the 100's of dollars. It's also a pain in the butt to stamp out the discs then stamp them into checks, it's slow. As for using the Herters press, that would be fine for turning 22 casings into jackets. As for making gaschecks it would be an overkill. From what I've heard from members that have used 22 cases for jacket swings to each extreme opposites with no middleroad, that is they either really suck or they really perform well. I've never made them, but I would have to say if you have good quality tools they would have be half decent jackets, afterall that's how Speer got started in the bullet making business.
I know talking to Buckshot he's not too interested in making gascheck making tools for anyone. Dabbling in machinework, he knows what is envolved in making them and I don't blame him.
Unless you have a precision lathe and time, preferrably a CNC lathe, don't waste your time, just buy the checks.
09-21-2006, 03:01 PM
..............The commercial presses do it in one shot. They punch the blank disc and then it gets cupped in the same operation. The machines run fast. For a guy to make his own you could do the same on a hand operated press. The ram to punch out the disc would be hollow and inside it, the cupping punch. The metal strip is fed through a slot and the punch comes up (or down depending upon the machine design) and cuts the blank and stops. It is holding the blank centered over the polished tapered cupping die.
The central ram continues upward and pushes the blank up through the hole, swageing and cupping at the same time. There would be a stripper to positively remove the formed GC from the ram head. Then the GC's get washed and annealed.
A simpler setup for a home shop guy would be 2 dies. One to blank and one to cup. Both rams operating interchangeably in the same body and with interchangeable blanking and cupping dies. There are any number of ways to feed the blank consistantly in a second operation over the cupping ram.
09-22-2006, 02:05 AM
Well, for the time being I don't have a lot of other stuff going on, so I wouldn't mind at least developing a prototype set of dies for doing this and then publishing the specs in .dwg files. I've done quite a bit of CNC work in the past, but normally work on prototypes on a hardinge tool room lathe I have access to, and a 24" atlas I have in the garage.
The gas check cutter, is similar to another project I am working on for producing primer cups.
I stopped by the art supply store, and was pleased to find they carried brass and copper, both in sheets, and in coils so I picked some up. After handling it, it may be a little bit thin for use as a GC. Apparently, it's a lot too thin, being only about .007" thick. Corbin uses .030" material for the gas check, so I need to go find some materials.
It's rather late in the day, and I wasn't able to go over and pick up any drill rod for this project, so I will prototype them out of 316 stainless. While it would be nice to have this attach directly to a commercial press with 7/8-14 dies, the press may be a little over-kill for production.
What I have decided to do was build the die in two parts, the body will contain a spring loaded plunger assembly which the ram will push up using some kind of intermediate punch. On top of the plunger assembly, will be a replaceable die and punch arrangement to allow for different sizes of GC's to be punched out.
I think if I were going to do huge production runs of GC's I would mount this arrangement upside-down so the GC's were punched out the bottom and a press with less travel was used.
The initial set I will make will be for .357 (for use in my wheel gun, and my friends lever gun).
If someone feels compelled to check my math:
cup-sidewall (bottom to top): .125"
I should have some time to work on this some more over the next day or so.
09-22-2006, 04:14 AM
The sidewall height of .125 sounds way too much. I believe Corbin has a formula for what size to make your gascheck discs according to caliber. My dies are a two set. One set cuts the disk, the other forms it into a cup. I feel to incorporate these into a press would be a pain in the ***. I mount the disk cutting die in a machinist vise on my drill press and the punch in the drill chuck and I cut out a bunch of disks fast using the drill press. Then to form them into cups I use the other die with a little brass hammer.
I still believe it's alot easier to buy the Corbin setup.
Four Fingers of Death
09-22-2006, 04:30 AM
I've always fancied doing this, but I suppose if it was easy and there was a market for them Paco would still be producing them. Probably one of those things to close your eyes and buy up big when you are cashed up, which happens every now and then. Group buys are another option, there is a 323 group buy going on at the moment, see the group buy page. Mick.
09-22-2006, 07:58 AM
............Toecutter, I'm not up on all the stainless steels, but for these dies you're going to want something that's hard and also tough. Both for the ram and the dies. Maybe something in the S series steels, or low carbon steel with a good deep case. It would be helpfull to also have your copper or brass stock soaped or wiped with a draw lube, like a case sizing lube.
09-22-2006, 09:52 AM
I have found that no lube is necessary. Heck the only friction you're dealing with it that little lip when you form it into a cup.
