A bit much on the stiff side but there is a solution - FAB Defense ARP Assault Rubberized Buttpad for GL-Shock and GL-MAG Stocks

Despite the nice cushy open look to this buttpad, it is much stiffer than expected so I decided to experiment and see if I could break in the rubber and reduce the stiffness. I completely collapsed the pad between 2 blocks of wood in a bench vise and left it collapsed for 24 hours. When I opened the vise jaws back up, I subjected the buttpad to about 20 complete cycles of full collapse followed by full relaxed over a 5-10 minute period. You have to completely collapse the buttpad so you cannot see any light through the triangular channels in the pad. The pad is very tough and after this break in procedure, there were no visible signs of distress or rubber cracking anywhere on the pad. I examined it under magnification and the rubber was not visually compromised.

The buttpad was definitely more resilient after this procedure and it is still resilient more than one month after the procedure. I used it on a 458 socom build. Between using an adjustable gas block (seekins precision)and the Fab Defense GL shock stock combined with this accessory buttpad, I have one nice soft shooting 458 socom that you can shoot all you want until you are out of money. Your shoulder will not complain. I'm 5 foot 9 inches and weigh 170 LBS so I'm not built like a brute that can take heavy recoil for very long without developing a flinch so these mods have made this gun my favorite shooter.