Yes, you'll need to fill the gap between the prongs, plus add a little bit of length to the prongs to recover some of the lost depth you get when you remove the inner nub. You also need to do it if you want to use heavier ammo.
I use car body filler and file it roughly to shape, then cover it in mitre bond, thats a builders super glue that 'really does' go hard in 10 seconds, to make it harder, I then file my shape into my arm nub more accurately.
You might find you have to have several goes at this before you get it right, so don't be despondant when it doesn't shoot straight on the first attempt
I use car body filler and file it roughly to shape, then cover it in mitre bond, thats a builders super glue that 'really does' go hard in 10 seconds, to make it harder, I then file my shape into my arm nub more accurately.
You might find you have to have several goes at this before you get it right, so don't be despondant when it doesn't shoot straight on the first attempt