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Post by sako75varminter on Jan 14, 2017 19:28:44 GMT
Ok fellas
Something I've been thinking about doing is necking .308 Palma brass down to .260 and .243 to get my ES/SDs down to single digits....what's your thought's on this?...I know that I will have to ream the inside of the neck so that I don't get any pressure issues, worth the effort?
Cheers Glenn
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Post by oaken on Jan 14, 2017 20:51:02 GMT
Ok, I discard my lap .260 brass when it gets tight in my shell holder which usually coincides with the primer pockets loosening. That's at around 6 or 8 firings with a relatively mild load (2700fps/140 berger). Admittedly I have been having some odd stuff going on with my brass but my instinct is to have as much meat in the web as possible. You may be on to a good thing with the Palma brass especially if you plan to chase velocity and if you can be bothered with all the prep stuff. If you do try it, I'll be watching with interest.
Can't comment on effectiveness of small primers on burn consistency, you need to talk to the f/tr boys for that.
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Post by tisme on Jan 15, 2017 9:25:33 GMT
I've necked some lapua .308 palmer down to 6mm. I had to turn the necks lots afterwards. I was hoping the primer pockets would last longer but the necks split before the pockets got loose after about 6 loads with is the same amount of times I load std 260 cases. I think you might be able to buy palmer 260 soon, I'm sure 6.5 creedmore are available now. If they come out I'll use them but I don't think it's worth doing them yourself.
Just like to add I used small magnum primers (cci450)
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Post by davet on Jan 15, 2017 10:06:00 GMT
Rup / Pete......A bit off topic but do you really only get 6 reloads from your 260 brass?
I reckon on a minimum of 10 ....usually more......and run reasonably stiff N560 loads.
I do get some primer pockets slacken off early but most of the brass goes past 10 reloads comfortably.
I try to minimally resize and probably do 50 / 50 neck size and FLS with .001 setback and with annealing every 3 or 5 reloads.
Even after 10+ reloads I see no case web thinning or neck splits etc but just figure that I have had my moneys worth after a while.....even then I will use that target brass in my stalking rifle on a shoot then discard basis.
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Post by tisme on Jan 15, 2017 10:54:03 GMT
I set the shoulder back .001 and FL each time with .002 neck tension. I anneal every other load. My rifle shoots with H4350 @ 2820 fps so not to hot. After 6 loads a case neck or two will split and the groups will open up to 1 moa or more.
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Post by oaken on Jan 15, 2017 11:17:00 GMT
Never have issues with case necks or thinning etc. just extractor marks and the web expanding. Never need to length trim either. I use the brilliant Lee Collet die and never need to fl size. I do use the tightest shell holder I have and figure that once the web has expanded to a tight fit, its time to chuck it away. Yes 6-8, some may go 10 firings, before they bind in the shell holder.
I guess these variations we find are why you should start low with load development. I can get nowhere near the velocities that some do.
Be interesting to see how Glen gets on with a chamber made to the same spec with the same reamer.
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Post by davet on Jan 15, 2017 13:16:56 GMT
In Petes case I would suspect a chamber neck that had been reamed much wider than the brass causing excessive expansion upon firing and then excess work hardening when resizing......for Lap brass to split that soon I can think of no other cause if pressures etc are within norms.....especially if its being annealed.
We have already discussed this and he has taken action but in Rups case if the chamber is not gripping the brass upon firing it will slam back into the bolt and show ejector marks even at safe pressures.
I check inside the case with a dental pick for incipient head seperation thinning rather than rely on a mass-produced shell holder as a gauge.....each will vary in tightgness.
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Post by davet on Jan 15, 2017 14:25:48 GMT
Pete
Just one more thought and I am sure you have got it covered but......I use bushing dies but have a standard Forster FLS which I used in the past until I found that it did a massive 'crush' on the neck OD before the sizing ball set the ID......talk about overwork the neck!
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Post by tisme on Jan 15, 2017 14:29:19 GMT
Pete Just one more thought and I am sure you have got it covered but......I use bushing dies but have a standard Forster FLS which I used in the past until I found that it did a massive 'crush' on the neck OD before the sizing ball set the ID......talk about overwork the neck! I'll have to have a look at that. Ta |
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