2 5/8 chamber and hunting
 

I’m looking at a 2 5/8 chambered 12 ga no 1 frame with 28” twist barrels. Are there shells available commercially for this? I’ve found 2.5 and of course there’s 2 3/4 in light loads. What could I shoot for hunting and occasional clays with this gun?

Jeff: period documents confirm that many makers (Parker, Fox, Ithaca) cut chambers about 1/8 inch shorter than the paper case roll crimped shells for which they were intended.

There is no data suggesting an increase pressure using modern 12g 2 3/4" plastic hulls (many of which are slightly shorter than 2 3/4") in 2 5/8" chambers.
Using 2 3/4" shells in shorter than 2 1/2" 20g chambers is of concern however.

The other issue is that only after your Twist barrels have been evaluated by a gunsmith with the interest, expertise, and equipment (wall thickness gauge and bore scope) to properly do so could load advice be given.

The way the measurement is taken is after the shell is fired. I have picked up empty modern 12 g hulls and compared them and found significant variations in overall fired length. However, and this is important, while I have found many that were shorter than 2 3/4", some significantly, I've never found one that measured over 2 3/4".

Spend some time looking for and measuring fired hulls and segregate the shorter ones. Then, spend some time looking for stats on the loads, particularly looking for chamber pressures (which are hard to get your hands on). Then, choose a shorter load with a lower pressure and with lower payload and velocity and you'll be fine, provided your gun is sound.

Here's an example of a "before firing measurement". Note how much less than 2 3/4" the shell is. Then, notice that this is a vintage era 3" magnum load and only measures 2 1/2" loaded.

https://www.jpgbox.com/jpg/74352_800x600.jpg

I found these at gmansportingarms.com
Use them in my 2 5/8 (but closer to 2 9/16) Trojan
$9.37 box plus shipping, to me was about $10 per flat

Shell at right is a 2.5", the others are 2.75. Quite the variation for consideration as to how this all plays into the forcing cone discussion.

After talking to someone locally who really seems to know his stuff...He said Parkers are not 2 5/8, but really 2 9/16.
I decided to get in touch with Michael Orlen and have chambers of couple of lesser guns lengthened to 2 3/4, if barrel wall thickness permits.
The Parkers that are truly original, I won't lengthen and invest in the RST 2 1/2 shells for them and just accept the high cost.
The real problem is availability. 16 ga not available right now. RST is out of stock and Claysammo has them in a container off the coast of FLA.

Think about a reloader Clark.. Alot of good information and loads right here on this site..

More show & tell

https://photos.smugmug.com/Shotshell.../Shells1-L.jpg

Any gun with short chambers is probably 80 years old or older and has also probably digested thousands of 2 3/4" shells without damage. Research has shown that the load in the shell has more to do with any possible damage to the gun than the length of the hull. Added pressure caused by the shell extending into the forcing cone is very minimal as long as the load approximates the original load the gun was intended to shoot.

They were meant for 2-3/4” shells.