Author Topic: Chamber Dimensions Question (Read 550 times)

MINNESOTA DICK · « **on:** November 22, 2003, 02:37:02 AM »

The question that I have is where on the net can I find information as to the typical chamber dimensions for 17 rem, 223 rem, 243 win and the 30-06? I have been able to find case dimemsions but no chamber dims.

I am just courious and wold like to loook at them. :?

thanks

Minnesota Dick

Iowegan · « **Reply #1 on:** November 22, 2003, 06:33:20 AM »

The Small Arms and Ammunition Manufacturers Institute (SAAMI) is an organization that is chartered to standardize chamber and ammunition measurements and a lot more. They keep the chamber dimensions "controlled". The chamber measurements must have a + or - tollerance to allow for variations in manufacturing processes such as tool wear. With a host of companies making guns and ammo, SAAMI makes sure all ammunition will chamber and fire safely with reasonable accuracy in all guns. Most manufacturers tend to cut chambers on the deep side of the specs, especially free bore, to accomodate oversized ammo.

So to answer your question, unless you are in a firearms, bullet, or powder manufacturing business, you probably won't have access to the chamber specs. By the way, SAAMI is a US organization. Foreign arms and ammo manufacturers are not obligated to follow SAAMI standards. See web site: http://www.saami.org/

gunnut69 · « **Reply #2 on:** November 22, 2003, 07:32:03 AM »

Clymer has a database of reamer dimensions at the link below..
http://www.clymertool.com/
Remember these are reamer dimensions not chamber dimensions. "Cartridges of the World" may have a listing of chamber dimensions, I don't really recall.. ANOTHER SENIOR MOMENT!!!!
Getting too many of those lately...

Iowegan · « **Reply #3 on:** November 22, 2003, 01:05:56 PM »

Gunnut69, I dug out a Clymer reamer for a 22-250. The spec sheet that came with it shows the same measurements as their web site. It is made to conform to SAAMI specs but doesn't state the actual specs. I would say the reamer specs would be the biggest dimensions for SAAMI. As the reamer is used, it "shrinks" with wear. At some point, it would hit the minimum SAAMI specs but they don't say what that is.

The reamer specs would be a good place to start. A thousandth or two on the diameter makes the difference between a good one and a worn out one. The exception being free bore depth where they can vary as much as .050". Free bore has a major impact on accuracy but because of military surplus and foreign made ammo, American gun manufacturers tend to ream deeper.

Sure glad you thought of that!

Cartridges of the World give the standard SAAMI case spec which is always a little smaller than the chamber spec. The same case specs can be found in most reloading manuals.

MINNESOTA DICK · « **Reply #4 on:** November 22, 2003, 03:00:17 PM »

Thanks for the replys. I think the chamber reamer dims is the info that I am looking for. I am just trying to understand the case length dims in relation to the chamber dims. I will study the reation of the reamer dims to case length for awhile.

thanks again

Minnesota Dick

gunnut69 · « **Reply #5 on:** November 22, 2003, 06:51:30 PM »

Perhaps the chamber specs lie somewhere between case specs(minimum) and reamer specs(maximum).

MINNESOTA DICK · « **Reply #6 on:** November 23, 2003, 02:22:16 AM »

Iowegan, I found this post of yours I think in the reloading section and I think it is pointing me I the right direction.

Check this web site for tools that measure chamber depth and precise bullet seating depth. http://www.cactustactical.com/reloading/reloading.html

gunnut69, I found the chamber reaming site very interesting, tanks for pointing me to it.

Just some info, I am just getting started into reloading and am trying to gather as much info as I can about it. I have both the Lee, and speer reloading manuals. I more I read them, the more questions it gives me to search out.

thanks again

Minnestota Dick