How long is a chamber that's too long

[redneckturkeycaller]

First let me thank Frank S. for all of his help.
How long is too long for the chamber on a hunting/ varmint rifle. This rifle is a 243 winchester and may have suffered from a lot of rounds. Thanks for all of the help in the past.
Jeff

 

[Larryh128]

GENERALLY, you have about 5 thousands to play with. A long chamber will usually require a lot of pressure to resize, & if it's really long, it will pop primers. Another issue is that after 2-3 firings you could see case/head separation. The only way to really know what you have is the use of go/no gauges.

 

[fdshuster]

jeff: I'm not clear on what you mean by a "long chamber". Are you referring to chamber length as it relate's to the 243 overall case length of 2.045"? Or do you mean throat, freebore as that relates to bullet seating depth? Or, as Larry said headspace length? "suffered from a lot of rounds" is what threw me, since that would only apply to erosion in the throat. Frank

 

[redneckturkeycaller]

I am referring to the over all chamber length as it applies to the 243 which is 2.045. I measured the chamber and it is almost 2.070. I am sorry that I misled you. Does a long chamber effect accuracy. Thanks to all who helped. Please overlook my limited knowledge. Thanks again

 

[fdshuster]

jeff: No big deal, just means you'll have a longer than normal gap in front of the case mouth when chambering all but the longest case lengths. You could just let the cases stretch beyond the 2.045" max length and not trim 'til they reach 2.055" or so, but any closer than that and I'd be sure to measure each one after every FL sizing. The 243's that I had did show a little more than average case stretching, maybe caused by the 20 degree shoulder angle(?). Not say'en, just a thought. I don't think there would be any effect on accuracy, the only downside may be the formation of the ring of carbon buildup that will sometimes form there.

 

[redneckturkeycaller]

Thank you very much for taking the time to answer my questions. This is wonderful site with very knowledgeable people. Have a wonderful New year @@@@@@ May the great architect of the universe smile on you and your family.

 

[boltfluter]

fdshuster is right on the money. Paul.

http://proprecisionrifles.com/

 

[Flouncer]

I am referring to the over all chamber length as it applies to the 243 which is 2.045. I measured the chamber and it is almost 2.070. I am sorry that I misled you. Does a long chamber effect accuracy. Thanks to all who helped. Please overlook my limited knowledge. Thanks again

How did you measure this ? A comparator would measure where the bullet hit something, i.e. the least dimension in it's path, hopefully the rifling. No the same as the end of the chamber if it's worn or eroded. Thanks !!

Clarify: He is using the term chamber and measuring same, not the throat or leade. Right ??