The BOSS

cdoc42 · August 31, 2020, 10:51 PM

I fell into the marketing trap for the Browning "BOSS" by eventually buying a .22-250, .270 Win and 7mm Rem Mag with that system.

But it works.

The question I pose here is the following:

1) You seat a bullet to factory specs -or any distance from lands that appeals to you, and you use an arbitrary load, perhaps just under recommended max charge and adjust the BOSS to perfection; is it any different than:

2) Seating a bullet to a specific distance from the lands and producing several sets of rounds various powder charges and seating depths until you hit that "sweet"spot?

Does #1 get you to the barrel vibration accuracy point more quickly than going through the process with 2?

**Unclenick** · September 1, 2020, 07:59 AM

It is all interactive. In your shoes, I would fire at least two small-charge-increment ladder strings over a chronograph to identify and then confirm a charge-increment vs. velocity flat spot. I would be sure the barrel had the same degree of fouling in both cases by cleaning it and firing two fouling shots before each string. I would then load enough rounds in the middle that flat spot to let me tune the BOSS to minimize the size of the groups.

The problem is that a ladder target doesn't distinguish between being on a velocity or a muzzle-swing phase flat spot. A velocity flat spot, by releasing each bullet with the same timing, tends to mitigate the effect of muzzle swing on POI. A muzzle swing flat spot mitigates the effect of small velocity and barrel time variation on POI. Either method can produce a ladder target flat spot and the target doesn't tell you which cause is which. But if you have both of these factors synchronized, you've pretty much done all you can to keep your groups small with the gun in the condition it is in. That last remark about condition is just meaning to be aware that other gun tuning steps, like recrowning or improving bedding and so on will still affect group size separately from load tuning.

cdoc42 · September 1, 2020, 11:15 AM

Thanks, Unclenick. If I understand your response correctly, you offered a method to essentially prove that each accuracy-seeking approach will get you there.

I think what I had in mind, and I probably should have said it initially, is tuning the BOSS for accuracy may avoid the need to load varying seating depths and powder charges since you alter the harmonics using a single load and bullet seat.

BUT: if you shoot a different bullet in that same rifle, you have to play with the BOSS all over again.

I don't see any marketing about the BOSS anymore. Did it fall out of favor for some reason?

hounddawg · September 1, 2020, 01:41 PM

Isn't the BOSS just a barrel tuner with a muzzle brake, similar to the Harrel tuner ? Benchresters have been using them for years. Rimfire benchrester shooters swear by them

cdoc42 · September 1, 2020, 06:59 PM

At first Browning offered the BOSS with a muzzle brake, then some time later also offered the unit without the brake holes, just a solid piece of metal like a barrel extension.

The BOSS/brake on my .338 Winchester made it recoil like my .270, so that was great. The 7mm Rem Mag is no big deal regarding recoil but the BOSS/brake is UNBELIEVABLY loud!!!

I was at the range one day (under roof) at the third bench, shooting the 7mm. At the first bench, maybe 20-30 feet away, was an elderly gentleman in his mid 80's, sitting on the ground, shooting a .243. He got up, walked past me without saying a word, opened a storage shed and came out with a 4 x 4 sheet of plywood and put it on his side of bench #2. Clearly spoke to the loud noise of that muzzle brake.

**Unclenick** · September 1, 2020, 09:49 PM

Yes. Muzzle brakes are no fun on the ears of the people adjacent to the firing point.

IIRC, I first saw the BOSS advertised in Precision Shooting Magazine as an independent product at the end of the '80s or early in the '90s. Browning bought the company out. The BOSS was patented, but I've not read the patent, so I don't know what claims of originality were made for it. The patent will have long-since expired by now.

Cdoc42,

I'm not suggesting they do the same thing, but rather that if your velocity flat spot and muzzle swing are not synchronous, you can fix that with the BOSS to perhaps get even smaller groups. If they happen to be synchronous, you can't improve on it with or without a BOSS. The ladder target result looks the same for either one alone and can't tell you whether your tuning found a velocity flat spot or a favorable muzzle swing phase or both at once.

**44 AMP** · September 1, 2020, 10:00 PM

If I understand it right, without the BOSS you adjust the ammo until you find the sweet spot.

With the BOSS, you adjust the BOSS without changing the ammo you are shooting to find the "sweet spot".

cdoc42 · September 1, 2020, 10:46 PM

Unclenick, thanks for the additional information.

