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help with necking down 270 brass

earlcurtis67

Well-Known Member
Joined
Apr 26, 2012
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235
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south fla.
I have some 270 barnes brass that I would like to neck down to use in a 25-06. I havent tried to neck down before so I thought I would prectice with some 2X fired RP brass.the problem I'm having is I keep getting donut/false shoulder on the outside of the case at the shoulder and neck junction, five of the six cases I've sized won't chamber, and the one that does will do so with a little persuasion so I guess that rules out fireforming. I'm using RCBS F/L dies( 270 and .25) and a Lee collet die fro the .25 I took the F/L dies apart and cleaned them well before I started. At first I F/L sized using the .25 die =donut,then I F/L sized using the 270 die then F/L sized with the .25 die = donut, I then used the .25 collett die then F/L sized with the .25 donut again, I sized the other three cases using the same processes but I used very little lube( Hornady one shot) What am I doing wrong? wrong case lube? brass too soft? should I have anneled first?...... I've tried seaches but cant seem to find an answer. I dont wont to have to buy a neck turnner because If I have too spend that kind of money I'd be better off buying some premium brass and saving the extra reloading step all together. as allways, thanks in advance.....E
 

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Make sure the front of the 270 case neck isn't bumping inside the die. A 270 is longer than a 25-06. You may have to trim the cases to get them to form correctly.
 
I have necked down a lottt of 270 brass to 25-06, and it does help to trim to length before running them through the f/l die. You may also want to make sure you check your clearance between your die and shell holder.
 
Make sure the front of the 270 case neck isn't bumping inside the die. A 270 is longer than a 25-06. You may have to trim the cases to get them to form correctly.

I have necked down a lottt of 270 brass to 25-06, and it does help to trim to length before running them through the f/l die. You may also want to make sure you check your clearance between your die and shell holder.

+1 on both counts...
Often when you are necking down brass you have to give it a bit of extra force into the die to get the brass properly formed.
Btw... what you have is NOT a donut, but a partially formed case.
Trim it down the .040", neck it down with a good "cam over" on the dies, and shoot the thing.
No multi steps are necessary here. I don't even run a two step necking 30-06 to 35 whelen... The expander has a bit of taper though in that case. I do, however use a middle step on the 375 h&h to 7mmstw conversion.
 
Try necking down in 2 steps. But more than likely you may need to turn the necks to get rid of the doughnut. Easy to do.

He shouldn't need to turn the necks unless his .25 caliber chamber was cut with a custom ordered reamer with tighter neck tolerances than the standard SAAMI spec. I use .270 Win brass to form my .25-06 AI brass, and it works fine for me. I FL resize the .270 Win brass with an RCBS FL .270 sizing die, then I FL resize it in my Redding .25-06 AI die with the decapping pin removed and the decapping stem set very high (the brass stretches and becomes longer once necked down). Then I trim the necks to my desired length, chamfer, and deburr. Then load and shoot.

If you don't FL resize them in a .270 Win die first, that could potentially be causing the issue. Not sure if that's the issue, but it wouldn't hurt to try it and see if it helps.
 
after measuring the first formed case I noticed the case was really long so I trimmed the rest of the cases before forming but the problem was still there. When I set up the dies, the shell holder just did touch the die so I will adjust to a good cam over and try again tonight. I picked up some different case lube the other day and will try that instead of the one shot, I read somewhere that you shouldn't use any lube around the neck, is that correct? What about annealing? should I anneal before or after forming or wait until I get a few firings on them. Also I'm going to try and polish the 25-06 die because the brass is showing some scratching on the head area. hopefully I can update tonight.....E
 
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