bloopers with green dot powder

There's nothing wrong with the recipe. You have a reloading issue....did the hulls hit the ground? could they be wet inside? otherwise, it's cocked wads or very light charges. You'd have to be dropping < 17 grains with that recipe to get a blooper. Check your powder drops.

If you're using a MEC, first check to make sure that the charge bar travels the full distance each and every time. I have a half dozen presses, load up hundreds of shells in a batch, and don't shoot a whole lot of 20 gauge. Bottom line, I struggled with bloopers for an entire year before I finally discovered that the charge bar travel was variable.

If that's not the issue, then you need to check your powder drops. Either by cutting open 10 rounds (especially if you have a bunch loaded up) and weighing the charges (and checking for cocked wads) or by loading a couple boxes and pulling every 5th round as you go and weighing the powder cahrge. If half of them have been bloopers, you shouldn't have to examine more than 10 rounds to find the cause.

If it turns out to be variable charges, then you have to figure out why. I'd start by emptying the powder bottle and setting the powder aside. Check the bar and baffle if you use one for an obstruction....could be a pheasant feather, a piece of string or even grass. If you can't find the obvious cause, put everything back together, put fresh powder in the bottle and start over.

AGAIN...there's nothing wrong that recipe. With good technique you should never get a blooper with it, and that's assuming it's 1 ounce. Even less likely if you're loading 1 & 1/8.

Make sure the shells are warm.

I read an article in some trapshooting magazine about a year ago about a guy that shot with the writer of the article in a winter league. His shells always sounded like crap so he gave him a bunch of his shells to shoot the next week. Next week rolls around and the guys shells sound exactly the same like crap. The writer ask the guy why he is not shooting the shells he gave him that always sound fine for him. The guy says he is shooting them.

The only difference was the guy that wrote the article kept his shells inside and then took them to the range. The other guy would put the shells in his car the night before and it was parked outside all night and day.

So you can't just warm them up by bringing them in for 10 minutes either.

Also some powders are also smaller and can get past some wads. Green Dot should not be one of them though. If the loader is throwing everything correctly just look at how you are storing the shells in the 24 hours before you shoot them. It might make a big difference.