Dan Bone Posted January 23, 2005 Share Posted January 23, 2005 First some background. I'm shooting an Brazo Open blaster that's quite old. The slide frame fit was getting ridiculous so I sent it off to get accu-rails installed. It came back tight as a safe. A bit too tight. It doesn't unlock smoothly. Vice tinkering with the locking lugs, I elected to shoot it for a bit and let it work itself "in". So far I've only had about 200 rds through it.... The load is DAMN HOT because I like it like that. The dot doesn't move! I'm using a 115 M.G. FMJ // 9.8 3N37 // 1.235 OAL.... Last weekend I'm shooting a stage at the local match. About the 5th round I seen an unusual puff of blue smoke come off the top of the gun and felt an appreciable amount of kickback in my hands. I had seen the shot on paper so I continued on with the stage. Three shots later I seen/felt the same thing and stopped. Something was obviously amiss and I wasn't willing to blow up my gun OR HANDS. After shooting I could see the black imprint of powder in the palm of my hand defining the silhouette of the grip safety and mag release. I assumed it to be a case seperation (we never could find either of the cases)..... So now the question. Why??? I've studied my reloads carefully and find nothing wrong with bullets, powder drop or crimp. So I'm left with two options. 1) the brass is just too old and I need to replace it. There's no telling how old it is. I Case Pro everything and it probably does need to be retired. I've done that already as a precautionary measure. 2) but for the question that I'm not smart enough to answer is... is it possible that the gun having a delayed/rough characteristic to UNLOCK cause pressures to increase above the ridiculous peaks I impose on it already? Link to comment Share on other sites More sharing options...
shred Posted January 23, 2005 Share Posted January 23, 2005 Sounds worse than a typical cracked case. I'd pass on shooting it until somebody competent looks at it. Link to comment Share on other sites More sharing options...
Dan Bone Posted January 23, 2005 Author Share Posted January 23, 2005 Nah... not a cracked case. We know that won't do it. More like a case head seperation. They were somewhat typical with .40 back in the day of the 175 PF. Most were caused by used brass, Nickel more so than brass, Clays powder. The gun ran good today. New brass, lighter load (124 gr // 8.6 3N37). 200 rounds through it without a glitch. That's why I'm sure it was either OLD brass / hot load or HOT load / guns timing affected by delayed unlock. Link to comment Share on other sites More sharing options...
mpolans Posted January 23, 2005 Share Posted January 23, 2005 9.8gr of 3N37??? IIRC, that's over a grain more than what I use. What pf are those loads??? How do your primers look??? Link to comment Share on other sites More sharing options...
EricW Posted January 23, 2005 Share Posted January 23, 2005 I Case Pro everything I know there's a bunch of people who use them and that I'll be publicly lambasted for saying this, but I'm extremely suspicious of roll-sized brass. It's hard for me to believe that the process could do anything but put a stress concentrator around the entire circumference of the case in the region you'd want it least. Link to comment Share on other sites More sharing options...
warpspeed Posted January 23, 2005 Share Posted January 23, 2005 I Case Pro everything I know there's a bunch of people who use them and that I'll be publicly lambasted for saying this, but I'm extremely suspicious of roll-sized brass. It's hard for me to believe that the process could do anything but put a stress concentrator around the entire circumference of the case in the region you'd want it least. I've never done it in 38 super, but I once did a test with 40 S&W . I bought 100 rds of factory ammo - Fed & PMC. Shot the factory loads and then roll size, reload and fire. Repeat process. Load was 180 gr w/ N320 - major PF load out of a Factory STI Edge. After 10 loadings, no sperations, cracks or blow outs. I decided that no one was going to keep brass 10x fired so stopped. Link to comment Share on other sites More sharing options...
rishii Posted January 23, 2005 Share Posted January 23, 2005 I Case Pro everything I know there's a bunch of people who use them and that I'll be publicly lambasted for saying this, but I'm extremely suspicious of roll-sized brass. It's hard for me to believe that the process could do anything but put a stress concentrator around the entire circumference of the case in the region you'd want it least. I case proed all my super brass around 3 or 4 times a few years ago, and started to have total case head seperations, around 1 every 100-200 fired. the case head were ripped off at the extractor groove. I never had that problem before, and it might have been operator error on my part, and some of that brass was beatup, but as far as I was concerned it ruined all of my brass. and I boxed it up and never used it again. thru all my super brass away, the only good thing that came from this was it gave me an excuse to switch supercomp. Link to comment Share on other sites More sharing options...
Dan Bone Posted January 23, 2005 Author Share Posted January 23, 2005 mpolans: 9.8 is a bit stout of a load, but I'm using a hybri-comp setup. I have more holes than barrel in this thing. So 9.8 only gives me a 171 PF. I've been using it for years and have been chrono'ed at a few major matches. It's always been consistently in that range. I personally like the Case Pro theory and before you guys start in on me. I already do use an EGW "U" sizing die. I won't go into that here because that arguement has been waged a few times in other threads. I think I was just being lazy/cheap by not replacing my brass periodically. I will now track it by "lots" and replace after 5 reloadings. I guess what I was after is to see if anybody knew that if the timing of the slide cycling serves a function to releave case pressure - i.e. does the delayed unlocking in my gun provide an increased pressure. Link to comment Share on other sites More sharing options...
MoNsTeR Posted January 23, 2005 Share Posted January 23, 2005 ...the case head were ripped off at the extractor groove. That's about what I would expect to happen if you roll-sized semi-rimmed brass. Supercomp, TJ, 9x23, 9x19, etc. should be ok, but roll-sizing .38 Super Auto strikes me as a no-no. Link to comment Share on other sites More sharing options...
Dan Bone Posted January 23, 2005 Author Share Posted January 23, 2005 What makes you you say that? The plates have a relief cut for the rim. There's not a lot (if any) pressure put on the rim. Link to comment Share on other sites More sharing options...
benny hill Posted January 24, 2005 Share Posted January 24, 2005 If you're going to shoot hot loads, try a slower power. Won't have all the pressure but will have the speed you're looking for.Also it will burn in the comp & shoot flatter. Link to comment Share on other sites More sharing options...
Jody Waring Posted January 28, 2005 Share Posted January 28, 2005 What powder's do you recommend Benny? Link to comment Share on other sites More sharing options...
benny hill Posted January 28, 2005 Share Posted January 28, 2005 My old standby, accurate #7, w-w 571, vv105, or HS7. Link to comment Share on other sites More sharing options...
eric nielsen Posted January 30, 2005 Share Posted January 30, 2005 I agree, the load sounds very hot. I wouldn't go much over 9.0gr of 3n37 - then I'd look for a slower powder. I like 3n38 a lot. Do a search if you're curious about that powder. Vectan SP2 is also very nice. Link to comment Share on other sites More sharing options...
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