Topic: Neck turning vs reaming?

[fj40mojo]

In the ongoing battle to get my 6.5x55 Swede to shoot consistently I've switched from Winny brass to Lapua, now I'm noticing that I've got problems with neck tension. The Lapua brass averages .003" thicker per side measured at the neck. This equates to a bunch more neck tension and force needed to seat bullets. I've never had to resort to turning necks and it's not necessary for the rounds to chamber, but I would really like to reduce and normalize my neck tension. Is there a reason why neck turning would be superior vs. just reaming the excess material from the inside diameter of the neck. My sized brass measures .262 for both the Winny and Lapua. I can likely borrow a .268 reamer which would take the .003" per side and then I'd have to resize the brass to get back to the .262 ID, but that would be better than buying a tool I'll likely never use again.

Is there a reason I can't do it this way or why taking the material from the OD ie neck turning is better.

[fj40mojo]

>crickets chirping<

[birddog1989]

I have heard that reaming is better but never got a solid explanation as way.  I think its 6's either way.  If you can use your case trimmer with a reamer I think it would be cheaper.

[fj40mojo]

I have heard that reaming is better but never got a solid explanation as way.  I think its 6's either way.  If you can use your case trimmer with a reamer I think it would be cheaper.

What I've heard and it makes sense is that neck turning is preferred because after the brass is sized all the inconsistency in the brass is pushed to the outside by the expander button and by removing stock from that side you are therefore removing the inconsistency. On that same note I propose that if you neck ream a fired unsized case you are accomplishing the same thing because at that point the neck has expanded to release the bullet and is now molded to the rifles hopefully concentric chamber and all the inconsistency is then on the inside diameter of the neck to be removed by the reamer. I've got to do some more measuring to determine which reamer to use as chucking reamers are available only in fractional and Letter sizes. I think I'll use the drill press, the reamer should only cost about $10 if I can't borrow one.

[ballardw]

I'm not sure if this relates to your case but one of the reasons for turning is to remove eccentricity of the neck. Some brass and/or sizers will end up with the thickness varying. So if the inside is "round" and the outside isn't turning fixes that problem.

Another option might be get a sizing expander that is another thousandth or so larger.

[J Mack]

I think I would neck turn before I would ream.
My way of thinking says you could run into concentricity issues with reaming your brass.
If you are going to stick with Lapua brass why not ream your sizing die?

[fastfire]

I have never reamed(guess I don't know all the ins and outs about it) I have allways just turned the necks,uniformed the primer pockets and deburred the flash holes.
I just purchased some Lupua brass, do I need to turn the necks here?

[J Mack]

I have never reamed(guess I don't know all the ins and outs about it) I have allways just turned the necks,uniformed the primer pockets and deburred the flash holes.
I just purchased some Lupua brass, do I need to turn the necks here?

I use Lapua brass and just load and shoot and have good results and would expect the same for you. I have some .308 Lapua cases that are on there 8th loading with no special attention.
FJ's situation seems unique in that he can not get reasonable performance from the factory brass in his setup. I suspect his sizing die could be at min and giving him some grief with the thicker Lapua brass, I know guys will use different neck bushings to get that last bit of performance from their load but when you see FJ's loads his issue would appear more of an extreme tight than just a slight tweak.

Good luck FJ let me know if I can help.     

[Nomad]

 To get what you need on the win brass may need to turn them.
 You may want to try some Redding Bushing sizing dies for your neck
tension by changing the bushing a thousand or so to get what you may need.
 I am with JMack never had a problem with Lapua brass....Less the cost. 

[J Mack]

You may want to try some Redding Bushing sizing dies for your neck
tension by changing the bushing a thousand or so to get what you may need.

Nomad this is what I"m thinking will be the long term solution for FJ.

[fj40mojo]

I guess a little further explanation may be in order. With the Winny brass as I worked my loads up and got to the point of compressing them the added pressure in concert with my seater stem was deforming the tips of the bullets and accuracy went to hell. With the Lapua brass the necks are so much thicker that I am experiencing the same deformation even when not compressing loads. I've got an A-max seater stem on the way, hopefully this will solve the bent bullet problem and I won't have to resort to thinning out the necks at all.

As I understand it, the only reason for neck turning/reaming to be required is when your chamber is so tight in the neck that a loaded round will not chamber ie combination of brass plus diameter of bullet exceeds the ID in the neck portion of the chamber. Or, you are so close to that dimension that there is not sufficient room for the neck to expand and release the bullet causing excessive pressure. Neither of these are my problem. What I'm seeing is bent deformed bullets as a result of the additional pressure needed to seat them in the thicker brass. Hopefully the seater stem will be the fix.

 Keeping my fingers crossed.

