I just a Rem 11-87 SM 28". The factory choke tube is a modified but doesn't list the diameter on the website. I was looking at Carlson chokes and saw ones that were listed as extended. They essentially stick out the barrel. Was wondering if anyone has any experience using these. Thanks

Inf I recall sorrectly, in general the Modified choke is about .020" less than the shotgun's bore. So called turkey chokes are essentially extrafull chokes ... about .040" restriction. It is typical for the turkey choke to extend well past the muzzle. Some more than others. Many are ported to assist in mitigating the recoil of heavy shot shell loads. A 3 1/2" 12 ga. max load kicks like a mule.

Extending beyond the muzzle is nothing to be concerened about.

I have a Carlson's on my Benelli and couldn't be happier. It's the extended, non-ported turkey choke. I shoot Remington Nitro's in #5, 3" and it's deadly accurate out to 40 yards.