Project - FX Crown Length of Pull Adjust
Silent Thunder Ordnance
We’re big fans of the FX Crown, no surprise there, so when a customer came to us looking for a length-of-pull adjustment for their FX Crown we took up the project. At its core, the issue is a simple one: how to make the stock on an FX Crown longer.
For those not aware, Minelli of Italy makes stocks for FX as well as most other leading airgun manufacturers. Their buttpads are injection moulded plastic, and offer a relatively elegant up-down left-right adjustment. Because the investment in an injection mould is substantial, they are probably shared across many different product lines they offer. The Daystate Redwolf for example also uses a Minelli stock, and the buttpad is a suspiciously similar looking part. So any solution for the Crown may well be applicable to a bunch of different rifles.
The first step, as with anything, is to figure out how the thing works in the first place. That means pulling it apart. This can be done with just a hex key and a phillips screwdriver.
As it turns out, the stock is attached with what appears to be two stainless steel wood screws of very similar dimension to your typical decking or sheetrock screw. That is very convenient, because it means sourcing new longer screws to fit with a spacer should be easy.
Clearly visible are the two recesses in the stock which the buttpad assembly uses for alignment. Alright, that makes this relatively simple. Design and prototype a piece which matches the profile of the rear of the stock and buttpad assembly, and has matching alignment points, male and female, on both sides.
This design can then, relatively trivially, be adjusted for length to suit the user and manufactured to fit. Stainless steel screws can be sourced to match the desired length increase, and the whole thing can be made quite light. Conversely, for a change in rifle balance, this would be an easy non-destructive way to add mass to the rear of the rifle.
And there it is, shown at left in high-contrast white to make the new part obvious. (any color could be used) This particular example is a 30mm LOP increase.
Perhaps the more interesting aspect of this could be a means to simply and easily add things like rear monopods, bag riders, picatinny rail sections, et cetera. All interesting future directions, but beyond the scope of this project.
7.16.20 update
The comments about a picatinny rail section grabbed people’s attention. So, bowing to pressure, we rolled out not one but three variants all 25mm. If you were looking for an easy and completely reversible way to put a rear monopod on your rifle with Minelli stock, this is it.
