??????? on clearance for tightneck

[22turborimfire]

Just started playing with the tight neck chambers . What kind of clearances should i be look at ? I have a .268 neck what should my loaded round mic out to be ? + and -'s. What is ideal clearance ? Is tighter better? Can it be to tight if goes in gun with ease to close easly. What is to much clearance?
thank you,
Jim

 

[markr]

Just go back to the basics and use your math! The loaded round must chamber without effort or resistance yet release the bullet when fired. I'm not gonna tell you my measurements for liability reasons...but good, live brass springs back .0015 to .002 after all is said and done.
Mark

 

[15Tango]

Sounds like you should be running neck thickness of .011-.0115 to me . . .

Wayne

 

[artbosco]

Just started playing with the tight neck chambers . What kind of clearances should i be look at ? I have a .268 neck what should my loaded round mic out to be ? + and -'s. What is ideal clearance ? Is tighter better? Can it be to tight if goes in gun with ease to close easly. What is to much clearance? thank you, Jim

A good rule of thumb with a bullet seated is .002" total clearance, .001" on each side, (which would include the pressure ring found on a custom made flat base bullet). The loaded round with a .268" neck chamber would mike out at .266".

Yes, It can be too tight. For instance .2675" total in a .268" neck is "not" recommended. However, .003" to .004" total clearance is used in some disciplines and not in others.

Personally, I use .0015" in my 6PPC and .002" in my 30BR.

 

[BoydAllen]

Although my 6PPC neck clearance has typically runs around .0015 total, recently I have learned that some very successful shooters are using up around .003. I would say that if your chamber neck is really as advertised, that your loaded rounds should measure from .265 to .267. Remember that if you run on the close side that you should check this dimension every time that you try a new bullet, and that you should check every case as you turn them, with a neck mic. or as loaded rounds, the first time that you load them, over the pressure ring, with a mic. that reads to .0001.

 

[LHill22250]

This is something that I monitor very closely with all of my rifles/calibers.. In my 6PPC & 6BR (like BoydAllen stated) I run right at .0015" with fully BR prepped brass. In my 22-250's, 243's & others I run a solid .002. I do run .003 in my 270WSM as it has proven to always be the tightest grouping configuration.

 

[4xforfun]

My first question to you is this....what is this gun used for?

If it is strictly a hunting gun, I would run .002 on each side (.004 total). If it is a bench gun, .001 per side (.002 total).

My reasoning.....A hunting enviornment is never as clean as a bench environment. Chamber a hunting gun to tight and you may be asking for trouble. It doesn't take much gunk to creat issues.

Just my .02

 

[Erik Cortina]

I run .003" total clearance on my F-Class rifles, that seems to work.