44AMP, you've said more clearly what I was trying to say. It really does work. There were some basic settings recommended for various calibers. For my 7mm RM, e.g., I might start at a setting of 6.8, fire a 3-shot group, move to 6.9, 7.0, 7.1, 7.2,etc. The group would tighten up at some point, then start getting larger again as you passed the "sweet spot. That spot for my 7mm with a 160gr bullet is 7.0. It is fascinating to watch the group go in and out.

hounddawg · September 2, 2020, 08:02 AM

here is a link to Harrels tuners/brakes http://harrellsprec.com/index.php/products/tuner-brakes

pretty easy to add one to any rifle

**Unclenick** · September 2, 2020, 08:47 AM

44 Amp,

You will have noticed that ammo tuning often discerns more than one flat spot and that they aren't always equally precise in their resulting group sizes. The tuner lets you minimize groups at any velocity flat spot, though the gun will still probably do its absolute best at a particular seating depth, so I'm not sure you escape dealing with that.

Nathan · September 2, 2020, 01:42 PM

Accuracy boils down to 3 main factors....there are others!

First is consistency of the load....this is basically lowest sd.

The second is consistency of system harmonics..basically barrel release angle.

The third is shooter error.

Ignoring shooter error, When measuring 100 yd groups, you are working on #2. Fine tuning the load dials this in.

There is always a condition where lowest sd can be slightly off best group. With boss, you should be able to find lowest sd and dial the boss to get the best group!

hounddawg · September 2, 2020, 08:16 PM

poor mans Boss https://limbsaver.com/products/sharp...arrel-dampener

**Unclenick** · September 2, 2020, 08:59 PM

That looks like a nifty least-modification approach to the other method of barrel tuning which is, rather than change the muzzle's moment of inertia, as the threaded weight tuner does, instead changing the null node location about which the barrel bends, for which lengthening slows the muzzle swing rate of change, and vice versa. Other examples include the Remington stock bumps, O'Connor bedding and the Smart Stock.

Bart B. · September 3, 2020, 10:30 PM

Browning's original explanation of how their BOSS worked was it changed the vibration frequency the bore axis at the muzzle so bullets leave the instant the bore was straight midpoint in its range.

They later changed their theory to the bore axis angle was stationary at the maximum upper or lower angle.

Neither are correct because the objective of changing the vibration frequency in the vertical plane is to fire bullets at the LOF angle to compensate for their muzzle velocity. Slower bullets must leave at higher angles above the LOS than faster ones. This is only possible if all bullets leave on the muzzle axis upswing. Typically just before the muzzle LOF axis upswing reaches its peak

The barrel's basic resonant low frequency (several dozen Hz) and several harmonic higher frequencies (3rd harmonic at muzzle several hundred Hz) are fixed for a given inner and outer profile. Moving the tuning weight closer to the muzzle lowers the muzzle axis vertical vibration frequency.

September 1, 2020, 01:41 PM	#4
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	Isn't the BOSS just a barrel tuner with a muzzle brake, similar to the Harrel tuner ? Benchresters have been using them for years. Rimfire benchrester shooters swear by them __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek

September 1, 2020, 09:49 PM	#6
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,076	Yes. Muzzle brakes are no fun on the ears of the people adjacent to the firing point. IIRC, I first saw the BOSS advertised in Precision Shooting Magazine as an independent product at the end of the '80s or early in the '90s. Browning bought the company out. The BOSS was patented, but I've not read the patent, so I don't know what claims of originality were made for it. The patent will have long-since expired by now. Cdoc42, I'm not suggesting they do the same thing, but rather that if your velocity flat spot and muzzle swing are not synchronous, you can fix that with the BOSS to perhaps get even smaller groups. If they happen to be synchronous, you can't improve on it with or without a BOSS. The ladder target result looks the same for either one alone and can't tell you whether your tuning found a velocity flat spot or a favorable muzzle swing phase or both at once. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

September 1, 2020, 10:00 PM	#7
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,897	If I understand it right, without the BOSS you adjust the ammo until you find the sweet spot. With the BOSS, you adjust the BOSS without changing the ammo you are shooting to find the "sweet spot". __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

September 2, 2020, 08:02 AM	#9
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	here is a link to Harrels tuners/brakes http://harrellsprec.com/index.php/products/tuner-brakes pretty easy to add one to any rifle __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek Last edited by hounddawg; September 2, 2020 at 08:09 AM.

September 2, 2020, 08:47 AM	#10
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,076	44 Amp, You will have noticed that ammo tuning often discerns more than one flat spot and that they aren't always equally precise in their resulting group sizes. The tuner lets you minimize groups at any velocity flat spot, though the gun will still probably do its absolute best at a particular seating depth, so I'm not sure you escape dealing with that. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

August 31, 2020, 10:51 PM	#1
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,690	The BOSS I fell into the marketing trap for the Browning "BOSS" by eventually buying a .22-250, .270 Win and 7mm Rem Mag with that system. But it works. The question I pose here is the following: 1) You seat a bullet to factory specs -or any distance from lands that appeals to you, and you use an arbitrary load, perhaps just under recommended max charge and adjust the BOSS to perfection; is it any different than: 2) Seating a bullet to a specific distance from the lands and producing several sets of rounds various powder charges and seating depths until you hit that "sweet"spot? Does #1 get you to the barrel vibration accuracy point more quickly than going through the process with 2?

