Aluminum vs. copper gascheck

[Akadye006]

Can someone direct me to a information on how Aluminum and Copper gaschecks compare/contrast? Or does anyone have any information on why Aluminum might be better than copper gaschecks or vica versa.


Thanks.

[n.h.schmidt]

Its not really about which works better. Its about cost. Its hard to make copper checks much if any cheaper than buying them. With aluminum, I can make five or more per penny. This is making 30cal or 8mm cal. Figuring on a 1/2" square of metal per check.
n.h.schmidt

[Wally]

I make my own out of aluminum---the accuracy is the same using them as using Hornady gas checks. Copper would be easier to work with IMHO..with aluminum one has to get the proper thickness that will work/fit with a bullets gas check shank. Aluminum has more "spring" to it than does copper.

[DrB]

When I first saw folks here using aluminum for checks i asked a good friend of mine who's a third generation gunsmith, tool and die maker, avid shooter, etc what he thought about lubricity and the effects of aluminum oxide on the bore.

His reaction was that he would think aluminum checks would be superior to copper. I believe he based his thought on his experience with high speed machining and tool wear... Although the shear rates are obviously totally different.

Anyway, only other thing I'm wondering is if the homemade aluminum checks are wrinkled at all at the top of the cup. I could see that maybe affecting accuracy at higher velocities with rifle, but I haven't yet read anyone post about it.

Eventually I expect to play with em as it sure sounds like folks are getting good results.

[sirgknight]

see if this helps: it helped me. I had four concerns for the aluminum check: fit on the bullet, compatibility with barrel, accuracy and cost. I've been convinced that the barrel may see a tiny bit of scoring after 100,000 rounds or so, and I've been convinced that the aluminum check will fit just as snugly as the copper. Accuracy is being proven often with personal testimonies and pics on this and other forums. With copper checks selling for as much as $40/1,000 the cost is a no-brainer. My personal feeling is that gas checks should be the least expensive component in reloading, but it is fastly rising to be the most expensive.

http://castboolits.gunloads.com/showthread.php?t=76487

http://castboolits.gunloads.com/showthread.php?t=78032

[Wally]

Have been using the aluminum checks for a few years now in numerous calibers --some with wrinkled edges---they shoot just fine.

A few years ago I bought 6 boxes of Hornady 6mm Gas Checks as I was told they would discontinue them. Then I found that their was available a Freechex tool to make my one. I bought it, tried it, & was delighted that they were as good as the Hornady checks. I sold the Hornady checks to another party and sent him a sample of 100 home made ones. He found the same thing and bought a Freechex tool and sold the factory checks.

[Von Gruff]

I use Al in my GC for my loads up to 1900fps but found Cu better at 1900 through to 2400fps. At least in my 7x57 it is.
I get roof flashing in Cu for a very good price and $5 gets me up to 500 GC's.
Use the Freechex tool with a solid disc cutter and seperate cup former made to suit my requirements. Fabtastic tool.

Von Gruff.

[RU shooter]

There is also brass for chex making that forms and shoots well and is cheaper than copper on average. Mc Master Carr sells brass and copper foils in various widths and thinkness

[DrB]

What about straight zinc? Just thinking about those Civil War williams cleaner bullets they used to scrape the bores in battle. I would think it would be cheaper than copper or brass, and it might go faster than aluminum (harder to cut and form, though, I expect).

[brnomauser]

how about brass? Like 22wmr cases? Annealed obviously

[.30/30 Guy]

I have made both copper and aluminum checks. My experience is that thickness is more important than the material. Fit is everything. Need to have the check thick enouth so it is tight after sizing.

[JeffinNZ]

Like Mr Gruff I have found that alum. seems to have a limit. I have yet to get down to the bones of the matter whether it is velocity or pressure but I suspect the latter.

The real point to consider is the hardness of either material. Depending on the source the hardness of both Cu and Al can vary greatly. If your tool is very tight on tolerances then in terms of forming soft or hard shouldn't make much difference however if there is a chance the material can stretch prior to shearing in the die the softer tyeps of Cu will be a nuisance and jam in the die. Half hard brass is a really good compromise and is half the price of Cu.

