Question about Fire Forming 257 bobs into 257 AI

sailorjim

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Thank you

The rounds I used were old factory Win. Super-speed (mistakenly id'd as reloads) and factory Win. Silvertips. My father who has reloaded since the 60's and still reloads quite a bit looked at the rounds that I was shooting and he is certain that the ones I thought were reloads were actually factory loads. I had one random Remington thrown into a single box, which caused me to think all of those boxes were reloads. Those are actually all 87 grain short Win. Super-speed soft points. These are considerably shorter bullets than the 100 gr. silver tips, which did not have any problems, so maybe they aren't setting deep enough and it may be a headspace issue.

My dad also suggested using new .257 Bob brass or find some pre-formed .257 AI brass. I have not seen either on the internet and finding them here in SE New Mexico will be impossible. Only thing that is sold here is Brand new Hornady at $75 a box. Not sure my wallet can take shooting those to fire form them.

My father thought he could pull the bullets and reduce the charge. While he has never dabbled in wildcat rounds, he has a good library of old books on reloading. He has an old book that mentions using a reduced charge, then cotton, then something like cream-of-wheat, followed by paraffin to fire form parent cartridges into AI cartridges. Is this the COW method you were talking about?
I have 5 boxes Winchester virgin brass. $100 + shipping.
 

Hugnot

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There is a possibility that your chamber is not spec or excessively large. I would measure the brass where the longitudinal splits occurred and compare it to this:


Excessive head space would be indicated by excessively flattened primers, fractures across brass indicating impending head separations or actual head separations. Excessive headspace beyond a certain point would result in fail to fire(s).

A proper rechamber job, as noted, would be to set the barrel back one turn and rechamber slightly short to enable cartridge crush fit. Ammo reloading might require a ground down or shortened shell holder to enable chambering rounds easily but having correct or minimum headspace.

Check things out real good to avoid trashing good brass. Been there & done that.
 

Seabeeken

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Ackley designed his improved so that regular ammo would have a crush fit when it is chambered. The headspace was decreased .0001 inch to insure not having excessive when firing factory ammo.This was accomplished by using the “go” gauge for the “no go” setting. If you did not feel resistance when you chambered regular ammo, then you have excessive headspace. Have your rifle by a gunsmith that is familiar with Ackley improved cartridges. Or buy or borrow some .257 Robert’s headspace gauges. You will confirm the headspace problem if you can completely close the bolt on the “go” gauge.
Ackley shortened headspace .004” according to his book.
winchester is typically a harder brass than others and doesn’t fire form well. I’ve ff’d ppu, rem, nosler, Norma, Peterson, hornady, and alpha. Only issue was with Hornady brass. COW works well when you don’t want to waste expensive bullets. I use 15 gr of red dot or imr red and top it off with coffee and a tuft of tissue. I switched to coffee because cow was leaving a lot of burnt cow in the shoulders and a nasty barrel and coffee is already burnt and the residue was much easier to remove. Coffee smells much better also 😁. You will like the 257ai, mine is super accurate and rivals the 25-06. You can use a standard 257 Robert’s go gauge as a no go gauge in the ai version.
 

Bret GRAVELINE Graveline

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Camino california
A quick and easy way to check if your rifle is headspace properly is take a Virgin round or case and place a single layer of masking tape on the case head, trim the excess with a sharp knife, the bolt should not close on the case without meeting resistance, if the bolt closes freely that's diffently the problem, I've been shooting and hunting with the 257 Ackley since the late 70's I have 3 with 1 being on its third barrel, my dad and brother plus a couple hunting partners use this round as well, I have chambered and fired nearly everything Ackley from the 17 hornet to a Ackley improved 338 lapua, I have improved thousands of rounds, I have tried all the recommended ways to do so, hydraulic forming to cow, what worked the best for me is a full case of slow burning powder, I like AA 8700 for this, years ago AA had a surplus powder called 8600 it was even slower than 8700 which itself is quite slow, I purchased 32 pounds of the stuff just for fire forming I'm down to about 2 pounds now, in trying faster burning powders to form cases I found even though it produces higher pressure the cases were not always perfect, A full case of the slow stuff almost always produces a perfect case with perhaps 3 percent needing a second firing, our deserts over the years have had a fair population of jack rabbits we usually spend summers picking on them while fire forming our cases, I've never used nosler brass, but hornady federal Winchester and remington both standard and nickel never had any problems with any of them, for big game I stick with The 115 and 120 gr slugs there are over a dozen powders That will safely push these slugs over 3000 fps some will produce over 3100 my go to rifle wears a 21 inch tube and weighs 6 pounds in the field it too produces over 3000 and its the one on its third barrel, A safe load should give 5 or 6 firings with the primer pockets still being tight,
 

