Useing a Forrester outside neck turner, I turn my necks down to where the neck wall measures .012". I get good results doing this for a .308 with a sporter barrel. I am useing Winchester cases. I haven't found any split necks after firing. Outside of shortening my case life, is there any reason for not doing this? What I'm trying to ask is, when it comes to outside neck turning, how much is too much??
Jimmy

Some folks would say any outside neck turning is too much for a standard factory chambered barrel. I'd love to hear what folks have to say about this one. I used to set up the neck turner to just round out the high spots, but never documented any difference in accuracy so gave it up. If someone has some documented experience with this, I'd love to hear too.

I beleive that if you take off enough to get an exact measurement around the circumference,.with little to no variation, (i.e. .012") then you will have an even neck tension at any point you check. This by itself should yield better accuracy. But, by rounding the high spots,..I have found that the neck thickness is still quite varied at the 4 corners.

Even though you have shortened the case life,..I would think that cleaning the necks to get a concentric .012" measurement,..would give the best results, (unless you could get a perfrect .013" and leave a little more material). Keep in mind,..that turning down your expander mandrel or decreasing your bushiing size by .001"-.002" may be necessary to get back to an adequate neck tension once the neck is turned this far.

I buy rem brass for my 300 wby. It's not of impressive consistancy. But with my elec. drill I can clean up the necks on 100 brass in about 1-2 hours and that gives me alot of shooting. I usually try and set the trimmer so I only see about 5% of the case neck not cleaned up. I think this usually yeilds about .013" of case neck.
I used to do alot of 300 wby shooting and can tell you that every stroke of the forester sizing die felt EXACTLY the same and so did the "feel" of the seating process. Loaded ammo is usually at .001" runnout or less.

In short I'm with JUSTC above--I think the benefit is perfect neck tension. My 300 wby would "thank me" by shooting 3" groups with barnes 180 xbt's at 300 yds. If the bullet didn't go where I wanted I knew it was me and not the gun or the ammo.

This should not be a big deal, but it keeps on coming up. I have neck turned cases for in excess of 25 years. I have a Forster, 2 Sinclairs, and a K&M tool. Long ago, I gave up turning necks, except for rifles that really required it--those with tight-necked chambers.

Unless you have really awful brass and can demonstrate an improvement, just forget it and buy better brass, like Norma or Lapua, maybe even some Federal. I was never convinced that the average rifle benefitted from it.

I have a .308 that has had the action blueprinted and a fancy schmancy barrel from a very famous manufacturer installed. I must neck turn for that rifle. It has a tight-necked chamber and the rest of the chamber is super tight. It will shoot, on average, half-inch groups any day that you want it to. I also have a Savage 112 .220 Swift, unmodified, that will shoot quarter-minute groups any day that you request it to and I do nothing to the cases except load and shoot them. Sometimes it will do better. Geo.

I measure the OD of several loaded rounds in multiple places and if the numbers are within .001", those are fired in the rifle.I then take one of the fired cases and place a bullet of the proper diameter into the neck. If it slides freely into the neck, no neck turning necessary for that lot of brass in that rifle. If the brass fails either test them are turned enough to pass both tests.Rick.

Welcome to the forum Rick.

A 270 that I just got has excessive headspace so I made some brass from 280 Remingtons. It shot very well but then I looked at a loaded round and the shape of the bullet could be seen on one side of the neck and not the other. This was a concern as there was .006" runout on some loaded rounds.

Now this old FN sporter shoots one hole groups at 100 yds and about two inch groups at 200. Thats the limit of my range.

So I turned some necks up to just clean up as Varming Al suggests in his site. That lot of ammo shot four inch groups at 200 yds. I have never had much luck turning necks accuracy wise but my hat's off to those that do.

Back to the drawing board.

You have turned the neck too much when the sizing die will no longer reduce the neck enough to hold a bullet! As long as the expander ball is contacting the neck when sized there will be no problem. Regards, Bill.

That is the exact reason bushing dies were invented. If you turn a neck down,..you need to size the neck circumference to a smaller diameter to get the correct neck tension.

I don't bother other than to knock off a high spot on the brass for a factory gun,..but even a non-tight necked chamber in a custom barrel should show a difference when done correctly and neck tension is correct.

[ 08-28-2003, 17:35: Message edited by: JustC ]