[Larry Gibson]

I've also found aluminum GCs to have a velocity/pressure "limit" in some rifles and others not. I'm suspecting a smoothness/roughness issue of the rifling/bore that may crack or cut the aluminum GC and it is lost in flight. I've some targets with a "fin" cut indicating a part of the GC was sticking out. When comparing .014 aluminum GCs to .014 brass GC the brass ones always work well but the aluminum GCs do not, especially at higher velcoity/pressure. Brass shim stock is available from McMaster-Carr for a reasonable price. .30/8mm GCs made from that shim stock are 1/2 the price of Hornady's and they are every bit as accurate as with Hornadys.

Larry Gibson

[HARRYMPOPE]

A friend i sent some samples to shot them @2000-2100 fps in a 30BR full BR rifle and shot 1/2-3/4 MOA at 200 yards for 10 shots.pressures are in the 50,000+ range with that load.In this case they seem to take pressures fine.it could be the close fitting chamber/throat etc...

HMP

[Whistler]

I've also found aluminum GCs to have a velocity/pressure "limit" in some rifles and others not. I'm suspecting a smoothness/roughness issue of the rifling/bore that may crack or cut the aluminum GC and it is lost in flight. I've some targets with a "fin" cut indicating a part of the GC was sticking out. When comparing .014 aluminum GCs to .014 brass GC the brass ones always work well but the aluminum GCs do not, especially at higher velcoity/pressure. Brass shim stock is available from McMaster-Carr for a reasonable price. .30/8mm GCs made from that shim stock are 1/2 the price of Hornady's and they are every bit as accurate as with Hornadys.

Larry Gibson

That is pretty much spot on with my observations.
I have had some success using them on slow heavy boolits with low pressure loads, but I simply cannot get the 158gn to work in .38 Special or .357 Mag with alu checks. On today's PPC match I even had a few boolits that had the gas check come off at 25 yards and stick in the target. Accuracy is nothing but abysmal. The funny thing is that the checks sit rock solid. They are even swaged with the boolit and look really uniform. I've made them out of .009 roof flashing with Charlies Freechex III.

So far the only stories of real success seem to be with .30 cal rifles.

[Ben]

Whistler :

If you could get access to some .014 " thickness Amerimax Aluminum I think you might develop some different views. I personally, have not had any success with .0092 ".

Ben

[HARRYMPOPE]

Whistler :

If you could get access to some .014 " thickness Amerimax Aluminum I think you might develop some different views. I personally, have not had any success with .0092 ".

Ben

I agree 100%

I use the same .0014 stuff and haven't had any luck with the stuff about .010.

HMP

[Whistler]

Have you used that thickness in revolvers? What calibers and velocities? Bullet weights?

I was recommended .009 by Charles and his contact that supplies the roof flashing. He advised that it was the max to be used for .357 tool.

I do have some .014 that was recommended for the .44 Mag.
I will try it, but I believe it will be too thick for the tools to work properly.

[Ben]

I use Pat's g/c making tool in .35 cal.

I make .35 cal. checks with .014" that work GREAT in my revolvers and my 358 Win. and 35 Ack Imp Whelen rifles.

Ben

[castalott]

I size my aluminuim gas checks on the bullets with this simple setup...first pik is of the bullets with checks...

2nd pik is of the tooling laid out

3rd pik is of the check being pinched on


Here is a snippet of a word doc I had about this years ago-

"a hornady collet turned on a lathe so that when compressed it will only pinch a gascheck 'so' tight. 2) a machined base that fits in the shellholder and pushes the collet into the collet die..3) and a hornady collet die with a normal collet inside. The bottom of the die has been rewelded (brazed) because I pushed the bottom out. It wasn't made for the pressure I put on it. IDEA..I wonder if the Lee neck sizing collet could be made to work. It is a much stronger looking die."

The die mounts upside down. The press handle pushes it shut. This inside of the collet is turned so it can only pinch the ch3eck 'so' much.It takes longer to explain it than to build it..

You can make your checks fit just as you want them. But I only used aluminium checks for full power loads. The bases always expanded out to groove diameter.