KB! In New G20. Ideas? What Next?

Discussion in 'Reloading' started by pasky2112, Aug 29, 2012.

  1. shotgunred

    shotgunred reloading nut

    As I stated earlier I am concerned with accuracy not velocity. Your paper target is never going to notice the difference. I know that a lot of guys think that a 10mm is close to an atomic bomb. But they are not. Unless you are trying to make your own BEAR load there is no reason to keep pushing it. The lower the pressure the more "mistakes" you can make without blowing your gun up. However if you want to push your loads a bit you are much better off using longshot than #7.

    Secondly looking at your pictures I would hazard a guess that part of your problem was you were over crimping.

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  2. Thanks for taking it as it was intended. So what flattens primers? Pressure, right? How could the pressure from AA #7 flatten the primer but still remain at a safer level than another powder that did the same thing? It just sounds like myth to me, luckily a myth that isn't too widespread.

  3. pasky2112,

    I am new to reloading handgun ammo, so I am not familiar with, "crimped with Lee FCD".

    Since it has been established that you were probably at the max (or maybe slightly over) powder charge, could you have possibly over crimped that failed round causing the KB?

    #103 SBray, Aug 31, 2012
    Last edited: Aug 31, 2012
  4. 10mm has slightly thicker case so it is possible to swage the bullet and reduce neck tension in the process. I measured it with my FCD. Also Lee's basically instructions for the FCD lead to too much crimp. So you do have that as a possibility. Especially if you did the "add a complete turn" thing.
  5. The best way to close up the case mouth on straight wall cartridges is with a taper crimp die. The Lee FCD is not highly regarded around here when it is applied to pistol cartridges. The rifle version is somewhat more useful.

    If your sizing die is adjusted properly, there is nothing for the body of the Lee FCD to do and whatever crimp it may apply is not necessary.

    Just close up the case mouth and don't dent the bullet in any way.

  6. Taterhead

    Taterhead Counting Beans


    The primer condition from the photos is consistent with what I have observed using Accurate no. 7 & 9 (A7 & A9) accross a wide variety of charge weights. Flattened primers might be an indication of excessive pressure but not always.

    I and others have noticed that with LPPs, A7 & A9 seem to flatten primers a bit extra no matter the charge. It is subtle, but a bit more than what I have observed with other powders. GT user Yondering on another thread hypothesized that because A7 & A9 granules are so tiny, they work down through the flash hole and completely fill the primer area voids with powder. Seems to make sense: more compustibles in the same volume of area could cause more pressure on the primer itself. I am not sure.

    Whatever the reason, I have done a couple dozen different workups with various lots of A7 & A9 and this seems to consistently be what I have observed. Starting charges to max charges: primers are a little bit flatter with these powders than with others. They look just like the 2nd from the right case in the OP's photo.
  7. IIRC the max load for No7 as stated in the Sierra reloading manual for 180 grain bullet is os slightly less then 11 grains.

    If you are throwing 12 grains of AA#7 I think you got lucky it was not worse.

    hey wait a minute is this a Joke post?
  8. I just started reloading, 20 rds. of 9mm so for and all are smaller than mouse farts til I learn alot more. Have a couple books, but this thread and others like it is also valuable info. in helping us newbies.
  9. dla


    Seems funny to me. After 100+ posts, I hope somebody realizes that a guppied case IS a an over-pressure sign - regardless of the load.
  10. WiskyT

    WiskyT Malcontent

    It could be the pics, you may see them better on your monitor, but I don't see guppies in the OP's pics. His initial description sounded like they were guppied, but after seeing the pics, they look normal to me.
  11. I truly hate to hear of this KB. :( I'm glad the OP is OK. :)

    I have a G20 and have never fired a round down the worthless stock tube. Glocks would be much better pistols if you could option out of having to buy there worthless barrels with the pistols. I've seen enough Glocked brass to last me a friggin life time. With most of that being retail ammo. The thought of reloading much less pushing max reloads in a Glock tube is the sort of thing Hollywood could make horror flicks out of.

    My G20 has a 5.15" LW barrel in it. Feeds and chambers fantastic! Don't need any of Glock's sloppy chamber characteristics to ensure the pistol is reliable. Much less there awful support.

    I shoot max loads and above with my G20 and LW barrel. Brass always looks great! I don't get concerned over flatten primers. I do get concerned... Very concerned over primers with no dent in them or flowing back into the striker slot in a Glock. Your then running up against a very big problem. And if you have a Glock pistol or load in said pistols that swipes the primer you got a big problem.

    I do all my initial work ups with Fed primers. There soft and easy to read. Once I get in the neighborhood I then switch to Rem, CCI or Win primers for the fine tune. And stock up on those rounds.

    And for goodness sake's folks. Get a set of check weights. This is so important. I don't care what style or price range your scale or scales are using. You have to have check weights and use them. They will save your bacon when you start pushing and going nuclear! They help to keep your scales and your self honest.

