An interesting experiment in adding the gas check feature.

[Catshooter]

About a year and a half ago I started shooting a Winchester 94 in lever action silhouette matches. Caliber was .38-55, which was a new one for me.

That meant of course that I didn't have squat to feed the rifle. Trying to avoid the added costs of gas checks, I purchased a Lyman 375248 mould, 250 grains plain base. It threw boolits out of wheel weight metal at .3795 and my bore was .3785, so we were good there. Ah, the best laid plans of mice and men.

Knowing that I wanted full or near full power loads to help me knock over those 200 yard rams I didn't even worry about light loads.

As soon as I passed 1600 feet, leading! Full length of the bore too, no messing about. No real surprise of course, but one can always hope. So, biting the boolit, I picked up a Lyman 375449 and gas checks to fit. Shot wonderfully and no leading.

With the passage of time, I thought maybe I would sell the #248, but then I got to looking at it, it and my Sherline milling machine. The 248 is a little lighter which meant a bit less lead used and a bit less recoil. What the hell. The worst I could do is ruin a mould.

http://i379.photobucket.com/albums/oo235/Catshooter45/Lymanmould.jpg

The results are in the pic above. The boolit on the right was what that mould originally threw, the one on the left is what it makes now. The gas check is a push on fit. Success!

Some time soon here I'll load up some and shoot them. I'll keep y'all posted.


Cat

[coyotebait]

Catshooter
That looks like a great idea. Keep us posted on how they cast and shoot.
coyotebait

[StarMetal]

About a year and a half ago I started shooting a Winchester 94 in lever action silhouette matches. Caliber was .38-55, which was a new one for me.

That meant of course that I didn't have squat to feed the rifle. Trying to avoid the added costs of gas checks, I purchased a Lyman 375248 mould, 250 grains plain base. It threw boolits out of wheel weight metal at .3795 and my bore was .3785, so we were good there. Ah, the best laid plans of mice and men.

Knowing that I wanted full or near full power loads to help me knock over those 200 yard rams I didn't even worry about light loads.

As soon as I passed 1600 feet, leading! Full length of the bore too, no messing about. No real surprise of course, but one can always hope. So, biting the boolit, I picked up a Lyman 375449 and gas checks to fit. Shot wonderfully and no leading.

With the passage of time, I thought maybe I would sell the #248, but then I got to looking at it, it and my Sherline milling machine. The 248 is a little lighter which meant a bit less lead used and a bit less recoil. What the hell. The worst I could do is ruin a mould.

http://i379.photobucket.com/albums/oo235/Catshooter45/Lymanmould.jpg

The results are in the pic above. The boolit on the right was what that mould originally threw, the one on the left is what it makes now. The gas check is a push on fit. Success!

Some time soon here I'll load up some and shoot them. I'll keep y'all posted.


Cat

Cat,

Nice work. So you added a plate of metal to the top of the mould and then machined it to a gas check huh? I notice you have lots of lead on the face of the mould that needs to be cleaned off. :bigsmyl2:

Joe

[dragonrider]

Well done Cat, and a great idea.

[cbrick]

Fascinating idea . . .

No wonder I hang around on castboolits.

Rick

[felix]

An idea is worth a million scientists, engineers, technicians. ... felix

[Echo]

I seem to notice that you faced off the top of the mold about the depth of the GC. In any case, great job! Hope they shoot as well as they look!

[geargnasher]

Nice work, Catshooter! ..... curiosity may have killed the cat, but satisfaction brought him back to life!

Gear

[theperfessor]

Nice idea, nice execution, good job!

Learn something new here everyday...

[Catshooter]

Thank you gentlemen.

Joe (StarMetal)

You're right, the block faces have lead on them need cleaned off. Next time I cast with it and the mould is hot I'll see about wiping it off.


Cat

[StarMetal]

Thank you gentlemen.

Joe (StarMetal)

You're right, the block faces have lead on them need cleaned off. Next time I cast with it and the mould is hot I'll see about wiping it off.


Cat

Just teasing you Cat. Nice work on the mould and great idea. Hope it shoots without leading for you too.

Joe

[longbow]

There's someone that is thinking (and doing)!

Great idea and great job. Now you have a convertible mould should you want plain base boolits too.

Longbow

[454PB]

Nice work and excellent photography!

