Quote:
Originally Posted by Pudelpointer
Well now, that is very interesting. Had a bunch of 140gr 6.5x55 loaded with 37.0gr of 4320 (powder lot was old, but properly stored and in good condition) that were insanely hot!!
I was reloading 140 Nosler custom competition bullets (loaded over RL22) and they were tumbling out of an old '96 Mauser. I had a bunch of the 4320 loads my uncle had loaded years before, so thought I would run a couple through the rifle to make sure it was the bullets. I fired four rounds with the 4th sticking the bolt. In theory the load should have been pretty mellow, likely around 2350 fps; but the recoil was unreal. I run 130s out of a similar weight 270 at 3050 fps, and the recoil from the 6.5 was noticeably worse.
In conversation with my uncle, he stated he had only ever shot one deer with the load, and the results were horrific. "Bloodshot from ear to a-hole" was his words.
I pulled all the bullets and weighed all the charges, all 37.0 gr. In hindsight, I wish I had kept one round to run through the chronograph, but frankly I would be too nervous to pull the trigger again.
I reloaded the same bullets in the same cases with 4831 and they performed reliably.
We have scratched our head about this for a while now, and your post may provide an answer. Do you still have the lot numbers? Do you remember what year it was?
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I had a drilled and tapped, semi customized mauser 96 6.5x55 blow up with 140 gr. X bullet and H4350 reloads......I had a seating issue the batch before and while working up loads with X's, stuck the bolt shut. C.O.A.L. issue I thought as the loads were well within the book data.So fast forward a year and I am working at it again, I used a load 1 gr under minimum with H4350, trying to be cautious.My reloading mentor was literally watching me load these and double checking my work as these rounds were loaded.I loaded three rounds.
I go to the shootin' spot, set up and fire a couple of 120 gr. ballistic tips, no problem, on paper.Fire the first of my three rounds, fires extracts, on paper, no problem.Adjust scope a bit, load the second.
Aim, squeeze.........BOOOOOM! Rifle comes apart, fortunate that it was as strong as it was.Bolt bent, head of case blown off, part of receiver gone, broken along holestapped for bases.20 feet away was the furthest out piece.Floor plate blown out at my feet. Bolt bent in receiver, saving it from going through my face.I got lucky, just a brown stain in my underoos, a ringing in my ears, and some brass bits in my face.One of the action screws was sheared, the casing was annealed in the chamber. The bullet hit dead center on the target, incidentally.
So the remaining round weighed in as it should.The moral of the story...
1. Be careful always, because that was close.
2. No going under min or over max in published data.Not even 1 grain either way.
I think it well may have been stress cracks from sticking the bolt shut the year before that got progressively worse over the 4 or so rounds between that moment and the detonation.
Or it could have been the phenomenon that has been rarely reported from just this type of situaton.Underloading slow powder has been said to cause detonation (rarely), but it is not an unheard of thing, just no solid empirical/ repeatable data on it that I know of.