264MHC

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Sep 3, 2019
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Since this is a savage action, your problem can be fixed very easily, assuming it is excessive headspace. As others have said, if the bolt closes with no resistance on factory ammo, the headspace is incorrect for an Ackley chamber. Research savage barrel swaps and you will have the information you need to adjust your headspace. Loosen the barrel nut, insert factory ammo into chamber with firing pin removed from bolt, screw barrel in until it just barely contacts the shoulder of the case in the chamber, then tighten barrel nut. Check several rounds of factory ammo or unfired brass to make sure they all chamber, but with some resistance.

if going this route it is best to have at least 100 of all the same brand/lot of ammo Or brass so you know they will all act the same when fired. Just be aware that other brands may not chamber, or may not have resistance, after doing this because you are setting negative headspace for a specific brand of brass.
I have never used the COW method, but I don’t think it will work properly without resistance when closing the bolt, because it will not be held solid to the bolt face. You either need to decrease headspace by screwing the barrel in farther as I have described, or create a false shoulder on new brass as others have described.
Welcome to the world of wildcats and all the problems they bring. It will be worth it once you get everything straight though.
 

Hugnot

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Take it to a competent gun smith & get a chamber cast - .257 R factory loads are the pressure light side. I think the case failures indicate a sloppy chamber, not excess head space. Excess head space would be indicated by head separations or impeding head separations, like cracks across the brass. Lots of sloppy gun smith work out there like rechamber jobs using drill presses.

The brass failures shown indicate stretching across the brass not along the brass and that would indicate a sloppy chamber - failures just above the web & at the shoulder. I have seen some examples of things like this, like rechamber jobs done using a drill press. As mentioned, Savage headspace issues may be fixed by screwing the barrel into the receiver and then locking it up with the barrel nut.

Consider the cost of buying expensive and scarce primers & brass against the cost of a new barrel. The results might just be more destroyed/unusable brass and no good ammo. A new barrel would cost $400-$500. No easy fix for a sloppy chamber. Brass from Quality might go about $1.00 each.

I have fire formed using the COW method - 6mm AI, .257 AI, .280 R from .270W, & .375-.338 from 7mmRM & .338W. Getting a good crush fit is essential. No head separations. As mentioned the AI case will headspace some .004 shorter than the parent case. Coffee grounds sound like an improvement over COW.

Are the formed brass dimensions same as what is shown here?

 
Last edited:

Gibbshooter43

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I fireform two 25 caliber cartridges - 250AI and 25:06AI - and use my normal loads with no problems, and as others have stated, no accuracy problems. But the real reason for my post is the OP’s comment about no AI brass being available. Try Quality Cartridge. I’ve purchased several unusual cases from them over the years and find their brass is very good.
 

watersfam

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May 17, 2021
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Carlsbad, NM
I fireform two 25 caliber cartridges - 250AI and 25:06AI - and use my normal loads with no problems, and as others have stated, no accuracy problems. But the real reason for my post is the OP’s comment about no AI brass being available. Try Quality Cartridge. I’ve purchased several unusual cases from them over the years and find their brass is very good.
Thanks!
 

Seabeeken

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Apr 30, 2013
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338
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Communist state of maryland
I fireform two 25 caliber cartridges - 250AI and 25:06AI - and use my normal loads with no problems, and as others have stated, no accuracy problems. But the real reason for my post is the OP’s comment about no AI brass being available. Try Quality Cartridge. I’ve purchased several unusual cases from them over the years and find their brass is very good.
Quality cartridge has discontinued all Ackley improved cases. They will however make a large run if necessary but at $2/ case, they can keep em.
 

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