Annealing 5.7x28 brass cryogenically?9

[Romeo_alpha01]

Hello again gentlemen.

As the title suggests, has anyone here attempted to anneal 5.7 brass? I would like to squeeze as much life as possible from the cases, and any collective advantage to prolong its usage would be fantastic.

Has anyone considered cryo treatment as an option to preserve the laquer coating on the cartridge? I've had decent success with stress relieving car parts in the past so I figure trying this out may be something of interest.

So without further ado, let's open up to discussion. Thanks gents.

[Divernhunter]

Most all I have spoke with have given up on reloading this round. I have dies but also have 4000 rounds of ammo so I doubt I will even try this finicky cartridge---and I load many other cartridges.

Best of luck to you

[Romeo_alpha01]

I've read numerous opinions on reloading the cartridge. I plan to do the painstaking task of reloading this caliber on a RCBS rockchucker, so yes, every round will be single stage.

I plan to reload in small batches until I fine tune my methods. I have reloaded .45 ACP, .223, and .308, in large batches, and in single stage phases. I don't mind if it ends up saving me money in the long run. Reloading keeps me from trouble anyhow.

Thanks for the encouragement however!

[9mmrevolver]

I know giruad had an annealer.

[kcstott]

Cryo is not annealing, Cryo is a stress relief process and has nothing to do with hardness and brittleness of brass.

[Ferrum]

Five Seven Forum has a lot of good info on reloading 5.7. Not sure if I have ever seen info on cryogenic anything there...

[maxx03]

I get about 8 reloads out of once fired brass before the shoulders give out.
Brass for 5.7 is cheap and plentiful as not many reload for it.

[Romeo_alpha01]

I trolled Fnforuns most of the day trying to figure out a consistent technique on reloading this brass.

Doesn't seem too commonplace to use cryogenics to anneal anything. I'll just pay the lab a visit and get their opinion. Hopefully we can yield some good results.

[Whiterabbit]

It's not commonplace because you don't change squat on any phase diagram at colt temps.

If you are not changing grain size, and if you are not changing your material phase, and if you are not moving dislocations (plastic deformation), then you are not changing your microstructure.

Which means you aren't doing squat.

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So ask yourself, what is cryo doing to the microstructure of the brass? what is it doing to the coating? If you can't answer that, or do not have a 100% understanding of what is happening there, the answer is "don't waste your resources".

[Romeo_alpha01]

I'll do more investigating before I figure out my plan of attack. Worst comes to worst I may just have to live with destroying the proprietary lacquer coat with traditional annealing methods, or skip the annealing process

[pacrat]

I'll do more investigating before I figure out my plan of attack. Worst comes to worst I may just have to live with destroying the proprietary lacquer coat with traditional annealing methods, or skip the annealing process

What type of brass reloadable cases, use a "proprietary lacquer coating"?

[Romeo_alpha01]

The 5.7x28 mm case uses a lacquer coating to aid in extraction and ejection on the ps90 and five seven. There's debate that the coating isn't necessary on the five seven, but it's absolutely necessary on the ps90/p90 platform.

[Czechsix]

I think you might be better served by figuring out what that "lacquer" coating actually is, and then recoating. Annealing would be a good idea, but for that cartridge...getting a really accurate propellant and projo grain weight is much more critical.

[Romeo_alpha01]

I think you might be better served by figuring out what that "lacquer" coating actually is, and then recoating. Annealing would be a good idea, but for that cartridge...getting a really accurate propellant and projo grain weight is much more critical.

There's rumors of the laquer coat simply being just clear nail polish, but I've read it in passing on an FNforums thread awhile back.

Until I feel absolutely comfortable loading the cartridge I plan to load to factory specs for plinking. Sometime later I'll probably work up progressively hotter loads. At 40-50k psi operating pressure, you bet I'm going to be particularly anal with this cartridge.

You think it would make any difference if I were to grind my powder much finer to create more precise metering? I've never heard of anyone grinding powder...

[Czechsix]

I think it's going to turn out to be a bit more than clear nail polish.

Even plinking loads in these things can get iffy...single hand loading, 1/10th grain accuracy is needed. Not much room to screw up with these weapons.

I think it'd definitely make a difference if you were to grind the powder. Much better chance of a grenade right next to your head. I'd stay completely away from that sort of thing.