This is a comparison of 6 different Kynshot hydraulic buffers. I purchased most of these for experimentation with the “Gentle Recoil” project.
| Model | Compress Force | Length | Weight | Body Dia. | Piston Shaft | Piston Throw | Intended Caliber |
| 5007 | ~5 lbs. | 4″ | 6.0oz. | .76″ | .2″ | .41″ | 9mm |
| 5015HD * | ~10 lbs. | 4″ | 6.0oz. | .76″ | .2″ | .41″ | 9mm |
| 5000 | ~10 lbs. | 3.25″ | 4.1oz. | .69″ | .15″ | .41″ | 5.56mm |
| 5000HP * | ~10 lbs. | 3.25″ | 4.8oz. | .76″ | .2″ | .41″ | .458 |
| 5005 | ~5 lbs. | 3.25″ | 4.8oz. | .76″ | .2″ | .41″ | .308 |
| 5004 | ~5 lbs. | 2.5″ | 3.8oz. | .76″ | .2″ | .28″ | .308 |
It’s interesting that the 5005 and 5004 are meant for the .308 platform, and yet require less force to compress the piston than the buffer meant for the 5.56mm platform.
Based on these measurements and compression characteristics, I believe the 5015HD, or the shorter 5000HP (marked with an asterix above), with the appropriate buffer tube and spacer weights, are the best match for the Gentle Recoil System. The other buffers should still work fine, though. See the Gentle Recoil System Part 1 and Part 2 for more information.
Compared to the 5000HP, the 5000 is lighter and has a thinner piston shaft, but has the same compressive force and can be found at a much better price (see bottom).
I’ve found Botach.com usually has the best pricing (about $90 each), but you need to create an account and sign in to see the better prices. Dack Outdoors had the absolute cheapest 5000 I’ve found at $63, but the wait time before the order shipped was literally about 30 days. If you want it cheap you have to be patient.
Blowback9.com 