Offroad Gary Posted May 26, 2015 Report Share Posted May 26, 2015 Just a quick reminder not to get complacent and always work your loads up properly! This load was safe last week when i developed it in norma brass, but a switch to federal caused some slight primer flattening.. Luckily the blaser r93 held firm and i got 3 foxes before i decided enough was enough. Anyone got a bullet puller? Link to comment Share on other sites More sharing options...
Elwood Posted May 26, 2015 Report Share Posted May 26, 2015 Well done for sharing Gary, as most wouldn't. Link to comment Share on other sites More sharing options...
BRYAN Posted May 26, 2015 Report Share Posted May 26, 2015 Were they obturating properly? They look sootie. Link to comment Share on other sites More sharing options...
maximus otter Posted May 26, 2015 Report Share Posted May 26, 2015 maximus otter Link to comment Share on other sites More sharing options...
Dorset Winmag Posted May 26, 2015 Report Share Posted May 26, 2015 Ouch! Well as you are posting (hopefully with the full use of all your fingers, cheekbone and both eyes) we can assume the scare stories of Blaser "blow ups" are somewhat "overblown" ! What bullet/powder combo were you using? I'm getting good results in both Norma and Federal brass with 47.5grains of Superformance behind a 85gr Gameking at 2.65 COAL But a cautionary tale....Thanks for sharing! Link to comment Share on other sites More sharing options...
phaedra1106uk Posted May 26, 2015 Report Share Posted May 26, 2015 It may just be me but I find Federal primer pockets enlarge very quickly, sometimes after only 2 firings. Link to comment Share on other sites More sharing options...
achosenman Posted May 26, 2015 Report Share Posted May 26, 2015 I use QL to see the effect case volume has on a load. Depending where you are in the envelope the difference can be startling. Norma cases in the 270 come in at 71gn vol, Nosler at 68gn vol. I have found that's enough to show significant distress on primers etc. Stay safe mate and thanks for the reminder, we walk a fine line. Atb Link to comment Share on other sites More sharing options...
achosenman Posted May 26, 2015 Report Share Posted May 26, 2015 Ouch! Well as you are posting (hopefully with the full use of all your fingers, cheekbone and both eyes) we can assume the scare stories of Blaser "blow ups" are somewhat "overblown" ! I'm beginning to suspect the trouble with Blaser scare stories is the truth gets a bit embarrassing for the participants. IMHO they should get a citation for effort from the Darwin Award certification board. Below lifted from another place. Here is an excerpt from the original post. So far no one has come forward with any evidence to,the contrary on this. The user had decided that his firearm did not extract as slick as he desired. He was using Hornady, One Shot case lube, in the chamber, and on the collet fingers between shots. Even after damage to collet fingers was observed, he continued to use the firearm, and lube between shots. Out of six shots, two case head separations occurred. The shooter continued to use the firearm. On the 7th shot, the firearm decided life was too short to put up with, and ended the shooter/blowupees range experience for that day. Not documented, but persons closer to the situation, have mentioned, that a Blaser barrel, in another caliber, this same shooter was treating with the case lube, had shown signs of similar bolt head finger damage, as the one that blew up. The shooter/blowupee, has refused to allow Blaser access to rifle, and ammunition. I use an R8 so have a keen interest. So far there always seems to be more to the stories. ATB Link to comment Share on other sites More sharing options...
Chris-NZ Posted May 26, 2015 Report Share Posted May 26, 2015 Lubing loaded rounds to "fix stickiness with warm loads" is increasing the thrust on the boltface as the case is less able to grip the chamber sides under firing expansion Link to comment Share on other sites More sharing options...
Shuggy Posted May 26, 2015 Report Share Posted May 26, 2015 And I'm pretty sure that overpressure rounds or lube in the chamber would have exactly the same result in a mauser actioned rifle! Link to comment Share on other sites More sharing options...
tackb Posted May 26, 2015 Report Share Posted May 26, 2015 could you not glue the primers in ? Link to comment Share on other sites More sharing options...
