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Posted By: techfish COW fire forming question. - 08/11/14
I just completed my 257 AI and this is my first experience with fire forming brass. What powders are acceptable for the COW method? I don't load for pistols and the fastest burning powder I have is IMR 4227. Will this work or do I need to pick up some Unique or similar burn rate? Thanks in advance for any advice.
I can't answer your question but I will say after doing that one time, I doubt that I will go that route again. I would just load some ammo to 257, near max loads, and fire form that way. miles
Posted By: Ackman Re: COW fire forming question. - 08/12/14
Don't screw with COW. A waste of time and components. Just load with bullets and go shoot. Choose a powder and bullet. Start at the top of std. 257 loads and go from there til you find best accuracy, that'll be your fireform load. It'll be as accurate as formed brass and very nearly the same velocity. My fireform load used W760 and an 85/87gr bullet doing high 3700's with 28" barrel.
I used Bullseye. PM Mule Deer and ask him. He seems to have some experience with it.
Originally Posted by Ackman
Don't screw with COW. A waste of time and components. Just load with bullets and go shoot. Choose a powder and bullet. Start at the top of std. 257 loads and go from there til you find best accuracy, that'll be your fireform load. It'll be as accurate as formed brass and very nearly the same velocity. My fireform load used W760 and an 85/87gr bullet doing high 3700's with 28" barrel.



+ 1!!!

BULLETS!
I have used Bullseye and a wax plug for fireforming. Do whatever you want.
Posted By: mart Re: COW fire forming question. - 08/12/14
I used Bullseye when I formed my first 400 Whelen cases. It was about the only way I had to make cases at the time as I didn't have reloading dies or an expander dies set for it. I used about 16 grains of Bullseye and topped it off with COW and jammed a crayon in the case mouth. It worked well.

However, for the 257 AI I wouldn't bother. Just load up your standard cases and fire away. Unless you just don't want to burn up that many bullets. In that case I think the 4227 would work. I'd start around 12 grains and go up till you come out with well formed cases.
Posted By: Otis Re: COW fire forming question. - 08/12/14
I'm with these guys, COW will form out about right, but the shoulder will still not be as sharp as it will be with a good stiff load! I got a box of plus P rounds and they still weren't hot enough to get it done completely!
Posted By: keith Re: COW fire forming question. - 08/12/14
Work up an accurate load with bullets, it will probably be an over max load for the regular cartridge, hunt while fire forming. Accuracy and speed will be spectacular. I am assuming that you are not shooting over 300+ yards.

I don't think that Bullseye can be purchased anymore, they may have closed the plant down in Va. that made Unique, Red Dot, Green Dot, American Select, and Power Pistol.

I too have used Bullseye and wax plug..works well...
I've used Unique and Bullseye in my 6.5-06 AI, but I gave up on it and just load cheap bullets and a max load of fast powder for the parent cartridge and shoot. My chamber is properly head spaced for the crush fit (I watched the gunsmith gauge it) but for some reason I got a few case separations with COW, go figure.

"Hunt while you're fireforming" would work with something like PDs, and would be a lot of fun. My FF loads were very accurate.
Not very glamorous, but you could just load up some according to a 257 Roberts recipe out of a manual and just go kill something.
Fireformed brass would then be a bonus.LOL

Best,

GWB
Sounds like the general concensus is to load and shoot. I dont really feel that "crush fit" and I dont have a gauge to check head space. However, it was done by a competent smith and a new barrel...I tend to over-think these things. Thanks for the advice, guys.
Posted By: mathman Re: COW fire forming question. - 08/12/14
Can't feel the "crush" fit? I'd be inclined to load the first batch of bullets into the lands.
Now you have me thinking again, Mathman. What type of charge do you recommend with the long seated bullet? Moderate or Max charge?
You'd be OK with the upper end charge for the parent cartridge, but there's nothing wrong with backing off a grain or two. If you have a choice, use a heavy bullet and a powder toward the fast end for the cartridge.
Posted By: mathman Re: COW fire forming question. - 08/12/14
257 Roberts max charges are pretty tame in the overall scheme of things. This is similar to the 250 Savage.

I recently formed some 22-250 brass for my 250 Savage, regular, not AI. I seated some 90 grain Sierras so they'd be firm into the lands, and loaded them with a full load. The cases fireformed quite nicely. Bolt lift and extraction were smooth and easy, and primer signs indicated a load that was still quite mild.

You're blowing out the brass to a larger chamber, which would lower pressures even more.

