First of all thanks for tthe welcome, here goes the first one: I know what to expect from the Accubrake, could someone expand on a Mercury Recoil Reducer? how much will it reduce the recoil with different calibers?

The manufacturer claims 50% or more, but I'd be a little skeptical of the claim.

Years ago, I could hunt deer with a slug shotgun only, and the brute punishment of trying to group off a benchrest grew tiresome, so I put not one, but two mercury reducers into the buttstock of the Remington 870 Wingmaster. Even with the short slug barrel and mounted scope, the gun was sure heavy! That probably attributed to quite a lot of the recoil reduction. You WILL gain a lot of additional weight with the reducer, so be prepared. My guess would be a more conservative 20% - 25% reduction with the device.