38 Super Auto/38 Tj

[riden]

While sorting 38 Super Auto brass, have come across some 38 TJ, and obviously separating it out. The case base measures .014 less in diameter. There are other visual differences, but thought I'd solicit feedback.

I performed a search and saw 1 post on Super Comp & TJ. I assume a gun tuned for Super Auto will have extraction & chambering problems. What else should be noted?

[kbear38S]

The case base measures .014 less in diameter.

That's the inside diameter of the chamber it was fired from. You can't measure range brass and draw any conclusions about exact diameter measurements of a properly sized round.

[Dream]

Depends on the gun my blaster runs 38super and supercomp just fine, with no extraction problems.

[PhilTerry]

38 tj is manufactured by Hornady and was developed by Honady and Todd Jarrett, like SuperComp it is a rimless case but has a slightly thicker wall at the base of the case than SuperComp. When the gun is properly set up for the case - particularly the extractor it feeds very well - it stacks better in the magazine than regular 38 super. A gun set up for 38 tj will feed SuperComp just as well.

When reloading 38tj a .223 shell plate is necessary - it will pull through a regular 38 super shell plate.

People who use tj appear to get an extra few fps out of the same charge weight as used in a 38 super - this appears to be due to the slightly smaller volume resulting from the thicker wall.

[joshua]

That's weird, I use the same set up to load 38tj and 38 supercomp using 9mm shellholder. My load for my 38 supercomp is 7.8 grains of Ramshot Silhouette capped with 125 Montana gold and Starline supercomp brass, that makes 168 pf with my Limcat turbo II comp and no blowholes. Using the same setup but with 38tj brass I will get 50 to 70 fps faster over the chrony. Those were brass I picked up at the range and they look like they have been fired at least 2x or 3x. 38tj are very similar to 38 MCM brass, they behave exactly the same over the chrony. josh

[Alan550]

The 38TJ is a sort of compromise between .38 Super, .38 Super Comp, 9X23 Win and 9X23 Super Comp with a thicker case webbing than the .38s much like the 9X23s for more strength. TJ changed a few minor measurements from the 9X23 and made it a proprietary cartridge with his initials on it. It shoots great in my 9X23 and reloads easily in that caliber dies and shell plate (.223)

[joshua]

I suppose if you fire the 38tj in a 9x23 chamber it will strecth out to those specs. That will explain why some range pick-up 38supercomp brass will superface with my 38super dies when I resize them. One of my open gun is reamed to 9x23 chamber and my 38supercomp and 38 super brass will not last more than 3 firings. Hmmmm... I suppose I need to get some 9x23 dies to get more firings out of those brass fired through that one gun. The gun is so reliable, it will feed superfaced 38super brass. josh

[Ross Chevalier]

Riden,

The theory on the brass is as follows; 38 TJ and Super comp have a recessed rim, (hence the need most of the time for the smaller shellplate) It is very common for brand new 38 Super brass to hang itself up in the magazine because the diameter of the rim is nominally larger than the diameter of the rest of the case. TJ and Super Comp solve that problem. Strayer Voigt actually sell different breechfaces for TJ/SC vs. regular .38 Super.

It is common to experience extraction problems on an inconsistent basis with TJ/SC brass in a gun with a .38 Super breechface where the extractor is set up for .38 Super. I have personally experienced "fascinating" problems with a .38 SC breechface (installed in error) and regular .38 Super rounds.

The top open shooters in my area seem to prefer Super Comp or TJ, but challenges with getting the brass up here leave most of us using regular .38 Super. Using once fired brass seems to eliminate any catching in the magazine.

Best regards,

Ross