Brass Growth

[matorre]

Hi,

I have neck sized some Lapua 6br 4 times. I find I cannot
get it to enter the Wilson case gauge even after bumping the shoulder
back.

Can I save this brass ? I have ordered a full length Forster sizer.

Thanks
Michael

 

[GermanS1]

Michael, if the loads fired in it were reasonable, it'll probably be fine after a full-length sizing. How far down the case is the interference?

 

[NorCalMikie]

A quick pass through a "body" die will do the trick also.
I'am not a fan of full length sizing but that's just me.

 

[matorre]

German-
the load is the popular 107gr SMK with 30gr Varget.

The interference appears to be at the shoulder body junction.
The brass was not easy to size, compared to a once fired new
piece passed through the same full length die. ( arrived today )

The older brass now has a slight double radius at the shoulder,
where it starts to curve, then the sudden crisp line
of the shoulder angle starts.

Not so with the new brass.

So.

I have stopped my efforts at this point,
as this is odd and unnatural looking.

I am pleased with the Forster, as there is only a .006 squeeze down
in the neck and a .002 pop up on the expander. Brass run on the comparater
is still +/- .0005.

Best,
Michael

 

[artbosco]

I have neck sized some Lapua 6br 4 times. I find I cannot get it to enter the Wilson case gauge even after bumping the shoulder back.

And that's why Full Length Sizing each and every time you size, eliminates this inevitable problem. Kudos for ordering the F/L die.

 

[fdshuster]

My standard procedure is the same as outlined by outdoorsman. Been doing it that way for many years & no complaints. Using the Redding Type S neck bushing FL dies for 222,223, 22BR, 6ppc, 6 BR, 6 BRX, & 308. Die is adjusted to push the shoulders back .001" to .002" each time the neck is sized. Gives me just a bit of resistance when closing the bolt, (bolt lugs are kept lightly greased), brass lasts a very long time with little or no stretching. As fired case head space length dimensions are taken using the Stoney Point/Hornady chamber over all length gauge & the die lock ring(s) adjusted for the .001"/ .002" shorter length. I personnally have no use for the Wilson case gauges. They are based on SAMMI specs. and my only concern is what my chamber dimensions are: I don't care about someone else's chamber. p.s.: My standard load for the 8 twist 6BR's is also 30 grs. of varget with the 107 SMK. Outstanding!

 

[matorre]

This brass has to function in a Highpower rifle that runs across the
course, so function is paramount.

Being a machinist, I cringe when I think of my locking
lugs being used for a brass sizing tool.

The note above about a neck die used to bump back shoulders........ is a little confusing,
as I have the Redding set-up, but the neck die doesn't get near the shoulder.

I have to switch over the to the body die, and that doesn't give me a
case that will chamber smoothly in the rapids.

In Highpower my bolt rifle is running along side gas guns, so any delay is costly,
in terms of concentration, and ultimately points.

My main concern is the brass growing to a point where it will not be sized any
more. Someone on this forum ( I thought it was FD Shuster ) was talking about that phenomena
but I may have the author incorrect.

Best,
Michael

 

[fdshuster]

Michael: I competed for many years in NRA Hi Power & the local CMP match's using my AR's. Lake City & Winchester brass was also sized using the Redding Type S neck bushing FL sizing dies, although for the gas gun(s), the shoulders were pushed back .003". Never used a Wilson or Dillon case gauge then either. All sizing with my dies adjusted properly is done with the die, certainly not the bolt lugs. Your problem may be trying to use a neck sizer only die, and that ain't (excuse my English) going to work. The shoulders must eventually be pushed back, so rather than trying to guess when to do it, and risk not being able to fully chamber a round ( time is also critical in our benchrest score match's), as outdoorsman, and many others, I find it simpler to just push them back with each sizing. Cannot remember ever having to call an alibi in NRA Hi Power or the CMP match's due to an ammunition malfunction/ works for me.

 

[PREMOD70]

Somewhere there is a thread on annealing that may be of interest also as a lot of folks that resize also anneal around the 5th firing. I don't shoot Hi-Power any more but back in the day I only neck sized my slow-fire brass and FL sized the rapid fire but all got annealed after the 5th firing. I fired a .308 and used Lee collet dies for neck sizing and a RCBS .358 Winchester FL die with the expander removed for F/L sizing followed by the collet die.

 

[matorre]

When my brass fits the Wilson case gauge, it also by happy coincidence
fits my chamber. I did check chamber fit with a stripped bolt.

My concern ( lost in all the shuffleing ) was the brass that was Neck Sized Only for
3 firings, did not seem to want to bump Down nice and snug fitting lie the 1 and 2 fired
full length sized brass.

I am hesitant to attack the "necked brass" in ignorance and treat them harshly.

Regards
Michael

 

[KevinThomas]

Hi Michael,

Given that you're using the rifle for XC competition, here's a good place to get away from the neck sizing altogether. If you really want to go this route, it's not as likely to cause you problems in the slow fire stages (200, 600), but is an alibi looking for the worst possible time to happen where rapids are concerned. Go with the F/L sizing for this, and use a gage to make sure you're not bumping the shoulder back too far (.002"-.003" is fine). If it's not overdone, F/L sizing isn't nearly as hard on cases as many seem to think it is, and you'll still get good life out of the cases.

 

[BoydAllen]

How much are the diameters of your problem cases reduced, by FL sizing, about .3 in front of the head? I have seen chambers that were too small at the back for standard FL dies to size them adequately. Lock you calipers at the shoulder dimension of of as case that has not been FL sized, and then use them a a gauge on a fired case. If the case is sized at that point, the calipers should make contact farther down the case. Next, do the same a the point of largest diameter that is in front of the extractor groove. The Wilson case gauge does not give sufficient information to look at body diameter sizing. I like the Hornady (formerly Stoney Point ) caliper attachment for checking shoulder to head dimensions. For future projects, if you start with your die, you can order a chamber reamer that gives the fit that you need, by sizing the most work hardened case that you can find, and using that to specify a reamer that produces the clearances that you want.