I am old enough to remember all of the Stan Baker alleged benefits from his extreme over boring of barrels. I never did any specific testing but, I could not reason why an overbore barrel would give greater velocity from that of a standard ID barrel. To my simple way of reasoning, if you increased the ID you would of course lower pressures; so how was that going to increase velocity?

It never did compute for me; but then what do I know. Since I never ran good empirical tests of both sized barrels; I could not say definitively. However, to this day the whole concept of severe overbored barrels providing greater velocity; seems counter intuitive and I remain VERY skeptical. Maybe Virginian or someone else can explain to me how that can occur.

Mcfarmer ,just pattern it at 30 yards with various choke/barrel set ups and see if the 2 step choking is notably different than conventional chokes. I would look for pattern uniformity with no hot spots over pattern size. You can always resize the patterns but uniformity is the goal. If we hear you are headed for the patent office after your session ,we will know something is up!

Bobcat

With an overbored barrel the area the gasses are pushing on is increased more than the greater linear contact area would contribute to increased friction is the theory. Now you will also have a greater volume for the gasses to fill, so you will need the right combination of powder and load to maintain the pressure long enough to achieve the greater velocity. I remember I got one (1) load with 4756 and a few with Blue Dot with 1-5/8, 1-3/4, and 1-7/8 ounces of shot for it to work. Not earth shattering but 50-75 FPS increase.
All of these loads were with a Tyvek strip wrapped around the shot, buffer in the shot, copper or nickel plated shot, individually weighed powder charges, and shotcups rolled in motor mica. I can hardly believe I was that serious about that sh*t back then myself.

Mcfarmer to your earlier question The receiver is clearly an 1100 and is so marked ,the 11-87 would be identical except for the markings. The only way you can I D the barrel is to take it off and see if there is a recess (groove) in the shroud for the gas relief ring which would appear on an 11-87 but not an 1100. https://www.trapshooters.com/cdn-cgi/im ... pg.215042/
The top barrel in the picture is the 11-87

By the way that's a really nice gun ,and the lefties command a high price.
Bobcat

1989 rem catalog page 12 explains the overbore (.745) trap barrel system.
Kopper13

Any way you can scan and post that page/part of page so it gets in the permanent record here for the next user with a question.

Bobcat

I can't. My PDF editor is corrupted.

Try this
1989-Rem-Dupont-retail catalog.pdf
hope this helps, and by the way, I am the proud owner of two 11-87 traps with these barrels,
and matching choke sets
Kopper13

Nice, thanks for that.