Browning rifles with BOSS system

what is a boss

I have several guns without boss systems and I have to load several variations to find the best group.They still rarely compare to the groups with a properly adjusted boss. I last year purchased a 25-06 Thompson pro hunter thumb hole with a fluted stainless bull barrel. Love it, fits like a glove and gets great groups , but they still can't touch my 7 mm or 300 with a boss.
 
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BART... your last post brings up an interesting thought... I'm wondering, if the stock were rigid enough ( like a premium composite ) & done in the full length style ( to the end of the barrel ), & the barrel fully bedded, not floated, do you think it possible to hold a barrel steady enough to make a difference, or would the wobble forces be so great, that it would "move" some place along the length, & thus negate the fully rigid concept ???

I do like my BOSS rifles, but just talking concepts at this point ( sorry to distract the thread )
 
"Barrels don't hesitate (stop?) their whipping and wiggling until long after the bullets left. Where does any force counter to what keeps them doing that come from?"

The intent of the Boss is not to stop barrels from whipping.

It's to change HOW they whip; in essence, to use that whip to your advantage.


I've seen one person try the "fully bedded barrel" in a centerfire rifle, just as an experiment.

To say that it was an abysmal failure would be kind. It took a rifle that had been shooting a consistent 1.5" groups and opened them up to 4 to 6" groups.
 
DREMEL... I was thinking about a spring clip, that could be spread enough to slip over the holes portion of the BOSS, that would spring back, & cover all the holes... or even like 3/4 of the boss, & could be turned independently, to cover the bottom 3/4 of the holes, so it would actually reduce recoil even more, & cut the sound through the holes by 3/4...
 
Can BOSS be added to a BAR, with out BOSS ?
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No, at least that's what Browning told me when the BOSS first came out as I wanted to install in on my Stainless Stalker. Obviously, you could have a competent gunsmith thread the barrel to be able to install a BOSS system but what you won't have is the engraved hash markings on top of the barrel which is needed to fine tune it to your load.

It appears as though Browning is phasing the BOSS out (along with the A-Bolt being all but gone) so if you're wanting to get one new, your only option is the BAR Mark II Safari but it's only being offered in four calibers with this. I picked up a new 7mm Mag Safari with the BOSS just a couple of months ago as this caliber is completely being discontinued (this should be the last year) in this rifle and it's a rifle/caliber combination I've always wanted. Here's a link to the guns Browning no longer offers or the discontinued caliber offerings of certain models.
http://www.browning.com/products/catalog/firearms/finder-historic.asp
 
Here's how BOSS works:

http://www.varmintal.com/aeste.htm

http://www.varmintal.com/alite.htm

http://www.varmintal.com/atune.htm

http://www.varmintal.com/amode.htm

As long as bullets leave anywhere on the muzzle axis upswing, the velocity spreads they have will be fairly well compensated for. Slower ones leave at a higher angle, faster ones at a lower one. This is why many rifles with all sorts of barrel stiffness and lengths shoot the same load very accurate. The range band with the best accuracy may be at close range, medium or long range; depends on where on the muzzle axis upswing they leave at.

Make your own "BOSS" system by threading the first few inches of the barrel's outside to some fine-pitch thread count. Thread two or three nuts on the barrel then snug 'em up together different distances back from the muzzle. Shoot and move them as your heart desires.
 
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Magnum Wheel ask:
I'm wondering, if the stock were rigid enough ( like a premium composite ) & done in the full length style ( to the end of the barrel ), & the barrel fully bedded, not floated, do you think it possible to hold a barrel steady enough to make a difference, or would the wobble forces be so great, that it would "move" some place along the length, & thus negate the fully rigid concept ???
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Nope, that won't work. The barrel will still wiggle a little bit and bounce off the wood stock as you sort of explained. That'll change its vibration characteristics, just like a barrel rested on a fence rail hoping to nail a pasture poodle 432 yards away. People have tried full bedded barrels in fore ends only to learn the pressure against the fore end from holding and resting gets transferred to the barrel when it shoots. Best accuracy is cylinder bore; like unchoked shotguns.

