Browning BOSS .243 "Sweet Spot" Settings

[Flesh Eater]

There's a lot of information on the internet concerning this BOSS system. Varying opinions on it, too. However, since I purchased a Browning A-bolt in .243 with the BOSS without really understanding what it was, it's become a love-hate kind of thing.

What I want to know is if there are any members with the BOSS on a .243 who have recorded "sweet spot" settings with different factory loads. I can find these sweet spots myself, but I figured I'd ask and save some ammo and time. Particularly, I want to shoot a 55 grain Federal load. As of right now I'm shooting quarter sized groups or smaller with 100 grain Federal Power-Shok loads. I tried the Hornady Whitetail 100 grains and they were shooting at about 1.5 MOA using the same setting.

I don't reload, so this is kind of handy to have. So, if anyone has a list of settings for their favorite ammo, I'm asking if you'd be willing to share your results. Browning's "sweet spot" setting for the 100 grain Federal was spot on. I think I adjusted it 1/16th of a turn from their setting, and that's it. If not, I'll just buy a few boxes of each and spend a day shooting.

 

[ackleyman]

I have worked with Browning and Winchester Boss in 270, 7 mag, BAR's. All of the rifles end up shooting bug holes, even the BAR's.

Browning has some recommendations, you should contact them.

It will take time to tune. The "tuner" will like being screws way out, or all the way in. I usually started all the way out, then worked my way in.

I shot two shot groups, never overheated the barrel, cleaned every 35 rounds to make sure that barrel fouling was not effecting my accuracy.

You are looking for two shots in the same hole or just about in the same hole, no larger than a 3/8" group.

I hope that you are using a good solid benchrest and rear bag to shoot off of. You should buy 4 boxes of ammo to start, contact browning, then start tweeking.

Write down your setting on the 100g.

I looked for gross adjustments where the groups started getting smaller working in 1/4 turns on the Boss. I would see that the groups would start closing down, then start opening up depending on whether the boss like to be screwed way out, or way in. Then start making full number ajustments, then finer adjustments.

Without fail, every BOSS rifle I have had shot very, very tiny groups. You should clean your rifle extremely well, often to keep groups tiny...de-copper frequently.

 

[Flesh Eater]

Originally Posted By: ackleymanI have worked with Browning and Winchester Boss in 270, 7 mag, BAR's. All of the rifles end up shooting bug holes, even the BAR's.

Browning has some recommendations, you should contact them.

It will take time to tune. The "tuner" will like being screws way out, or all the way in. I usually started all the way out, then worked my way in.

I shot two shot groups, never overheated the barrel, cleaned every 35 rounds to make sure that barrel fouling was not effecting my accuracy.

You are looking for two shots in the same hole or just about in the same hole, no larger than a 3/8" group.

I hope that you are using a good solid benchrest and rear bag to shoot off of. You should buy 4 boxes of ammo to start, contact browning, then start tweeking.

Write down your setting on the 100g.

I looked for gross adjustments where the groups started getting smaller working in 1/4 turns on the Boss. I would see that the groups would start closing down, then start opening up depending on whether the boss like to be screwed way out, or way in. Then start making full number ajustments, then finer adjustments.

Without fail, every BOSS rifle I have had shot very, very tiny groups. You should clean your rifle extremely well, often to keep groups tiny...de-copper frequently.

I've watched all the Browning videos and understand the process. I was just hoping for some starting points to try.

My 100 grain Federal setting is almost dead-on with the Browning recommendation.

However, it's good to know you were getting accurate results with 2-shot groups. Browning recommends 3-shot groups, but that can get costly with factory loads, since most are $24 per box.

I have a nice bench, however I don't have a rear bag. I should probably just buy a solid rest for it, but figure if I'm shooting quarter size groups without it, then I'm confident it'll be dead on in the field. Most of my shots on coyotes or deer will be within 150 yards, so I'm not trying to tune this for a 500 yard or greater shot.

I'll grab 4 boxes of the 55 grain and get to work when the weather gets nice.

 

[243kimber]

I have used the BOSS on 2, BAR's in270 win, 1 in 338 win mag. When I started, I did not know as much as I do now. Like A-Man said, keep it relatively clean. I ran out of patience and set them on the middle setting , and then did an OCW test. Problem solved. That being said, I could probably get them tighter, but 1/2 MOA was good enough for me. I used blue loctite on all models.
I suggest wipeout for cleaning the barrel. I screwed my 270 piston system up by using Barnes CR10. It pitted the housing. I l had to replace it.
I recently shot a half MOA 3 shot group @ 500 yards with my 270 bar using berger 130's.

 

[10ring1]

I have tried the factory recommendations without much success. I love the BOSS system and have it on many rifles and they all shoot phenomenal. I dont' have a 243 though but for mine, a setting that works for one may not work for the next even the exact same gun.