Home Forums Hunting & Shooting Ask The Gunwriters JB or Anyone - Fireforming .257AI with COW

John,

In your Gun Gack book, you mentioned using 18gr. Unique to fireform 6.5 Creed. Would that same charge be sufficient to fireform .257 into .257AI or would I need to up the charge a little? Thank you.

wildcat: what is COW? never mind...figured it out!

I used to use 12.0 gr of Red Dot, then a pinch of Dacron tamped over the powder, then filled the case with Cream of Wheat, and sealed the case mouth with a couple of drops of wax.

That didn't sharply fill out the shoulder, so I quit using COW and now I just use a .257 load with 75 grain bullets for plinking, and that completely fills out the AI case.

Wildcathunter,

I would sure guess it would work to form .257 AIs, since the case length and powder space is pretty similar to the 6.5 CM--but the only way to tell for sure with COW forming is try it. (As I've noted before on here, there is no handloading manual of COW loads!)

I use 10 grains of Bullseye under a case full of COW to fire form .25-06 AI and get good, sharply defined shoulders. I don't seal it with anything, just keep it upright until I touch it off.

cra1948,

That's the easiest way--and can be done in most loading rooms without upsetting the neighbors.

I find It hard to get the cream of wheat poured in there and still have room for the cinnamon and hot water and milk.

I like to be wasteful and use full house standard 257 loads to see where they "pattern" in case I ever need to shoot them in the AI chambered gun, a Ruger 77, rechambered by Bob Dunlap. I also get very uniform fire-formed brass.

An old friend had a nice Husky Improved Mauser 1640 in 7X57 ICL Tortilla (same as AI, but with 45 degree shoulder). He forgot his ammo and ended up in Lander WY to hunt antelope without ammo. If you knew his wife it would make more sense...Banshee. She was all over his case for abandoning her for a long week.

He bought two boxes of 7X57 ammo in Idaho Falls after a hasty trip back and loss of a day's hunting. He said the ammo printed 10" higher at 200 yards than his ICL loads.

BTW, I bought the 7X57ICL from him cheap, and it's my go-to antelope rifle, a tack driver.

Personally, I never use a COW when reloading. I find them to be heavy handed & awkward in the reloading room. A lot of crushed cases.

I use bullseye with no cow or other filler. Works great.

I use toilet paper wadded on top of the Bullseye. Works fine and no residue as with COW.

I do the same Bob..but really like the smell of burned Cream of Wheat!!

I use a healthy load of Bullseye and a wax or play dough plug. On fired a couple in my shop, way too much smoke inside.

Back in 2002 I got a lathe, a 257 Roberts Ackley reamer, (4) Lothar Walther light varmint barrels, and built (4) surplus Mauser rifles for myself and (3) hunting buddies.

The first rifle was mine, and we used a new piece of Win 257 Roberts brass as the headspace gauge.


After that we learned to headspace a 257 Roberts Ackley 0.004" shorter than a 257 Roberts.


We amateurs in 2002 did not know that the firing pin will push a non Ackley cartridge case forward into the sharp Ackley chamber neck base, cutting a ring 0.004" deep. When the powder goes off and the case expands, the case grabs the chamber walls. As the pressure gets even higher, the case head is pushed back against the bolt, thus stretching the brass.

In 20 years I have not set that barrel back. I learned to put 10 gr. of any pistol powder in the case and cover with COW [instant cream of wheat]. I slather the case with moly grease [What my father called 50,000 psi grease] I shoot straight up. If I am at a range and cannot shoot straight up, I poke the case mouth into Ivory soap to hold the COW in the case. This forms at least half a shoulder. With half a shoulder I can use full 257 Roberts Ackley loads with full accuracy.

The irony is that my rifle is more accurate than the other (3) rifles. [maybe because how my brass is formed]. Mine has shot a 0.45" (5) shot group at 100 meters for me. I handed it to another guy who shot one group and that was 0.50" (5) shots at 100 meters.