Home Forums Hunting & Shooting Ask The Gunwriters how to outside neck turn

The main reason I turned it was the subsequent necking down to 7mm size. I didn't shoot it in the 7mm08 beforehand, no comparisons done.

I know a lot of people size down 308 brass to 7mm08 without turning, but the two factory 7mm08 chambers I've worked with left no margin for error if I used anything but thin WW 308 to start with. Cases formed from Lapua 308 won't chamber.

The loaded rounds with turned brass came out with .311" necks. Fired brass from the present rifle comes out .314" across the neck.

A friend of mine picked up the rifle used. The stock has some wear and tear, but the crown looks good and the bore cleaned up quite nicely as best I can tell w/o a bore scope.

When I first started working with it I was getting 1 1/2 to 2 inch three shot groups at 100 yards. (This was with FC brass from 7mm08 factory loads.) I blamed it on the trigger which was heavy. (No way it was my handloads, right? ) So I took the rifle apart to get at the trigger adjustments and fortunately the rifle was old enough so the adjustment screws actually adjusted things enough to be much easier to shoot while remaining safe.

When I reassembled the rifle I noticed the magazine box was in a bind. So I spent a goodly amount of time stroking its bottom edge against a file and trial fitting until it just wiggles in the assembled rifle.

Voila! Smaller groups. The FC brass loads give triangles of 1 moa or a hair less, and the new loads in the turned and sized down RP brass give 3/4 to 1 moa.

I stayed with three shot groups because the soda straw barrel goes from cool to quite hot in four shots. It ain't like load testing in my 40X!

What Mule Deer said for the most part. Have found each rifle to be an individual in this regard. Some are more tolerant of cockeyed ammo than others. An index mark on a case gives handy reference for loading and chambering in the same orientation for single shots. Never tried it with repeaters

If you shoot a .20 Vartarg you will become familiar with turning case necks. I use the RCBS tool that has a cutter with beveled edges allowing me to get into the junction of the case neck and shoulder a bit. My Vartarg has a tight chamber and I have to take about 0.022 thousandths off the parent Firball case to chamber them. I found it best to do this in 3 passes, and neck-sizing the virgin cases before the final pass in the Vartarg die. This leaves me a consistent neck rim thickness of ~.043". I was worried about necks splitting but have fired cases prepped in this manner 4 times and have yet to see a split neck.

mathman,

I've often tried to isolate the factors that can make a rifle shoot more accurately, but to do so requires range tests under reasonable conditions after each change. If we make several changes and accuracy improves noticeably, which was most important?

One thing I will note is that even very lightweight barrels can keep plunking them in there if properly stress-relieved and bedded. Many people, for instance, are astonished when they find the light Douglas barrels on New Ultra Light Arms rifles keep zipping bullets into the same group even when screaming hot. But factory button-rifled barrels aren't usually nearly as, uh, heat-resistant.

The other factor, of course, is heat waves rising off the barrel affecting our aim.

DigitallDan,

Over the years I've become convinced that many rifles will shoot bullets with long bearing surfaces accurately even if the bullets show considerable run-out, due to the bullets being forced straighter when they enter the bore. This seems to apply most to relatively "hard" bullets, especially monolithics.

I agree with that, yet my observation comes from same caliber/same bullets in different rifles. It seems more critical in smaller calibers but that is far from absolute.

Yeah, no doubt the throat and bore dimensions of individual rifles have a lot to do with how sensitive they are to "crooked" bullets.

In general my experience is that short, light bullets (which tend to be most common in smaller calibers) are more sensitive to crooked seating, but have seen exceptions.

Another factor often overlooked in striving for straight ammo is how well the seating stem fits a partcular bullet. Target shooters are normally far more aware of this than hunters.

My first .270 Winchester was extremely accurate with 150-grain Hornady Spire Points and the old mil-surp H4831, shooting around an inch for 3-shot groups at 300 yards!
Back then I didn't know anything about bullet concentricity because I'd never found anything about it in any of the many magazines and books I'd read, but when I finally did buy a concentricity gauge almost 20 years later, I found my .270 dies seated that bullet far straighter than any other, even in brass with relatively uneven necks.

I agree. Aside from other changes test to test, the neck turned RP brass and the stock FC brass contained quite different loads.

What is the procedue you use to measure for uniform neck thickness? I think that is one of the problems im having reloading for my .220 swift with new winchester brass.

I use a ball mic to check neck thickness. I do extensive work on my comp. brass, but nothing on my hunting brass. A waste of my time and I see no advantage to it. I do use RWS, Norma, and Lapua brass on my hunting rifles and they are good to go as is. I have never missed an animal because of my loads or rifle. My misses have been on me.
Now I know a lot of you enjoy spending time at the range and working up the ultimate load. I am really happy that you like doing it, but it ain't me.

