First you have to know how fast the action is now.
One can either measure the average bolt carrier velocity or the cyclic rate. If either are higher than say - Colt M4 mean spec, then you can use an H2 or H3 buffer. Absent of knowing those things, you could see if the brass seems to be ejecting too far.
The flat wire buffer spring concept makes no sense… Flat wire springs are normally good because the spring won’t come as close to solid height - but that benefit is when you have the room for a larger OD or a smaller ID. On the AR, the buffer tube and buffer constrain the spring so that a flat-wire version is merely missing some material and hence would be higher stress than a round-wire spring. I would expect it to be more likely to break.
Since Bushamsters are known to be overgassed I would go with an H or H2 buffer. Though you need to make sure to test it with the different ammo that you use.
I also think that the Battle Comp is one of the best AR accessories to come out in a long time. It actually makes a positive contribution to the system.
:agree: Couldn’t have said it better. The Tubb flat wire spring is just another bottle of snake oil right along with those marketed as extra power or reduced power or just plain magical. Stick with a properly manufactured USGI spring and call it good.
I was aware that linear operation of an AR-15 was prone to muzzle climb that wasn’t shooter induced.