Paul,
I have a tab-lock Buckhunter. On Bob's site this is the DK-TF7. The Trapper models are listed as having the tab-stop. I have had the other model and there is a difference in how the locks are set up but they both do the same thing.
The Buckhunter, Workhorse, and Folding Dagger are all set up the same way. First thing I will mention is the THICK handle slabs. Thickest I have seen on a folder. Thicker than the ones on my MADD MAXX. The locking bar is a T-shaped piece of titanium that is nested and screwed into the ti handle. When you open the knife this liner springs over to engage the entire back of the blade tang. The lockup is very tight with NO blade wobble at all. Spine whack after spine whack resulted in no failures. Haven't really torqued the blade yet to see if it unlocks but doubt that it would. Bob has the fit down pat as the knife is very secure when closed. At the halfway point of closing you feel the blade engage the ball of the liner, and when closed the liner snaps in. Has a walk and talk of the best slipjoint! I would reccomend this knife to anybody.
The Trapper is a newer style that operates a bit different but results in the same end. The Trapper has a double liner lock, one up top as the stop and one down bottom as the lock. I had this one and sold it, don't know why, and the first thing I noticed was the thickness of the liners. Again I have never seen liners this thick, a bit more than half the blades thickness. Lockup was tight with no blade wobble and closing was the same as on my Buckhunter.
I can't praise these knives enough. Very simple lines with superior materials and Bob's craftsmanship have resulted in some very heavy duty folders. Add a clip and you have an outstanding product!
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Art Sigmon
"I can do all things through Christ who strengthens me"
Php. 4:13
"For the word of God is living and powerful, and sharper than any two-edged sword"
Heb. 4:12