[jhrosier]

Nice piece of work.
I might have added a couple of small pins to each plate to reduce the possibility that they could move after many heating/cooling cycles. I just never trusted flathead screws much.

Jack

[largom]

I hope Al Nelson of NOE see's this. Opens up a world of possibilities. Great idea!

Larry

[JIMinPHX]

The people on this board never cease to amaze me with the good ideas that they come up with.

That is a really great idea.

[Buckshot]

...........As they say, "And that's the way you do THAT!" :-) Sure looks like good clean workmanship.

................Buckshot

[SCIBUL]

Wow ! Very good idea! The more simple and the better it is for sure ! Let's see how it shoots now :shock:

[303Guy]

Brilliant! :drinks:

[PatMarlin]

Sweet!

[Catshooter]

Thanks for the kind comments gentlemen, I thought it may be of interest of some here. I'll post back when I shoot it, though it may be a while.


Cat

[462]

Ingenious, a dual-purpose mould.

I'll venture that we all said, "Why didn't I think of that?"

[MtGun44]

Now THAT is a seriously good idea. The execution looks great, too.

Bill

[Nrut]

Wow!..
:holysheep
What a great idea..:idea:

[44man]

Sweet!
I agree, wonderful idea.
How the holes were indexed is what holds me back.

[PatMarlin]

Cat got smarter since he moved and started breathing South Dakota air ...:mrgreen:

Better looking too.

[Ricochet]

I think that's an awesome idea!

[theperfessor]

With replaceable plates you could make plain base, gas checked, or bevel base bullets of the same style and approximate weight. Might be a good way to test a few old wives' tales about leading and accuracy...

[HollowPoint]

Earlier this year I drew up some 3D images of a mold that I've dreamed of making. It includes these removable inserts that would allow me to mold bullets with all the various types of bases available in most bullet molds of today; including a different variation of a gas-check that I call a "QJ" gas-check. (QJ stands for Quarter-Jacket because it covers the lower quarter of my bullet and it is in the Boat Tail configuration)


In addition to the removable Base-Inserts, I also included my Adjustable Cramer Hollow Point Pins which would allow me to make bullets in various Hollow Point depths which in turn would allow me to cast bullets of a multitude of different weights and configurations.

Of course these drawing are just that; drawings at this stage. When I made up these 3D images they were only ideas I had. I wasn't really sure if they would or could work.

Now since it's been proven to work by one of our own bullet casting brothers, that's just awsome. Excellent work. Absolutely Excellent. I like the pictures too.

HollowPoint

[MtGun44]

Just guessing, but if it were me - After making the two top plates and
screwing them down to the mold halves, without any boolit cavity holes
in them, I'd remove the plates, mount the blocks in 4 jaw chuck, then
dial indicate one cavity. Remount the plates, drill a pilot hole and
then turn the GC diam hole on that cavity. Remove the plates,
move the blocks over and dial indicate the second cavity. Put plates
back on, drill and bore again.

Is that how you did it, Cat??

Bill

[HollowPoint]

Indexing these new plates for drilling is fairly straight forward. (I think)

I'd do it the same way I do it when hollow pointing one of my inexpensive lee aluminum molds.

First, I cast a few bullets, water quenched so they're as hard as possible. Then I'll chuck at least three or four bullets into my lathe and drill a hole all the way thru-dead center.

I then put the bullets back into the mold and use those dead-center holes to index my drill bit on my vertical bench mill. Then re-attach the plates onto the mold and drill my gas check holes dead-center right where they need to be.

At least that's how I've done my DIY hollow points.

HollowPoint

[theperfessor]

Just clamp the mold in a vise, indicate the center of each cavity, write down the reading, and then put the cover plate on. Go back to each reading and you should be right on the money.

This would be on a milling machine of course.

[Catshooter]

MtGun44 has pretty much nailed it. I used my little Sherline mill though, not a lathe. After locating the holes (one at a time) I then drilled them undersize and then bored them to size.

It wasn't that tough, just took some time.

I didn't use your method theperfessor, I did them one at a time. I ain't the machinist you are, that's fer sure.

Hollowpoint,

That drawing sounds excellent. Now all you have to do is put them into metal! That sounds like one hell of a mould. Wouldn't be cheap to make or buy, but it sure would be versitle.

Pat,

You got that right! Especially the better looking part. It sure is fun being retired, and having some time to some of the things I allways wanted to do.

