Great thought, I have never loaded for shotgun but.
I have progressive press Dillon 650. For rifle if you are going to put a hole in a hole at distance, you have to reload for that kind of accuracy. With handguns accuracy and function are a big factor when shooting completion as is price. Reloads are far, far superior to even the best match ammo you can buy off the shelf. Also, is a great hobby I enjoy it very much.
Wow you're all set. I have a 550B myself. When I got an M1A I got a setup for loading it too on the 550 and I accidently stumbled upon a championship load. 180gr match bullet with 42gr or maybe it was 42.5 gr of 4064. That was an awesome load for any rifle we tried it in but I started not liking to load the 308s on the 550 and went back to loading them single stage. More control over each step made them a wee bit nearer to perfect than on a progressive press. But it works just fine for 5.56 and 45s!
Have you ever wondered what is it about match ammo that make it match ammo? I have concluded that it's about 80% the bullets themselves. The thing about match bulets is the weight of them. A very precise consistent weight. Break open a box of match bullets and see for yourself! They are so consistent in weight that you can zero your scale with them lol. I'll us match bullets as weight checkers.
But the thing is, I cast most of my own bullets. So I wondered where that would leave me. I was looking at a new batch of cast bullets and thought that would be nice. I already make sure the melting pot is at the same temperature for casting. Dumping bullet sprues back into the pot willy nilly is the biggest mistake that new casters make. Still, it was a pretty big job to go through my cast and weigh each one then segregating them into groups of exact weights and when finished I took the big pile and mixed all the others together again like I have for years.
And a funny thing happened, there was a significant improvement in these cast loads. I have a big family and so I was the ammo man, lol. But I loaded the "match" 45 slugs for my own personal ammo to shoot and made normal ammo for everyone else. Lol. Every time we went to the range we'd all toss $10 in the can and winner take all. I smoked them all, regularly. Learned all my sons and BIL's a good lesson, lol. But yeah, bullet weight means an awful lot of difference. Other things that can help is the more brass prep you do, the more match it is. Trim them all (not for 45's Geez!) and deburring the inside of the flash hole helps give consistent flash patterns for consistent ignition.
The only difference between 5.56 brass and 223 Reminton is that mil spec brass has a thivker web inside the case so since the outside size remains the same, the thicker web makes them heavier than 223 commercial brass. So seperating the 223 from the 5.56 mil spec brass helps too, as well as then trimming and weighing them for precise weight and that does a lot for rifle cartridges because if the outside size is the same and the inside of the brass is thicker then when you weigh them and segregate them the combustion chamber is the same size which helps a lot to consistent pressures. Yessiree, I can easily make ammo 10X better than factory ammo.
Now if only I could reload 22 rimfires lol.