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Badger's ballistrickery...

Posted: Sun Jul 24, 2016 5:38 pm
by meles meles
Well oomans, we have survived our foray into paw loading cast bullets !

We started our Saturday evenin' shoot at 600 mards with GGG 7.62x51 in our DTA: no problems there apart from we miffed the markers by sending them a radio message suggesting, ever so politely, that they should remember to mark our fall of shot with the orange disc. "We are!" came the reply, 'we just haven't needed to move it for the last three rounds." We apologised. Smugly. shakeshout

Next up was our AIA jungle carbine chambered for 7.62x39. With Tula milsurp we needed to hold over by almost 7 feet at 600 mards and the dispersion was far greater than with the DTA. We could keep all our rounds in the black, but no better than that. Still, in a brisk breeze at 600 mards, we were happy.

After that, with fear and trepidation, we chambered a few rounds of our big 'efty 247 gn cast, gas checked, boolits sat atop 23.3 grains of Alliant 2400. We squeezed the trigger gently and ... Bang! Not a big BANG, but a nice, safe Bang ! All body and rifle parts intact. The empty case ejected easily and the primer showed no pressure signs. A modicum of sooting around the case neck but nothing worse than the GGG cases. We fired 4 more rounds, inspecting each case carefully. No apparent issues. The group size at 600 mards was nowhere near as tight as with a condom bullet, but this was our first effort and we were happy to keep them all in the four ring. We thinks there's plenty of scope for improvement. Slowly and carefully.

Relieved that we were still alive, we next loaded some subsonic rounds for a 100 mard shoot. These were the 247 gas checked lead boolit sat over a starting load of 8.6 grains of Ramshot Zip, and incrementing up in 0.1 grain steps to 9.6 grains. All worked well, giving a pleasing phut... and no pressure signs. The rounds loaded at 9.1 grains seemed particularly good, grouping to 1.5 inches at 100 mards.

We think we're going to like this efty cast boolit malarkey...

Re: Badger's ballistrickery...

Posted: Sun Jul 24, 2016 5:46 pm
by dromia
Well done!

See even badgers can shoot cast.

I would still move away from the 2400 with that load especially if primers and ease of ejection are what you are using to indicate pressure. Sheep's entrails poked with a stick will tell you more about the pressure of your round of ammunition than peering at fired primers. If you are getting hard ejection then it is too late and you have already reached high pressure.

Re: Badger's ballistrickery...

Posted: Sun Jul 24, 2016 5:51 pm
by meles meles
The rounds ejected easily, no hint of hard ejection.

The primer indentation looked identical on the paw loads as it did on the GGG factory cases

The primers hadn't flowed anywhere.

The primers hadn't flattened.

The cases hadn't bulged.

The cases hadn't split.

The necks appeared to have obturated identically to the GGG.

What else should we have been looking for ?

We'll happily move on from the Alliant, especially if we can tighten the group.

Re: Badger's ballistrickery...

Posted: Sun Jul 24, 2016 6:00 pm
by dromia
meles meles wrote:The rounds ejected easily, no hint of hard ejection. So if there had been hard ejection then you are over pressure and in the danger zone so no indicator until it is too late

The primer indentation looked identical on the paw loads as it did on the GGG factory cases All that means is that they look the same, are you suggesting that these loads generated the same pressure as the factory

The primers hadn't flowed anywhere All that means is that the primer hasn't flowed, flowed primers can occur in situations other than high pressure

The primers hadn't flattened See previous reply

The cases hadn't bulged Like my gun has just exploded but I'm uninjured so its OK to do the same load again

The cases hadn't split I despair

The necks appeared to have obturated identically to the GGG Did you measure them both before and after?

What else should we have been looking for ?Have you read the sticky on pressure at the top of this forum?

We'll happily move on from the Alliant, especially if we can tighten the group.
Cannot promise that but a slower powder will give you more latitude to safely work up to an accurate load.

Re: Badger's ballistrickery...

Posted: Sun Jul 24, 2016 6:13 pm
by meles meles
Yuppity: we've read that sticky more times than you can shake a head at... All our observation above were in addition to anything mentioned in the sticky. There were no witness marks of any sort on the cases or primers, we derived our load from what we believe to be credible published data, double checked with Quick Load AND a Grown Up. After previous warnings and admonitions, you don't know how close we came to pulling the whole lot and resolving only ever to fire factory ammo but, after checking with others and showing them our working out, we went ahead...

Re: Badger's ballistrickery...

Posted: Sun Jul 24, 2016 6:19 pm
by dromia
So what was the velocity of the loads?

Re: Badger's ballistrickery...

Posted: Sun Jul 24, 2016 6:27 pm
by meles meles
Sufficient...

Re: Badger's ballistrickery...

Posted: Sun Jul 24, 2016 6:31 pm
by dromia
Is that fps or mps?

Re: Badger's ballistrickery...

Posted: Sun Jul 24, 2016 6:34 pm
by meles meles
They got out the barrel and made it to the target...