8mm Brass Shortning...Help!!!

[Depreacher]

Thought my firing pin spring was going out. Shallow indentions in primers, then finally a misfire. I ordered a wolff spring. While waiting and neck sizing my brass it came to my attention that the brass had shortned about .005" from several loads of 16gr. 2400/170gr. Lee. So, what do I do. Trashcan it, drill out the flashole to .098 and try to expand it out, fireform it with cream-of-wheat,or what. cbp

[mike in co]

0.005 should not allow a misfire...unless the firing pin protrusion was marginal to begin with. i'd look for firing pin length....

[stocker]

When you say the brass is 5 thou. short are you referring to overall length? That would cause no problem. More critical is any change of length at the shoulder which affects your head space. If the shoulder has been moved back significantly that would cause the problem you describe.

If that has occurred try running a 375 cal expander button through the case neck and then resize with your regular die only enough to create a false shoulder in front of the neck/shoulder junction. You will have to tinker a bit so you get a slight crush fit when you chamber such a case in your rifle chamber.

Reform the case with a fairly stout load and you should get a properly headspaced case again. Examine all fire formed cases for any indication of internal thin spots which may cause separation.

If headspace isn't your problem you've already had good advice on where to look.

[XBT]

I’m with Mike on this one. Assuming your gun is a Mauser, the fireing pin protruson should be about .060. I would look there first.

[Depreacher]

Well boys, I found two things wrong with the K98. The firing pin protrusion is only .053 to .055. I then put my calipers on a business card and found it to be .012". Tore off a small piece to cover the bolt face. With a neck sized brass, the bolt would close with just a little difficulty. Assuming (I know, I know) that the powerful camming action will compress .012 to maybe .007 to .008" it still looks like trouble. The brass has been loaded several times and may split with a .375 expander, if I had one. Do have a .357 expander. Aside from the firing pin problem, what can I do to stop case shortning in the future. I am shooting 170gr. Lee/16gr. 2400. Drill flash hole out to .098, use Kapok, Dacron, polyethylene, or grex filler, take up bowling???? I have 300 Canadian dominion cases made in 1942. Excellent condition. Weird huh? I am tempted to trash can the Remington brass and use 65 year old brass. Hope it isn't brittle by now. If dangerous tell me now! THANKS cbp

[carpetman]

Castboolitpreacher---You have 300 Canadian brass ---weird huh? No,with Canadian brass it would be weird eh?

[swheeler]

.050 to .060 if fine for pin protrusion. Make your brass fit the chamber OR have the shoulder set back on the barrel and reamed to min headspace. As reloaders we have the option to make all of our brass fit the chambers perfectly, you were given sound advice above, use it. Changing to some new brass will let you start over again, with the same ROOT problem, you'll be right back where you are now- SHORTLY!
Scooter

[felix]

Cman, I thought the Canadian Brass was a jazz band. And, all this time I thought the Dominion was a bunch of bad guys on Star Trek. Live and learn, right? ... felix

[fourarmed]

Preach, as previous posters have pointed out, you have excessive headspace WITH THAT BRASS. Either the brass was shortened in the chamber due to the low power of the load, or it was too short before it was fired. I would consider the latter possibility first. Try some other brass that you know is correct length. You can check this with a case headspace gauge, or get some factory ammo. Checking it in your chamber only tells you that one is longer than the other, not which is correct. If correct brass produces misfires, then you have a long chamber. The business of throwing up a false shoulder with a larger expander will fit the brass to your chamber in any case. If brass fit to the chamber shortens, then you need a longer firing pin. You might also try Federal primers and see if that fixes it.

[NVcurmudgeon]

CBP, I started in the 8mm business with a 1933 Obendorf which had a mismatched bolt and plenty of headspace. Never had any troubles with it, but to be on the safe side I made false shoulders on the cases, then partial sized for maybe a dozen firings. The old Obendorf is now in the hands of a friend who has no trouble either. My current 8 X 57 is a new 1948 Yugo. In both rifles I shot mostly 19.0 gr. 2400, Winchester LR Magnum primers, and the Lee 175 gr. or Buckshot's 240 gr. Loverin type. Brass was W-W, Rem, or formed from GI .30/06. Just a long range guess, but I think it may be your brass.

