Neck sizing .308

[Nature Boy]

Up until recently, I've FL sized everything. Once I bought some expensive (Lapua & Nosler) brass I decided I'd try to get a bit more life out of them and try neck sizing. I picked up an RCBS neck sizing die and set it up per the instructions.

My understanding is the neck sizer only adds tension back to the neck and doesn't affect shoulder dimension or headspace, correct?

I've also noticed that my WFT trimmer which was set up to trim to 2.005 on FL sized brass, needs to be adjusted now to accommodate neck sizes cases since the WFT locates off the shoulder. I assume that makes sense and is normal?

Trying to be cautious here as this isn't range pick up brass and I don't want to scrap any due to a bone head mistake

 

[Nature Boy]

One other observation as I was trimming. The neck sized brass tended to get stuck in the WFT, whereas I never had that problem when FL sizing. Also, trimmed length varies more on the neck size vs FL sized cases

 

[Walkalong]

I'm a firm believer in the FL bushing style sizer. Forster will also hone out the neck of a FL sizer to your dimension (Picked for the neck thickness you will be working with).

PSA had this RCBS one on sale for $27, so I bought one, even though I already had a Redding FL bushing sizer and a Forster "bump" die bushing sizer which sizes the neck, "bumps" the shoulder, but doesn't size the body.

If you just want to neck size, I would recommend the "Forster Precision Plus Bushing Bump Neck Sizer Die" I linked to.

Yes, the RCBS neck die sizes the neck and nothing else.

 

[Nature Boy]

Well, the proof will be down range and I'll know more tomorrow than I know today.

And I picked up the RCBS die for the same reason you did. $27 bucks

I may eventually migrate to FL bushing dies, I'm just not there yet

P.s. Runout was great, all but 2 out of 50 were <.001

 

[amlevin]

Neck sizing alone will just add some life to the brass as you aren't working the entire case when sizing.

Unless you have some really good brass that has really uniform neck wall thickness you really won't gain much else.

If you turn your necks just enough to make the neck wall thickness uniform THEN you're going to also see better uniformity in neck tension and less runout in finished rounds.

 

[Nature Boy]

Have not done any neck turning yet.

 

[243winxb]

Necks go first. Standard FL or neck , with expanders, work the neck the same. No longer case life. Hone or bushing works. Its possibe to get longer neck case life by outside neck turning , when using factory FL dies. I tested it with 223 and 243 .

 

[Nature Boy]

I'm going back to FL sizing. There was a noticeable increase in group size with the neck sized loads. Neck tension was inconsistent, trim length was inconsistent, OAL was inconsistent, likely because of the variation in neck tension.

 

[MCMXI]

I use mostly competition Redding dies and neck size only using the TiN bushings for the more accurate rifle/cartridge combinations i.e. 6.5 CM, .308 Win, .300 Win Mag, .338 LM and .375 H&H Mag. I have to anneal .308 Win brass after every 3rd firing in order to control neck tension and shoulder bump. I'll typically bump the shoulder back .002" after three firings.

 

[Walkalong]

I am using a FL bushing die, while MCMXI is using bushing neck sizer and using the body die to bump as needed. To me, this is so similar as to being pretty much the same thing. (He may disagree ).

I agree, you must anneal after no later than after the third firing or go down a bushing size due to brass spring back (Work hardening from the firings/sizings), but annealing keeps things more consistent IMHO.

 

[MCMXI]

I am using a FL bushing die, while MCMXI is using bushing neck sizer and using the body die to bump as needed. To me, this is so similar as to being pretty much the same thing. (He may disagree ).

No disagreement here but I am a little confused about the description. How is the RCBS die in the link a "full-length" bushing die if it's only sizing the neck? I always think of FL as sizing the entire case. I like the Redding competition micrometer dies because I can easily dial in the length of the case neck to be sized without moving the die up and down. I reload for four rifles chambered in .308 Win so this is a useful feature for me.

http://www.midwayusa.com/product/160954/redding-competition-bushing-neck-sizer-die-308-winchester

 

[Walkalong]

Now I am confused, but I think the answer is.....Yes, he just got a straight neck sizer, not a bushing style neck sizer like you are using, or a FL bushing die like I am.

And maybe I just missed something.

 

[Nature Boy]

I got the plain Jane RCBS neck sizer with decapping pin/expander ball

 

[Walkalong]

and I picked up the RCBS die for the same reason you did. $27 bucks

Pick up a bushing to go with it. I am using an RCBS .338 with Lapua brass that measures 14.0 to 15.3 thousandths neck thickness. We always end up with more than one bushing though.

 

[fguffey]

I've also noticed that my WFT trimmer which was set up to trim to 2.005 on FL sized brass, needs to be adjusted now to accommodate neck sizes cases since the WFT locates off the shoulder. I assume that makes sense and is normal?

It sounds like you have listened to reloaders on the Internet promote products that you do not need. If you have been full length sizing until now you have been sizing your cases with total disregard for the length of the case from the shoulder to the case head. You purchased a Little Crow Gunworks trimmer. It should be common knowledge amount Internet reloaders the Wilson case gage is a datum based tool. It measures the length of the case from the datum forward to the end of the neck and from the datum back to the case head. It is not necessary to trim the neck length of the case when it is determine by a case gage the neck does not protrude from the case gage; even if the case head does protrude.

I have cases when fired from one rifle protrude from a 30/06 case gage .011”. I do not insist on full length sizing the case and when trimming the case length from the case head to the end of the neck I add the additional .011” to the trim length. When checking the case in a case gage the end of the neck does not protrude because the case gage is a datum based tool. What does that mean? The Wilson case gage has been with us from the early 50s, that is 65 years ago + and the gage came with instructions that have not been read or understood.

