Marking cases for consistent chamber alignment? How to?

arthurj · #1 07-10-2005, 03:57 PM

I shoot a factory rifle, and I was wondering about how to mark my cases to feed them into the chamber the same every time. Is my understanding of this correct: since my chamber is probably out of alignment, the goal of this is when a case is fired into "the banana shape" if you neck size only and feed the case back into the chamber the same way there should be more consistent alignment of the round? If I am starting with new cases should I mark each case near the shoulder with a sharpie and set them in the chamber the same way? If someone could help explain this I would appreciate it.
Thanks in advance

dcb · #2 07-10-2005, 04:12 PM

I think it is a waste of time. Have you checked the fired cases from your rifle for neck case run out? That will certainly tell you if the chamber is out..
That is where I would begin.
IF you fire form the case to your chamber and only partial neck size when reloading that will give you the best fit to you rifle. good load work up, bullet seating depth,(sweet spot) and straight ammo is the key to good accuracy.

arthurj · #3 07-10-2005, 04:39 PM

My fired cases average a hair less than .002 runout on the neck. So you don't think it would be worth it?

dcb · #4 07-10-2005, 05:20 PM

ART .002" tir = (+-).001" or less.
i would check the wall thickness of the neck and probably turn them to 60/70% just enough to clean them up. partial neck size . save 5 or 10 cases that are marked for aleignment. so you can compare groups. i would shoot groups at 3ooyrd . 100yds is to close for you see a diffrence. if any.
I tried that several years ago with a 22/250 and a .308
And decided i had not gained any thing.

arthurj · #5 07-10-2005, 06:06 PM

Ok thanks dcb, I guess I may give it a try just to see.

brian b · #6 07-10-2005, 07:13 PM

arthurj,
the practice you are talking about is called INDEXING, it does have some merit in factory guns but if there is a question it is much better to have a competent gunsmith true (blueprint,square, whatever)your action and barrel than resort to this Voo-Doo technique.
B

arthurj · #7 07-10-2005, 07:40 PM

Yeah, I wish I could have the action trued up on this rifle but unfortunately right now that is not an option. (I just bought a Nightforce 8-32 for another rifle so funds are a little low!) Maybe I will give the indexing a try, just to see if there is any noticable improvement. Thanks