September 1, 2020, 07:59 AM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,076	It is all interactive. In your shoes, I would fire at least two small-charge-increment ladder strings over a chronograph to identify and then confirm a charge-increment vs. velocity flat spot. I would be sure the barrel had the same degree of fouling in both cases by cleaning it and firing two fouling shots before each string. I would then load enough rounds in the middle that flat spot to let me tune the BOSS to minimize the size of the groups. The problem is that a ladder target doesn't distinguish between being on a velocity or a muzzle-swing phase flat spot. A velocity flat spot, by releasing each bullet with the same timing, tends to mitigate the effect of muzzle swing on POI. A muzzle swing flat spot mitigates the effect of small velocity and barrel time variation on POI. Either method can produce a ladder target flat spot and the target doesn't tell you which cause is which. But if you have both of these factors synchronized, you've pretty much done all you can to keep your groups small with the gun in the condition it is in. That last remark about condition is just meaning to be aware that other gun tuning steps, like recrowning or improving bedding and so on will still affect group size separately from load tuning. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

September 1, 2020, 11:15 AM	#3
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,690	Thanks, Unclenick. If I understand your response correctly, you offered a method to essentially prove that each accuracy-seeking approach will get you there. I think what I had in mind, and I probably should have said it initially, is tuning the BOSS for accuracy may avoid the need to load varying seating depths and powder charges since you alter the harmonics using a single load and bullet seat. BUT: if you shoot a different bullet in that same rifle, you have to play with the BOSS all over again. I don't see any marketing about the BOSS anymore. Did it fall out of favor for some reason?

September 1, 2020, 06:59 PM	#5
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,690	At first Browning offered the BOSS with a muzzle brake, then some time later also offered the unit without the brake holes, just a solid piece of metal like a barrel extension. The BOSS/brake on my .338 Winchester made it recoil like my .270, so that was great. The 7mm Rem Mag is no big deal regarding recoil but the BOSS/brake is UNBELIEVABLY loud!!! I was at the range one day (under roof) at the third bench, shooting the 7mm. At the first bench, maybe 20-30 feet away, was an elderly gentleman in his mid 80's, sitting on the ground, shooting a .243. He got up, walked past me without saying a word, opened a storage shed and came out with a 4 x 4 sheet of plywood and put it on his side of bench #2. Clearly spoke to the loud noise of that muzzle brake.

September 1, 2020, 10:46 PM	#8
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,690	Unclenick, thanks for the additional information. 44AMP, you've said more clearly what I was trying to say. It really does work. There were some basic settings recommended for various calibers. For my 7mm RM, e.g., I might start at a setting of 6.8, fire a 3-shot group, move to 6.9, 7.0, 7.1, 7.2,etc. The group would tighten up at some point, then start getting larger again as you passed the "sweet spot. That spot for my 7mm with a 160gr bullet is 7.0. It is fascinating to watch the group go in and out.

September 2, 2020, 01:42 PM	#11
Nathan Senior Member Join Date: July 1, 2001 Posts: 6,338	Accuracy boils down to 3 main factors....there are others! First is consistency of the load....this is basically lowest sd. The second is consistency of system harmonics..basically barrel release angle. The third is shooter error. Ignoring shooter error, When measuring 100 yd groups, you are working on #2. Fine tuning the load dials this in. There is always a condition where lowest sd can be slightly off best group. With boss, you should be able to find lowest sd and dial the boss to get the best group!

September 2, 2020, 08:16 PM	#12
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	poor mans Boss https://limbsaver.com/products/sharp...arrel-dampener __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek

September 2, 2020, 08:59 PM	#13
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,076	That looks like a nifty least-modification approach to the other method of barrel tuning which is, rather than change the muzzle's moment of inertia, as the threaded weight tuner does, instead changing the null node location about which the barrel bends, for which lengthening slows the muzzle swing rate of change, and vice versa. Other examples include the Remington stock bumps, O'Connor bedding and the Smart Stock. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

September 3, 2020, 10:30 PM	#14
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Browning's original explanation of how their BOSS worked was it changed the vibration frequency the bore axis at the muzzle so bullets leave the instant the bore was straight midpoint in its range. They later changed their theory to the bore axis angle was stationary at the maximum upper or lower angle. Neither are correct because the objective of changing the vibration frequency in the vertical plane is to fire bullets at the LOF angle to compensate for their muzzle velocity. Slower bullets must leave at higher angles above the LOS than faster ones. This is only possible if all bullets leave on the muzzle axis upswing. Typically just before the muzzle LOF axis upswing reaches its peak The barrel's basic resonant low frequency (several dozen Hz) and several harmonic higher frequencies (3rd harmonic at muzzle several hundred Hz) are fixed for a given inner and outer profile. Moving the tuning weight closer to the muzzle lowers the muzzle axis vertical vibration frequency.