Replace barrel in SG550 with SG550-1 barrel
Was thinking of purchasing a SG550-1 barrel for my SG550. The -1 barrel is longer. I am wondering are the barrels identical except for length, so that it would be a simple swap? Also, are there legal implications for doing this, or is it a state by state issue? Washington state has no assault rifle restrictions that I'm aware(except on full auto). Thanks for your help.