    As for the load and powder? I've seen AA7 do some strange things when you push it hard. Some strain gauge testing many years ago showed me some ugly 2nd and 3rd wave pressure spikes. It tended to go whacko when pushed. And i think the OP just experienced some of those whacko psi spikes in a useless OEM Glock Barrel.

    Have Fun!
  12. Just my opinion, but if you need to switch barrels your pushing things too hard.
  13. pasky2112

    pasky2112 Senior Member

    The Lee FCD is a Taper Crimp, no?

    Regarding the Crimp possibility...
    I set up my crimp die to just take the flare out. When i first set it up, I pull the first few rounds after I get the flare out to make sure I, to the best of my knowledge, do not over crimp....e.g. >1-2 whacks, the ring dent I believe u are referring to and gouges or excess 'scratching'. When I started loading for 10mm, I backed my crimp die way off so that it wasn't doing anything. Then I gradually tightened it down until I could 'feel' it. I'd measure the case mouth dia. Repeat process until it measured .422-.423" and fit freely in my case gage. IMO, the Lee 'turn one...' generic instructions seemed...well...generic. I prefer things more precise.

    To clear up the 'bulge', 'guppy', 'glocked brass' thing. Best I can put it is I see cases 'misshapen'??... near the base on one side vs. the other whenever I shoot out of my glock stk bbls...reloads AND factory, 10mm .40 .45 (as seen in the pic I posted).

    BTW, the left one (#1) is the factory Hdy 155 JHP case I fired post-KB. It's primer doesn't look much diff than the other 2 intact cases, IMO. I realize the pic doesn't show the case head too well but that was kind of the point of the exercise. ;-)

    Anyway, I don't see the "misshapen" cases in my AM bbls. I DO in stk Glock bbls. This, in my limited experience, is what I consider 'usual bulging' and what I meant in my orig post.

    So, How else would one objectively measure an over crimped rnd? Why would I NOT crimp?? as someone suggested? The only rnds I don't crimp are my single-fire rifle rnds.

    Thanks again,

    - Dave
  14. No! The die is doing a lot of stuff including trying to swage the bullet diameter. There is absolutely no love for that die by the majority of people on this forum. It attempts to solve a problem that doesn't exist and creates some new ones while doing it. You just don't need it.

    A taper crimp die is the proper way to get the flare out of the case mouth.

    You want to straighten out the flare without swaging the bullet diameter. You don't want the case mouth to indent the bullet in any way.

    You should crimp bullets that have a cannelure - particularly heavy recoil cartridges like .357 mag or .44 mag. You shouldn't crimp cartridges that headspace on the case mouth like .380, 9mm, .40 S&W, 10mm, .45 ACP. AFAIK, the story is the same for .357 SIG because SAAMI says the cartridge headspaces on the case mouth. I believe it really headspaces on the shoulder like every other bottle neck cartridge. In any event, no noticeable crimp. Just straighten out the case mouth.

    You can use a lot of different dies to attempt a taper crimp. However, the taper crimp die is actually intended to slowly taper the case mouth and is much easier to get set up properly. Most other dies want to make a roll crimp and might be coerced into closing the case mouth but it will be highly dependent on case length.

    There's just no reason to use the wrong die. Taper crimp dies don't cost all that much.

    #114 F106 Fan, Sep 2, 2012
    Last edited: Sep 2, 2012
  15. FCD is a post sizing die and a taper crimp die.
  16. Richard,

    I just want to confirm that the Dillion Crimp Die is a taper die, correct?

    Since I got back into reloading handgun ammo, I have been using plated bullets and have come to the conclusion that I am never going to buy them again because it takes very little effort to over crimp them. Also, I just don't think there is any real saving in them over jacketed bullets.

    In an effort to avoid over crimping, I just adjust the die down until I feel it touch the case and then turn the die down in about 1/8 of a turn and put the round in a case gauge, (to repeat this process) until it goes in without hanging up.

    To double check, I take the round apart and check the bullet for crimp rings or scratches that would suggest it had been over crimped.

  17. Dillon is a crimp die in pistol calibers. Roll in revolver calibers.
  18. Thanks Steve
  19. Taterhead

    Taterhead Counting Beans

    100% agree!
  20. Yes although I got along for a long time with an RCBS taper crimp die.

    I tried them and have decided that if I need a jacketed bullet, I might as well use a real jacketed bullet. By edict, my grandson shoots ONLY jacketed bullets but I load lead for myself. So, I buy bullets from Percision Delta. They're not a lot more than plated and my loading manuals have data. I like printed data.

    Sounds right! I usually use a pair of dial calipers to ensure that the casemouth diamter seems reasonable and then I check a sample of rounds in a case gauge and, sometimes, in a barrel. I just like to check the results.


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