The Vallaha design by virtue of being a spigot mounting is best suited to situations where it can be fitted at the very end of the fore-stock. This type of design offers some advantages in increased stability, by moving the fulcrum point between the bipod & rifle further forward (As fitted to the Sako M10 in the image below).
The Valhalla bipod is only offered with either a Picatinny or an M-Lok adapter fitting. These adapters are attached directly to the rail and bipod mounts separately to the spigot part.
Rifles with M-Lok rails tend to be relatively straightforward to attach the adapter to as the cutout slots in the rail usually start close to the muzzle end of the rail and extend its full length.
Rifle stocks that have fore-ends with full-length Picatinny rails that extend to the (muzzle) end of the rail/stock are also suitable for the Valhalla adapter fitting.
The image below illustrates this situation, where two identical Tikka Tac A1 rifles have been fitted with Valhalla bipods, (mounted on the spigot of the M-Lok adapters.) The rifle on the left has the adapter fitted on the first section of the rail. This gives the bipod room to cant left & right. The rifle on the left has the adapter mounted one slot rearwards, and the amount of cant is compromised because of this.
Some styles of rifles have smaller sections of Picatinny rail, which are typically set further back from the end of the stock.
We've rigged up the Picatinny rail in the image below to illustrate the type of scenario sometimes encountered.
(These are normally in the area that a sling stud would be located.)
If the Picatinny rail is located too far along with the stock (towards the action), there could be difficulties in fitting the bipod onto the rifle or achieving full functionality.
The main issue will be to assess if there is sufficient room to mount the Valhalla on the Picatinny rail at its foremost position, without conflict with the sides of the stock and still have unimpeded cant?
In the example shown in these images, the fore-stock (from a Sako S20), is just over 1.5" wide.
As you can see that Picatinny rail creates a little bit more room between the adapter and the spigot of the adapter.
The Valhalla bipods have a maximum gap of 1.8" between the shoulders.
As you can see in the next photo there is space between the centre of the bipod body and the stock. The problem here is the amount of movement available for left & right cant is restricted because of the reduced space between the shoulders of the bipod and the stock. This wouldn't necessarily be a big problem on the range, but in the field or in a 'PRS' type competition it might be.
A wider stock than shown in this example would exacerbate the situation and so regrettably not likely to fit or function as intended. This is also a shame for us as we like to sell bipods!
As discussed above the best option and the original concept of the Valhalla design was to mount it as far forward as possible. The science of this comes from the physics principles of 2nd class levers because of their mechanical advantage.
2nd class levers are known to only produce a small range of movement (less wandering of the scope crosshairs) because the short resistance arm (rifle/muzzle) is moved closer to the fulcrum (bipod) and further from the effort applied to move it (the shooter). Because of this the 'resistance' (rifle/muzzle) cannot be moved quickly because force is applied further away from the fulcrum (Bipod)