John:

I arrive late and offer my thjought too.

The key to the issue is pellets in the pattern. If what you are seeking can be reliably killed by a decent 20g load, more power to you. If you require more than 1 oz ( actually 7/8) lead or Bi by volume, then I would pass on it with the 20g.

For turkeys, since the intent is to head shoot, I would expect the 20g with larger pellets will work just fine, inside the range where a clean head shot can be obtained.

All of this begs the question - why not just handload some decent 2-7/8" ( or other appropriate length ) Tens, and go from there, without messing with the sub gauge tubes?

Regards

GKT

Texas Declaration of Independence 1836 -The Indictment against the dictatorship, Para.16:"It has demanded us to deliver up our arms, which are essential to our defence, the rightful property of freemen, and formidable only to tyrannical governments."