I am signed up for some kind of benefit shotgun shoot for work. I know that Ill need 100 rounds for the course.

I have a Remington 1187 semi, What Choke is going to be best?

What size shot do I need? I think I already have some 8's and 7.5 dove loads

Choke depends on how far the shots are, but even that's not really important. I use a modified choke for trap shooting, and those are relatively far shots. Modified or light mod is also probably the best for all-around shooting, in my opinion.

8 and 7.5 work well for clay shooting.

I have an improved modified already, whatever that does

Yes - really depends on what you are shooting - skeet, trap, sporting clays course, five stand. Skeet (regulation skeet from 8 stations) is best shot with skeet or IC and #9 or #8 shot - but you can still have fun with the IM and #7.5 shot; trap will employ all kinds of chokes depending on what handicap line you are shooting from and how fast you get on your target - but probably an IC to IM would be normal with #7.5 or #8 shot - but you can still have fun with the IM and #9 shot; sporting clays and five stand will have both far shots and near and a doubles gun that can select a tighter or looser choke depending on the target with Cyl to Full chokes, on a single barrel gun probably a LM is most employed, both guns using #7.5 or #8 shot - but you can still have fun with the IM and #9 shot. Have you noticed a trend yet? Go out and have fun!!

You probably have a Cyl choke or IMP Cyl which is about Skeet..All a choke does is intensify your patter or not depending
on the range..tight chokes denser smaller patterns ect..DD

If you are a fair shot, use a LM and truck on, it may cost you some close targets, but will definitely help you on any longer shots.

7 1/2s and don't over think it, miss one, move on. When it is done, it is done. Take your time and follow each shot thru and have fun.

If it is 100rds, more than likely sporting clays. Where is the shoot?

Some buddies and I shot in one Saturday at the Dallas Gun Club. They all shot 12's I shot with an old 20 with a fixed modified choke. For most of the shots a cyl. or improved would have worked fine. Unless you have extended chokes that are easy to change I would just go with the improved choke.

It is a lot of fun and our team took 3rd.

I think it's at Dallas gun club. All I know it's 100 rounds. I'm going to go in with my 1187 and do what I can

Just have fun, it isn't life and death. I get so tired of going with some of my gun club members, they get so angry when things don't go their way. I just giggle and laugh and if it isn't my day, oh well. I had fun.

I use modified with 7 1/2 shot.

Have a great time, I personally love going on charity trap shoots.

Well I finished the shoot today at the benefit supporting the CASA of Denton. It was my second time ever to shoot the trap course. I wish I would have practiced before but it is what it is. I shot a 69. I think I could have done high 70's or maybe 80 if I would have took my time. I totally choked on a few rounds. The benefit raise $97,000 just off of entries not including mulligans and the raffle. Im sure it was a homerun for them despite some crappy afternoon weather.