Chamber neck clearance

[glockdan78]

So i asked about neck turning 260 lapua brass in an earlier thread. Now I have another question. How much neck clearance do most of you consider ideal for a rifle set up for tactical type matches. I'm trying figure out how much to take off of the necks of my 260 lapua brass. My chamber has a .295 neck and the lapua brass is measuring .294 when loaded....so we are at .001 neck clearance. Not a lot. I live in Texas and shoot predominately through a suppressor, so chamber temps will be on the high side. Is that something to think about with neck clearance? How much should I turn them down?

 

[bjay]

Is this a bolt or gas rifle? For bolt? No turning, ok to litle tight for your purpose IMO

 

[glockdan78]

It's a surgeon 260 bolt I just bought.

 

[bjay]

When you say .001 thats half of thousand around the neck to throat wall... if you can shoot 50rds and stil can pull an cased shell and chamber a round without forcing then your safe which i realy doubt it.. specialy on what type powder your using and seating dept on bullet some powder creat more carbon build up around the neck and wont take more than 5 rounds to create .0005 foul on the throat.. i would neck turn hust to be safe..

 

[bjay]

By the way thats a beutiful rifle...love the stock

 

[glockdan78]

When you say .001 thats half of thousand around the neck to throat wall... if you can shoot 50rds and stil can pull an cased shell and chamber a round without forcing then your safe which i realy doubt it.. specialy on what type powder your using and seating dept on bullet some powder creat more carbon build up around the neck and wont take more than 5 rounds to create .0005 foul on the throat.. i would neck turn hust to be safe..

Not to mention, I will be shooting with a suppressor so carbon buildup will be more likely. So guess the question is, what is a good neck chamber clearance since I can really pick any?

 

[turbo54]

For a field rifle, I think at LEAST .004" diametral (.002"/side) is a decent bogey.

The only tradeoff is "brass life" due to slightly more cold working, which annealing addresses anyway.

Dont forget .004" is about the thickness of a sheet of paper, so even then you've precious little clearance to work with.

Last point: I don't think a "tactical" or "field" rifle should require neck turning.

 

[glockdan78]

For a field rifle, I think at LEAST .004" diametral (.002"/side) is a decent bogey.

The only tradeoff is "brass life" due to slightly more cold working, which annealing addresses anyway.

Dont forget .004" is about the thickness of a sheet of paper, so even then you've precious little clearance to work with.

Last point: I don't think a "tactical" or "field" rifle should require neck turning.

Well that all depends on the brass you select to use.

 

[turbo54]

Well that all depends on the brass you select to use.

I'd argue you should select a chambering reamer with suitable neck diameter to provide adequate clearance for your intended brass.

 

[glockdan78]

Agree....but I'm looking forward to having very uniform brass. Even lapua has varying neck thickness. I'm thinking I'm going to turn down to .291-.292

 

[lightman]

I think .your .291- .292 is a good place to start. I run .0015 in my benchrest rifle, and that is too tight to be reliable in most other types of shooting. Nice looking rifle! Lightman

 

[JGorski]

My next 6 Creed build is going to have .002" clearance, a little tight but it should work for shooting 600BR/F-class or maybe a tactical match if I ever get a wild hair up my arse. LOL

 

[oldfatguy]

Agree....but I'm looking forward to having very uniform brass. Even lapua has varying neck thickness. I'm thinking I'm going to turn down to .291-.292

Measured 200 new Lapua 260 Rem cases and found as much as 0.002" neck wall thickness variation. Some were almost perfect with no measurable variation. The distribution was pretty much a classic bell curve.

Might as well neck turn to make them more consistent.

OFG