I have a 376 steyr SBS prohunter. The fired brass seems to be about .005" over sized after firing. This shows up as a ridge where the web ends. the cartridge drawing I have shows a base diameter of .501" (.494 rim)fired brass mics .504" .32" up from the base of the cartridge. Shoulder dimension should be .473" fired brass is .478". this was Hornady Factory ammo 225 and 270 grain. The unfired ammo mics right on spec.
Is this an over sized chamber for this cartridge? I have not been able to find the chamber specs. for the 375 Steyr. Any help would be appreciated.
Thanks

BAD-KARMA,

Clymer's database shows their .376 Steyr reamer
to be .5083 base and .4756 shoulder.

WC

Thank you for the reply. Based on what you told me I found the Clymertools site. I have never been there but have bookmarked it now. At first I thought the database must be wrong based on the .007" diff. between case and reamer. Then I found this on the Clymer tools site.

"Nothing looks worse than an unsightly bulge at the base of a case fired in a brand new wildcat-chambered gun. This can be avoided by carefully selecting a lot of brass and having the special reamer ground to match. In its published tolerances for centerfire rifle cartridges, SAAMI allows cartridge diameters to vary by as much as .008". Necks can be turned, case lengths can be trimmed to close dimensions and shoulders can be blown out and forward without much grief, but it is difficult to change the base diameter of the brass. When buying a lot of brass, a number of cases taken at random (10 % should be sufficient) should be measured to assure they fall within variances you consider reasonable. A little extra time taken at this stage can save quite a few headaches later on."

.008" is the allowable diff. that is much more than I would have thought.

Based on this information, and that when I called Steyr service they said that Europeans often ream to the large side of the spec., I am now thinking the rifle is OK. I just wanted to be sure.

Guess it is time to buy some neck sizing dies.

Yep, sounds like you're about at max slop there.
Not a real problem in and of itself, but it also sounds like you have some soft brass. Did you mention the brand of brass?
You might try another brand and see what happens.
Worst case, you could get some 9.3x64 from Europe, and neck/trim.
Horneber has then for $1.7 ea. !

If it ever comes to triming 9.3 Brenneke brass for your Steyr, you can get brass (at a reasonable price) from The Old Western Scrounger.
It's RWS brand.

Costs about the same as 404 Jeffery brass does...in other words, not outrageous.

Garrett