How do you fireform?

[logan1080]

Going to start reloading my .300wsm for some long range precision shooting. I was just wondering what is the best way to go about fireforming my brass? Which powder to use and how much? What to use as a plug to hold in powder and how do you plug the case? Never seen it done and never done it so just looking for some help. Thanks

 

[grouch]

If you're using the right brass to begin with, there's no need to do anything different. Your first normal firing will fireform the brass to your chamber. If you're starting with another brass that, when ready to load has some part of the case left too small, then you load a light load of fast powder behind a bullet(cast bullets are good for this) and fire it. I would guess something like 7 - 9gr of Unique would do it. That's what I'd use in 30 - 06 anyway.
Grouch

 

[logan1080]

I am planning on using brand new brass. only 7-9g thats not much at all. I thought it would be more. Good to hear though, saves on powder.

 

[Kelly Timoffee]

I used a light load of pistol powder behind some cream of wheat capped with some tissue.

It works, but there is a down side and that it does leave for a bit of cleaning afterward.However, it saves on using a regular load of your good powder, bullets and barrel wear.

 

[logan1080]

I used a light load of pistol powder behind some cream of wheat capped with some tissue.

It works, but there is a down side and that it does leave for a bit of cleaning afterward.However, it saves on using a regular load of your good powder, bullets and barrel wear.

I have heard of the cream of wheat method. Another one I know of is using wax to plug the mouth of the case. That doesn't sounds like fun to clean up either though.

 

[Lodi]

Are you wanting to fireform .300WSM brass in a .300WSM chamber?

 

[ben hunchak]

I fireform with bullets, cast or jacketed and seat bullets well out into the rifling, I use a mild load with a fast burning powder, however i am making cases for a totally different caliber.

 

[GRiNGo]

I reload for 300wsm, and if you are using 300wsm brass there is no need to fireform. In fact I've found for the long wsm shoulder I can not even rechamber once fired brass, so no neck sizing only full length.

 

[logan1080]

Are you wanting to fireform .300WSM brass in a .300WSM chamber?

Yes, purely for accuracy benefits if there is any.

 

[logan1080]

I reload for 300wsm, and if you are using 300wsm brass there is no need to fireform. In fact I've found for the long wsm shoulder I can not even rechamber once fired brass, so no neck sizing only full length.

That sucks, I hope my brass will fit after I fire it as I was hoping only to neck size. Rifle is at gunsmith right now or I would go try.

 

[Ganderite]

Weigh and sort your new brass, and sort into pails of, say, 0.5 gr increments.

Load the ammo with your match load, or start doing your load development. the testing will fireform.

 

[GRiNGo]

That sucks, I hope my brass will fit after I fire it as I was hoping only to neck size. Rifle is at gunsmith right now or I would go try.

That is my gun, yours may be different. I also found that I had to grind off my shell holder a couple of thou to bump the shoulder enough to chamber. It is a Sako A7.

 

[Mighty Peace]

I use medium/hot loads fireforming new brass for my 338-06 AI. I use new 338-06 AS headstamped brass. These initial loads will work for a hunting round if I need to in a pinch!!

 

[vviking]

After trying cream of wheat, and full power 'while working up' fireforming, both of which have downsides in my experience(case stretch at the web).

Now, it's the cheapest bullets I can find, seated out to the point that bolt close has some resistance, with a moderate charge of whatever odds and ends powder is laying around.

This way, load testing with those expensive components is more likely to be consistent and repeatable with the results from later, often fired, cases.

And, that expensive brass lasts longer, having never been stressed at the web on its initial firing.

 

[Pathfinder]

I worked up as usual with wildcats but I did notice more stretching on the top end loads. Not a big deal because they all get neck sized before the next firing

For fireforming 300 WSM brass to a 300 WSM chamber Im not sure the results will be worth fireforming as a seperate operation but If I had to I would use the pistol powder / cream of wheat method .

 

[Al-Sway]

If you're using the right brass to begin with, there's no need to do anything different. Your first normal firing will fireform the brass to your chamber. If you're starting with another brass that, when ready to load has some part of the case left too small, then you load a light load of fast powder behind a bullet(cast bullets are good for this) and fire it. I would guess something like 7 - 9gr of Unique would do it. That's what I'd use in 30 - 06 anyway.
Grouch

I think you would be very disappointed if you tried such a light load to 'fireform' your cases. Case volume much higher than .30-06, brass is much heavier, and this is a very light load to begin with (almost sub-sonic with most bullets). You would waste powder and primers and not accomplish anything.
If you want to fit to your chamber, load normally and use the first reload of your new cases to practice with and load development.