Im finding that when I seat a bullet (new win factory brass sized by a hornady new dimension f.s. die and a hornady 52 bthp match) I was getting a really tight feeling seating push that was even scraping the bullet. 3"+ groups at 200. Factory was shooting about 1.5" at 200. I then would do another pump with the sizing ball after a full stroke with the f.s. die (on new brass) then really debur and chamfer the case mouth and scrub it with the rcbs .224 nylon brush. This helped a lot and got groups down around 2ish" with the same load. Wondering if neck turning would just be the easy answer here.

I've been using the K&M Neck turner exclusively for 10 years at least. I stopped looking for anything different. Maybe someone, such as those you mentioned, has a better mouse trap. However, the K&M tool will consistently adjust 0.0002" per mark on the knob/thimble that advances the cutter. One full revolution of the knob/thimble is 0.002". It's easy to use and I'm just accustomed to using it. I like K&M reloading tools in general.

While I don’t shoot in competition, I am teaching my grandkids to shoot and reload. I want them to know how to get the best ammo for competition and hunting. I use RWS and Lapua brass for competition level loads. But for hunting, we use mostly Winchester, Federal and Remington brass in that order of preference. We neck size with Lee dies and use a body die when needed. We clean the flash hole on all brass one time. Before each reload we check the overall length, trim as needed, chamfer, de- burr and clean the primer pocket. That is all we do for hunting brass. Are we doing too much for hunting brass?

Truk,

I load to the quality of the rifle.

For a standard hunting rifle, with new brass I trim and camfer, and then I don't worry about it again until it gives me a reason to. I may turn the necks if I need to mitigate run out.

I like to neck size, but do FL size if the rounds may be used in more then one rifle.

For my custom rifles made by top accuracy smiths, I debur flash holes, weight sort, and turn the necks, neck size, and use top of the line dies.

For high volume stuff, I just size and go.

_____________________________________________________________

John:

Over the years I have read, heard and seen that the 6mm PPC is purported to be the most accurate cartridge ever, supposedly twice as accurate as any other according to reports. Why ????

I have also observed that my 6.5 mm x 57 Swedish Mauser seems to have a LONG bullet comparatively and that it delivers better consistency and smaller groups than many of my other rifles.

For the most part I have to agree with you that, in reality, longer bullets seem to deliver more accuracy with less deviation than shorter. It just make sense.

Bill

Thanks for the help antelope sniper.

One question I would like an answer to. I purchased a tight neck barrel that came with 100 prepped cases that had been fired in that barrel. When I started to load those cases, I found that they all had a donut inside the neck. To remove the donut I used a reamer to cut it out. Would it be better to fire the case, moving the donut to the outside and use a neck turner to cut it off?

Richard

Turk, I've never suffered "The dreaded donut". I think some guys inside neck ream them. Since I don't have an inside neck reamer, I'd address it as you described, sizing it with a Forster neck die, then turning off the excess.

I believe Mathman and some other have dealt with this issue as well, as they may have some additional idea's on how to deal with it.

I don't think firing will move the donut to the outside. In fact, if the chamber neck is straight and round so too will be the outside of the fired case neck, leaving the donut inside.

I have a die body that takes interchangeable mandrels. It's used to expand the necks after the brass is full length sized in a regular FL die without an expander ball in place.

The full diameter portion of the mandrel is long enough to go completely through the neck. So when the neck is pushed over the mandrel any irregularities and/or donuts are pushed to the outside. When it's a thin brass tube vs. a titanium nitride coated steel or solid carbide mandrel, the brass loses. So the undesirable parts are skimmed off by the outside turning cutter.

The dreaded donut is one reason I prefer necking brass down rather than necking up--such as using .270 brass to make 6.5-06's instead of necking up .25-06's. This avoids turning the top of the shoulder into part of the neck, the cause of the donut.

That said, often it doesn't make much difference, depending on the brand of brass. Some apparently have thinner brass in the shoulder than others, and if a bullet's base doesn't reach down to the donut, it just doesn't matter.

“Would it be better to fire the case, moving the donut to the outside and use a neck turner to cut it off?”

That was dumb! I was not thinking when I typed that. Firing it would do nothing to the donut.

In this case I assume the donut was created when the brass turning was stopped before it reached the shoulder, leaving part of the neck thicker. When the brass was fired, the thicker part of the neck was pushed inside by the chamber, creating the donut. Is that correct? The more I learn, the more I realize I don’t know!

Thanks for your help, everyone.

Richard