Annealing aluminum gas checks?

[Motor]

A friend sent me some 30cal aluminum gas checks to try. I have found that they are springing back instead of crimping on. The material is .014" thick.

Can I anneal these to make them malleable so they stay crimped.

Thanks, Motor

[35 shooter]

Motor i use .014 ameri max material for my 35 whelen and had the same problem.

I don't truly anneal, but have found that 1 hr. at 400 to 500 degrees in a convection oven and just let air cool takes the springback out of them for me.

True annealing takes more heat, but this has worked for me, so i've stuck with it.
They size on super tight now and accuracy improved.

[Buck Neck It]

450 degrees (max setting) for 15 min. in a cheapskate Salvation Army toaster oven works good for pb pop can gas checks. Makes a difference. This oven does not heat evenly for serious work.

[Motor]

35shooter. Thanks for the reply. I shoot a 7.5x54Mas. I'm using a Lee 160gr 2R TL boolits. I have tried them both A-Lox lubed and powder coated and with Hornady gas checks it shoots great. With the same boolits using aluminum gas checks it's wild. I was shooting a group today at 50 yards and threw in one checked with the aluminum gas check. It shot 8 inches to the right. I shot 20 with aluminum checks on labor day and couldn't hit a 8" diameter swinger at 50 yards.

I'll try the oven. It won't be hard to tell if it works. Thanks again for the feedback.

Motor

[35 shooter]

Wow, that is some rough grouping for sure. Sounds like they may be coming off in flight?
Are they easy to pry off after sizing?

Mine were originally a bit loose and had the spring back, but were shooting great up to about 1900 fps.
I had to heat teat them to get accuracy past 2000 fps.

I get better accuracy now from my homeade .014 al. checks than i do from the Hornady's(after the heat treat).
I also use Sage's Outdoors .010" hard al. checks in the same 35 whelen and i don't think i could get them off with pliers without ruining the base of the boolits.

Hope the annealing works for you!

[Motor]

I'm pretty good with calipers. The exact measurement isn't important just the comparison. I compared one that I crimped on (and pulled off with my thumb nail) to a unused one. The inside diameter of both are the same. I guess I could have just as easily mic'd the od but the result is still the same.

I probably have a couple hundred aluminum checks left. It would be nice to be able to use them.

Motor

[gpidaho]

I use a few simple pieces of plumbing pipe (3/4 inch) to make a heat sink in my mag 20 pot. Goes like this, cap on bottom of 3 1/2 pipe nipple to elbow another 3 1/2 nipple to pipe tee as counter balance. toss in some checks in the pipe and let them soak in the 700+ while you cast. Gp

[Motor]

I used 35 shooter's method. I baked them in my powder coating toaster oven @ 500 degrees for an hour.

It worked. The checks stay the size you size them. I also found that I can still "work" them off of a powder coated boolit. I'm sure the powder coating is acting as a lubricant plus they only have a .002" crimp. To prove this to myself I put one on a bare cast boolit. I can't get this one to move. Since I never tried it before I also decided to put a Hornady copper check on a powder coated boolit and try to pull it off. I was not able to but the Hornady check material is .004" thicker than the aluminum which gives it a lot more squeeze on the check diameter.

Thanks for the help guys. I may need to check them then powder coat then re-size them to insure that they don't move. It's an extra step but if it works that will give me another gas check option.

Motor

[Cmm_3940]

Any idea what alloy the check material is? It makes a difference. Typical annealing instructions for some alloys I looked at say "Anneal at 775°F for 3 hours and use controlled cooling at rate of 50°F per hour down to 500 F. Then air cool" but the melting point for some of these alloys is a little over 900°F which would make things tricky. Also, heating to lower temps and letting cool will make the aluminum harder, not softer.

http://www.steelforge.com/custom-forged-shapes/forging-capabilities-chart/?alloy=6061

I also ran across a technique where you coat the aluminum sheet with acetylene soot, then heat the sheet just enough so that the soot burns off, then let it cool. This is probably be what I'll try the next time I'm making checks, since I don't have the fine control over temp to do it the 'right' way.

[Retumbo]

First batch I threw a hand full on top of my lead, few minutes later just scooped them out. Lead did not stick to the aluminium

[fcvan]

I cut strips of Amerimax Aluminum for my CheckMaker and dip them in my casting pot for about 5 seconds. Done. I usually dip 5 strips at a time holding them with plers. Aluminum transfers heat very quicky, the strips become soft quickly, and the soft strips cut and form well into checks.

[Motor]

fcvan. Thanks for posting. I'll forward that idea to my friend.

Motor

[montanamike]

Put a mark on them with a black sharpie, take a torch to them, when the mark disappears there are annealed.