I use Accu-Shot with a 300RUM BDL(Remington Ultra Magnum) 26" barrel, with factory stock, and a recoil pad.
The inside accu-shot body is metal, and outside is "kind of hard sponge" good for very cold weather (to don't freeze your fingers).
The bottom part what is in contact with the ground (soil) is plastic cap. (this one if you shoot from very abrasive area) like gravel, rocks, can got screatches.
The part what is in contact with your stock is metal, and have stick to it one piece of leather, for protecting your stock. (So if you have in plan to sell your stock , is looks like new, without damage.
Advise: if you decide to get one, please get with double locking system (one locking system is for fixing Accu-Shot in rock solid position) and the second one is for locking the bold in the desired elevation position.
You can see the Accu-Shot web site for brochure (User guide).
How I used this one: I just setup the elevation to medium for Accu-Shot, and when I am in the field, I just use the bipod for front rest, and ... when I have time I can play with elevation from monopod (accu-shot).
On quick shots - I just leave the accu-shot how is (at medium position) and just drag the rifle back till I am in the right elevation. (In normal shooting situation your bipod is on vertical position without the angel between stock and soil, at 90degree) but on quick shoots, when you do not have time, just pull back the rifle,till you have angle between your bipod and stock (90-45 degree).
That's is how I use this on the field.
Of course when the games is far away, past 500 yars you willl have enough time to get the right position and you can play on small adjustment with your Accu-Shot)
Don't worry about damage your stock, or accu-shot, because till now I shot lots of ammunition, and without damage. (except some scratches on the protection cap = where the accu-shot make contact with the ground).