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sucngas
08-14-2010, 11:55 PM
I stumbled onto this video today, and to the rest of you I'm sure it is old news, but I found it extremely intriguing. Just wondering if any of you have tried it, and what were the results.

It could be the most interesting thing I've seen for a while. They are called wilks gas checks, basically you use copper bands instead of lube on a cast bullet, and they can be pushed to jacketed velocities. You can also use soft lead making it perform like a big game bullet. Found it cool enough I figured it was worth sharing. Don't miss parts 2 and 3 of the video.

http://www.youtube.com/watch?v=q8bU0Jr73P0

Hang Fire
08-15-2010, 12:58 AM
Interesting concept. I (probably along with many others) have thought about a special mold that would utilize a longer single length of thin wall copper (soft copper sizes easily) tubing insert, where one could for all intent, cast jacketed bullets, then gas check and size them.

I use the hobby thin wall brass tubing for making fire pistons, but drawn brass is work hardened during the drawing process, retaining considerable memory. Doubt if the lead melt is enough of a high temperature to anneal it.

HeavyMetal
08-15-2010, 01:21 AM
Saw an article on the orginal Wilkes check system years ago.

In it he used a punch set up to knock out the bottom of a standard 30 cal gas check, which left a shoulder at each driving band, to anchor it to the boolit.

Both accuracy and velocity claims were factual the real issue was inserting the checks into a hot mold!

The video show a single flawed boolit but me thinks the rejection rate is pretty high, much higher than our "director" wanted to film I'll bet.

I actually played around with the idea and a couple of Lyman 429421 molds but production was horrible, inserting the checks before the mold cooled off was a joke.

What I don't get is the need to size lube the boolit after it's cast??? The bands are .3085 as is the base gas check so other than a need to crimp the check on the base isn't the copper band actually meeting the barrel?? No lead contact or at least very little??

The bottom line here is this guy is going at this wrong! Mind you it is a good idea and for the sake of testing I can see doing a batch as he has done.

But trying to make this idea work in a pre-existing mold design is "spitting into the wind"!

To make this idea work in a real world senario one would need a mold with the bands specifically cut to hold a specific size driving band and specific sized bands cut square, to fit the mold. Done like this he would not have to worry about them "cocking" when the mold closed because they could not!

This would make them easier to install quickly with out a lot of heat loss. This would also have to be done with steel mold that would hold the heat longer! Perhaps cut in a thicker block???

My thought at the time I was playing with this idea was a 3 cavity mold and a custom set of reverse pliers ( squeeze to hold / release to open) and a little tab to hold the mold in a special holder ( slide the tab in install check slide the tab out) and one might be able to do this fast and get much less scrap.

However after playing with this set up for a month or two, and actually casting some banded 429421's, I decided that the cost of a mold and the set up to make the correct size driving bands was going to cost more, by the time I had a mold cut and fabricated the band cutting tools plus the time to actually cast them, than going to the local gun shop and buying jacketed bullets!

Mind you this was 1978! Today this may not be that far fetched a concept considering the lack of jacketed projectiles on the market today.

In my mind this idea is never going to fly long term. Some guys are gonna play with it and, just like I did, are going to realize that thier time is better spent doing something else in the long run!

robroy
08-15-2010, 01:31 AM
I use the hobby thin wall brass tubing for making fire pistons, but drawn brass is work hardened during the drawing process, retaining considerable memory. Doubt if the lead melt is enough of a high temperature to anneal it.[/QUOTE]

Ken Howell recomends in Designing and Forming Custom Cartriges for Rifles and Handguns a temp of between 600 and 650 to aneal cartrige brass when forming. I haven't checked the book just now for the exact temperature range Howell recomends but I think most of us cast a bit higher than that. It may bring the brass right up to its annealing temp.

Eagles6
08-15-2010, 02:04 AM
Stopped watching after he said 4"-5" groups with terrible leading.

Artful
08-15-2010, 03:57 AM
Walt at NEI made some .375 copper tubing jacket molds in years past
http://a.imageshack.us/img152/7203/nei293375j2cavity7.th.jpg (http://img152.imageshack.us/i/nei293375j2cavity7.jpg/)
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http://img152.imageshack.us/i/nei293375j2cavity7.jpg/


All you needed to due is cut the tubing into the right length (test fit with the mold itself) then when you close the hot mold you just push them n from the top before you close the sprue plate.

Sort of self solder's itself to the jacket as I never lost a jacket and I was pushing them up to 2800 fps out of my .375 Weatherby.

Grouped under 3 inches at 100 yards with usually a flyer changing it from 2" to make it into 3" (course it could be my flinching - mainly at the cost of the 88 grains of powder I just used up).

Bent Ramrod
08-15-2010, 09:13 PM
It's not too hard to get decent boolits with the Wilkes gas check (or the SAECO H-B or Henninger-Barnes driving bands, in another incarnation) as long as the width of the lands between the grease grooves fits the little metal ring. Simply cast a bunch of plain boolits until the mould is good and hot, then insert the ring(s) in the land(s) of one half of the mould, holding it horizontally, then carefully close it and cast as normal. (A pair of tweezers helps here.) Besides the SAECO designs, Ideal 311291 fits them IIRC. With a little practice, it goes as fast as casting HP's with only rare incidences of a ring or band getting cocked in the cavity.

Make sure you save the good unbanded ones you cast to get the mould hot. With the same powder charges, they always shot more accurately than the banded ones for me. The banded boolits will not (as claimed) support high velocities with any semblance of accuracy either, at least as far as my experiments showed. I water quenched the boolits as they dropped out of the mould, but didn't heat them in the stove and quench them.

Like that lion trap in The Ghost and the Darkness, "in point of fact, they didn't work, but they were a good idea nonetheless.":-(

cbrick
08-15-2010, 09:49 PM
The Wilk Gas Check - HandLoader #134 July-August 1988, page 34, by Dave Scovill
Also reprinted in Wolfe's Bullet Making Annual #1, page 6, 1990

Rick

runfiverun
08-15-2010, 10:52 PM
mold temp is easy enough maintained [with a hot plate] and you just sit the jackets err bands on the edge of the pot to pre-heat.
i cut mine and pre-size to fold both ends over to make a mechanical lock.
sizing isn't so easy but a lee push through and correct fitting push rod helps.
don't know about the wilkes bands or wire wrapped either but tubing works well enough.