If you actually read the Q&A on their site, the question is answered in there;
The MagnetoSpeed can be used with various muzzle brakes and flash suppressors provided that the muzzle gasses are not diverted directly into the V-block, muzzle strap, or blast beam (arched portion). That being said, the blast beam was designed to handle the muzzle-blasts of most common shoulder-fire rifles, shotguns, and handguns. If your muzzle brake or flash hider is long you may consider the V2 model which has an extra inch of clearance for these devices. Our 1:1 scale print outs are a good way for you to be able to print out a scale outline and hold it up to your firearm to see if it will work.
Yeah I read that before but the .338lm is not your common caliber IMO, but it could work. I probably trust it up to 300 win though.




















































