22-250 Ackley Improved?

[Robc84]

My father in law had a rifle handed down to him recently which was a custom built gun. They barrel is stamped with 22-250. The problem is another family member mentioned to him that it might be a 22-250 ackley improved but he wasn't sure. I haven't seen the gun and know very little about the improved round other then the shoulder is different. My question is how do you tell the difference in a rifle between the two. Can you shoot regular 22-250 in it? I've already went out and bought him a rcbs die for 22=250 will that not work if it is an improved round?

 

[Jim Watson]

A real Ackley Improved will shoot the corresponding factory ammo safely, it will fireform into the Improved shape for reloading.

Standard reloading dies will not work on an Ackley Improved.

Depending on the age of a custom rifle, it might predate the standardization of the .22-250 in 1965 and the chamber might differ from the present .22-250 Remington.

The Official Timid Internet Recommendation would be to have a gunsmith make a chamber cast to measure and see what it really is.
Or you could just go by the barrel stamp, insert a .22-250 cartridge, pull the trigger, and see what comes out.

 

[taliv]

note that if you put a regular 22-250 cartridge in an ackley chamber, it should be a little hard to close the bolt. this is intentional that the ackley is a couple thou short so that it centers up well and doesn't fireform crooked brass.

welcome to THR

 

[Arizona_Mike]

Ackley chambers are set up to be 0.004" shorter at the shoulder neck junction. I've found a lot of factory case to be too short to develop a crimp there. As a result, you get a variety of neck lengths after first trimming. I've experimented a bit with forming .257 Ackley Imp cases from 30-06 and then neck reaming but never got far. The gun shoots sub MOA regardless.

Mike

 

[Robc84]

Thanks for the info guys. A lot of knowledgeable folks here. My guess was if it didn't say akley improved it was going to be a regular 22-250.

 

[stringnut]

Just because it's not stamped imp or improved doesn't mean it isn't. There have been a lot of hobbyist gunsmiths who did such things in their basements. Reaming an improved chamber is easy and can be done by hand. I know people who have done it. A machine cut is better. As has been pointed out you can shoot factory ammo in a proper improved chamber.

Another good point is it could be a non standard chamber. Before it was a factory chambering it was a wildcat for a long time. A lot of gunsmiths had their favorite design and chambered rifles with a reamer designed by them. Many continued to use them for years. What can really be an issue is headspace. This is high pressure rimless cartridge. If the headspace is excessive you could have a case head separation. Believe me this is an experience you don't want. I saw the results from one and it made an impression on me.
It may be worth doing a chamber cast or investing in a no go gauge. Both are cheaper than a face full of gas and metal particles. If you handload a bullet can be seated into the rifling and a starting load used. This will fireform the brass to fit the chamer. Then a more direct comparison can be made to factory dimensions.

 

[entropy]

Chamber casting would be advised. Cheap insurance.

 

[RevJim]

Simple, take a 22-250 factory load, pull the bullet. Plug the neck with candle wax or similar, chamber, point it at the sky and fire it. the case will come out formed to whatever it is.

 

[SmokingFrye]

The difference is the shoulders. AI shoulders are 40 degrees, most factory are around 23 degrees, also, the AI rounds remove most of the taper that many factory rounds have (good for brass life). I had a similar issue with a rifle I picked up that wasn't stamped but was clearly 6mm. I shoot 6mm Rem factory loads to do this. After casting, I knew that it was 6mm AI, but had to fire form 6mm Remington rounds to get the brass. Ultimately, the neck will be longer and the shoulders will be around 40 degrees for an AI. If you find out, though, have the barrel cast and stamped by a Smith, many states will not let you sell that rifle, if you choose, without the barrel stamped.

 

[rcmodel]

many states will not let you sell that rifle, if you choose, without the barrel stamped.

You sure??

I've never heard of that before.

Can you name a state law that requires caliber stamping on barrels?

Rc

 

[SmokingFrye]

I'll have to find the law verbiage to quote it because I have not seen it, but a couple years ago, I could not buy a rifle from a private party in Iowa using the normal 4473 process because the rifle did not have the cartridge/chambering stamped on the barrel. The transfer agent told us that it could be an issue, and the transfer didn't happen. I took his word for it when he said that many states require it for safely purposes. Made sense to me, honestly, but now I'm curious.

Found it....ATF guidebook on ATF.org, but it reads as if it may be use/importer/exporter (state or country) dependent. Check it out and let me know how you interpret the wording. I'm guessing this, whether interpreted correctly or not, is/was the reason for the confusion.