MEC single stage reloader. I think it's now called the 600. They sell a short kit, which raises the portion of the reloader that holds the shell base by 1/4 inch so you can get a good fold crimp using a 2-1/2 inch shell. If you find only 2-3/4 inch hulls (likely, as 2-1/2 inch shells seem to be completely missing from the market, particularly in 16 gauge), Ballistic Products sells a kit that allows you to shorten the hull to 2-1/2 inches. Or, instead of the short kit, you can trim a fired hull to 2-1/2 inches, which will leave a bit of the crimp, and use an overshot wad (available from Ballistic Products) that you insert before crimping the hull using the standard 2-3/4 inch setup. The crimp won't close the mouth of the shell completely (hence the need for the overshot wad to keep the shot from falling out) but will crimp sufficiently to hold the overshot wad in place. If I recall correctly, this is called a Hardin crimp.
If they will feed through the action, you may find that low pressure loads in 2-3/4 inch reloads will work safely in the gun. There are a lot of opinions pro and con on this issue, but starting off with a low pressure load (something in the 8000 psi or less range) will not normally create excess pressures when fired in a 65mm chamber.
In addition, you'll find some nominally 2-3/4 inch hulls are not actually that long. I've measured nominal 2-3/4 inch hulls as short as 2-5/8 inches and a number of different makers at 2-11/16 inches. If your chamber is a true 65mm (some of the earlier guns actually have shorter chambers, which helped to form a gas seal when firing paper shells using paper or cork wads instead of plastic shot cups) and there is a forcing cone, you should be ok.
Hope this helps.
