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Small Pistol Primer in 10mm

Discussion in '10mm Reloading Forum' started by osucowboy8, Dec 23, 2010.

  1. osucowboy8


    Jan 5, 2010
    I'm kind of new here and new to reloading 10mm although I've been reloading other calibers since the late 80's. I did some searching on the web and couldn't really find any definitive answer to this question.

    I recently bought some once-fired 10mm brass. About 40 of the cases have a head stamp "FC NT" and they take small pistol primers. Do I need to make any adjustment to my loads to account for the fact that these are small pistol vs. large pistol? Should I use magnum primers? Thanks in advance for your replies.
    J Shaw
    Last edited: Dec 23, 2010
  2. _The_Shadow

    _The_Shadow Ret. Fireman

    Jul 23, 2007
    Southeast, LoUiSiAna
    I have some also, they are Federal NON Toxic small pistol primered and are for indor senerios for mostly LEO. I wish I could get even more of them to play with. Be sure to keep them seperate at all times so they don't get mixed in the reloading process.

    The short anwser is no! If you normally use a magnum LP use a Magnum SP or viceversa Std. LP use Std. SP.

    BTW welcome to the forum!
    Last edited: Dec 23, 2010

  3. Objekt


    Dec 3, 2006
    NM, USA
    If you've been reloading since the 1980's, you probably know more about substituting primers than I do. In my experience, switching brands makes practically no difference in muzzle velocities, often indistinguishable from random variation. Even magnum vs. regular may not change things much. Some of my 10mm recipes using a Federal #155 Magnum primer perform almost identically to the same load using a Federal #150 Standard primer. A few are faster with the magnum primer. One batch was actually a little slower.

    Ultimately, the answer is "it depends." The safest method is to work up a load with your chosen primer, as if you were starting from scratch. It's an open question whether a regular or magnum small pistol primer would work better, a question which you can answer only by trying both & chronographing the results.

    The real question is, whether the extra effort is worth your while. For me, it wouldn't be. I would just throw away the 40 NT cases and forget about it.
  4. xdmikey


    Dec 5, 2009
    Cypress, TX
    is federal the only mfg producing these?
  5. _The_Shadow

    _The_Shadow Ret. Fireman

    Jul 23, 2007
    Southeast, LoUiSiAna
    If Mr. Shaw wishs to get rid of the Fed NT cases he could just send them to me! PM me and I'll advise him where to send them.

    I have done some substitutions for Magnum and Standard in various test and some do show better results. But we need to understand what is happening...ammunition used in colder climates benifit from hotter primers in some instances. In very hot weather, like that in the LA Bayou, standard primers help maintain reasonable pressures for some loadings. Dense heavy charges, compressed loads or slower powders may need hotter primers...

    The "Brisance" of a primer (shattering affect) breaks up the larger grannules of slower powder and drives the heat and flame deeper into the powder charge for better ingnition properties for the most part. Either way the powder charge needs to be fully ingited before the bullet moves! As pressures build and heat increases the the powder continues to burn at the accelarated rate of consumtion.

    I think there are others who are making NT ammunition but maybe not for 10mm.