[blown_primer]

In my view, the only time neck reaming is really necessary is to remove the "dreaded doughnut" (what benchresters call it) of brass that has flowed through successive firings from the shoulder into the neck, creating an annular constriction near the base of the neck, which in turn plays havoc with neck tensions.  However, proper neck turning (whereby the cutter travels slightly up, and into, the shoulder) will keep the "doughnut" from forming anyway.  Neck turning, if done properly, doesn't just thin overly thick necks (and keep a "doughnut" from forming); it brings consistency to the neck thickness, all the way around, and allows for greater cartridge concentricity (alignment of the bullet with the case body) since one side of the neck won't be thicker than the other side.

As long as you're happy with the thickness of your neck walls (all the way around – not just from one measurement at on point of the neck), you don't need to neck turn (though you may still need to ream if you develop the "doughnut" inside the base of the neck after numerous firings).  Just use a good bushing-style neck die (I'm a huge fan of Redding's Competition Neck Sizing Dies – I set the micrometer to size no more than 2/3 of the way down the neck, and have gotten really good results).  With some experimentation of different diameter bushings, you should find something that works really well.

[RGinIdaho]

Not likely your problem or solution but...

Neck turning is not just about chamber dimensions. You can solve a tight chamber issue with it but that isn't it's primary purpose. It is a concentricity issue for the pickiest among us.

More concentric ammo should/might = even tighter groups. More consistent neck thickness along with fine tuned neck tension can affect accuracy and optimize burn rates with many powder/brass/bullet combo's. Read better SD's. Reducing long range vertical stringing for starters.

Neck turn once when new to uniform the thickness of the brass all the way around the neck. Then use a bushing neck die to acheive the tension you desire.

After you turn the NEW brass, size it. Seat a bullet. Measure the outside thickness at the neck. Subtract .002" for the bushing size. I like to order .001 under, .002 under and .003 under. Remember each brand/lot combo of bullet and brass might require a different bushing. After you are set up with turned brass and bushings you can experiment with differing neck tensions until you find the spot where accuracy is best or burn rate is most consistent. Which ever you are chasing...

A larger expander plug might solve your problem. Then again, maybe not. You might actually have to use a powder that does not fill the case quite so completely.

Let us know how it works out.

[J Mack]

Any updates?

[fj40mojo]

Any updates?

Being that you helped me solve my problem I'm guessing your doing this for the masses. I'll bite.

Turns out that my problem was not related to the thicker Lapua brass but a combination of a couple of things. 1) Despite setting my sizing die up per the mfg's instructions, I was having a headspace issue not related to the chamber. I was setting the shoulders back .012" and that brass had to flow somewhere-the neck. This also accounts for the premature case failures I was experiencing. 2) I purchased and began using an A-Max seater stem. Near as I can tell the new stem has a lot more relief in the upper end of the bullet cavity which means it's pushing on the jacket further down the bullet where there is core material supporting the jacket. The original stem was actually pushing on the plastic tip of the bullet and initiating premature expansion when sufficient pressure was used to seat the bullet.

JMack discovered the problem one day after we'd been out shooting the rifle and experiencing more of the same problems. He grabbed his calipers and a Hornady LNL headspace bushing and measured a fired round vs. a piece of my loaded ammo-big difference and a big problem. Next step was to borrow the appropriate set of GO/NO-GO headspace gauges which popsgunner was able to provide (I'll get them back to you soon RK) and rule out that the rifles chamber was cut improperly-it's not. I ordered my own set of the LNL headspace bushings which work in conjunction with the same body portion as the LNL OAL gauges and this allowed me to set my sizing die with a precision I'd never had before (my plan now is to use the same process for the rest of my bolt guns). I'm now bumping the shoulders back .002" compared to a fired case +/- .0005". In the past I'd always set my sizers per mfg instructions and never had any problems with headspace. Just goes to show-never assume, it makes an ASS outta U and ME. The rifle is shooting much more consistently now, my cases aren't tearing apart just in front of the web and my bullets are no longer crunched during the seating process. Just in time for deer hunting.

[RGinIdaho]

I ordered my own set of the LNL headspace bushings which work in conjunction with the same body portion as the LNL OAL gauges

Every handloader should procure a set for the very reasons you point out.

[fj40mojo]

Every handloader should procure a set for the very reasons you point out.

Not long ago I would have been skeptical but I've been shown the light.

[J Mack]

Being that you helped me solve my problem I'm guessing your doing this for the masses. I'll bite.
 
it makes an ASS outta U and ME.

Yes for the masses, and thank you for the excellent wright up.

 

[luvmy45]

The LNL Headspace tool is great, and another one to have in the toolbox as well is the RCBS Precision Mic.
http://www.realguns.com/archives/035.htm

For whatever reason the LNL wasn't giving me the data I needed on my .223, switched to the RCBS Mic and whamo, bammo, found my problem and fixed right up.