Plastic Coating and Bullet Size
- Thread starter Dimner
- Start date
Dimner
Named Man
Well. I got to the range today.
Tested the 70gr NOE plain base PC bullets. That went pretty well. Then as I was sighting I'm my 73gr MP NATO Heavy loads.... luck/fate/chance/complacency caught up with me.
Double charge of BlueDot. 16 grains. I haven't done the numbers yet, but it is definitely not going to be a good number for chamber pressure
The bolt is stuck firm with the case in the chamber. And it blew out my Bob sled single round carrier from the mag well. Big gust of gas blew in my face. All in all, I feel very lucky. I had the gas block turned off, so it didn't try and cycle the bolt. Not really sure, but I have a feeling that was a very good thing. Sat at the bench for about 10 minutes thinking how lucky I am and how stupid I am. This has never happened before. Yes, same sad reflections as heard a million times on the internet. I feel myself to be a very cautious reloader that takes pains to ensure safety. But I got complacent and ignored my reduced load rule that I had always followed before I got obsessed with cast bullets in the AR.
The only safe charges are ones that
1) if doubled it will still be a load within safe pressures.
OR
2) if doubled it over fills the case
I though just using a flashlight to inspect the cases before seating a bullet was enough. But it turns out a single charge from a double charge are very easy to miss.
Broke my spirit for the day. I was really looking forward to being at the range today in this beautiful weather, but I ended up packing up my toys and going home.
Tested the 70gr NOE plain base PC bullets. That went pretty well. Then as I was sighting I'm my 73gr MP NATO Heavy loads.... luck/fate/chance/complacency caught up with me.
Double charge of BlueDot. 16 grains. I haven't done the numbers yet, but it is definitely not going to be a good number for chamber pressure
The bolt is stuck firm with the case in the chamber. And it blew out my Bob sled single round carrier from the mag well. Big gust of gas blew in my face. All in all, I feel very lucky. I had the gas block turned off, so it didn't try and cycle the bolt. Not really sure, but I have a feeling that was a very good thing. Sat at the bench for about 10 minutes thinking how lucky I am and how stupid I am. This has never happened before. Yes, same sad reflections as heard a million times on the internet. I feel myself to be a very cautious reloader that takes pains to ensure safety. But I got complacent and ignored my reduced load rule that I had always followed before I got obsessed with cast bullets in the AR.
The only safe charges are ones that
1) if doubled it will still be a load within safe pressures.
OR
2) if doubled it over fills the case
I though just using a flashlight to inspect the cases before seating a bullet was enough. But it turns out a single charge from a double charge are very easy to miss.
Broke my spirit for the day. I was really looking forward to being at the range today in this beautiful weather, but I ended up packing up my toys and going home.
Ian
Notorious member
Ouchie. Glad you're ok. Might need to check the headspace after that one.
I did a similar stupid with my AR today. Threw together a load with the new to me 225646 powder coated (same thing I shot in my bolter a couple weeks ago) but adjusted overall length for the AR. Like last time, i used primed brass from my subsonic case pile. After producing a dismal group at 50 yards and something like 6" group at 100, I went back to scope the bore and looked at cases. The primer indents weren't. Most were flush. Oh chit. Checked the note in the brass container and sure enough, CCI small PISTOL magnum. Been using these up on my sub loads. Oops. Well, nothing bad except the groups, so the primers are good for at least 45,000 PSI.
I did a similar stupid with my AR today. Threw together a load with the new to me 225646 powder coated (same thing I shot in my bolter a couple weeks ago) but adjusted overall length for the AR. Like last time, i used primed brass from my subsonic case pile. After producing a dismal group at 50 yards and something like 6" group at 100, I went back to scope the bore and looked at cases. The primer indents weren't. Most were flush. Oh chit. Checked the note in the brass container and sure enough, CCI small PISTOL magnum. Been using these up on my sub loads. Oops. Well, nothing bad except the groups, so the primers are good for at least 45,000 PSI.
Ian
Notorious member
Well I shouldn't say "good" but the margin and tight firing pin bushing saved my bolt face. I can see 40K easily being safe working pressure. There's a reason I ALWAYS wear safety glasses when shooting or even hunting. I don't often screw up but the law of averages says sooner or later it will happen.
