Need Help fella's. Got a Forster neck turning tool. I have been turning the necks to not completely cut around the neck. I am taking off just enough to make the neck round. It leaves a little of the smallest part of the neck.

Is this enough or do I need to completely clean up the neck?

Anyone got any experience with this?

If this is a factory chamber, and you are not trying to fit necks to a certain size chamber neck size, what you described, (just cleaning up the high side), is a good way to go. If you are using regular dies, (non bushing), the more you take off the necks the less neck tension on the bullet you will have. (could be good or bad) Bushing dies allow you to vary neck tension as necessary. ol blue

Neck turning is counterproductive in a factory chamber. Our host, Saeed, published his results and has found it so, as I have. I believe it still may be posted somewhere on this board if you do a search.

Best thing to do is to check neck wall thickness. With the quality in brass today it's easier to find one lot of brass with neck walls varying less than .0015". Use that instead, dump a bad lot, and avoid the work of turning. Removing material just creates a sloppier fit, moves the cartridge, and particularly the bullet, further from the centerline of the bore and this will affect your accuracy.

Having stated my piece, if you persist in turning, measure the thinnest neck wall you have, set your neck turner to clean the high spots so that the 25% or so of that wall is cleaned, then turn all the rest to that same thickness. Depending on how good or bad your brass is, you should end up with necks cleaned up between the 25% and about 75%, but don't expect better accuracy.

I agree that turning for a factory chamber, (as long as good brass is used), probably won't help very much. But I don't know how you figure it will, "move the cartridge, and particularly the bullet, further from the centerline of the bore and this will affect your accuracy". Actually, assuming a chamber cut basically in line with the bore, if the neck wall thickness is even all the way around, and then it is run through a good concentric die, alignment of the bullet with the bore should be enhanced. That enhancement probably will be negated by many other problems commonly found in factory rifles, but, at any rate, I don't think the cartridge will be moved further from the centerline of the bore. ol blue

[ 02-27-2003, 20:39: Message edited by: ol blue ]

My own experience with neck turned brass in factory rifles is that it does improve accuracy somewhat. I'm satisfied with no more than about 75% of the neck cleaned up.

If you think of the case as a cylinder and the chamber as a bore, discounting the tapers which would be "equal" so to speak, when the round is fired it fills the chamber except for a slight amount of brass spring back. The case should theoretically fit the dimensions of the chamber and any irregularities, i.e., differences in thickness of the neck sould be reformed to the interior of the case. In otherwords all the miss shapen stuff should be ironed into the inside. Theoretically, that is.

When you resize the case, the reverse happens and the difference in diameters gets pushed around some more. Because the case isn't supported and is allowed to move around, you dont know where the difference in thickness actually goes but it does go somewhere. Theoretically, of course.

The only reason I turn my necks for factory chambers is to allow a more uniform release of the bullet, hopefully starting the bullet out straight instead of slightly off center.

Here is the "REAL" story. First, you have to turn the case neck on a mandrel so the different diameters are ironed to the outside of the case and you are only cutting the high spots on the outside of the case neck, theoretically speaking. Then you resi

I agree with ol blue, "if" you neck size only. The case will lay on the neck, well it would lay lower in the chamber if the body and headspace were not tight as a fireformed case. The cartridge centerline would indeed drop as compared to the bore centerline if FL sized, and alot of guy FL size all their hunting ammunition so it makes sense you would be reducing the accuracy potential in this case.

On the other hand, if you neck size you won't have this alignment problem. I believe that a 75% cleanup on the neck is minimum and 100% is better, just use the right bushing to keep tension where you want it to be. This WILL increase accuracy, by how much is debatable.

I do not use the "Forester" neck turner of mine for the simple reason it torques the case head in the collet and will cause uneven thickness when cutting.

It holds the cases neck tight against one side of the mandrel because the collet will not let the neck float on the mandrel.

It then cuts the opposite side deeper because the cutter cannot force the case neck away from the cutter keeping the neck against the mandrel as it rotates around it. It doesn't matter how tight your mandrel is either, it will do it with one that is super tight too, it's a nice concept, just a bad design. If you loosened the screws holding down the collet holder to the base, and let it "float" a bit while turned them you would probably do ok though.

A hand held unit such as K&M's will let the neck stay on the mandrel directly under the cutter, which has either a 4 or 10 degree back cut on it to force it to stay against it too. This will give you consistant neck thickness.

The more you turn off the brass, for a factory chamber, the more your brass will be worked, just something to keep in mind. Factory chambers are already ridiculously loose, so I would suggest keeping them no more than 100% cleanup.

I recommend a $15.00 Expandiron die of K&M's to iron out all the variances to the outside before turning too.

[ 02-28-2003, 07:13: Message edited by: Brent Moffitt ]

if you full length resize, you may a condition of the the cartridge laying off the centerline because of gravity. But if you only neck size, then the larger body size will help keep it more in the centerline of the chamber...if you seat the bullets to touch the lands you could do even more to keep everything in line. Of course you will have to watch for pressure signs as you move up with the load increases. Then if you have a long throat and are using short bullets, you may be able to seat against the lands and keep enough bullet in the case. What other accurracy tools do you plan on using?...bob

I will do all the other stuff. Clean up the primer pockets inside and out. Trim OAL and chamfer the cases.

As I stated. I have never neck turned before. I have a friend in the Benchrest Game and he does it before he ever uses a case. I have a test group for my .223 to test it. I have loaded 5 normal cases with historically good loads and 5 that have been neck turned. All other variables being the same. Hope to get out tomorrow and test. I shoot all my groups at 200 yards. The rain and snow has been almost constant for about 5 weeks.

turkey scouting in the morning also.

Thanks to everyone for your input.