Case Neck Turning?

Redhook · March 1, 2002, 02:59 AM

Based on Charles E. Pettys high recommendation for case neck turning in an article in the April 2002 issue of Guns Magazine, I've decided to give it a try.

I'm new to handloading for my .308 win, but the process makes sense and if he achieved a 30% increase in accuracy with a Rem 700P (same as mine), I figure it will be worth the experiment. However, I plan to set up a fixture on my lathe and turn them that way.

What I want to know is how far back from the neck should I trim? Should you go as far as you crimp the bullet or all the way to the shoulder?

While I've got your attention, what is your personal feelings and experiences with neck turning?

-Red-

Khornet · March 1, 2002, 07:50 AM

Should extend as far down the neck as the bullet base reaches, stopping before cutting into the shoulder. Generally it is not necessary to remove brass all around the circumference of the neck; only about 75-85% of the surface will do. That way you don't remove too much metal and make the neck too thin.

I use a Forster mini lathe-type tool, and it works great. I don't know how much difference it makes for my rifles, because I also do all the other brass prep steps: weigh and sort, trim to uniform length, uniform primer pocket, ream flash hole. But brass prep overall significantly improved my group sizes, so that I can get 5-shot 100-yd 1/2" groups from a scoped 03A3 Springfield.

KP95DAO · March 1, 2002, 08:49 AM

Turn all the way to the neck- shoulder junction. In addition use a good bullet seater like Redding's Competition seater with full case/bullet support. Use of that seater has dropped my culls to one to three out of a hundred compared to 7 to 12 with a RCBS Comp seater. And do all the rest of the before mentioned steps. It seems a lot of work until you start shooting those 5/8" 10 shot groups (Savage 10fp 308 with over 4000 rnds) consistantly.

Bogie · March 1, 2002, 12:33 PM

Suggestion - Spend the $60-70 bucks, call Ron Hoehn (you can find him under Gunsmiths at www.benchrest.com) and get one of the K&M turners he sells with a carbide (if you're shooting one of the calibres he supports with carbide) mandrel. You'll also need a K&M Expandiron (about $15 or so) to get the proper sizing. Or you can make one, but it'd probably be easier to just buy the things.

You have to support the inside of the case mouth to get a consistent turn, and if you insist on using the lathe, you'd better hope it has very low runout...

Here's what I do: I take a .22 bore swab, splooge the case mouth with tranny fluid, and expand it. Splooge again, really slopping it inside, then I clamp the case in a Lyman drill press trimmer holder, and hold it in my left hand. In my right hand is a low-speed variable speed drill, with the turner chucked into it. The mandrel goes in the case mouth, I increase RPMs to about 30-60 (guesstimation), and let the turner do its thing. I don't force things. When it turns to my preset (another plus of Hoehn's carbide mandrels), I increase the speed to the drill's max, and back it out. Since both hands are freefloating, I don't have to worry much about runout. I turn my 6PPC brass to 0.0087, but if you're turning for a factory chamber, you're going to want to do it VERY LIGHTLY - Adjust your cut so that you're only scoring about 1/2 the case mouth area - Just clean it up, and don't go too deep, or your cases will wear and split prematurely.

Redneck2 · March 1, 2002, 06:47 PM

go to Varmint Al's website. He THOROUGHLY covers how to sort cases, how much to trim (see Bogie's post above)...most guys trim too much...

lots and lots of good info

Might also get Sinclair's book on precision shooting

March 1, 2002, 02:59 AM	#1
Redhook Senior Member Join Date: January 25, 2001 Posts: 254	Case Neck Turning? Based on Charles E. Pettys high recommendation for case neck turning in an article in the April 2002 issue of Guns Magazine, I've decided to give it a try. I'm new to handloading for my .308 win, but the process makes sense and if he achieved a 30% increase in accuracy with a Rem 700P (same as mine), I figure it will be worth the experiment. However, I plan to set up a fixture on my lathe and turn them that way. What I want to know is how far back from the neck should I trim? Should you go as far as you crimp the bullet or all the way to the shoulder? While I've got your attention, what is your personal feelings and experiences with neck turning? -Red-

March 1, 2002, 07:50 AM	#2
Khornet Senior Member Join Date: December 11, 2001 Location: NH Posts: 585	Neck turning Should extend as far down the neck as the bullet base reaches, stopping before cutting into the shoulder. Generally it is not necessary to remove brass all around the circumference of the neck; only about 75-85% of the surface will do. That way you don't remove too much metal and make the neck too thin. I use a Forster mini lathe-type tool, and it works great. I don't know how much difference it makes for my rifles, because I also do all the other brass prep steps: weigh and sort, trim to uniform length, uniform primer pocket, ream flash hole. But brass prep overall significantly improved my group sizes, so that I can get 5-shot 100-yd 1/2" groups from a scoped 03A3 Springfield.

March 1, 2002, 06:47 PM	#5
Redneck2 Senior Member Join Date: April 25, 2000 Location: Northern Indiana Posts: 519	For a "complete" explaination... go to Varmint Al's website. He THOROUGHLY covers how to sort cases, how much to trim (see Bogie's post above)...most guys trim too much... lots and lots of good info Might also get Sinclair's book on precision shooting

March 1, 2002, 08:49 AM	#3
KP95DAO Senior Member Join Date: December 30, 2000 Posts: 699	Turn all the way to the neck- shoulder junction. In addition use a good bullet seater like Redding's Competition seater with full case/bullet support. Use of that seater has dropped my culls to one to three out of a hundred compared to 7 to 12 with a RCBS Comp seater. And do all the rest of the before mentioned steps. It seems a lot of work until you start shooting those 5/8" 10 shot groups (Savage 10fp 308 with over 4000 rnds) consistantly.

March 1, 2002, 12:33 PM	#4
Bogie Senior Member Join Date: June 6, 2000 Location: Job hunting on the road... Posts: 3,827	Suggestion - Spend the $60-70 bucks, call Ron Hoehn (you can find him under Gunsmiths at www.benchrest.com) and get one of the K&M turners he sells with a carbide (if you're shooting one of the calibres he supports with carbide) mandrel. You'll also need a K&M Expandiron (about $15 or so) to get the proper sizing. Or you can make one, but it'd probably be easier to just buy the things. You have to support the inside of the case mouth to get a consistent turn, and if you insist on using the lathe, you'd better hope it has very low runout... Here's what I do: I take a .22 bore swab, splooge the case mouth with tranny fluid, and expand it. Splooge again, really slopping it inside, then I clamp the case in a Lyman drill press trimmer holder, and hold it in my left hand. In my right hand is a low-speed variable speed drill, with the turner chucked into it. The mandrel goes in the case mouth, I increase RPMs to about 30-60 (guesstimation), and let the turner do its thing. I don't force things. When it turns to my preset (another plus of Hoehn's carbide mandrels), I increase the speed to the drill's max, and back it out. Since both hands are freefloating, I don't have to worry much about runout. I turn my 6PPC brass to 0.0087, but if you're turning for a factory chamber, you're going to want to do it VERY LIGHTLY - Adjust your cut so that you're only scoring about 1/2 the case mouth area - Just clean it up, and don't go too deep, or your cases will wear and split prematurely.