First, the legal answer:
Your detachable magazine rifle (rimfire/centerfire doesn't matter) can have one additional "bad feature" from this list:
- pistol grip
- folding/collapsable stock
- threaded barrel/flash suppressor/sound suppressor (NFA)
- grenade launcher
- bayonet lug
If you had a rifle that had 2 or more of these features on or before Sept 13, 1994, it is a grandfathered "pre-ban" AW. Rifles that were NOT in AW configuration on or before this date are NOT grandfathered AWs, no matter when they were made.
Now, reality:
If your rifle was made before Sept 13, 1994, *and you can prove it*, you can generally get away with adding pre-ban features to it.
-Troy
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"They that can give up essential liberty to obtain a little temporary safety deserve
neither liberty nor safety."-- Benjamin Franklin