Case Length Question.

[boogershooter]

Does case length, and trim to length remain standard in custom chamberings? I ask because I have a few custom tight neck rifles and so far I have just been keeping an eye on the growth of the brass length and I kinda feel like its a guessing game. Should I take a more accurate approach to this, and how?

 

[HolyMeekrob]

I would look up the SAAMI specs and see if your chambering is listed. To my knowledge neck size (ignoring freebore and leade angle, etc) is the only dimension that varies from reamer to reamer, but if you're shooting a wildcat I wouldn't bet on dimensions being standardized. If in doubt or if you want to know the dimensions of your particular chamber you could always make a cast. I would imagine someone's determined an easier way, but if all else fails...

 

[boogershooter]

Thank you for the reply. One of them is a 6brx, .269nk , and the other is a 260,.292nk

 

[fdshuster]

I firmly believe in the chamber length gauges as sold by Sinclair, page 37 in their 2010-B catalog. Well worth their cost of $6.95 for each caliber, and re-usable. With them you are able to get the exact chamber length in your barrel, and trim (or not) accordingly. Many chamber length's (especially factory) will be as much as .035" longer than max case length and to follow the loading manual's "directions" of trimming .010" shorter than max case length will result in excessive trimming. Chamber length is one of the dimensions I specify when I order a new reamer, and I keep it at .010" longer than max case length, otherwise you can get whatever the reamer maker decides to make it.

 

[boogershooter]

Thak you FDShuster for that,I didnt think they would work in a tight neck.

 

[fdshuster]

Sinclair does offer a 6mm chamber length gauge for a standard neck diameter, (#G-243) and a tight neck .262" #G-243T. For any other caliber a solution may be to simply turn down the diameter for the smaller neck. A good question to put to Sinclair.

 

[fdshuster]

Randy: Yes, I like your method, an alternative to the Sinclair gauges. I was confused until I visualized a "slip ring" that is free to move over the seated bullet, to the rear as the case is chambered.

 

[artbosco]

Does case length, and trim to length remain standard in custom chamberings? I ask because I have a few custom tight neck rifles and so far I have just been keeping an eye on the growth of the brass length and I kinda feel like its a guessing game. Should I take a more accurate approach to this, and how?

The one thing that's standard is SAFETY. ALWAYS ensure that your brass does not encroach into the .010" SAFETY ZONE that should always exist between the end of the case neck and the end of your chamber.

The Sinclair Chamber Length Gage mentioned above is a great tool for finding the true length of your chamber.

 

[brxbrad]

Maybe I'm confused, but booger's question sounded like he was referring to Case Length not COAL. The 6BRX is built off the 6BR Norma. If you want to find the difference between the BRX and the BR case length, measure the length of a new 6BR case and compare it to the length of a fireformed BRX case. I believe you'll find they will be same. The 6bR has SAAMI specs but the BRX does not. The BRX is a wildcat. The Remer used to cut your BRX will have the Specs on it. I've included the link for Cartridge Diagrams if you care to use them as a guide. If you want to check the COAL for your chamber, yes, use the Sinclair guage.

http://www.6mmbr.com/cartridgediagrams.html

If you have a .260 Remington, it's included on the above link.....

 

[fdshuster]

brxbrad: Chamber length is the one dimension not shown on any of my chambering reamers. Neck diameter and freebore, yes. It is shown on the accompaning reamer drawings, for my spec'd reamers always .010" longer than max case length. I would think that if someone bought their own reamer and did not specify chamber length, they might get whatever the reamer maker decided to make it. I've seen very large differences, all with the same cartridge in factory chamberings, but that may be lawyer mandated. One of my Remington factory rifles has a chamber length of very close to .040" longer than max case length. Another is a closer .015".

 

[boogershooter]

Thank you for all the replies,I have been using the cartridge page on this site as BRXBrad mentioned/linked, as a guideline. But I have always pondered my O.P. Because I have heard they vary. I sure like Randies method ,and will try it . Seems fool-proof.

 

[Cameron SS]

+1 vote for the sinclair case length gauge. I neglected to specify max case length, later measured and it was .027" longer than SAAMI max. I only trim cases now to ensure uniformity across the lot. Most of my cases wear out for other reasons long before they stretch past .017" above max.