Which powder to fireform?

[novaman64]

Pickup my custom 280ai today from my FFL. Been a long wait but finally here! That being said I have 100 rounds of Norma brass, already prepped and primed with WLR primers. I bought a box of blem 150gr bonded spitzer boat tails from Midway because they were cheap and didnt feel like fire forming with expensive 168 VLD's...

H4831SC is what I will be shooting my AI loads with, but its been scarce around me, and I only have 1lb of it, so wanted to fire form using some powder I had on the shelf that Im not currently using for any of my other cartridges...

So that leaves me with Reloader 17, Varget and H4350. I have never had a ackley before or had to fireform so looking for advice on what powder and load.

My old reloading book doesnt have 150 gr bullets, only 145 and 160. Varget with a 145gr bullet is saying a min load of 42 and a max load of 46. For fireforming where in that range do I want to be?

 

[Jaxdialation]

I'd just use any load that's in the manuals for the powder and projectiles you have. It wont make any significant difference in the forming of the brass so long as it's book load. It will take 2 firings for your brass to be fully formed. But most people figure 1 firing is good enough for AI loading.

Hope this helps. I've only owned 2 AIs. A 243AI presently.

 

[MagnumManiac]

This is totally up to you, but I do not fire form any of my improved cases with bullets. I just don't see the point of hunting with a round that is 100fps or more SLOWER than the parent case, and wastes barrel life.
I fireform with a fast pistol/shotgun powder, Clays is great, it has a high load density for weight, start with 1/3 of case volume/maximum charge with 100% load density, and increase in .5gr increments until a case comes out fully formed. I use a twist of toilet tissue, 1/4 sheet for 22-250 size, 1/2 sheet for '06 size case and full sheet for all magnums, twist it in and poke until it 'squeaks' a bit and is tight, but not too tight, fire, and done. Have also plugged the case with bees wax, candle wax, potato and pumpkin, all work to form brass.
I have also used non calibre ammo bought from the LGS cheap to just fire and form brass, it's amazing how good the brass comes out even with the bullets rattling down the barrel. Have used 300 H+H in 300 Weatherby, 340 Weatherby and 375 Weatherby to form brass. Also used 375 H+H in 375 Weatherby.
If I get factory ammo really cheap, my 22-250AI and my 257AI will get that ammo used in them to fireform, but this is not regularly how I do it.

Cheers.
gun)

 

[Garycrow]

I wouldn't fireform with Varget or H4350 because they're hard to come by also. H4831SC is a lot easier to find than Varget or H4350. I'd probably use magnummaniac's method if I had a lot to do, no real reason to burn up hard to find powders for fireforming.

 

[Birdhunter1]

I've never fire formed for an AI case by my reloading mentor uses Unique and a cottonball, mostly on small and fast calibers (.17 ackley hornet).

 

[the jigger]

I have three AI rifles. I fireform with a near max load for the parent cartridge. Any powder that is listed for your bullet weight will do the job,
GOOD LUCK and GOOD SHOOTING!!!

 

[Barrelnut]

I believe if a SAAMI spec reamer was used, then Nosler 280AI brass can be used and you shouldn't have to fireform in the future. Maybe check with the smith if not sure.

 

[novaman64]

I believe if a SAAMI spec reamer was used, then Nosler 280AI brass can be used and you shouldn't have to fireform in the future. Maybe check with the smith if not sure.

I went with the traditional chamber...

 

[FEENIX]

Pickup my custom 280ai today from my FFL. Been a long wait but finally here! That being said I have 100 rounds of Norma brass, already prepped and primed with WLR primers. I bought a box of blem 150gr bonded spitzer boat tails from Midway because they were cheap and didnt feel like fire forming with expensive 168 VLD's...

H4831SC is what I will be shooting my AI loads with, but its been scarce around me, and I only have 1lb of it, so wanted to fire form using some powder I had on the shelf that Im not currently using for any of my other cartridges...

So that leaves me with Reloader 17, Varget and H4350. I have never had a ackley before or had to fireform so looking for advice on what powder and load.

My old reloading book doesnt have 150 gr bullets, only 145 and 160. Varget with a 145gr bullet is saying a min load of 42 and a max load of 46. For fireforming where in that range do I want to be?

I use H4831SC on my .270 AI and developed accuracy loads on both non-fireformed and fireformed brass.

 

[novaman64]

Thanks guys. Did 50 loads of 52.5 grains of H4350, and 50 loads of 46 grains of Varget... Book max on both...

Ive determined this rifle will shoot anything accurately. Used a box of 150 grain midway softpoint boat tail blems that was on sale to fireform with...


These are my groups for fireforming. Didnt play with seating depth, or anything...
Here is a 3 shot group of Varget at 100 yards...

And a 3 shot group of H4350 at 300 yards...

And heres 3 shot group at 700 yards my gunsmith sent me from when he was working up the load for it (H4831SC, mag primer and a Berger 168 VLD)...

 

[FEENIX]

Thanks guys. Did 50 loads of 52.5 grains of H4350, and 50 loads of 46 grains of Varget... Book max on both...

Ive determined this rifle will shoot anything accurately. Used a box of 150 grain midway softpoint boat tail blems that was on sale to fireform with...


These are my groups for fireforming. Didnt play with seating depth, or anything...
Here is a 3 shot group of Varget at 100 yards...

And a 3 shot group of H4350 at 300 yards...

And heres 3 shot group at 700 yards my gunsmith sent me from when he was working up the load for it (H4831SC, mag primer and a Berger 168 VLD)...

I agree ... now go them critters! gun)