I don't believe Remington ever made a 788 in a heavy varmint barrel such as the ones on current Model 700's. As you note, the standard 788 contour was a bit heavier than the Model 700 Sporter contour.
As to two different stocks, I believe that was due to having two different receiver sizes, one for 6mm and .308 and the other for the .223 and .22-250.
They were pretty neat rifles, I had five including a .44 Magnum. The first honest 1/4" five shot group I ever fired was from a 788 in .223 with some cheap Bushnell scope mounted on it. Load was the Speer 50 grain Spitzer and 21.5 grains of IMR4198, and that rifle and load were responsible for lots of red mist after I moved here to Idaho.
Jim,
I found this on the 'net:
Basic Action Dimensions (all calibers)
Action diameter: 1.326" Measured my 6mm and a pair of .222s, both share the same diameter and length.
Barrel Threads: In short, the 700 barrels will not fit.
Rem 700
Thread 1 1/16" (1.062") X 16
Engagement .69 (11 threads)
Rem 788
Thread 1" (1.000") X 20
Engagement 1.1" (22 threads)
Rebarreling a Remington 788 on Steelchickens.com
The 788 has a 1-20 pitch threaded shank that is 1.560 long. Why such a long shank on the 788 barrel and why a thread relief in the middle? Dave, you will have to ask the design folks at Remington as to why such a long shank. The bolt enters the front of the action only about 3/16 inch. No gas bleed port needed with this little entry. The relief cut is to allow clearance for the front action screw. It barely touches the barrel when tightened at this point. Threads would get damaged if they were there. I guess they could have gone with a shorter screw, but the action wall is .05 thinner than a M700. Who knows what Wayne Leek was thinking on this one. A unique design to say the least. The relief is for the front action screw. I suspect that the long engagement is to stiffen the joint. I have read that the whole action was designed to cost less than a 700. Seems to me though that the 700 could have been done just as easily on a turning center as folks are now doing with 700 clones.
Action "Lengths" actually the distance between the two action mounting bolts:
Long 243, 6mm, 308, 7mm-08 7.1" Hole Spacing
Short 222, 223, 22-250, 30-30 6-3/4" Hole Spacing (I guess the .44mag is also the "short" action)