I would say reduces muzzle rise by 75% - OpticsPlanet Exclusive Maxim Defense Industries RDB Roller Delayed Blowback System

This is coming from someone who shoots a JP-5. Easy to install or swap out . I replaced my JP silent capture spring with the Roller delay buffer. My gun shoots awesome. Here's the issue . It's takes almost 3 to 4 times the pressure and strength to cycle the rifle. If I get it and lock it back it's okay. Or if I have a chamber flag in it & the bolts is not all the ways closed it's okay. But if the bolt is closed it's a bear. I had it initially in a side charger (Gibbz Arms on top of a JP lower) configuration and it was very hard to hand cycle, had to wear a glove just to prevent cuts. So then I put it in a QC10 rear charger and it was much better. Still hard to cycle but much better. I do compete and I got the same from several others who had purchased the system . This for me was more of a let's see purchase. I have several PCC's & after shooting my JP-5. I did shoot it in a match & did fine but had no empty starts and my bolt locks back on empty . I wouldn't get another one but I will keep & use the one I have. I do not regret the purchase . Reducing 75 % felt recoil for under $200.00 is unheard of .