Great collection, just my opinion only I would remove the front grips.
That's pretty interesting looking one. How's it run? Sweet rifle BTW!
I got a chance to take her out to the range, and left some pics in another thread but just in case you didn't see them there, the brake works great. It makes spectacular fireballs, but it does a good job keeping the muzzle from moving a ton:
http://4.bp.########.com/-dIi4q-SIM6U/VlVFQEDDKoI/AAAAAAAAZiA/-PkdkQ_I5hE/s1600/Screenshot_2015-11-23-12-10-03.jpg
http://2.bp.########.com/-TNkc5G1YKZE/VlVFUXmPhJI/AAAAAAAAZi0/24HkiWzqtKs/s1600/Screenshot_2015-11-24-06-46-07.jpg
http://4.bp.########.com/-BvFmUbvww34/VlVFWtcITgI/AAAAAAAAZjQ/rpyoXjWd6Dc/s1600/Screenshot_2015-11-24-06-48-17.jpg/img]
I ended up changing grips to keep my fingers away from the heat. It actually wasn't that bad.
[img]http://2.bp.########.com/-8Aa2sYnUgls/VlVFRSRCzLI/AAAAAAAAZiQ/AEB4-hPW0uc/s1600/Screenshot_2015-11-24-06-41-40.jpg
http://2.bp.########.com/-DPuTt-Mz0YI/VlVFSizuCjI/AAAAAAAAZik/QNyXTzHbu30/s1600/Screenshot_2015-11-24-06-42-43.jpg
http://1.bp.########.com/-33aBzBw9KiI/VlVFS76HryI/AAAAAAAAZio/VFhSx8i1coI/s1600/Screenshot_2015-11-24-06-44-04.jpg
In comparison though, I have another brake on a different rifle that does just a good a job of controlling muzzle rise, but doesn't make nearly as much fire:
http://4.bp.########.com/-BNyByDt2IVU/VlVFQbJLybI/AAAAAAAAZiE/G4S1Y7XoUpA/s1600/Screenshot_2015-11-24-06-40-44.jpg
very nice!
looks like the SPARC is too low, have you tried the riser ?