Seems like every forend I run across/buy does not always fit as far as the barrel forend screw/lug spacings. I just purchased an MGM 11.5" 44 mag barrel and it has rifle forend spacing....probably because it was a special order barrel. However I've run into this in the past...forend screw spacing not matching.
A walnut T/C forend I have fits this 11.5" barrel and comes right up to the muzzle, but the combination is heavy. I purchased a Pachmyer finger grip and forend set from Amazon [new] and find out the forend screw spacing is shorter than this MGM's screw lug spacing. I also have an old Pachmyer forend and it has a steel bar making that forend's single mount screw adapt to a pistol lug spacing. ALSO, it has molded into the forend inletted area 'bull barrel', but the newer bull barrels are larger than the forend barrel channel. I'm remembering that older 'bull' barrels had some taper to them [I think].
Anyway, I've considered having a friend with a milling machine cut another dovetail so I can mount the new Pachmyer forend to this barrel.
Maybe it's just me... : )
Follow up: Just figured out the older Pachmyer forend with ONE screw and bar device will fit MGM barrel if I remove the forward barrel holddown lug nut. Now wer'e cookin'....