Forming 22-250AI from 22CM brass

[Mike D Texas]

Has anyone attempted to form 22-250AI brass from 22CM brass?

Some of the dimensions are different such as base to body/shoulder junction (+.034 on the AI) and overall case length (+.028 on the CM).

I really want to figure out how to make some small primer cases and the 22CM seems like the easier option.

Yeah just chambering to 22CM would be the most sensible, but I would need a new barrel as the one I have had been set back a couple of times already and the shoulder diameters are different at least on the 22-250AI drawing I was able to find. I'll need to measure one of my fired cases to confirm as they are only .003-.004 different.

 

[Seabeeken]

I made some 250 ai brass from 6.5 CM and it worked but fit very tight. As you mentioned, the CM brass is a few thou larger at the case head. Once I got near max pressure I had extraction problems. The slightest expansion of the head was enough to cause clickers and a few times I had to tap the case out with a cleaning rod.
I scrapped the idea and made it from 22-250 brass. If your chamber were to be cut to 308 head diameter you would be fine

 

[Mike D Texas]

I made some 250 ai brass from 6.5 CM and it worked but fit very tight. As you mentioned, the CM brass is a few thou larger at the case head. Once I got near max pressure I had extraction problems. The slightest expansion of the head was enough to cause clickers and a few times I had to tap the case out with a cleaning rod.
I scrapped the idea and made it from 22-250 brass. If your chamber were to be cut to 308 head diameter you would be fine

Yep I knew that was a potential issue. It may be a fruitless venture because of that.

I wonder if I ran it through my 22-250AI sizer, fireformed with a relatively mild load and had a custom reamer made if that could be resolved. Of course then it really becomes a wildcat that may not be worth the effort.

 

[VinceMule]

Mike/Seebee, are you speaking of Lapua brass?

 

[Mike D Texas]

Mike/Seebee, are you speaking of Lapua brass?

I'm just looking at the SAAMI cartridge drawing for 22CM and a random drawing I found for 22-250AI.

I'm looking to use Alpha 22CM SRP brass if I can get this to work.

EDIT: Orrrrrrr if I could get some of the 277 Fury hybrid cases with the steel case head to work…….

They make the 260AI pretty impressive. I tried them with 140 Barnes Match Burners over the weekend.

 

[just_jon]

I suspect you may need a small base body die to get them to chamber. I know I did when going from 6.5CM to 250AI.

 

[Mike D Texas]

I suspect you may need a small base body die to get them to chamber. I know I did when going from 6.5CM to 250AI.

I could have one made pretty easily. I've had Whidden make me small base dies for my 6.5 & 300 SAUM Improved cartridges.

They drop in like butter into my Wilson chamber style arbor dies that were cut with my chamber reamer.

 

[can1010]

why not just use 6xc brass it has the same .468 base dia. as the 22-250.

 

[Mike D Texas]

why not just use 6xc brass it has the same .468 base dia. as the 22-250.

Large rifle primer. I'm wanting to use SRP.

Wasn't aware they were similar. Unsure of case capacity.

 

[can1010]

Large rifle primer. I'm wanting to use SRP.

Wasn't aware they were similar. Unsure of case capacity.

Peterson brass has lrp and srp but like most brass finding in stock is the biggest problem. Peterson has been consistently lower case capacity compared to other makes, but it is strong and a solid choice. i use it in 284 win and 243 and has stood toe to toe with other high end makes.
DONT use the Alpha 6xcII brass it is larger in the base and needs their own reamer design.
you can also go to David Tubbs website if needed, he sells all supplies for the 6xc seeing it is his design originally.

 

[Seabeeken]

Mike/Seebee, are you speaking of Lapua brass?

I used Alpha brass. Can has a good point. The XCII is the 6XC with a 308 head size. Almost bought XCII dies for my XC before I discovered the difference

 

[Mike D Texas]

Peterson brass has lrp and srp but like most brass finding in stock is the biggest problem. Peterson has been consistently lower case capacity compared to other makes, but it is strong and a solid choice. i use it in 284 win and 243 and has stood toe to toe with other high end makes.
DONT use the Alpha 6xcII brass it is larger in the base and needs their own reamer design.
you can also go to David Tubbs website if needed, he sells all supplies for the 6xc seeing it is his design originally.

My experience with Peterson is that is has more capacity, at least in 300 & 338 Norma cases vs Lapua and ADG.

I'm a big fan of Alpha brass so if it has weird dimensions in 6xc that just rules out 6xc cases for me.

 

[del2les]

Yes, I have done this with good results. I do run the 22CM brass through my 22-250AI size die prior, and it comes out about 90% or so complete. For my chamber, I have not had any problems.

 

[Mike D Texas]

Yes, I have done this with good results. I do run the 22CM brass through my 22-250AI size die prior, and it comes out about 90% or so complete. For my chamber, I have not had any problems.

Good to hear since I have 100 pieces of Alpha brass on the way.