I have a K&M neck turner that I rarely use.
Basically, I see no difference in accuracy between brass that has been turned, and that brass that is "factory". Run out remains basically the same on turned brass and unturned brass.
I will occasionally take a "bad" case, one that keeps giving me bullet run out of .004 or more, and it does seem to help some. I guess.
My question is this. Why should I be turning necks? What benefits should I see when the necks are turned?? And most importantly, how should I be turning necks?? How far down the case neck??
Heck, maybe I have been doing something wrong all the while. Iam sure I have..sakofan..TIA [img]images/icons/rolleyes.gif[/img]
It's only rock and roll....But I like it!
There was a time when I meticulously prepped cases for my hunting rifles/cartridges. I don't anymore. I would sort cases by weight and/or volume, drill the flash holes, uniform primer pockets, measure the thickness and diameter of the rims (and this can make a difference in the WEIGHT of a case--but has no bearing on the VOLUME--something to think about when we sort cases by weight), check runout to ungodly tolerances, turn the necks and neck size only.
Today I still will sort cases by weight, but only to throw out really, really bad ones (my paramenters are much wider now, deburr the flash holes, and PARTIAL RESIZE. If we are talking about hunting rifles with normal chambers, partial resizing correctly may be one of the more important steps in accuracy--in chambers that are chambered to accept all the factory rounds from different manufacturers. This includes custom barrels
on hunting rifles.
Now back to neck turning. Those hunting rifle chambers have necks that are generally large enough that turning them just doesn't make a difference. But I have an Ultra Light Arms custom rifle that does like to shoot neck turned cases. Many of these high dollar custom hunting rifles will produce amazing groups--but with the ammo they were developed and chambered for (ie. Fed Gold Medal Match, Black Hills, etc). These rifles need those "cutomized" cases to shoot handloads well.
The bottom line? I found that I hurt or made no difference in accuracy in most of my hunting rifles by turning the necks. Runout in neck and loaded rounds is important, but we can measure things so accurately with our tools these days we have a tendency to "over" focus on these things. Something I have to constantly remind myself: The benchrest world pays a lot of attention to these things because they have super custom, super tight fitting chambers with super finicky rifles/loads built to each shooters ideas of what makes accuracy--these things make a difference under those conditions.
Location: The rifle range, or archery range or behind the computer in Alaska
Re: Neck turning
The biggest reason I neck turn is to have 1, a concentric alignment of the bullet and 2, to have the same neck tension on each bullet. For typical hunting its not neccesary. If you want the kind of accuracy to kill small targets way out there, the more quality case prep the better. Neck turned and neck sized cases with primer pockets uniformed and flash holes deburred is the differance between a .75 MOA load and sub .5 MOA loads. At 600-1000 yards, that makes a HUGE differance.
Ask your self how far do you want to shoot?
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.
In a factory rifle it is rarely worth the trouble to turn necks. There are so many variables when shooting factory guns and barrels that any gain in consistency would be lost within the many other unaddressed things that enhance accuracy.
When turning necks for a factory saami chamber, you should only turn enough that you clean up 60-70% of the case neck. If you take off brass all the way around than you took off too much. The neck should be cleaned from the case mouth to the neck/shoulder junction.
Here's a question about taking off too much metal. I turned all my cases with a K & M. I think I was probably in the 60 - 70% metal removal. On some, I did did take off metal all the way around the neck, but not necessarily all the way down the neck. After you fire that turned case, isn't expansion and resizing going to bring things into a more consistent concentric fit in your chamber? My point is, if you took off a bit too much metal from turning, won't it be a better fit after sizing for the next firing? Just wondering...
IMO if you haven't turned the necks from the case mouth to the neck/shoulder junction then yo haven't accomplished much. You will also have created varying neck tension along the neck. I haven't a clue what that does for accuracy.
When turning necks you should turn them down along their full length, and a slight mark on the shoulder is a good indication of that. Notice I said "slight".
Another thing that may be worth mentioning, that I have never seen posted on the boards; It is sometimes necessary to get a cutter blade in your neck-turner that matches the angle of your case shoulder. Some blades can not be run down to the base of the neck without cutting into the shoulder. 40 deg shoulders normally require a blade that is cut to an angle that is intended for these cases.isn't expansion and resizing going to bring things into a more consistent concentric fit in your chamber?
"isn't expansion and resizing going to bring things into a more consistent concentric fit in your chamber?"
No, not in my opinion. Firing and resizing is not going to iron out a bad case. A concentric chamber and quality, concentric dies will help maintain concentricity in a uniform case.