Cow Fireforming and muzzlebrakes

Discussion in 'Reloading' started by abinok, Feb 9, 2006.

  1. abinok

    abinok Writers Guild

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    Just wanted to get opinions on COW fireforming and muzlebrakes. I know that using a plug like toilet paper over the cow is a bad idea, as it opens inside the brake and traps gas (aka brake is toast) just like a sabot.
    Anybody have any thoughts or experences on just straight COW throught a muzzle brake?
     
  2. LRHWAL

    LRHWAL Well-Known Member

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  3. Centre Punch

    Centre Punch Well-Known Member

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    Abinook,
    can you not unscrew your muzzel brake for COW fireforming? /ubbthreads/images/graemlins/grin.gif

    Ian.
     
  4. LB

    LB Well-Known Member

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    The cream of wheat, frankly, is a bad idea. My opinion. It gets into everything; some of it doesn't exit, rolls back down into the chamber, sticks to the sides and makes dents on subsequent chambered brass. Can also get into your locking lugs and trigger, if you are not careful. You should have compressed air handy to blow it out after every few firings. Adding the tpaper, can't see what that will do, besides keeping the cow from falling out? But, it won't fall out if you elevate the barrel.

    Therefore, I have found, (if this is the method you choose to fireform), that you just use your surplus fast powder in whatever amount seems to work best, and wad up a little tp, stick it in the neck, which will create a small pressure buildup, and <font color="red">forget </font> about the cow.

    Otherwise, full power loads with bullets are fine, if you are not concerned about using up a portion of your barrel life with substandard performance?

    The option I really like is having your gunsmith cut a chamber in a junk barrel, <u>using your same reamer</u> and installing it in a "loaner" rifle. You don't even need a scope, just go to the range with 100(?) loaded cartridges, and shoot rocks downrange. In an hour, you are done, perfect fireformed brass and then you gratefully return the loaner. Works for me.

    Good hunting. LB

    PS muzzle breaks are generally removeable(?) I don't understand why is it important to use one when fireforming without bullets?
     
  5. Varmint Hunter

    Varmint Hunter Well-Known Member

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    Why would you use a brake when COW forming?
    Why would TP cause any problem with a brake? The pressure would easily blast it through the ports if that is where it ended up.

    I saw a guy at the range who put a hose clamp around the holes in his brake to see if it affected group size. One shot and it blew the hose clamp to pieces. It was lucky that he didn't injure anyone on the line. I can't imagine that TP could do anything harmful.
     
  6. LB

    LB Well-Known Member

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    Maybe you missed the point? What is the purpose of the muzzle break, in the first place? How much recoil are you going to get from cream of wheat, or any type of fireforming without a bullet? Muzzle breaks don't impress me much, in the first place, speaking as a public range shooter. TP harmful; maybe not? So, are muzzle breaks required; maybe not? Sure looks sexy, though. /ubbthreads/images/graemlins/wink.gif

    Good hunting. LB
     
  7. royinidaho

    royinidaho Writers Guild

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    Heard that Hornady(??) is coming out with a die that takes the initial case filled with H2O then you WACK it w/a hammer and WAAA LAAA its "fire formed". I think I could enjoy that. /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif
     
  8. Black Diamond 408

    Black Diamond 408 Well-Known Member

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    I toured the Hornady plant this week, i ordered one of their Hydraulic form dies, $120 for small cases, $137 for large cases. They dont list them in the catalog, you have to call to order them. Seems like the best way to do it.
     
  9. Charles B

    Charles B Well-Known Member

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    This off of Varmint Al's pages. This loader was using rag as wadding for fire forming.

    [​IMG]
     
  10. Ringman

    Ringman Member

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    abinok,

    I used cow once. I added the weight of the cow to the bullet weight to determine the powder charge. I was a carefully weighed out a light load of powder. I used a hammer to open the bolt. The case head had expanded .017"! You read that right. The chamber was bulged.

    The gun smith checked the action and decided it was O.k. so he put a new barrel on it. No more cream of wheat for me; except in a bowl for breakfast.
     
  11. BountyHunter

    BountyHunter Writers Guild

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    The best way is to expand the case up one size with a neck expander $15 and then neck the case down a little at time until the bolt will just close with pressure on the false shoulder. You are basically leaving a small bulge on the bottom of the neck where it chambers and it will form perfectly with a regular load.

    www.6mmbr.com has a good article on forming cases like this so you can see the false shoulder.

    http://www.6mmbr.com/6BRImproved01.html

    BH
     
  12. abinok

    abinok Writers Guild

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    Bountyhunter,
    I am fireforming belted magnum brass, and since there is over .020" differance in location from virgin brass to chamber dimensions, i am fireforming them with a false shoulder presicely as mentioned. Ie done a couple hundred on barrels without brakes, this is just the first barrel with a brake on it. I tried fireforming with the standard load, and it dosen't seem to shoot as well as normal... more than .5moa larger, hence the flying, flaming breakfest chow.
    Thanks to all who responded, especially for the pic of the break. I think ill just take it off to be safe.