SmallCaliberCentral

Rooster
I have been experiencing the same problem, and it is frustrating. I use a Redding bushing die and notice that I can feel a very slight difference in resistance when seating the bullet. Thinking that maybe the inside of the case neck might have some high spots I contacted Bob at Foresters Products, and explained the problem. He agreed and of course, he makes an inside neck reamer that will take care of the problem. The following day I drove down to Forester Products with some fired cases a few Sierra 39 BK. and a few of the pilots from my trimmer, for him to measure. All of his pilots and reamers have a larger shank then my RCBS, but he agreed to regrind one to fit my trimmer. As of yet I have not received the reamer so I cannot post any results, this might be a avenue you may want to research.

Rich, this sounds interesting, keep me posted after you try it please.

If you can drop a bullet in a fired case without needing to apply some pressure you probably won`t see any gain from neck turning. Unless the assembled cartridge neck is closer then 0.003" of a fired case neck diameter you are wasting your time and probably causing more working of the necks during resizing then you want.

If your loaded 204 cartridge as example measures 0.230" and a fired case mouth runs 0.235" you have a lot of slop already. The brass springs back after fireing and the actual chamber area of the neck is likely close 0,238" or so. Take anything off and the case just gets looser in the chamber as well as causing your dies to not being able to reduce the mouth ID as much as may be wanted. Case life will be reduced too due to over working from expanding the extra few thousanths and being thinner.

Just for reference, the standard SAAMI chamber neck I.D. is .232" for the .204 Ruger. I've noticed that my Cooper 20VT also uses a .232" neck.

From experience, I'll again mention that it's seldom desirable or necessary to turn case necks for a factory chamber....you just will never see any gain at the target, and if shooting a factory barrel, you'll probably need to go to bushing dies just to hold a bullet from too thin a case neck after turning. Been there. JMO

Rick in Oregon wrote:Just for reference, the standard SAAMI chamber neck I.D. is .232" for the .204 Ruger. I've noticed that my Cooper 20VT also uses a .232" neck.

From experience, I'll again mention that it's seldom desirable or necessary to turn case necks for a factory chamber....you just will never see any gain at the target, and if shooting a factory barrel, you'll probably need to go to bushing dies just to hold a bullet from too thin a case neck after turning. Been there. JMO

All of the fired cases that roll out of my .204 measure 0.232 O.D. at the neck. The I.D. of the fired cases runs from 0.2055 to 0.207. The brass has been shot several times and is ready to be tossed.

Ol` Joe wrote:If you can drop a bullet in a fired case without needing to apply some pressure you probably won`t see any gain from neck turning. Unless the assembled cartridge neck is closer then 0.003" of a fired case neck diameter you are wasting your time and probably causing more working of the necks during resizing then you want.

If your loaded 204 cartridge as example measures 0.230" and a fired case mouth runs 0.235" you have a lot of slop already. The brass springs back after fireing and the actual chamber area of the neck is likely close 0,238" or so. Take anything off and the case just gets looser in the chamber as well as causing your dies to not being able to reduce the mouth ID as much as may be wanted. Case life will be reduced too due to over working from expanding the extra few thousanths and being thinner.

I understand your point and agree, but I'm talking about neck tension by uniformity of the inside of the neck surface.

Rich V wrote:

Ol` Joe wrote:If you can drop a bullet in a fired case without needing to apply some pressure you probably won`t see any gain from neck turning. Unless the assembled cartridge neck is closer then 0.003" of a fired case neck diameter you are wasting your time and probably causing more working of the necks during resizing then you want.

If your loaded 204 cartridge as example measures 0.230" and a fired case mouth runs 0.235" you have a lot of slop already. The brass springs back after fireing and the actual chamber area of the neck is likely close 0,238" or so. Take anything off and the case just gets looser in the chamber as well as causing your dies to not being able to reduce the mouth ID as much as may be wanted. Case life will be reduced too due to over working from expanding the extra few thousanths and being thinner.

I understand your point and agree, but I'm talking about neck tension by uniformity of the inside of the neck surface.

Rich V
The inside diameter is the only measurment that controls uniform neck tension,and on standard dies it is set by the expander button on the decaping rod.Doesn't matter if the outside of the neck is out of round.The comfusion comes when switching to neck bushing dies and not turning necks,but removing the expander button.This causes thicker necks to increase tension.Two choices,that I can see;1.Turn necks for uniformity,or 2.Use a expander button of the size you want.(I just talked to a tec at Forster,as I have a neck bushing bump shoulder die from them).the button,which didn't come with my die,is .001 less than bullet diameter.This should give .002 tension,but they will make them in the size you want.Now my tension should be constant with an occasional thicker/thiner outside diameter, of a loaded round.

Joe O wrote:

Rich V wrote:

Ol` Joe wrote:If you can drop a bullet in a fired case without needing to apply some pressure you probably won`t see any gain from neck turning. Unless the assembled cartridge neck is closer then 0.003" of a fired case neck diameter you are wasting your time and probably causing more working of the necks during resizing then you want.

If your loaded 204 cartridge as example measures 0.230" and a fired case mouth runs 0.235" you have a lot of slop already. The brass springs back after fireing and the actual chamber area of the neck is likely close 0,238" or so. Take anything off and the case just gets looser in the chamber as well as causing your dies to not being able to reduce the mouth ID as much as may be wanted. Case life will be reduced too due to over working from expanding the extra few thousanths and being thinner.

I understand your point and agree, but I'm talking about neck tension by uniformity of the inside of the neck surface.

Rich V
The inside diameter is the only measurment that controls uniform neck tension,and on standard dies it is set by the expander button on the decaping rod.Doesn't matter if the outside of the neck is out of round.The comfusion comes when switching to neck bushing dies and not turning necks,but removing the expander button.This causes thicker necks to increase tension.Two choices,that I can see;1.Turn necks for uniformity,or 2.Use a expander button of the size you want.(I just talked to a tec at Forster,as I have a neck bushing bump shoulder die from them).the button,which didn't come with my die,is .001 less than bullet diameter.This should give .002 tension,but they will make them in the size you want.Now my tension should be constant with an occasional thicker/thiner outside diameter, of a loaded round.

Joe
I have not used an expander button with my neck-sizing bushing die now for many years. After reading an article in 6mmBR.com, Froggy on reloading http://www.6mmbr.com/TacticalFroggyA1.html I decided to try his suggestion. The first thing that I noticed by removing the expander button was, my neck run out went to near zero. I did not have to trim cases as I did before. No doubt to me, it is because, the button was not being pulled back through a sized neck an extruding the brass. The O.D. of the case neck does not change and I found that case life is longer.