I loaded some 1 ounce 12 gauge trap loads today and a few 1 oz slug loads using everything exactly the same. The trap loads had more of a kick to them than the slug rounds which really surprised me??? any ideas why?

Probably something to do with back pressure, assuming you used the same wad..

60

If you used the same powder and weight of powder for each load I expect that your "trap" loads were actually over pressure. NEVER assume anything when loading ammunition. This means that you consult a loading manual for the specific load you are building.

In this case I suspect that powder you used was a good one for slugs but had an inappropriate pressure curve for a shot charge.

quote:

Originally posted by Scooter123:
If you used the same powder and weight of powder for each load I expect that your "trap" loads were actually over pressure. NEVER assume anything when loading ammunition. This means that you consult a loading manual for the specific load you are building.

In this case I suspect that powder you used was a good one for slugs but had an inappropriate pressure curve for a shot charge.

why would that matter? 1 oz shot 1 oz slug they weigh the same they both go in the same wad same crimp. the only difference is 1 is solid one is not so there would be some give to the shot but one would think it would make for a softer round not hotter. the shot was from a recipe book. and they are light trap loads.

quote:

the shot was from a recipe book. and they are light trap loads.

OK, I am now baffled. I consider shot shell loading to be recipe driven, pressures are low and are affected by every component. But a published load should be OK. But where did the slug application come from?

A guess: The slugs start moving immediately as gas pressure builds, but the shot loads are able to pack themselves tighter for a fraction of a second while pressure builds and then they’re forced to start moving when they can no longer pack themselves further among their fellow balls (no pun intended). That extra time results in higher pressure when the shot load gets moving and, since every action has a reaction, you experience a higher kick from the greater pressure as the load starts going down the barrel. No idea if this is BS or not; just tossing it out there!

quote:

Originally posted by Jim Watson:

quote:

the shot was from a recipe book. and they are light trap loads.

OK, I am now baffled. I consider shot shell loading to be recipe driven, pressures are low and are affected by every component. But a published load should be OK. But where did the slug application come from?

I just decided to stick a slug in one of my trap loads, yes I know it's risky but it wasn't a magnum load. I have been loading for 50 years.

quote:

Originally posted by tsmccull:
A guess: The slugs start moving immediately as gas pressure builds, but the shot loads are able to pack themselves tighter for a fraction of a second while pressure builds and then they’re forced to start moving when they can no longer pack themselves further among their fellow balls (no pun intended). That extra time results in higher pressure when the shot load gets moving and, since every action has a reaction, you experience a higher kick from the greater pressure as the load starts going down the barrel. No idea if this is BS or not; just tossing it out there!

makes perfect sense to me.

I've never loaded slugs so I have no experience with it. However most shotshell loads employ a wad with a "cushion" between the shot cup and the powder cup. Way back this was done with a "cushion" Wad some times made with balsa wood and more often made with felt. In modern loads with plastic wads the cushion is a highly engineered shaped plastic bridge between the shot cup and the powder cup. As for why this is done, it helps to reduce the shot pellets deforming during that initial "push" from the powder charge and because it also helps reduce the felt recoil. BTW, I have had some old timers tell me that the old felt wads did kick a bit harder than the plastic wads once they figured out how to a good effective bridge working. There used to be a lot of arguments in club houses about who's wads were the softest shooting.

Checking for slug loads on the Net indicates that cushion wads designed specifically for slugs are available. Visually the cushions on these wads are shorter and much more robust than the cushion on a typical Target shell wad. Basically they are designed to reduce the felt recoil and may have some design compromises to insure good accurate results. Basically if a shot cup tips a tiny bit during the initial ignition phase in a shot shell it won't effect the resulting shot string in any detectable way. However if a slug is tipped slightly during the ignition phase that may shot up as a "flyer" down range and slug shooters won't like seeing 5 or 8 inch "flyers" on their target.

The end result is that I would expect the slug loads would hit a bit "harder" in terms of felt recoil. However that difference won't be very large and it may be small enough that some would doubt there is any difference at all.