flyingfisherman Posted January 7, 2014 Report Share Posted January 7, 2014 How do guys, Just posting about an observation, i cut all of my new 6.5x284 brass to 15 thou neck walls. Now its all once fired and reloaded. the loaded rounds are coming out at .291, which would make the walls 13.5 thou. Is this what you would expect to happen? It makes sense i suppose that brass flows and if the cases have lengthened (which they had, by about 4-5 thou), it would probably be reasonable to think the necks may be thinner? If this is the case, do necks get thinner and thinner? Ive not noticed this with other calibres? (OK, the 6.5x284 load is pretty tasty..) Or, is this just something which happens on the first firing? Ive not changed the bushing (0.291) from new brass to the first firing, because i didnt notice the neck walls being thinner. Ive not noticed any difference in velocity or accuracy with the 40 odd rounds ive shot since. Link to comment Share on other sites More sharing options...
The Gun Pimp Posted January 7, 2014 Report Share Posted January 7, 2014 Yes, necks do get thinner - however, it normally takes several loads before you need to drop a bushing size. In your case - could it be a measuring problem? Did you measure the turned neck-wall thickness with a tube(ball) mike? Link to comment Share on other sites More sharing options...
flyingfisherman Posted January 8, 2014 Author Report Share Posted January 8, 2014 HI Vince, i havent as yet, but will do that tonight. When i was cutting them initially (using the K&M cutter) i used a dial indicator to measure neck wall thickness. Last night, when i found the loaded rounds to be .291 in diameter, that was using a standard set of digital calipers. Link to comment Share on other sites More sharing options...
The Gun Pimp Posted January 8, 2014 Report Share Posted January 8, 2014 Thousandths of an inch 'come and go' when neck-turning............ Link to comment Share on other sites More sharing options...
Alycidon Posted January 8, 2014 Report Share Posted January 8, 2014 Let the tool or gauge warm to room temperature before using otherwise it will give a false reading. I found that with my K&M neck turner, do a few and put it away spot on, do a few more another night and its cutting to much off, after a while its perfect again. A Link to comment Share on other sites More sharing options...
flyingfisherman Posted January 9, 2014 Author Report Share Posted January 9, 2014 Interesting.. At the moment, im not too fussed about changing it as all of the brass is cut at the same time to the same dimension. The rifle shoots its nuts off too which suits me. Just a bit of a new one to me. Also, the fact that an overall diameter is .291 and the bush is .291 should say that theres 0.0 neck tension...? But theres more than that.. the bullets dont pull out on extraction of a round from the chamber, its absolutely fine..? So whys that then? It feels like the bush is 'working' when your sizing the cases (im neck sizing only). I will measure the O/S diameter of a sized case, see what theyre coming out at.. OK: so this answers my last question. A sized case comes out at .289 and the inside diameter of the bushing is .289 (although it says its .291.. Its a forster. Is this just a variance or is there some sort of explanation behind the size of the bush? Link to comment Share on other sites More sharing options...
The Gun Pimp Posted January 9, 2014 Report Share Posted January 9, 2014 Again, it's probably a measuring problem - you can't accurately measure the ID with digital calipers - you need an 'inside' micrometer. Link to comment Share on other sites More sharing options...
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