I have done a search of the FAQ and don't find an answer.
What is the difference between New England Firearms 980 Ultra Slug, Handi Rifle, H&R, NEF, etc.
Are the frames all the same? If not, how many different sized frames?
I have a New England Firearms 980 Ultra Slug and wonder if I can fit a rifle barrel on it?
Thanks,
Bill
SIZE, only one size. As long as we are speaking on current and recent production frames, In and of them selves, H&R/NEF no appreciable difference. (The one exception is the SIDEKICK black powder receiver. Its smaller from the hinge to the firing pin and no other barrels from the factory will fit.) From the tiny 17 M2 to the 500 S&W or the 10Ga goose gun. The physical size of the frame is the same. Butt stocks and forends are interchangeable.
BUT there is differences between some of them.
Sportster is a rim-fire only receiver. It has a different firing pin and built like a shotgun receiver.
SB1 is primarily a shotgun receiver. Recently it has been fitted with a small firing pin for some pistol calibers like 357mag and 44Mag. (Also used for the Huntsman line of blk powder rifles.)
SB2 is a rifle caliber receiver, safe for about any caliber sans the belted magnums. Even then was chambered for the 450 marlin for a while.
The 098 used on the Ultra Slug guns is kinda a hybrid between the SB1/2 closer to a SB2 rifle receiver. But the factory will not fit rifle calibers to it.
The SIDEKICK is the one exception to the "one size" comment I made above. its a black powder receiver made explicitly to get around the rules some states had about muzzle loading rifles. It also can be sold thru mail order outfits as no paperwork is required.
Then there is the old 158 frames. Used for about everything that H&R chambered. 45-70, 30-30, 357, 44 etc. For all intent and purpose, its pretty much a SB1.
Then some really old models (50+ years ago) had a tang barrel release. Some time in the 1960's they also changed to a bolt on forend form the snap on so common on dbl barrel shotguns.
This information is in the FAQ's just maybe not all in one place or thread.
CW