Stop shooting 50 rounds at a time on B-27s at 4 yards. If you want to diagnose and improve your shooting, you need to be shooting 1 to 6 round strings, evaluating what is happening and then taping your target. Use that target carrier switch, that's what you are paying Reds the big bucks for.
Buy or make some 4" dot targets and put them at 7 yards. On the first one, shoot the best 6 round group you can. Fire one shot, follow through properly and set the gun down. Stretch your neck, hitch up your pants, pick your nose, do whatever you need to do to ensure that each shot is a separate process from beginning to end. After all 6 shots are done, this is the native accuracy that you are capable of that day.
On the next target, shoot 2-shot groups as consecutive pairs, that's 2 trigger presses and 3 good sight pictures. Make sure that you see the sights correctly before you press the trigger, don't shoot on a timed cadence and don't shoot hammers, make them be consecutive pairs. Get a timer or a phone app and figure out what your splits are between the shots. It's a pain on an indoor range but you need to know that info. (and write it down in your notebook, you do have a training notebook, right?)
Make sure you are hitting both shots inside the 4" dot. If they are outside of the dot then you are pushing too fast, the gun is not returning to the original position (not managing recoil correctly) etc. Fix what is not working. If you need to bring the target back to 6 yards or 5 yards, do it. This is all about getting you a baseline of the speed of the splits that you can shoot 2 shots into a 4" dot.
Make sure you tape the target so you can see your hits. I only tape the misses to save time. You don't want to be looking for hits while you are shooting the gun, check that after the gun is back down.
Once you know how long it takes you to shoot that second shot at 7 yards, say 1.25 seconds, try to decrease that time just a little. You still have to have a good stance, good grip, good sight picture and good trigger control but you are doing it just a little faster. Instead of 1.25 seconds your goal is 1.05 seconds. If the shots start going a little wild, stop and figure out why. Are you smacking through that trigger instead of a smooth press? Fix it. Is your support hand not gripping correctly? Fix it.
Once you fix all the issues that the increased speed brought out, congratulations, you just got better, met your goal and are ready to set a new goal, say .85 second splits.
There is a real temptation to getting bored with this slow but steady improvement. I fight it all the time. My brain says "Hammer that target" and with perfect stance, grip and luck I can pull off a .35 split and both hits will be in. But 70% of the time, I miss. All that I am teaching myself that way is how to do it wrong.
As your splits improve you can increase the distance, change from a 2-shot to 3 or 4 shot string, maybe add a transition to a 2nd 4" dot.
The reason that I am writing so much about this that 14 years ago I was in the same place. Shooting at Reds ( It was called Cook's Sureshot back then) and wanting to get better. I had my CHL and was doing pretty poorly in IDPA. Until I got serious about setting goals and measuring my performance, I just kind stayed in a rut.
Figure out how much time, money and ammo you can spend on improving your shooting, set your goals accordingly, and see the improvement come.
Gringop