Hello all:I am new to this forum and I could use some assistance.I am having a rifle built in .223AI on a surgeon action,and I am looking for a fire forming/barrel break in load. The barrel is a 1 in 8 twist bartlein,the brass I will be using is new lake city.any and all ideas will be apreciated.
fire forming load
- Thread starter debubba
- Start date
Re: fire forming load
The AI chamber should be ~.004" shorter than the standard chamber, so cases are formed when standard ammo is fired.
If not .004" shorter than the case, the firing pin will push the standard cartridge forward .004" as the sharp base of the chamber neck cuts into the case. The case fires, expands, grips the chamber walls, and then stretches .004" to touch the breech face. This causes case separation behind the shoulder in my 257RAI.
So I have to fire form differently.
After 100 experiments, I have resolved the easiest thing to do is:
1) Put 10 gr of any pistol powder in the primed case.
2) Fill the rest of the case with cream of wheat [COW] or instant cream of wheat.
3) Lubricate the outside of the case with high pressure lube like Lyman moly bore cream or moly grease.
4) Fire the case with the barrel pointed straight up, so the COW does not spill. Or alternatively, put Ivory soap in the case mouth and fire the round horizontally at the range.
5) The Ackley shoulder is now half formed, and plenty solid to stand up against a firing pin.
6) Partial neck size the case by partial sizing with a FL sizer die.
7) Load a full Ackley load, fire it, and expect full accuracy.
8) The case is now formed, and will present a full Ackley shoulder.
The AI chamber should be ~.004" shorter than the standard chamber, so cases are formed when standard ammo is fired.
If not .004" shorter than the case, the firing pin will push the standard cartridge forward .004" as the sharp base of the chamber neck cuts into the case. The case fires, expands, grips the chamber walls, and then stretches .004" to touch the breech face. This causes case separation behind the shoulder in my 257RAI.
So I have to fire form differently.
After 100 experiments, I have resolved the easiest thing to do is:
1) Put 10 gr of any pistol powder in the primed case.
2) Fill the rest of the case with cream of wheat [COW] or instant cream of wheat.
3) Lubricate the outside of the case with high pressure lube like Lyman moly bore cream or moly grease.
4) Fire the case with the barrel pointed straight up, so the COW does not spill. Or alternatively, put Ivory soap in the case mouth and fire the round horizontally at the range.
5) The Ackley shoulder is now half formed, and plenty solid to stand up against a firing pin.
6) Partial neck size the case by partial sizing with a FL sizer die.
7) Load a full Ackley load, fire it, and expect full accuracy.
8) The case is now formed, and will present a full Ackley shoulder.
Re: fire forming load
I was at the range the other day and it was raining creme of wheat. now I know why..........
I was at the range the other day and it was raining creme of wheat. now I know why..........
Re: fire forming load
The near max load is a good way to split shoulders from my experience, but this will work.
An easier way to make sure you don't split necks and don't have to jam bullets is to:
Neck up the 223 to 6mm, then neck it back down to 223 while leaving part of the neck still at 6mm to act as a "false shoulder". This will make the round properly headspace on the neck portion that's 6mm and the actual shoulder is able to freely move and fireform.
Once I started to do this it gave me significantly fewer split shoulders in the 30-06 AI.
The near max load is a good way to split shoulders from my experience, but this will work.
An easier way to make sure you don't split necks and don't have to jam bullets is to:
Neck up the 223 to 6mm, then neck it back down to 223 while leaving part of the neck still at 6mm to act as a "false shoulder". This will make the round properly headspace on the neck portion that's 6mm and the actual shoulder is able to freely move and fireform.
Once I started to do this it gave me significantly fewer split shoulders in the 30-06 AI.
Re: fire forming load
I don't know about "any pistol powder" but 10 gr. of 2400 or bluedot under COW with a cotton ball plug works for me also. Unique kinda gives me the willies so I stay with slower powder.
I don't know about "any pistol powder" but 10 gr. of 2400 or bluedot under COW with a cotton ball plug works for me also. Unique kinda gives me the willies so I stay with slower powder.
Re: fire forming load
Its a 223AI....why sweat it, just load a max load recommended for a 223 with the bullet you choosing. then load the bullet into the lands, pull the trigger.
I know a guy who had over 4000 rounds on his 223ai. Just shoot the darn thing.
Its a 223AI....why sweat it, just load a max load recommended for a 223 with the bullet you choosing. then load the bullet into the lands, pull the trigger.
I know a guy who had over 4000 rounds on his 223ai. Just shoot the darn thing.
Re: fire forming load
Sorry just not my style. I prefer to have the brass formed up first and don't really like using 80 gr. VLD's to form brass. I fully expect to get twice that many rounds out of this barrel.
Sorry just not my style. I prefer to have the brass formed up first and don't really like using 80 gr. VLD's to form brass. I fully expect to get twice that many rounds out of this barrel.
Re: fire forming load
COW for the win. Been making .410 out of 303 Brit for years using cream of wheat.
Have fun!
COW for the win. Been making .410 out of 303 Brit for years using cream of wheat.
Have fun!