So I suggest you avoid all of this advice you are getting from members that are trying to sell you something and do more research. I would suggest you learn to determine the length of the chamber from the shoulder to the bolt face. And then there is the Wilson case gage.

F. Guffey

 

[Nature Boy]

fguffy,

Thanks for the info, although I have to admit I'm a bit confused. I'm trimming the case to 2.005, mainly because most of the reloading manuals (Hornady is one) recommends 2.005. That may not be necessary, but it's coming from a reputable source.

I have a Dillon case gage, not the Wilson, but I'm using calipers to determine case length. I'm using the Hornady headspace gage with calipers to determine headspace, which would be from the datum to the case head. In other words, I believe I'm getting to the same results, just taking a different path.

And I haven't had any members try to sell me anything. Also, it's always prudent to understand the advice you get and decide for ones self which to take, with a grain of salt or a whole bag of it. That applies to the internet, the gadflies at the end of the counter at your LGS, or that nutty uncle every has.

 

[MCMXI]

he just got a straight neck sizer, not a bushing style neck sizer like you are using, or a FL bushing die like I am.

Walkalong, now I'm up to speed. Thanks.

I'm trimming the case to 2.005, mainly because most of the reloading manuals (Hornady is one) recommends 2.005. That may not be necessary, but it's coming from a reputable source.

Nature Boy, SAAMI shows the length of the .308 Win chamber from the bolt face to the end of the neck to be 2.025 with a tolerance of -.000"/+.015". I can guarantee you that not all .308 Win reamers are the same but many will have the dimension from the bolt face to the end of the neck at 2.0325" which is the SAAMI dimension plus half of the tolerance. So trimming the brass back to 2.005" is most likely unnecessary depending on the dimensions of your chamber. Trimming to 2.020" or greater might be reasonable. The SAAMI ammunition spec of 2.015" +.000/-.020" is for factory ammunition and not an absolute.

 

[fguffey]

Thanks for the info, although I have to admit I'm a bit confused.

It happens all the time. I have case trimmers that set up on the shoulder of the case. When trimming I hold the case in my hand meaning the length of the case from the shoulder to the case head is not part of the included length.

Back to the Wilson case gage and or the Dillon case gage: Both gages are datum based. If the case neck protrudes from the case gage measure the amount of case neck protrusion from the gage then trim the neck. If the case neck does not protrude from the gage do not trim the case neck.

I do not have a nice/polite way to say reloaders should know more about the tools they use. I would suggest you learn to measure the length of the gage. In the perfect world the gage will measure the same length as a perfect case. The case can protrude from either or both ends of the gage. I suggest you refrain from insisting on trimming the case based on the length of the case from the mouth of the case to the case head.

One more time I have rifles with long chamber when measured from the shoulder of the chamber to the bolt face. When I trim those cases I add as much as .014" to the trim length of the case. I want my case necks to cover the chamber and I want all the bullet hold I can get.

F. Guffey

 

[Nature Boy]

Thanks MCMXI,

I guess if you're going for consistency, which I am, you got to pick a number and I settled on 2.005 as my number. Is there a compelling reason to pick a different one?

I recently bought some new Lapua and Nosler brass. Measuring their length out of the box showed 2.010 and 2.000 respectively, for what that's worth.

 

[MCMXI]

Thanks MCMXI,

I guess if you're going for consistency, which I am, you got to pick a number and I settled on 2.005 as my number. Is there a compelling reason to pick a different one?

Not really. Any trim length that (1) allows the case to fit in the chamber and (2) allows the neck to adequately support the bearing surface of the bullet is good. If you need to trim cases regularly then it makes sense to trim back to a length that reduces the frequency of trimming while still satisfying (1) and (2).

 

[Walkalong]

I use my WFT to trim my more serious .308 to very close to 2.005. Then I use my Wilson trimmer to finish them up.

For an application where the best accuracy isn't a must, the WFT would be fine. And besides, most guns/people aren't going to shoot the difference anyway.

MCMXI gave an excellent answer to your what length to trim to question.

 

[Nature Boy]

The reloading hobby has put me into the precision death spiral. I'm trying to get the most accuracy I can out of me, my rifle and my loads.

The WFT produces a consistent 2.005 for me, as long as I'm FL sizing. I've got to brass to play with this weekend so we'll see if I can figure it out.

In the meantime, I'm starting to look at annealing options.

(dang fguffey, they've gone and sold me on annealing now )

 

[RecoilRob]

The Lee Collet neck-sizing die has the advantage of more consistent tension that is less affected by neck wall thickness variations. It might not be quite as good as having precision turned necks and a bushing that fits exactly right, but it's a pretty good intermediate step that rewarded me with better accuracy than I was getting with the FL die and is inexpensive and easy to use.

 

[Walkalong]

they've gone and sold me on annealing now

That can be done cheap too. But if you want to, there are some super nice options out there which be be more precise and repeatable.

 

[MCMXI]

In the meantime, I'm starting to look at annealing options.

At some point you won't be able to control neck tension or shoulder bump due to work hardening of the brass and this will affect accuracy/precision and potentially reduce case life. When you get serious about annealing, decide if you want induction or flame. Both work but I find induction annealing faster to set up (good for small batches) and more controllable and definitely more repeatable. I've used a Bench Source unit which when set up is excellent and better for large batches. There are many options available now which is good for us.