Turn necks twice

[jsthntn247]

I turned the necks on my brass when it was new. It has 2 firings on it now and I need to take another 1.5 thou off for better clearance. Do I need to cut into the shoulder like I did the first time ?

 

[ShootDots]

You probably don't NEED to, however, I would take just a shave off otherwise you may leave a little ridge at the juncture of the neck and shoulder.. You only need to go down ever so slightly...

 

[Dans40X]

Depending on your first turning-
Ensure your trim length is consistent w/in a couple thou.002"

To turn .0015" on you next turning,I'd accomplish the task w/ 2 turnings for better consistency.
ie;set up & turn .0013" on all case necks to witness line on shoulder to eliminate doughnuts later.
set up & turn the remaining .0002" to the same witness line.

 

[jsthntn247]

I turned into the shoulder pretty deep the first time. I can clearly see the line. Might just barely touch into it this time. Bullets are a long way ahead of the donut area when touching the lands anyway.

 

[tenring]

I have turned necks a second time with several calibers. What I found is that turning into the neck/shoulder junction again, thins that area and splits quickly occur. Move the adjustment just above the cut.

 

[dkhunt14]

If you are not careful you will launch a neck down the gun. I have seen more then one good barrel ruined by somebody turning again and biting into the shoulder. It is not pretty when it happens and the barrel is junk. Matt

 

[Joe Maisto]

You probably don't NEED to, however, I would take just a shave off otherwise you may leave a little ridge at the juncture of the neck and shoulder.. You only need to go down ever so slightly...

+1;
and we're only talking a couple of "thousands." ! That means making an adjustment on your turner as well. Figure on messing up at least one case till you get it right. (just went through that)

 

[jsthntn247]

I've heard of folks blowing necks off down the barrel is the reason I asked. Gonna make sure I really need to turn them down more and If I do I will stop at the neck and leave the shoulder alone. Thanks fellas.

 

[Ares]

If you don't have a cutter blade on your trimmer, that fits your shoulder angle you should be careful with the relief cut indeed.
Prefer the 21 st century lathe model, with matched cutter, makes consistently turning necks very fast and easy, and the matching cutter for each case shoulder removes the issues of cutting too deep into the shoulder pretty much.

My 284 cases goes through the turner every reload, have yet to find any issues.

 

[jsthntn247]

I use a k&n with cutter to match the shoulder of a 308.