09-22-2006, 03:21 PM
toecutter, I sent you an e-mail with information about 22 jacket making from rimfire cases.
check it out and please get hold of me if you like.
09-22-2006, 04:41 PM
I made a set of press mounted tools last winter. They worked well, but spring came and I haven't had time to refine my design and build the second generation. For .357 I was using .010 copper material and punching at .500 dia, which was just a little too big in dia. (caused some stretching of the edges).
I think for .357 I would recommend punching at .450
For the punch, start a few thou over the shank of your boolit and polish down as required for that "perfect" fit.
The name of the game is concentricity.
09-22-2006, 05:07 PM
First think you have to do is determine the measurement from the gascheck shank on the bullet to the diameter it's going to be sized to. Whatever that measure it is, you have to use stock metal that is that thick, or if you don't and seat your homemade check on the bullet shanks two things will happen: One the check won't grip tight and two, most important, the check won't be out all the way to the edge of the driving band of the bullet, thus not seal and be useless.
09-22-2006, 07:44 PM
I built the cutter assembly that slips into the shell holder. This will allow the attachment of whatever type of cutting head. The cutting head is going to be O1 drill rod if I actually make a production unit. But for now, since I have pile upon pile of stainless 316, and it doesn't cost me anything, I'm using that.
As for other design considerations. My understanding of gas checks is somewhat limited. From what I remember reading about them a while ago, is you want the ID of the check to be at bullet size (heel base bullets are normally used for this?). When the check is crimped on to the bullet, the gas check is placed on top, and then swaged in. Kinda like the same way a bottle cap is swaged onto a pop/beer bottle.
The main reason this is getting put into a press for the time being, is that it's an easy way to guarantee alignment of the parts. If I were to do this commercially, I would have a machine body made up just for doing this.
I need to go out and buy the steel for the upper cutter this weekend and will post some pictures of my progress as I go along.
Thanks for all your help guys!
09-22-2006, 08:33 PM
With the disk cutter the cutting punch, which has to have the minimum amount of clearance fitting into the cutter body, will be more clearance then a wobbly ram and loose shellholder can deal with. That's why presenting I'm using a clamped down machinist vice on a quality Rockwell drill press. There's no movement when I got it set up. The only other way to do a cutter die in the reloading press is to have a body with a window slot in it the check material slided throught and the punch resides in the body, never coming out. Hard to in a press being that the punch will be far down when the ram is down, unless you make the punch usually long, or you make a tapered relief area in the die mouth.
Like I said, these aren't easy to make, especially make so that they are efficient, easy to use, and fast.
09-23-2006, 04:52 AM
The Fouling Shot had an article awhile back that described how to form thin aluminum or brass checks on plain base bullets. The description didn't seem too bad. The actual process may be a little more involved to get good results. The big difference between this and making cupped gas checks to fit bullet bases is that the disc is punched out and then formed on the base of a plain base bullet.
09-23-2006, 08:00 AM
45 2.1 posted all about what you are describing and it's called Freecheck. Nobody seemed interested. It involves a modification to your sizer die and retaining nut in the Lyman/RCBS type luber/sizers. It's an ok system but it doesn't solve the problem for rifle or pistol bullets that are mean to have a real gascheck in my opinion.
Four Fingers of Death
09-24-2006, 12:46 AM
Maybe Paco would be interested in doing a group buy for Freecheks, rathere than just fiddling about with one at a time.
09-24-2006, 08:21 AM
..............It'll be interesting to see toecutter's photo's.
09-24-2006, 08:42 AM
Sure will buckshot, as you and I know they aren't exactly easy to make.
09-24-2006, 10:00 AM
If I'm not mistaken, didn't the Freecheck system use aluminum soda cans as the raw material ? I read an ad or two back when they were producing the setup. I think it was the Hanned Line, or something like that ? I never paid much attention at the time, but I wish I had now.
Is there a .30 cal group buy going on the Gator checks ?
09-24-2006, 10:03 AM
Yup, soda cans or beer cans.
09-27-2006, 04:15 AM
Currently, this is a work in progress, however, a few people were interested in pictures. I took these at uber hi-res so you can make out as many details as possible.
I havn't had much time to work on the gas check cutter. Pics will be posted as soon as I get some work done on it.
09-28-2006, 10:45 PM
.............The case swager for jackets looks simple enough. Might want to re-size the photos down a bit. Folks with dialup will have trouble downloading them.
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