Necking 30-06 to 25-06 results in blown primer

To all and for CBS,

Help me understand this in simple terms. The 'mass' of brass in the neck of a 30-06 case is greater that that of the 25-06. So, it seems to reason that you are going to have some excess brass after sizing down ( the donut). Thus, the need to turn, and then possibly neck size once again. This would depend if you were sizing with an expander ball and sizing from the inside or a bushing sizing from the outside. Regardless, wouldn't it be prudent to anneal the brass beforehand, thereby having more malleable/ductile brass that would cause less stress on the sizing process?
Read my post just above yours, I think it will help you. As far as annealing, in general you are far better off to anneal AFTER sizing. Too soft a brass just promotes necks collpasing when you neck down. One thing that will make necking down much eaier, and less prone to over thickening the necks is to remove the stem from the seating die, set the die one full turn off of contacting the shell holder, then run the 30-06 brass into the 25-06 seater. Then run them through the FL sizing die. Using the seater as an intemediate step really makes sizing much easier.
 
I like my 25-06 with light bullets but I don't consider it "light" recoiling. It is not as harsh as my 30-06 with 180 gr spitzers of course, but a recoil sensitive shooter will struggle with it.
With a brake a 25-06 is very manageable for a young shooter.
 
Necking from .308 down to .257 is a long way to stuff brass together. That is .051 reduction in neck size, the brass has to go somewhere, so it thickens the neck. I have had it make a donut in a .264 case and extend the neck .012 in length. If your case neck is .015 thick you will often add .003 to .005 thickness to the neck. A tight chamber neck may not like a neck that thick. If you size the neck first you may not be able to get the lathe mandrel into the smaller neck. Trim neck thickness down to .012-.013 before resizing. That has been my best experience. It caused enough of a problem in my 6.5-06 that I changed to ,270 brass and finely opened up 25-06 brass for the best results.
 
I agree, there is no point turning a neck until you know what it needs to be turned to.
I have never run across this problem.
Have necked down 7mm to 6.5mm, 270 to 257, 375 to both 338 and 308. My biggest re-forming is going from a 416 Rigby case to a 338, this is done in 3 steps with annealing BEFORE each step. Norma 416 Rigby necks are not overly thick, mine average 14 'thou. Hornady brass is another story and I don't re-form that brass for my 338-416 Rigby Improved. After the sizing they average 16 'thou and I trim to clean them up and have a 4 'thou clearance in the chamber. An untouched neck has 2 'thou clearance, which is too tight for me.

Cheers.
 
Did the smith that barreled your gun use an SAMMI spec reamer? Maybe his reamer was worn and you got a tight neck? Probably made over 2,000 cases from 30-06 brass formed from military, and about every type of commercial brass. Never had any issues such as you are having. Maybe get antelope to send you some factory brass and see if you still have the problem. You might also make a chamber cast, simple to do. Brownells has the stuff and the instructions.
 
Thats my point, turning before you necks down is just guessing even if you measure neck wall thickness before.
 
If it's anything like I remember from sizing a .284 down to .25 it needs to be done in 2 steps and it will look ugly enough so that it won't turn clean worth squat so maybe you'd be better off turning it first, but I'd trade for something could use.
 
You dont just neck down and go to turning you have to run the necks either through a expander button or mandrel to push all the imperfections to the outside.
Its best to anneal after necking down before the expander or mandrel.
Most really good turning kits have a specific sizing mandrel to fit the case turner
 
You dont just neck down and go to turning you have to run the necks either through a expander button or mandrel to push all the imperfections to the outside.
Its best to anneal after necking down before the expander or mandrel.
Most really good turning kits have a specific sizing mandrel to fit the case turner

True but my recollection from long ago was that the case mouths looked flared and I ended up turning after I fire formed them. Everything worked out as I recall.
 
True but my recollection from long ago was that the case mouths looked flared and I ended up turning after I fire formed them. Everything worked out as I recall.
I know thats the fun in reloading necking up necking down turning and reaming necks fire forming etc etc the older I get I want to load and shoot keep it simple find a bullet that performs( Hammer) a powder that works a primer brass load and shoot that being said I neck down 338 win mag to 30 cal for a 30 -338 no problem just barely clean up necks it shouldnt be that complicated I think something else is going on tight chamber headspace die set wrong using brass that was fired in another rifle get some 2506 brass see if the ptoblem goes away
 
I know thats the fun in reloading necking up necking down turning and reaming necks fire forming etc etc the older I get I want to load and shoot keep it simple find a bullet that performs( Hammer) a powder that works a primer brass load and shoot that being said I neck down 338 win mag to 30 cal for a 30 -338 no problem just barely clean up necks it shouldnt be that complicated I think something else is going on tight chamber headspace die set wrong using brass that was fired in another rifle get some 2506 brass see if the ptoblem goes away
One thing I haven't seen mentioned in this post unless I read over it is headapace causing a blown primer we all know that can be the chambering or you can cause excessive headspace when resizing if the die is set wrong a friend of mine blew a 222 R mag Sako Vixen up by pushing the shouder back when the die moved accidentally blown primer extractor split stock and floorplate blown open
 
Top