I just purchased a used slug barrel for my 1187, on the barrel it states 23/4-3 inch slugs. On the receiver of my 1187 special purpose it says 23/4-3" to 31/2" shells, can this be used on my 1187? Any help would be appreciated, and thank you in advance.

You will be able to use it but you will be limited to 2 3/4" slugs only, despite what is stamped on the receiver.

You will always be limited to the largest common length between the two components (barrel and receiver), which in this case is 2 3/4"

MikeD, unless i'm reading what he posted wrong he should be able to shoot both 2 3/4" and 3" slugs thru his new barrel on his original receiver, BUT NOT 3 1/2" slugs.

Sorry, my bad, I misread the original post and didn't catch the "-3" at the end and thought it was a 2 3/4 inch only barrel.

TuJays is correct. You can also shoot 3" slugs through that barrel.