I have a .22-250 AI and a regular case chambers easily...
It needs to for fire forming
It made 4000 rounds before the barrel was replaced.
A year ago, a friend of mine was given a 22.250 by an uncle who was on his last legs, sadly, by the time the variation was done, his uncle passed away, so any information regarding reloading data etc, died with him, the rifle shot well with factory ammo, so he used the rifle but kept the cases until he got some dies, after a bit of fiddling and experimentation, he found a good recipe.
Roll forward to several months, he called me over as there was something wrong, l duly trundled over to find out what the problem was, he showed me the fired cases and the ones he'd sized, there was a marked difference between the two, l checked the dies, case length, then after a few minutes of head scratching, it hit me what the problems was, l fired his laptop up and confirmed my thoughts, the rifles was chambered as a 22.250AI, he ordered some dies and we knocked some loads up and tried them, not bad but a bit more tinkering found a decent accurate load, but none were as good as the loads made with the standard dies, after more jiggery pokery, we could not get the rifle to shoot any better, so now, he's sticking to loading with the standard dies.
Strange eh?
I have a .22-250 AI and a regular case chambers easily...
It needs to for fire forming
It made 4000 rounds before the barrel was replaced.
Can you put up a picture of a factory round and one he has loaded from fireformed brass. The main reason being standard brass is .414 at the shoulder and AI is .454
Do nothing, achieve nothing
Not strange mate. Remember that rimless cases headspace on the shoulder, and that being a taper, means that the case will tend to self centre in the chamber.
This means that the case doesn't need to fill the chamber as fully as possible in order to get good accuracy, perhaps there may be something in it for benchrest shooters chasing that final tenth but for a sporting rifle I find that full-length resized ammo shoots as well as neck sized stuff.
This discovery pleased me endlessly as my rifles are for hunting and ease of chambering and especially unchambering is more important than raw accuracy. If you have been hunting 12,000 miles from home in 40 degree heat and you get one chance of a shot in two weeks you will no doubt agree with me...
Fireforming cases for AI chambers is mainly so you can more of a slower powder in the case than would be possible with the standard round, it makes no difference to the pressure or performance of the load unless there would be significant compression of the AI load in the standard case.
As to burning barrels it depends on how intelligently you load and shoot the rifle.
Rapid fire of full charges of the slowest powders will burn the barrel out faster than slow fire of full charges of faster burning powders. Looked after there a .22-250 fox rifle will outlast its owner. It's not a 308 but the idea that it eats barrels out in a way a .25-06 for example, wouldn't do in similar circumstances is patently silly.
"An infinite number of monkeys banging away at type writers for an infinite period of time will eventually reproduce Hamlet" Thanks to discussion forums we now know this to be untrue.
kernal, point out to your friend that if he carries on using standard brass in standard dies then firing them in a improved chamber he is going to end up with a very large pile of improved brass that cant be resizes in standard dies.
TB.
The problem with using standard dies is that he's overworking the case body.
If he sets his FL die to just kiss the shoulder, ie not set it back too much, it is unsurprising that the accuracy with the standard dies is so good.
Kernel, does your friend have to trim cases like buggery?
"An infinite number of monkeys banging away at type writers for an infinite period of time will eventually reproduce Hamlet" Thanks to discussion forums we now know this to be untrue.
I'll let him know.
My 243 AI was more accurate when using a 243 sized case with a stiff 243 load. When using formed brass, I could never repeat the accuracy I was getting with 243 brass and load with fireformed brass and an AI load.
I would be very surprised if a knackered chamber would generate a fired case you could mistake for an AI formed case.
It's not a knackered chamber, it could be a 28 degrees AI as opposed to a 40 degrees?......or?
Lets see some before and after case pics.
The plot thickens.
this---^
A chamber simply can't wear that much, if it was as a result of a bulge then the barrel would let go long before the chamber?
Can you not resize 243 AI in standard 243 dies? That does surprise me. Is that they over-work the brass or something else?
A friend has a 22.250 with a tight chamber, done By Kershaw I think, that if underloaded to the point of case sooting ( Ie at the beginning of a sensible load development process) would leave cases in some sort of state where they would re-size properly. Never got to the bottom of that but stiff loads cured it for some reason...
"An infinite number of monkeys banging away at type writers for an infinite period of time will eventually reproduce Hamlet" Thanks to discussion forums we now know this to be untrue.
My mate is on his hols for two weeks, but l'll ask him when he comes back as to whats going on.