42 Izzy at 472 yards

[ShootnMathews]

Shot my 42 Izzy sporter that you've all seen pictures of on here yesterday to verify my drop after installing the muzzle brake a while back. It really didn't seem to changet the drop of the bullet any. The location I shot at yesterday only allowed me to shoot at 472 yards. After running all the numbers through my ballistics program I seemed to have maybe lost around 25 fps. Not exactly disturbing but a difference. More shooting will tell. I only shot maybe 15 times. I didn't even count. The gun seemed to group pretty well cold but then opened up with each shot. I did not allow any cool time between shots. I shot 3 times, then allowed some cool time then 3 more and so on. I also shot some Hornaday HPBT .312" 174 grain and saw very little difference in point of impact or grouping. The Hornaday had a slightly lower impact of maybe 4" but still moved up and slightly to the right with each shot as did the SMK.

Target and shots:

Target is a 12"x12" steel plate at 472 yards

You can see a 5 shot group that is really tight near the center, then 2 shots close to each other about an inch or so higher and to the right. then a couple shots right at the top of the plate.

The 5 shots are cold bore. then the 2 higher are 2nd shots, and the ones at the top of the plate are 3rd shots. I'm pretty sure that is correct but not totally since I was spotting for myself. I made this gun for a sub 500 yard deer gun so I'm happy with it so far for that. It is a blast to shoot further though when I have time. I plan to do a comparison test later with the brake on and off to see if there is a definate group difference or not.

Here's the target

[Shepard]

Great shooting. I had a Savage 3006 with a pencil barrel. I would shoot it 4 times and it stayed on target at 150 yards. As you continued to heat the barrel it would rise slightly and start to the right and as you continue more it walked a circle like a clock.
Your muzzle brake you made should not be slowing your bullet. How far from the chronograph are you shooting? If your to close -- less then 10 feet it can give you a false reading. Also a properly built muzzle brake will increase your accuracy by helping to hold the rifle in position -- decreasing barrel whip and keeping on target. If its off center even a few thousandths it will cause deviations in your bullets strike.

[ShootnMathews]

Shep. I didn't shoot it through a chrono. I just had to add one more click to my dope it seemed. It may not even be 25 fps slower could only be a few but I would attribute that more to the fact that I messed up the threads the first time and had to cut off approx. 1/2" to 5/8" then rethread.

It shoots pretty well with the brake, but I really feel it shot better without it. I honestly haven't shot it enough to know for sure yet though. Time will tell. The brake helps with recoil. I'd guess cutting 35% off of recoil. It's not as effective as I had hoped. My 6.5x284 with a factory brake that's ported 360 degrees kicks far less, but blows crap everywhere. That's why I went with the side port. I guess I shouldn't complain with the cheap brake that I bought. I might try another later. I gill brake perhaps.

Jared

[ShootnMathews]

Shep, I guess I really didn't lose any velocity. Upon closer inspection I noticed I still had a 12 degree incline programmed into my calculator from a previous shooting day. After setting that to zero everything went back to normal.

Jared