Those will definitely not fit into your typical deluxe domestic Transformers. You'll have to mod them for them to fit into the hand hole.
They will only fit into Transformers with hands that can be manipulated. Only the Alternators and Masterpieces come to mind.
I bought myself some 1/6 scale rifles and pistols for my Gundams a few years ago.
Nothing like a Gundam packin' heat with a '9 mil in one hand and a colt rifle in the another.
Which gives me the idea...Nemesis Prime with a fully automatic machine gun with drum barrel...I don't think Masterpieces' will work, they're too big.