Tuning a Little Bastard muzzle break

[A/1-61]

As mentioned in another post, I finally picked up my 7 mm STW with a new Hart barrel. Among other adjustments, they put a Little Bastard muzzle break on the barrel. It has four side ports on either side and two rows of small ports on the top side of the brake and a bag of Allen screws.

I read the tuning instructions and started with all eight screws in place. I fired a round, and the rifle pulled left. I took out one screw on the left, the closest to the action. In the course of three shots, I settled on the third port from the action as the open port.

My question is, should I be holding on to the fore stock with my left hand to work through this process or should I have my left arm under my trigger hand and let the muzzle go where it will? The technique that I used was to hold on to the fore stock with my left hand.

Also, the rifle isn't grouping very well yet, although in the course of 10 shots the first three grouped about three MOA and the last three grouped one MOA. I stopped at 10 shots and came home and cleaned the rifle with a brass brush and hoppe's #9. My break-in instructions said to leave a coating of hoppe's in the barrel and dry patch the next time you shoot. That will be tomorrow.

Again, my question is about tuning the little bastard break. If anybody has any tips, I would appreciate it.

 

[biednick]

Shoot it the same way you'll be shooting it in the field most frequently. It'll recoil differently depending on the rest you're using. Tuning off a bipod if you'll be shooting off a bag in the field won't do much good.

 

[FEENIX]

Shoot it the same way you'll be shooting it in the field most frequently. It'll recoil differently depending on the rest you're using. Tuning off a bipod if you'll be shooting off a bag in the field won't do much good.

This!

 

[RichCoyle]

I tuned one from the bench. BUT when I fired offhand, the tune was off.

 

[K9TXS]

I always do my testing from the bench. I can find my issues faster from the bench than my field shooting positions.

After my load development from the bench and the other bugs worked out of it, then I fine tune it to my shooting positions.

 

[josh_127]

Leaning with hoppes is a waste...live the smell of it but if you run a camera down the bore you'll see it's a waste of time.

 

[buckbrush]

I tuned one from the bench. BUT when I fired offhand, the tune was off.

 

[RichCoyle]

This is not exactly correct. I tuned the brake so I could see my hits on 20X at 100 yards when using the bags. When I was holding the rifle, it always jumped to the left. I redid the brake while I was standing. It was a 6.5 on a 7 Weatherby case. Some of us are diseased.

 

[A/1-61]

Leaning with hoppes is a waste...live the smell of it but if you run a camera down the bore you'll see it's a waste of time.

I've heard that from lots of people, but when a guy from the prestigious hart rifle barells tells me to use it, I have to at least try it . I've been using chameleon for quite a while now with good luck.

 

[A/1-61]

At round 64 through 68 with this five-shot group I believe that the new barrel is broken in fairly well and the muzzle break is tuned. I haven't measured it yet with a caliper but it seems 3/8 MOA or slightly less. This barrel has sightly more freebore than the old one.and this round is as long as you can get it and still fit 2 rounds into the magazine. 79.7 gr of H1000. Cartridge length 2.850 and overall length 3.650. 3165 fps. Overall loaded weight, 10 lb. Can hardly wait for my trip to Utah next October