Offroad Gary Posted May 26, 2015 Author Report Share Posted May 26, 2015 Load was 38.8gn n150 under a 85gn tsx set .050 off, with the norma brass i'd been up to 39.4gn with no pressure signs. I shot a vixen and 2 cubs at 200m and was in the "zone" about to do the other 4, which i will have to get tonight with a bolt gun until i've sorted out this issue. I'm surprised the change of brass caused such an overpressure, ive done it lots of times before with no problems whatsoever, even with apparently hotter loads. I will also be checking case dims incase I've incorrectly sized the brass. The shots felt very punchy! Link to comment Share on other sites More sharing options...
achosenman Posted May 26, 2015 Report Share Posted May 26, 2015 I've just run QL mate and TBH you should be fine. I have no idea what your real world case vol is but 38.8 needs a 4gn vol reduction from the default case to get you up to where I wont go pressure wise at 56967psi. The limit is 60191psi standard chambering. Something else might be at work here. ATB Link to comment Share on other sites More sharing options...
Dorset Winmag Posted May 26, 2015 Report Share Posted May 26, 2015 Agree.... although all copper do behave differently at times. 38.5 gn of N150 even at a coal of 2.50 is only just into the purple with a case capacity of 54gr H2O under a 85gr TSX Was it a particularly hot day? Rounds sitting in the sun prior to firing? Link to comment Share on other sites More sharing options...
Offroad Gary Posted May 26, 2015 Author Report Share Posted May 26, 2015 No, it wasnt hot. 19.50hrs last night. Rifle had had a deep clean about 20 rounds earlier. Shot about 10 rounds of 55gn noslers to re-zero then 3x3 test rounds in the norma brass to develop this load. Primers were normal during the tests @ 38.8, 39.1 and 39.4gns. Was same powder, primers and seating depth. Federal brass was once fired and f/l sized with the same die setting as used for the norma brass which is headspaced to .002" to chamber in the blaser. Primer pockets felt normal. Link to comment Share on other sites More sharing options...
gun nut Posted May 26, 2015 Report Share Posted May 26, 2015 Given all of the above, any chance you used a different powder? Just a thought. Link to comment Share on other sites More sharing options...
The_Dogge Posted May 26, 2015 Report Share Posted May 26, 2015 I found just using a different batch of cases of the same make (Remington) gave pressure sign, though I'm talking about a visible extractor mark, not totally blown primers! This was with a mild mid table load which showed no sign at all with the first set of cases. I would guess swapping brand without working up would be a bad idea, and it looks like it is. As well as the safety implications, the load won't be optimised if you change the case, thanks for sharing, a good reminder to everyone. Link to comment Share on other sites More sharing options...
furrybean Posted May 26, 2015 Report Share Posted May 26, 2015 As a separate point, has it pitted your bolt face? Link to comment Share on other sites More sharing options...
Gandy Posted May 26, 2015 Report Share Posted May 26, 2015 Goes to show how much pressure a rifle action will take. I would be interested to see the water volume be weight difference and or case weight difference just out of curiosity. Link to comment Share on other sites More sharing options...
achosenman Posted May 26, 2015 Report Share Posted May 26, 2015 I did that experiment a few years ago. While its an indication of a trend, I found no useable correlation between weight and volume, other than the heavy cases stand a grater % chance of having less volume. I now always measure H2o vol. I take a fired case with the primer still in place, weigh, then weigh again full of water. I take an average of ten measurements and use that for the batch. Lapua, followed by Norma are by far the most consistent cases I have found to date. ATB Link to comment Share on other sites More sharing options...
Offroad Gary Posted May 26, 2015 Author Report Share Posted May 26, 2015 Quick update. Bolt not damaged Charge confirmed as 38.8gn Bullets weigh 85gn at .243" od Headspacing 0.001-0.002" Powder definately n150 (n135 looks different) Fresh federal cases and fired sako(norma) cases weigh the same +\- 0.1gn Barrel cleaned, a little soot and copper removed Twitch applied for... Link to comment Share on other sites More sharing options...
MrCetrizine Posted May 26, 2015 Report Share Posted May 26, 2015 I've only seen a case look like that once before. It was a factory .38sp that was perfectly made with the exception of not having a flash hole. Link to comment Share on other sites More sharing options...
Gandy Posted May 26, 2015 Report Share Posted May 26, 2015 Fair play think I would twitch too. Link to comment Share on other sites More sharing options...
tackb Posted May 26, 2015 Report Share Posted May 26, 2015 There's no way you got some large pistol primers in the cases somehow is there ? Link to comment Share on other sites More sharing options...
Offroad Gary Posted May 26, 2015 Author Report Share Posted May 26, 2015 There's no way you got some large pistol primers in the cases somehow is there ? Dunno, just used round shiney ones like always Link to comment Share on other sites More sharing options...
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