Neck Sizing Questions for Bolt Action Rifles

[Sgt Dog]

Hi All,

I'm not new to reloading (but not an old salt either) and I'm usually on one of the lever gun or cast sites but just acquired a 300 Win Mag and a 25-06 and being the only two bolts I have I’m thinking there is a good possibility I may neck size as opposed to full length sizing. I’ve never used a die specifically for neck sizing but like the idea of keeping head space close (even in a belted cartridge) and not overworking brass.

I read where many bump the shoulder even with a full length sizing die just a smidgen and call that neck sizing. Guess I don't understand how you avoid sizing the body considerably in the process if you take the case far enough in the die to bump the shoulder with a full length sizer???

Anyway, I kind of fastened on Forster but see they have two options:

Forster Bench Rest Neck Sizer
http://www.midwayusa.com/product/235...chester-magnum

And for $40+ more, a Forster Precision Plus Bushing Bump Neck Sizer.
http://www.midwayusa.com/product/964...chester-magnum

The latter has three bushings to customize the neck tension but not having neck-sized before I'm not sure what that extra $40 is buying or if it's overkill? Forster says you can bump the shoulder with either. I've read Forster's descriptive sales pitch several times but still don't know if the bushings (in addition to the neck size) add more fine tuning with the shoulder-bump capability than does the bushingless version.

I’m not a bench rest shooter but don't mind the time at the bench pretending like I am.

Would appreciate any input on your experiences, your process or even your prefered dies from anyone, especially concerning the 300WM.

 

[daniel1daniel2]

Just make sure you full size them first and then fire them in your gun then you can neck size them I have a savage 300WM and was given some brass from a guy that had a McMillion and his chamber was enough bigger than mine that they would not fit into the chamber at all. I can't say anything about the Forster dies I have a Lee neck sizing die that works just fine I am grouping under 1/2 MOA ( don't know if yours will be the same but my 300 likes a 0.120 jump between the bullet and the lands)

 

[Sgt Dog]

Thanks Daniel... I got about a 180 cases with the rifle (Winchester Model 70). It was my best friend's gun. He passed away from ALS two years ago and I just bought it from his widow. A whole batch of the brass would not fall in the chamber and actually bottom out about 5/8s from the belt so I'm thinking he may have picked up the brass at the range. That said, I did plan on FL resize initially, then trim, fire and start out neck sizing from there. Appreciate the response. See a lot of mention of the Lee Collet resizer.

 

[Blitzfike]

When you get down the road with your brass, if you have any that don't want to chamber after full length sizing, give me a shout. I have the collet die that resizes the belt area. I have had to do that to several pieces of used brass I bought in order to make them usable. If you do have any of those, check for loose primer pockets, as this won't fix that.. I use this on 7mm rem mag, 300 win mag, 338 win mag and 375H&H Blitzfike

 

[Sgt Dog]

Blitzfike, good tip on the primer pockets. Thanks! Hadn't thought to look at that. When I deprimed for tumbling some came out much harder than others and a few did come out easier than I thought they should. After seeing several of the brass I have stop short in the chamber so far from the rim/belt I remembered Larry Willis' product at Innovative Technologies. I've got one of his guages for measuring the datum. Anyway I was thinking that may wind up being needed. Is that the collet die you have? If so, I'd be real interested in how you like using it and if you FL resize when you do or just partial? According to him you can do either but I think he recommends FL. If that's the one you have then I may PM you with some more questions. I'm happy to talk on this thread though cause I have some dies, brass and bullets I want to sell here and need the posts :-)

 

[Sgt Dog]

Very nice offer by the way!!

 

[becker_atc]

Blitzfike,

Correct me if I am wrong but the collet die you use does it just sqeeze just above the belt where the 'bulge' develops over time? I also have a 300wm and have loaded a very little bit for it using FL dies and am considering switching to neck sizing.

Which method of sizing you think is more common to getting the bulge? If neck sizing and you also use the collet die is the fire form fit lost?

