10mm High Pressure looks like this... Pic's attached...

Discussion in 'The 10 Ring' started by Burien, Mar 29, 2011.


  1. dm1906

    dm1906 Retired SO

    428
    0
    136
    Not necessarily just "working up a load". Working with new components and a high pressure cartridge. Any can fail, and damage can occur. When you cross the 30K PSI range, bad things go really bad. As you can see, it could have been very bad. As I said in the post, had this round been fired in the OEM barrel, there is no doubt in my mind the case would have ruptured. Gloves (among other safety gear) are old habit when working magnum loads up to the max (which is why I have/like magnums. Why bother with "special" rounds?). Gloves are inconvenient, uncomfortable, cumbersome, and take away from the "feel". I have very large hands/fingers, so gloves add a handicap, with already marginally sized trigger guards. I started out with 2 eyes and 10 fingers, and would like to leave with them, if possible. I've seen the results of really bad, and I do what I can to minimize the risk. Cartridge component combinations can be unpredictable. Change one thing, just a little, and the result can be quite profound. There's a fine line between "just enough" and "too much". I often find myself "up to and touching".
     

    Wanna kill these ads? We can help!
  2. _The_Shadow

    _The_Shadow Ret. Fireman

    Blue Dot when you get some compression of the powder, I feel the magnum primer provides better ignition, but working up powder charges and testing with good inspections of every casing after each shot is the only way to decide if things are actually working for or against your expected results.

    Sometimes you can work up a load by making a primer change rather than adding more powder for a given test.
     

  3. dm1906

    dm1906 Retired SO

    428
    0
    136
    I've done this on occasion, but only with the slowest of slow powders, and nowhere near max. Switch up primers on fast powders, especially full loads, and all bets are off, bad gonna happen.
     
  4. pasky2112

    pasky2112 Senior Member

    236
    0
    136
    Thanks. I see the value in them for added protection now. I don't think I could purposefully load rnds hot enough that I'd want to wear gear for blast protection. I appreciate the 'top fuel dragster' mentality, mind you. Magnums are great fun and useful. But to the point of risking life/limb? ....naahh...
     
  5. pasky2112

    pasky2112 Senior Member

    236
    0
    136
    Excellent point! The 10mm really IS flexible. I've loaded mostly .40's and used the primers in the book. But I noticed some manuals footnote a mag primer with some loads. makes sense now... Thanks!

    I'm SOOO looking fwd to this!
     
  6. Taterhead

    Taterhead Counting Beans

    Go with 300s. There is nothing about 10mm auto that requires mag primers. I do use 350s for a couple of my pet loads with Accurate no. 9 (A9). A9 is about the slowest-burning powder suitable for 10mm Auto. It doesn't necessarily need mag primers. I did workups with mag primers years ago and I have loads that work great. Standard primers would probably work fine too. I just have not fiddled with re-tests since I have loads that work very well.

    Bottom line is that mag primers can alter the burn speed of powders and impact presure in an undesirable way. All of the powder manufacturers that I know of call for standard primers (or in-between Winchester LP) for 10mm. Speer calls for mag primers for certain powders, but they are a rare exception in the various 10mm manufacturer data.
     
  7. pasky2112

    pasky2112 Senior Member

    236
    0
    136
    Great point about the mag removal. I've seen 2 blowouts in 5.56 AR's and the mags were destroyed, thankfully... and not the face of the shooter.

    Man! I'm really getting some great tips for handloading from you all... THX!
     
  8. dm1906

    dm1906 Retired SO

    428
    0
    136
    Each to his/her own, but I wouldn't call it "risking life/limb". Only getting the most out of a potential, minimizing the risk at every opportunity. Start reading post #105 of this thread, and you'll see bad things happen, even when you do everything right. I don't cross hard lines. Those KB!'s weren't even warm, let alone up to 10mm pressure. Top fuel? Yeah, that's a pretty good comparison. I run 1320 faster than John Force. Eddie Hill was the first on asphalt, I'm first on paper (or freezer-fodder). I won't try to talk you into anything uncomfortable, unsafe, or compromising. Don't do anything that doesn't feel right. Ever. You'll live longer that way. I've been doing this for near 4 decades, and ain't slowing down now.
     
