RE: What next to improve my groups?
1. UMC is cheap
2. Simmons is garbage
start by fixing those two things. Then look to your techinique. I doubt you've been shooting long enough to recognize andcorrect yourself if you are doing something wrong. Get someone that has been shooting and have them help watch and make sure you aren't jerking etc.
I don't shoot Savage so I don't know what kind of potential you can expect from them but If you can get down to 1.5-2" I'd be pretty content.