RBHarter
West Central AR
I have my own story about using recognized data in a recognized cartridge and loading that should have reduced pressures . The load data and chronograph were speaking clearly to one another too . Then poof case vent ......well pre-owned brass , maybe this one was over worked . No primer or anvil but the Carcano action let's stuff fall free out.the bottom .
Enter the stupid . There was no sticky lift , a touch gravely maybe , so I chambered another and got the same results . Both rounds showed about 200 fps slower . The primer pocket was .220+ in the large rifle brass . Appearently launching even paper patched bullets down a .007 larger bore (7mm vs 6.8) using data for a 130 jacketed with a 141 gr bullet runs the pressures up a little . Also appearently H322 goes squirrel dung right about 65kpsi . No leading though , so that was a good thing and the 7×6.8SPC Carcano was proofed at about 85kpsi with no injury .
I can't say that I've double charged a case .......
Enter the stupid . There was no sticky lift , a touch gravely maybe , so I chambered another and got the same results . Both rounds showed about 200 fps slower . The primer pocket was .220+ in the large rifle brass . Appearently launching even paper patched bullets down a .007 larger bore (7mm vs 6.8) using data for a 130 jacketed with a 141 gr bullet runs the pressures up a little . Also appearently H322 goes squirrel dung right about 65kpsi . No leading though , so that was a good thing and the 7×6.8SPC Carcano was proofed at about 85kpsi with no injury .
I can't say that I've double charged a case .......
Dimner
Named Man
Is there *any* chance this was a case head separation issue? My instinct is that I made the mistake rather than a component failure. However, I have about 400 of this headstamp of brass. 100 of which are loaded up with cast bullets to test using various loads of Rx7, H4895, and Shooter's World Match Rifle. (All of those loads have 0% chance of being double loaded, it would over flow the case if that were to happen).
I've never had case head separation before and do not really know what it would look like.
I've never had case head separation before and do not really know what it would look like.
CWLONGSHOT
Well-Known Member
That's not Case head separation
this is.
As seen in the pictures a case of separation is in the sides of the case were at things from the web into the walls of the case.
What you have there is just a case head blow out it's the least supported area of that case when you had your massive pressure wave from the overcharge or from the wrong powder or both.
CW
this is.
As seen in the pictures a case of separation is in the sides of the case were at things from the web into the walls of the case.
What you have there is just a case head blow out it's the least supported area of that case when you had your massive pressure wave from the overcharge or from the wrong powder or both.
CW
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Dimner
Named Man
okay good, thanks guys. Definitely and over charge then. With the correct powder however. Any other powder the I have on hand with a double charge would have actually been preferred. Bluedot is the 2nd fastest powder I own. Trailboss being the fastest, and that much trailboss would have overfilled the case with a double charge.
CWLONGSHOT
Well-Known Member
Bluedot is or can be VOLATILE. ITS NOT recomended for some calibers!! I have serious issues with it in my 350 legend!!!
I lie the powder allot but its not at all universally "friendly".
CW
I lie the powder allot but its not at all universally "friendly".
CW
Spindrift
Well-Known Member
What a nasty experience, @Dimner - glad you’re OK!! Actually, it seems your rifle is salvagable as well?
Whenever I do mistakes that don’t end up hurting me, I file under «useful learning experience». I have double charged once, but to no ill effects other than unanticipated recoil. And I have made a cartridge without powder- but I noticed without finding out what happens if you fire the next round against a bore obstruction.
Sometimes, I have assembled my cartridges with a feeling of haste. «Got to finish these before tomorrow!». That’s when I do stupid, dangerous mistakes.
Whenever I do mistakes that don’t end up hurting me, I file under «useful learning experience». I have double charged once, but to no ill effects other than unanticipated recoil. And I have made a cartridge without powder- but I noticed without finding out what happens if you fire the next round against a bore obstruction.
Sometimes, I have assembled my cartridges with a feeling of haste. «Got to finish these before tomorrow!». That’s when I do stupid, dangerous mistakes.
Blew out the case at the feed ramp. And the carrier tried to cycle. Gas pushed the mag out. Gas can't crack the carrier. FP hole is probably 'enlarged'. Check dim. of lower mag well and pin spacing. I posted a pic of 300 BO that appears 'belted' now. Your case looks different.