It should but I would double check with the manufacture.
Yes, the KynSHOT AR-15 .223/5.56mm Carbines Recoil Buffer can be used with the Geissele super 42 braided wire buffer spring.
No. I would recommend using a buffer that weights between 5.0-5.4oz (H3 Buffer). I would also say using a standard spring would be ok unless you started to notice reliability issues. Then I would consider upgrading to a different spring.
The best buffer to use would be the RB5000HP with your suppressed FRT, AR-15
The best buffer to use is the RB5000HP for your DDM4
This buffer fits in the carbine length buffer tube.
Yes, this will work with a 6mm arc build.
Yes, this buffer will work in a .458 carbine.
The best buffer to use with your firearm would be the RB5000. Feel free to reach out to KynSHOT technical support if you have any further questesions
The buffers weight is 4.2 ounces, and replaces both H2 an H3 buffers based upon our patented hydraulic dampening. Feel free to reach out to KynSHOT technical support if you have any further questions!