Fireform barrel idea

[Mram10us]

Norma 270 Win brass takes 25,000 psi to fire form decently to 6.5 Sherman with fast pistol powder and COW, with slower powders you won't get it formed as well even at higher pressure, the time to peak definitely changes fire forming, time under the curve does not seem to effect it as much.
I chamber my fire forming barrels for rifles I've chambered at .000 headspace, that lets me basically just neck size with a FL die and not touch the shoulder at that .002 headspace for the case. If I'm making a fire form barrel for something I have not chambered I want fully fire formed brass from it so I can set the fire form chamber to match well for the rifle.

I haven't heard the 25k psi number. Thanks

 

[birdiemc]

Shouldn't need anywhere close to 60k to ff. I love the idea!!

And for all the naysayers worried about ATF, if you took the approach and built your own "receiver"/firing mechanism, it wouldn't be a rifle action so pistol length barrel is perfectly legal, we are allowed to build a gun from scratch if not with the intent to sell.

 

[ntsqd]

I'd be more tempted to make a hydro-forming station than to fire-form. Can safely do that in the garage or shop w/o worry about noise, local ordinances, ATFE, etc.

 

[Mram10us]

I'd be more tempted to make a hydro-forming station than to fire-form. Can safely do that in the garage or shop w/o worry about noise, local ordinances, ATFE, etc.

Sure would be nice to stay on topic .....

 

[bigngreen]

I haven't heard the 25k psi number. Thanks

It comes from pressure testing barrels on 6.5 Sherman's with a Pressure Trace so it's pretty good numbers.

 

[J E Custom]

Again, atf and safety aside, any input would be helpful. If not, I'll do it and post results.

After hearing many different reason to proceed or not to proceed, I would use a take off barrel of the same caliber and just chamber it with the same reamer and fire form away, If you don't want to put rounds down the good barrel.

You could reduce the loads and fire form all of your brass. plus you wouldn't have to clean the bore

I may have a take off barrel that you could use and would be happy to give to you to prevent/risk injury.

J E CUSTOM

 

[MNbogboy]

To me there is no such thing as a lousy $200 bucks....actually that is a good chunk of my monthly retirement income.
I have a chunk of 6.5 caliber barrel that I chopped off to save weight. Often have thought of chambering it with my 6.5/257 Bob reamer. Then drilling out the rifling, hone it smooth. Make a "tight" fitting piston/rod combo to "hammer" on. Cap the breech end to stop case at appropriate head space. Need an o-ring to seal the neck and venting near the neck shoulder junction.
Pressure can be calculated by piston size and force applied. Think it would work.
Just thinking out loud again.

 

[Mram10us]

After hearing many different reason to proceed or not to proceed, I would use a take off barrel of the same caliber and just chamber it with the same reamer and fire form away, If you don't want to put rounds down the good barrel.

You could reduce the loads and fire form all of your brass. plus you wouldn't have to clean the bore

I may have a take off barrel that you could use and would be happy to give to you to prevent/risk injury.

J E CUSTOM

Thanks JE. Got some barrels here, but appreciate it.

 

[Mram10us]

Just talked to atf and they have no problem with the idea I came up with for personal use. If I patent it, then they say I need to come in with plans

 

[ntsqd]

Sure would be nice to stay on topic .....

I was on topic, I don't think fire-forming is how I do do it. I did not go into the details of how I would do it because that is not on topic, yet I see a 'like' for the post that does go into the details of how to hydro-form instead of fire-forming. hum.

 

[Mram10us]

I was on topic, I don't think fire-forming is how I do do it. I did not go into the details of how I would do it because that is not on topic, yet I see a 'like' for the post that does go into the details of how to hydro-form instead of fire-forming. hum.

The thread is about making a fireform barrel using a smaller diameter hole in the barrel to increase pressure while using as little powder as possible. I'd like to get ideas regarding that. Hydro is totally different

 

[crystalgayleguy]

in my books it a free country isn't it go for it it's worth the try

 

[Mram10us]

It's hard to troubleshoot an issue if half the posts are saying it's not safe, I'd use this method instead, etc. Plus it's hard for anyone to navigate the thread to find the meat of the topic. I'd be interested in a thread about improving hydroforming.

 

[adam32]

How about threading the end and using some type of valve (maybe like an air compressor drain?) so then you can fine tune the pressure?