Man there are some boring threads lately. I put some theory to the test the other day and while the results were predictable, they were interesting and yielded a cool photo.
I found a Christensen Arms MPR in 338 Lapua for a price I couldn't pass up. The rifle comes with their side baffle muzzlebrake which has 4 closable ports on top, closeable by set screw. The theory is that you can tune the muzzle rise by opening/closing the ports on top of the brake. I had to break in the barrel anyway so I thought I'd set up a slow motion video camera to see how many ports I needed to open to get the rifle to recoil straight back, not up. My iphone will do 240fps video, which is just fast enough to tell me what I wanted to know.
I loaded some 300gr Bergers at a starting charge weight, packed up my gun cleaning supplies, and headed to the range.
All ports closed: first frame of recoil, the first movement of the muzzle was up.
1 port open: same as all closed
2 ports open: same as all closed
3 ports open: first frame of recoil, the first movement is straight back
All ports open: first frame of recoil, the first movement is down
I could tell a slight difference in recoil when the muzzle was going straight back vs up or down, although it was still a little too much recoil to stay on target while shooting free recoil. I will also say that this muzzlebrake is very efficient. 300gr Berger doing 2750fps with a rifle weight of 9 pounds scoped and I would compare the recoil to a 280 Rem.
Interestingly, I managed to get a photo of one of the projectiles about 5" in front of the muzzle.
I found a Christensen Arms MPR in 338 Lapua for a price I couldn't pass up. The rifle comes with their side baffle muzzlebrake which has 4 closable ports on top, closeable by set screw. The theory is that you can tune the muzzle rise by opening/closing the ports on top of the brake. I had to break in the barrel anyway so I thought I'd set up a slow motion video camera to see how many ports I needed to open to get the rifle to recoil straight back, not up. My iphone will do 240fps video, which is just fast enough to tell me what I wanted to know.
I loaded some 300gr Bergers at a starting charge weight, packed up my gun cleaning supplies, and headed to the range.
All ports closed: first frame of recoil, the first movement of the muzzle was up.
1 port open: same as all closed
2 ports open: same as all closed
3 ports open: first frame of recoil, the first movement is straight back
All ports open: first frame of recoil, the first movement is down
I could tell a slight difference in recoil when the muzzle was going straight back vs up or down, although it was still a little too much recoil to stay on target while shooting free recoil. I will also say that this muzzlebrake is very efficient. 300gr Berger doing 2750fps with a rifle weight of 9 pounds scoped and I would compare the recoil to a 280 Rem.
Interestingly, I managed to get a photo of one of the projectiles about 5" in front of the muzzle.
