Detachable bottom metal conversion for Howa 1500 in a GRS stock?

[OldSteve]

Evening all, I'm currently mid (extremely drawn out) build of my first "proper" full-bore rifle; Howa 1500 short action in .308, Steiner M7xi, a Spuhr mount as soon as I actually have the above two in the same room and work out what I want, and either a GRS Bifrost or GRS Berserk stock (bought both and am incapable of making a decision).

Having had it out on the range with another scope on, I've come to the conclusion that loading through the top of the action is a right faff and as such am looking at a replacement bottom metal and detachable mags, and am bit overwhelmed.

Does anyone know of a replacement bottom metal for the Howas that a) will use unmodified AICS mags and b) will fit in a GRS stock with minimal fettling? From what i've seen, the WR DBM wants modified AICS mags, and the MambaMags DMB uses their own proprietary mags at an eyewatering price.

Failing that, has anyone had any experience with either of the above in a GRS stock?

[Woodlander]

Regarding your stock option, I believe the Bifrost has less flex, that would be my choice.  I’m just going on reports, not shot either myself.