If you want to be prudent, you could make up a series of one each at increasing charges to get a feel for it.
Not a waste of time when opening necks up to larger diameter!

Probably a waste of time if only AI'ing the brass!

Mike

Its probably a toss up. A one lb. can of shotgun powder, vs. some cheap bullets. C of W can get pretty violent, but I use a 5 gal. bucket with a lid, lined with carpet scraps, in my garage.

Hornady's new hydraulic case forming die doesn't completely fill out the shoulders either. Dupont 700X is what I use. Start out at about 10 grains, and work up until its close enough to filling the shoulders out. Powder plus a primer, vs. Powder, primers, and bullets. Neil Jones specified that I should fire three full power loads, to get my cases formed out, completely.

The brass stabilizes after three firings. The C of W makes for decent first shot fire forming duties.
Posted By: fremont Re: COW fire forming question. - 08/18/14
When I've done it, I've used Bullseye.
Posted By: RinB Re: COW fire forming question. - 08/18/14
Use Bullseye. You want the fastest powder available. Charge is 20% of what max charge weight is for your formed cartridge. Adjust until you get a formed case. Don't over do it. The case will not look as crisp as one fired with a full working load. Use PISTOL primers for forming step. Put those pistol primers away after forming!
I use any type of fast-burning shotgun powder. 15 grains forms the case well in a .308 sized case.

Here is the method. I used Polenta. Wheat is bad for you smile

I just used large rifle primers because that's what I have...

Prime and throw powder then fill with COW or Polenta...

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Cook the rest for breakfast...

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It's always funnier than hell,the lengths and antics people will go through,to keep from actually shooting.

Hilarious!..............
Just curious here...how many boxes of cereal do you boys shoot up in a good day?

Laughing!.....................
Hey BS!

It really helps save some barrel life with chamberings like the above; 7mm RUM. I'm not into shooting a couple hundred rounds down the bore with so so accuracy just to fire-form and lose about 20% of the barrel life.

It also really helps when you are forming a new batch of cases for a competition rifle. I usually do 500 new cases.

If you do load development in NEW cases that are not formed to your chamber, all bets are off.


Have a nice day boxer!
Hey neato...really "great" idea.

Pass the bullets,hold the fluff and all the "reasons" not to shoot.

Laughing!...............
Tee hee hee!

What's up with your sig' line?
Do tell about a "Competition" Rifle that needs 500 pcs of brass.

Couldn't you pick a better chambering,with better Virgins and a reamer slated to same...rather than Handloading Cocoa Puffs,while wearing your helmet,drool bib an a seat belt?

Laughing!...............
Most of the big Precision Matches have a round count around 200.

You really should get out and shoot more.
Posted By: RDFinn Re: COW fire forming question. - 08/18/14
Originally Posted by Big Stick
Just curious here...how many boxes of cereal do you boys shoot up in a good day?

Laughing!.....................


That was funny.
Originally Posted by rcamuglia
Most of the big Precision Matches have a round count around 200.

You really should get out and shoot more.


You're on FIRE!

"Big" Precision Matches. Do tell,how there's correlation to case capacity and the leader board and I reckon...they must sweeten the pot with a free case of Cocoa-Puffs for the Winner?

Laughing!................
What a coincidence! I'm laughing too!

Not too much funnier than Fire-Forming Cocoa-Puffs,while swilling Soy Milk and frosting it with your Avatar.

Laughing!..............
Ha! That was awesome!

Are you working a club in Vegas?
Oblivious Stupidity,is THE "gift" that keeps on giving.

Congratulations?....................
I'll check on that. I've always been taught that it is much more rewarding to give than to receive.

Mr. Oblivious Stupidity, whoever that is, must be one heck of a thoughtful person.
You give laughs...even if on "accident".

Thanks!..............
Posted By: Mavrick Re: COW fire forming question. - 08/18/14
I shoot competition rifle and need a bunch of cases, too. I have NO problem using COW and 12-18gr of pistol/shotgun powder. I usually use Red Dot, but almost any of the fast powders work fine.
With my .257 Bob-Imp I usually load .257 loads and shoot, but I am using IMR 4895. With my .270 WinImp and 6.5/06 Imp I usually fireform with COW.
I don't usually go to the matches where they supplement the prizes with Cocoa Puffs, whether or not I like cold cereal, but COW is better hot...if I have any left after fireforming, lol.
Have fun,
Gene
Posted By: laker Re: COW fire forming question. - 08/19/14
Pass me the lead over the cereal any day. I don't hate practicing
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