[Depreacher]

I forgot to add that the bolt will not even start to close on my no-go gauge. There is no long chamber on this rifle. I will get some factory rounds tomorrow and see what happens. All advice well taken. If something was wrong with the rifle, I'd bet neither the nazi factory nor the slave union would stand behind it. I shoulda bought a vanguard. cbp

[Depreacher]

Stocker, your trick for the false (faux???) shoulder worked perfectly. I never woulda thunk of that. The .357 expander did the trick. 50 gr of 2520 behind a 150 gr. J_____ boolit plus a almost full length resize (just enough to leave the false shoulder) streeeeetched out those cases. One leetle question though. How am I going to stop the case shortning again????? Someone sugested federal primers. How would that help? I still want to shoot 16 gr. 2400/170 gr. lee load. THANKS AGAIN for the good advice. cbp

[swheeler]

Preacher; I hate to keep pickin' away at ya, but did you striop the bolt down to just the body to check headspace, if not did you place the no-go gage under the extractor and ease it into the chamber to try it? Sometimes extractors are altered or worn enough to jump over the rim on a cartridge, but may not jump it on the headspace gage. I like to check the headspace with the bolt stripped down(ext,ext collar, mainspring, cocking piece, and shrowd removed) chamber, lugs and lug recesses cleaned really good, that way you can get a good feel for it. Factory loaded ammo will chamber with several thousanths clearance, 99 percent of the time it will chamber in a rifle that will not close on a go-gage(a whole lot of rem senderos) You never said how many firings you had on the casings. I just went in and opened the cabinet, 8mm has 11 hash marks- first loading would have been 46 grs 4895 and 175 sierra(soft seated)- the last ten loadings were 19.0 4759 and 170 Lee, this load is approx the same as you are using, the brass has not shortened. It is r-p, the only thing done to it is inside flashole deburring, and trim, now maybe you have a lot more loadings on your brass, I don't remember off hand how many times I loaded the batch before this, but I only partial fl size, maybe new brass and your collet sizer will fix the problem.

[Depreacher]

Swheeler, Took your advice (bare bolt) and did a check with the forster no-go. The bolt will still not even attempt to close. I do know enough to not use excessive force when doing this. Was in the gun repair bus. for 7 years (25 years ago). The brass has had 3 or 4 loadings of hi-power (H380) and probably 7 or 8 loadings w/cast boolits/medium range loads (1800 fps or so). I have centered this whole thread around one misfire on a CCI 200. It ain't beneath them to make a bad one!!! I have had 2 or 3 in my 44 years of reloading. All CCI. Still, I want everything safe. Stockers trick on the faux shoulder worked fine. I can now feel a little crush when closing the bolt, and the 2520 (love that powder, and so does my lyman 55) expands everything nicely. Now I can go back to 2400. Still may go out to .098 on the flash hole dia. like sc03a3 recommended. After all, 98 is a magic number to all mauser lovers. I've only got 2 Mausers, but love them both. As love for material things goes, of course. THANKS AGAIN for your advice.

[stocker]

CB PREACHER: Now that you can get cases formed to fit your chamber try to get by with neck sizing only, and not all of the neck. Mausers have a pretty heavy cocking piece and firing pin assembly and a substantial spring to power the pin. With lower pressure loads the firing pin impact can progressively force the shoulder back with each firing. As long as you aren't full length sizing to the shoulder you should get quite a few firings before you have to tweak them again. Loads with more pressure have the effect of pushing the brass back to the bolt face and maintain proper length to shoulder.

You might also try seating bullets to give moderate bullet contact on the lands which will also keep the case pushed back to the bolt face a bit better. If shells loaded that way are not too long for your magazine try it and check whether accuracy improves or declines as a result. This can boost pressure a bit as well so don't do it with maximum loads with out working up in a proper manner.