mossy33oak

ok, got a question, to date I have only full length resized my 7mm because I have 2 different guns. But today I picked up my new 300 rem ultra mag, and need to press some shells for it. I need to know how to set my die so I am not f/l resizing my brass, ( I assume I dont need to f/l resize since I will be using this brass in the same gun). I guess what I'm asking for is a detailed instruction on how to properly put my die into my press and determine if Im only neck sizing or f/l resizing. Any help would be greatly appreciated. I shot it for the first time today, and got about 1.25" groups, with factory rem premier ultra/ 180 gr nosler partitions, maybe I should just shoot them, but at $31 a box I'd rather reload.

HighDesertWolf

asfar as I know you will need to buy a neck sizing die, I dont beleive there is anyway to adjust a F/L die to just neck size, Usually when I look at die sets there are F/L sets and neck sizing sets or lee has a set that comes with both a F/L die and a Neck sizing die. good luck

Swampdog

Somebody correct me if I am wrong.But doesn't the 7mm rem. space off of the belt? If this is true does it have any effect on the round? I am interested in neck sizing for mine because most anything I ever loaded that way were more accurate rounds than full sized ones.

1mile50

What you are asking about is the "poor man's neck size". From where your die sizes at full length, start backing it out. Usually 1/3-2/3 turns is about right. You will not get a full neck resize, but it will be enough. You will know how much of the neck is being resized by looking at the necks. There will be a discernible line where the sizing stopped. 3/4-7/8 or so of the neck will be just fine. As far as headspacing is concerned, any bottlenecked cartridge can be made to headspace from the shoulder, including the .375 H&H. I just wouldn't want to hunt dangerous game with such loads. After a few loads you will need to full length resize. The shoulders will creep forward and will need to be set back.

DM

Belted mag cases "only headspace" off the belt for the first fireing, "IF" you DON'T push the shoulder back when resizeing!!!

As for neck sizeing with a FL die. I like to back the FL die OFF the shell holder one full turn. I then take a blk magic marker, and blacken the neck and shoulder of my case. Then i lube the case and size it. Now i look at how far the case was sized on the neck. I ajust the die untill i "just" size the neck, but NOT touch the shoulder!!! Once done, i try the case in my rifle and see that it chambers "ok". If it doesn't, turn the die IN 1/4th turn, size it, and try again!!!! Continue untill it's where you want it....

This works on ALL bottle neck cases.

Hope i explained it well enough for you to understand!!

Drilling Man

bigcountry

Check out my results with FL and partial.

http://forum.hunting.net/asppg/tm.as...1&key=&#742750

I think alot of people are kidding themselfs some by doing it blindly without any sort of measurements. I have a Neck sizer if you want to try it. It caused me bad runout. You could do it once and get by with it. But not twice. Let me know, and I can meet ya at my house. or somewhere.

mossy33oak

ok,
I think I have a good idea about it, but I'm a little unsure, maybe I can hook up with you Bigcountry. I'll send you a pm. Thanks everybody else for your help too!!!

mossy

bigcountry

Tenatively, we can meet Sunday. But it will have to be early or at night. I will bring my Stoney point shoulder guauge and neck sizer and runout guauge.

1mile50

That's the expander ball, more than anything else, hanging up on the "discernible line where the sizing stopped." Hornady rifle dies are the worst offenders, no matter how you size, the eliptical expander has a lot of drag. A dragging expander can not only pull shoulders forward, it can and will adversely affect runout, expecially with a neck sizing only die. I always polish my expanders by chucking the rod in a drill and using some dremel polishing compound untill I get a fine finish. That and Imperial sizing wax make a big differerence.

I had a NK sizing die once that caused me a lot of grief, in the runout department. Polished the expander, some improvement, not much. Flipped the lock ring, BIG improvement. Not perfect, but much better. Lock ring was not true on one side, canted the die ever so slightly in the threads. Bushing dies are defiantly the way to go, eliminates a lot of hassles.

Sniper151

I like to full length size my brass. I've been using Redding's competition shell holders and this bumps the case plus precisely sets the headspace for that rifle. This one item greatly improves accuracy and the shell holder set didn't break the bank.
Good Hunting...