SnowpeakAP900/ 1000 Air Venturi Alpha Adjustable Butt Hook (Versions with/without Bag Rider)

This is a fully adjustable butt hook for the Snowpeak AP 900/ 1000/ Air Venturi Alpha PCP.

The core (BH_Core) fixes directly to the standard stock using the factory fixings. The three elements can then be positioned on the core and the postion altered to suit different scope heights, shooting styles or the shooters' build, giving a far more secure and repeatable fit to the rifle.

You will need 6 M4 x 25mm socket cap head screws, 6 M4 Nyloc nuts, 2 M5 x 25mm Socket cap head screws and finally 2 M5 Plain nuts. I've used stainless steel in the photos for corrosion resistance.

The parts BH_Upper_Left and BH_Upper_Right are loosely joined with one of the M4 bolts and Nyloc nuts through the hole closest to the curved face that will touch your shoulder. They can then be slid onto the core. Repeat for the Mid and Lower components.

The hook elements can then be secured one to the upper, one to the lower using the M5 screws and nuts. Note that the hook elements are identical.

Note that although there are two more holes in each element you're only going to need one screw for each. The holes are actually offset relative to the hole spacing in the core to allow a larger range of posible positions for each element. 
Once you have the positions to your liking there are circular and hexagonal plugs included to fill the spare holes both sides if you wish.

I'd sugest printing with 5 walls and 30% infill, 0.2mm layers. The individual files are already oriented for best print definition.
All parts will print with no support. The smaller parts need no brim if you have good bed adhesion.
I would suggest a brim for the core, and I used organic supports as additional insurance against print failure.
The parts are oriented on the bed in the 3MF so that if you define the seam location as 'Rear', the seam will be hidden when the parts are assembled

There is now a version of the core available that includes a bag rider (BR_BH_Core).