.243 AI fire forming load

[potatoe]

I was wondering if someone could give me some pointers on the load data they used to fire form .243 AI. I'm planning on using H414 and 1 grain under max to fire form, but wanted some outside input as far as cases sticking, using max load, etc. Any .243 AI loads for a 1:10 would also be appreciated, thanks.

 

[bheadboy]

you are right on, i have always used near max load for std chamber with bullet jump of about .010", never had a stuck case, or fail to fill out. cases match fired case from AI loads to a t.

on the 243 i would use varget 4064 or 414, depending on the bullet weight, faster powder for lighter bullets.

Bob

 

[Ackman]

The .243 is semi-improved already. When formed to AI the shoulder diameter increases only a couple thou. But it does blow forward quite a bit and there's enough difference to give a nice velocity increase. Winchester 760 powder is about perfect in that case....when I was doing 2 of these guns, 760 and 414 were close but not the same. Fireforming loads are for shooting.....start with your 1gr under max load and go up til you find best accuracy, just like with any other cartridge. The fireform load will be more than book max for a std. 243. Both fireform load and velocity will be not a whole lot less than with formed brass. My fireform load was W760 powder, 70TNT, CCI250 at 3765-3860.

 

[LWolken]

I would first check with an empty new unfired case and stripped bolt to make sure you have positive pressure on the neck shoulder junction if not then you need to make sure you seat the bullets into the lands to prevent case head seperation. Starting fireform loads should be around max 243 win loads. You should be able to find a fireform load that shoots as good as your final load.

 

[AckleymanII]

My fire form load in Hart 12 twists is 47-47.5g of H414(760) and a CCI 250, with a 70g bullet at 3750 fps...groups in he 3's.

 

[shooter63]

you could always use the cow method works for me in my brx especially good in really nasty weather&no wear on that rifling to speak of unique 9 grs. & small mag pistol primer& pack cream of wheat to nk shoulder junction then poly fiber just a pinch packed on top of cow to hold in place blows cases out very good at hardly any cost or wear just be sure to dry brush every 8 or 10 rds. and i use compressed air to blow any foreign material out you can do this in basement with a bale of attic insulation open up ahole through insulation tostick barrel in &fireform away hardly any noise but do keep in mind to not over heat barrel agood alternative in miserable weather or low cost low wear on barrel hope this helps in some conditions nothin will replace above coments on a beautiful day at range ps fiber is attainable out of wifes spare bedroom pillows thanks alan

 

[ollie]

I also used the cow method with a 22-250ai. I started low at about 9gr of red dot and went up till i saw nice crisp shoulders. About 14gr. It saves barrel life and the cost of bullets.

 

[mj2evans]

For my 243 AI I used COW method - 10g Unique worked fine. Actually used chocolate malt-o-meal the kids didn't like (tasted nasty) but gives a nice chocolate smell at the range.

 

[ollie]

Chocolate sounds better than what i used. a little toilet paper in a ball to fill up the neck.

 

[Randfal]

Stick with your first plan. One grain less than max with H414. You'll be happy with the results. Save yourself the brain damage. I've formed my 243AI brass with a bunch of different powders and they all turned out good as long as it's near max load. Tried a couple with starting loads of A4350 and it was almost enough, the edges were just a little soft/rounded.

 

[bsc4444]

Ollie,
New or used.....THHH. Sorry couldn't help myself.

Brad