  9. pasky2112

    pasky2112 Senior Member

    236
    0
    136
    I hear you. I wasn't trying to be critical or implying anything. My apologies if I came off that way.
    I like to creep toward the edge too. My first reloads we .40 S&W out of a G22 with a MG 180g CMJ SCREAMING at 780 fps! :) The guy who's chrono I was using said "These would be great for your wife to shoot." LOL Now, I need a 10mm to go the next level. I do appreciate your points about safety and carefully measuring and reducing risks and to expect the unexpected... Mr. Murphy rearing his ugly head! ;) Sometimes we find ourselves at the edge without having walked up to it.
     
  10. pasky2112

    pasky2112 Senior Member

    236
    0
    136
    Thanks Mr. Taterhead. Speer is exactly where I saw the #350's referenced. I've seen them in some rifle loads in Hodgdon 2012, too (for BLC2, I believe). I ordered 5# of BD and 1# of A7, W231 from PV for new 10mm. I already have kegs of powders for my .40 loads like A5, Power Pistol, Unique, WST (favored in that order). If mem serves me right, PP is the slowest but i don't think it'd warrant LPM's except maybe for experimenting. Don't think I'll b experimenting too much for now in 10mm. I've only been handloading/reloading for about a yr. but have gotten into it heavily. Precision Rifle forces you to do that ;-) It's fun to me.
    So have you used any of those powders above I mentioned for my .40 loads in 10mm?
    Seems most folks use BD.

    Thanks again for sharing.
     
    #130 pasky2112, Aug 7, 2012
    Last edited: Aug 7, 2012
  11. I don't know for certain what happened here, but I do know the intended loads were below published max. A true double charge is extremely unlikely as 21 gr of HS6 won't go in the case I don't think, but it's possible I somehow short-stroked the press a second time and added a grain or two.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    Interestingly, when this one lit up it didn't feel or sound any different than the previous 30 or so rds from the same box, other than the fact the action was open and wifts of smoke were emanating from every nook and cranny of the gun (EAA Witness Hunter).

    Lucky me (as usual), no apparent damage to the gun or to me. I believe these loads were 10.6gr HS6 and 165 gr JHPs, although clearly there was 'an issue' with this particular one. All rounds fired felt quite modest.

    Check out the stretch on that case base--whew. Very lucky for ductile brass, eh?
     
    #131 Bongo Boy, May 31, 2013
    Last edited: May 31, 2013
  12. dm1906

    dm1906 Retired SO

    428
    0
    136
    More likely, the brass was defective. I've seen it a few times. Yours look very similar to those I posted earlier in this thread. That brass was in fact defective, and recalled by the mfg. Mine failed with 9 gr. BD under a 180 gr. bullet. Those also seemed uneventful at the time, and I didn't discover the first fired round (lost in the grass) until after the second.

    I can't quite make out the headstamp. What was the brand?
     
  13. _The_Shadow

    _The_Shadow Ret. Fireman

    A USA brass, I believe is Armscor...
     
  14. That headstamp is 'A USA', which is Armscor USA.

    If my sloppy handloading practices are in fact to blame, I at least know two things I can do to improve my odds. The first and most important is to completely unload the entire shellplate, empty any charged cases, and start the cycle from scratch after 'correcting' a problem. I've cut corners in the past by continuing an already-started cycle after pulling one case to fix a primer problem, a bad case mouth problem, etc. I'm not going to do that anymore.

    The other step will be to not load ammo after 11 pm.
     
    #134 Bongo Boy, May 31, 2013
    Last edited: May 31, 2013
  15. _The_Shadow

    _The_Shadow Ret. Fireman

    Bongo Boy, it will be interesting to see if the pulled rounds scale out at the correct charge weights. If this wasn't a progressive press double or short stroke, then possible powder bridging on the powder drop tube or powder drop changed its setting????????????
    Glad you weren't hurt or your gun.
    Good luck figuring it out!
     
  16. dm1906

    dm1906 Retired SO

    428
    0
    136
    Looking at the brass (and now knowing it's Armscor, which has little of my respect), I still suspect defective brass. I've seen this too many times over 40 years.
     
  17. We'll keep an eye out for bad process, but I just shot another 200 rds of the stuff today without incident--and in fact it was some of more accurate shooting as of late. :)
     
  18. "Captain, she can't take much more."

    LMAO!
     
  19. When I go out to the desert to shoot I sometimes pick up a lot of brass
    that someone else left on the ground, if it looks like a range fire has
    happened the brass could be annealed, could be very bad.

    We have too many range and forest fires in Idaho.
     
  20. Found some more 10mm cases out at the public shooting pit, looked like someone did not read this thread :)
     

Share This Page