Thanks for the kind comments gentlemen.


Cat

[theperfessor]

Catshooter-

You're a better machinist than I am if you figured out how to do this as well as you did all on your own. You had a good idea and carried through with it and were nice enough to share with everybody else, sparking new thoughts in a lot of people, including me.

I learned the trick of efficiently making matching or even mirror image parts from an old guy. Rather than take a bunch of measurements to line up holes in cover plates and stuff he would just put the actual part on the table or in the vise and find the hole centers. Put his matching part in place, set axes zeroes to whatever common reference surface/point the two have in common, and then move back to each spot and do the work. You can get things to match up perfectly this way and it eliminates errors between what your measuring tools read and where your mill actually positions itself. If your careful you can reposition within +/- .0005".

This was before digital readouts were common, even easier with them.

[Catshooter]

*blush* For once I didn't have to machine the parts two or three times! I got them right the first time. (I could hardly believe it. :) )

It took a little work to get the two plates machined to fit exactly. I didn't want to have any overhang anywhere all around the two blocks.

It was interesting that the two cavities weren't on the same centers by .002. I almost just assumed they were on the same center.

If I've helped anyone here, then that's great.



Cat

[Topper]

Now that's a very interesting way of modifying a mold design.
Good thinking;-)

[opentop]

It’s work like this that I think this site is the BEST site related to our addiction………..Errr……..I mean sport.

That is a really nice job and a great idea!!!

Job well done!

[Catshooter]

Shot the experimental boolit today. I loaded them over the same load I use for my silhouette matches, thirty grains of AA 2230. They averaged 1721 fps, about 30 fps less than the heavy ones show.

Shot three rounds into an inch and a half at one hundred yards.

I'd call it a sucess! :)


Cat

[Echo]

Hot Da**! I KNOW how proud you are, and deservedly so. A big

WAY TO GO!

[Caveape]

Cat,

The original problem was leading. Did you notice any this time?

If not, then MISSION ACCOMPLISHED!

Caveape

[Catshooter]

No leading. It leaded badly without a copper butt plalte, but now that it wears one, it's good to go.

:)


Cat

[nanuk]

simply amazing work, and thinking outside the box

Now.. design it to be swappable with a PB, or multiple plates for increased weight

[Catshooter]

nanuk,

I could/would do that, but I have no need. I have another copy of the same mould un-altered so it's still plain base.

For more weight I have a 375449.

If I ever intended to remove those little plates I would install pins for consistant location. The screws might do it, but they might not either.

Glad you liked it.


Cat

[drinks]

I just chuck the bullet in the 3 jaw, set a tool to remove the correct amount of metal and run them through as fast as I can chuck them up.

[Catshooter]

That's a good solution too Drinks. Simple.


Cat

[eagle27]

Great idea Catshooter, I found as you did, that plain based boolits don't shoot so well in larger calibres when the velocity gets up a bit so much so that I found splashings of lead back on the outside of the case neck when loading for my .404J and accuracy was pretty hopeless. I got around this by turning a gas check shoulder on the boolits using the lathe and an RCBS bullet puller die body and collet to hold the boolit in the 3 jaw chuck. Posted photos in Cast Boolit page under "Lathe collet for cast boolits".

I see Drinks just uses the three jaw chuck to hold his boolits. Only problem I see is potential crushing of boolits especially if lathe chuck is a larger one. The puller collet grips the boolits firmly without marking or deforming, and the boolits index same depth into the collet each time.

Your idea looks a permanent fix to turn a mould into a gas check type. I had considered altering my Hoch mould to achieve the same but the aligning pins did not easily allow this so just stayed with my lathe method which works a treat.

All good learning curves on this forum.

[leadman]

Very nice job on the mold modification!

I don't have a mill so if I want to gas check a plain base bullet in a straight walled case I invert the gas check in the mouth of the case and let the bullet push it in. Dave Scovill wrote this up many years ago in Handloader.
I do not shoot these over my Chrony though!

[JIMinPHX]

They say that imitation is the sincerest form of flattery.

http://castboolits.gunloads.com/showthread.php?t=76745

[Catshooter]

Jim! How did I miss that thread?

Nice job. I like the adding the plates, that way you can just pull 'em and you're back to the original boolit.

Imitate away my friend! *blush*


Cat