the Gauge will get you in the ball park as to what it MIGHT be choked , but you have to put it on paper, that's the only way !
Scott

Trudeau and Blair BAN 12 Gauge and 10 Gauge SHOTGUNS!
 

Extremely interesting read about Canada and what happens with screw in chokes.

https://myemail.constantcontact.com/...IJHPBAqPrmkry0

Not in the case of earlier guns.
I have had IM and Full choked guns measure as IC or Cyl with drop in gauges. If they are over bored enough. That is pretty out of the ballpark.

I agree with what everyone has said about drop in gauges.They can be very misleading.The older guns had to have more choke to compensate for the less advanced ammo.Now with harder shot and shot cups much less choke is needed.I have a 16ga.VHE choked cylinder and mod from the factory.The cylinder barrel is true cylinder with zero constriction.It throws a perfect modified pattern at 30 yards and the mod barrel patterns full.You always need to put them on the pattern board to really see what you have.

Let’s face it, very few guys have bore gauges to measure choke relative to the bore diameter. At best, we had a little drop in gauge to give us a rough idea. If the choke gauge stop at F, odds are it’s going to shoot pretty darn tight patterns. If it drops in to C, it’s gonna shoot a more open patter. Something in between will give something in between. A pattern board helps a lot. Best things is to go shoot clays with it.

We all know or should by now that earlier guns are over bored ( I just take that for granted) that's the ball park part of it. I shoot A LOT of test patterns . I found that for the most part these guns shoot tighter that what the chokes say they should. I have shot 1 oz loads of old Remington 4's from the late 40's to early 50's with out the plastic wads and got 83 % patterns out of my .035 (full) choked 12 ga.. parker would not worry about constriction, they would shoot until they got what pattern they were looking for I would think ??
scott

......and very few guys take the time to pattern their guns. Here is an idea, maybe some of the vintage gun shoots could set up a bench and a target frame at 40 yardsf rom it and sell the pattern sheets at the registration desk.

Joe from Mo; Don't drive yourself crazy worrying about chokes.

Pete and Scott do it the right way and are diligent pattern testers and their success in the field and on the clays course show it. I pattern every gun I own as soon as I get it and am more concerned with the point of impact (POI). It does'nt matter what choke you have if it's not going where you want it to.

My advice falls in line with Joe G. Shoot all those guns with whatever load is comfortable for you and shoot lots and lots of clays. A comfortable load allows you to shoot more, period.

Remember- Chokes are measured in inches; Misses are measured in feet.
Keep shooting until you are not chipping targets on a regular basis and are getting nice even breaks. Then you will know that target is in the center of your pattern no matter what choke constriction you have. You will be surprised at how well you can shoot a tightly choked gun.

A man could remain happy if he never does the following: pattern his shotgun, checks his cholesterol, or has an AIDS test.

Love all the comments, learned a few things new to me. So thanks for all the input.

I shot 4 rds of trap with the Trojan yesterday, using herters low recoil 1060 fps target loads. I am not the best trap shooter in the world, but it's managing to bust 20+ birds per round, which is about par for me. I am getting better at shooting this gun, and can't wait to have some pheasant or ducks in front of it. Still not shooting it as well as my Citori's, but it's getting better. Seems like it hits just a tad lower than my Citoris.... But that's just the way it feels. They used to have a patterning board at that gun club, but they no longer do... I'll have to go out to the other gun club to pattern it, and that's a bit longer drive for me.

I just find it interesting that my Ithaca made guns are exact to the gauge, and some of my other guns are not. Never realized that the choke was relative to the bore, I just thought a full choke was a specific diameter..... The right barrel is definitely a bit more open, so I assume it's M, and the other F. Unless someone actually did take a F/F gun and make it IM/F. Either way, it's fun to shoot, and it should do nicely on pheasants.