 

[MoBoost]

What kind of accuracy are you expecting? For "normal" use Lee Dies will do just fine. Collet die works fantastic and does not require lube. After several firings you'll have to Full Length size.

If you are after every bit of precision - Forster Neck + Shoulder bump die is one of the finest resizing tools out there. The neck tension is very uniform and is adjustable in .001", so is shoulder bump.
However, you'll have to invest in couple of other (not cheap) tools as well to make it work.
You'll have to turn your necks and neck junction : http://www.21stcenturyshooting.com/Neck_Turning_Tool_Kit.php
and you'll have to buy a precision case mic: http://www.midwayusa.com/product/302361/rcbs-precision-mic-300-winchester-magnum

Without uniform neck - bushings are useless, and without gauge - bumping shoulder can be disastrous (yes, even on belted cartridge).

daniel1daniel2 : I believe you mentioned 1/2 MOA rifle before ... care to share the rigs you doing that with?

 

[Sgt Dog]

MoBoost, Really informative! Thanks!! There was something there I'd not read before. Looked at both products and I'd never seen the precision mic. I AM after accuracy in just about anything I have but have to admit, whenever I've happened on posts about neck turning I always said, "I'm not going there". Then again, I didn't start out with intensions of shooting cast, and I darn sure didn't start out with the intension of casting my own projectiles. Still don't think I'll go there on the neck turning though.

Anyway, yours is the first mention that 'without uniform necks the bushings are worthless' which would lead me back to my basic question about the difference in utility between those two dies. The more I read the more I'm thinking the Lee collet die is the best starting point if I do move away from FL resizing. Which sort of answers your question about accuracy. Guess pretending at benchrest only goes :-)

I'd be satisfied to full length if I found my die was close to chamber size, particularly for the datum. But if it's a big jump then I know I won't be. I've read of fairly significant differences between some chambers and the die used. I partial resize a lot of my straight wall (45-70, 375Win and 45Colt) but for different reasons – mostly cause the cast diameters are bigger and the case bulge is more pronounced if you size em all the way back down.

Away from the datum considerations and moving back to the head and belt area, I noticed when I resized a sample of the 300WM while up North last month, that even with the FL resizing die adjusted to touch the shell holder, once it had a case in, with the ram all the way up, there was still daylight (maybe 1/16th) between the shellholder and the die, I guess due to flex in the press. Looking at the brass I could see the die is unable to go 'absolutely' all the way to the belt even if you bottomed out completely on the upstroke. Which is what Willis' collet die does do, according to the literature anyway - speaking of which, the opinions are all over the map on that. I’d love to try one before buying!

But again, a lot of the 187 cases I had looked like they came from another chamber cause they stopped short of chambering - some by as much as 3/4 of an inch. Couldn't have come from the same gun and might account for some of the tough FL strokes and press flex. My buddies gone so I can't ask him about where the ‘all’ the brass came from.

Once I baseline all of it with an initial FL resize, maybe it'll all sort itself out. I'm remote once I get there so need to bring my ‘neck-sizing-fallback-solution with me. It's becoming obvious that the Lee Collet will be the most practical thing to toss in my bag. Thanks Again!

 

[MoBoost]

Full length sizing - you need to make sure that the press cams over.

For accuracy you want consistency, with bushing neck sizing you are trying to achieve ultimate neck tension consistency.

Neck tension is determined by how hard the brass is, how much interference with the bullet there is, and how long is the bearing surface.

Hardness of the brass is addressed with annealing.

The length of the bearing surface is kept consistent with trimming and seating depth.

Neck interference is kept constant with an expander ball in most dies - the neck gets over-squeezed and then expanded - leaving fairly consistent interference fit with the bullet.

Since there is no expander ball in bushing die - the neck just gets squeezed to the right size. Since the bullet diameter and bushing size are constant - the neck thickness has to be constant, and that's why you have to turn necks to take advantage of the bushing die.