You could use a 6" thick 24 inch barrel as it wouldn't wiggle very much at all. Or drill a hole in a 2-foot long six inch square metal block, then epoxy the barrel in it. That would stiffen it about 50% more than a 6" diameter barrel.

It's best to let barrels whip and wiggle all they want to and not bounce off anything doing it (that includes no epoxy pad under the barrel's chamber). It's very repeatable from shot to shot when they're totally free floated. And they're probably the most repeatable part of the shooting system.
 
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MWM, yeah, there are brakes built similarly to what you describe, where they can simply be "turned off", but I believe the Boss system was all or nothing - either a brake Boss or no-brake Boss. I could be wrong. Never had one.
 
derelict asked if BOSS systems were used on long range rifles.

I've never seen one in a long range match, but they would work. Benchresters sometimes use them on their short range rifles. But when one uses reloads, they'll often tweak the powder charge for best accuracy at long range. The British Commonwealth long range competitors liked the SMLE because it compensated very well at long range with the cordite loaded arsenal ammo they had to use. The SMLE's shot more accurate with that ammo (huge velocity spread) at long range than a Mauser 98 action rifle did, but the Mauser out performed them at the shorter ranges with the same lot of ammo. It's all about barrel whip angle and muzzle exit timing of the bullets.

They're often used by smallbore rimfire rifle shooters; it really works with them because they cannot adjust the powder charge for best accuracy. That's usually easier than trying out a dozen or more lots of ammo trying to find one whose muzzle velocity is in tune with the rifle's barrel whip frequency.
 
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The one that I made for my 243 didn't have the brake and it was great. I have never used a real BOSS, but it is also my impression that they were full-time brakes or full-time not. As for hearing protection ... I have found that braked rifles are almost always louder, but the extent to which the punishment goes to the shooter or their buddy varies between designs. The BOSS should be used for long range because it allows you to shoot the fastest loads your rifle is capable of and tune the harmonics so that those loads are the accurate ones. People will say "It's only 75 fps" but 75 fps makes a difference when you are pushing a cartridge all the way to the point where it goes trans-sonic ;)

Saands
 
The BOSS should be used for long range because it allows you to shoot the fastest loads your rifle is capable of and tune the harmonics so that those loads are the accurate ones.
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I disagree if you're going to use handloaded ammo. Adjust the powder charge for best accuracy. There's typically a one grain spread in charge weight where best accuracy won't change. And some recipies will shoot very accurate and equally well at long range in several barrels' different profiles and lengths.
 
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Bart,

If you are shooting well within the distance capabilities of your cartridge, then I agree that there isn't any reason not to just adjust the charge to get accuracy (except maybe if you are using one of those crazy barrel burning calibers that only give you 750 rounds of barrel life ... in my experience, the BOSS tunes with far fewer rounds than it takes me to tune a load to a rifle). If, however, you are pushing your caliber all the way to the point where it goes subsonic, then the extra velocity that the BOSS might give you (not every rifle happens to like max loads) could make the difference between arriving supersonic and stable or arriving in the transonic region. Even most long range shooting isn't right at the edge, so the BOSS might be considered a niche tool and certainly isn't for everyone ... and it IS one more thing that can come loose if you aren't paying attention :eek:

Saands
 
however, you are pushing your caliber all the way to the point where it goes subsonic, then the extra velocity that the BOSS might give you
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How does the BOSS give more velocity to a given barrel?
 
How does the BOSS give more velocity to a given barrel?
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A normal barrel will typically have a few accuracy "nodes" (muzzle velocities that yield the best accuracy). These nodes correspond to velocities that put the bullets at the muzzle when the muzzle is at an extreme deflection. Because the speed of the muzzle is at a minimum at max deflection, small changes in the load don't lead to large changes in the point of impact. This makes for nice small groups. Where the BOSS helps is that these accuracy nodes rarely happen at the max load in a normal barrel ... sometimes they do, but not often. When you tune the barrel harmonics with a BOSS, you change the velocities of the accuracy nodes. So ... while the BOSS clearly doesn't add velocity to the barrel, it can (and usually does) allow for higher velocities to happen at the same time that max accuracy is also achieved. So, if optimum accuracy is a constraint on your loads, the BOSS will let you run at higher velocities most of the time.

Saands
 
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