Win 70 30-06 Boss removal

Thread starter #1

DeweyDuck

Senior Member
Just getting into handloads for this gun using 175 Gr BTHP's. The BOSS data from Winchester only shows settings for 3 bullets. There are hundreds of possible settings with this thing which would take buckets of ammo to optomize. So, I thought about just removing it and putting on a barrel cap if I can't find a sweet spot. Has anybody tried that and did it work out?
 

Lilly001

Senior Member
You could get a cap with the correct threads. But it isn't, in my experience, hard to calibrated the boss.
Just set it at the recommended setting for the weight bullet and then go up and then down a half turn at a time. You should see a change for better or worse in one or two groups. If it gets better continue a half turn at a time until it stays the same or gets worse. I go both ways to be sure.
A box of cartridges should get you real close. Then you can fine tune it from there if you want.
I've gone from various brands of 150 and 180 in my 300 wsm with boss useing this technique and it has proven to be very accurate. I routinely get sub 1" groups and have gotten to just over 1/2" with Silvertip 150's.
 

Darkhorse

Senior Member
I've got a Browning 300 Win. Mag with the BOSS and I wouldn't consider removing it in a thousand years.
True. It takes a lot of bench time to really get it nailed down to shoot tiny groups but it's no worse than finding that perfect load just by handloading. When you handload you are trying to tune your loads to the gun. With the BOSS you tune the rifle to the load. In both cases your searching for the spot (node) in the oscillation of the barrel where the bullet exits the bore at the same spot each shot. I find it much easier with the BOSS.
The factory recommended sweet spots are worthless but you gotta start somewhere. FWIW my rifles sweet spot for my chosen loads is 9.
There are several settings that will give good to excellent accuracy so you could try this to get 1.0 or better groupings. Start at setting 2 and fire 2 shots off the bench. Turn the BOSS to 4 and fire 2 shots. Same thing at 6 and 8. These should be shot at separate targets. Now compare targets and see which has the 2 shots closer together. Use this number to fine tune from.
Now move the BOSS 5 marks in and shoot 2. Move the BOSS 2 marks out from original setting and shoot 2. One of these should be closer than the other. Fine tune the setting with the closest shots by moving one or 2 marks at a time.
FWIW 9 out of 10 shooters couldn't figure out the BOSS, they bought a rifle with one because they thought it would automatically produce one hole groups.
It doesn't work that way. My tightest 3 shot group was .188 and it shot consistently .5 and under. My elk load shot under .600 and averaged at .520" I consider that well worth the effort I put into it.
 
Thread starter #4

DeweyDuck

Senior Member
I've got a Browning 300 Win. Mag with the BOSS and I wouldn't consider removing it in a thousand years.
True. It takes a lot of bench time to really get it nailed down to shoot tiny groups but it's no worse than finding that perfect load just by handloading. When you handload you are trying to tune your loads to the gun. With the BOSS you tune the rifle to the load. In both cases your searching for the spot (node) in the oscillation of the barrel where the bullet exits the bore at the same spot each shot. I find it much easier with the BOSS.
The factory recommended sweet spots are worthless but you gotta start somewhere. FWIW my rifles sweet spot for my chosen loads is 9.
There are several settings that will give good to excellent accuracy so you could try this to get 1.0 or better groupings. Start at setting 2 and fire 2 shots off the bench. Turn the BOSS to 4 and fire 2 shots. Same thing at 6 and 8. These should be shot at separate targets. Now compare targets and see which has the 2 shots closer together. Use this number to fine tune from.
Now move the BOSS 5 marks in and shoot 2. Move the BOSS 2 marks out from original setting and shoot 2. One of these should be closer than the other. Fine tune the setting with the closest shots by moving one or 2 marks at a time.
FWIW 9 out of 10 shooters couldn't figure out the BOSS, they bought a rifle with one because they thought it would automatically produce one hole groups.
It doesn't work that way. My tightest 3 shot group was .188 and it shot consistently .5 and under. My elk load shot under .600 and averaged at .520" I consider that well worth the effort I put into it.
Wow, best advice I've ever recieved anywhere about shooting. You and Lilly001 are much appreciated. I'm gonna try all of your tips on my next outing. I got about 1 1/4 inch group with it set at 2 but the half turn tips sound like the answer I'm looking for. Gonna try all of your tips on my next outing.
 

Darkhorse

Senior Member
My Browning is in the back of the gunsafe so I'm working from memory here. The BOSS is marked similar to a set of micrometers. Between each number there are 10 marks (not marked, just a line) with a longer line at the midpoint. These are the marks used to fine tune a BOSS.
So with the BOSS set at the number 2, turn the boss 5 marks to the halfway mark and fire 2 or 3 shots. Then turn the boss back the other way to the halfway mark and fire another group. One should be tighter than the other. Go with that one and move the boss 2 or 3 marks and fire a group, do the same the other way. One should be tighter than the other. You could further fine tune it by moving 1 or 2 marks and shooting another group.
One thing to keep in mind is as you shoot your barrel heats up and many rifles begin stringing the shots, which plays havoc with your judgement about settings on your BOSS. For instance, my .300 (as bedded by the factory) will shoot 3 shots into a very tight group, but shots 4, 5, and 6 begins to string horizontally left as the barrel heats up.
What I had to do was allow the barrel to fully cool between groups. I don't think your '06 to be nearly as dramatic, maybe hardly any stringing at all. Only shooting will tell you that.
I would suggest you create or find online targets similar to the one attached as it gives you an instant comparison between different boss settings.
This target was shot with a 1981 7 mag. with no boss. Instead each group has a different seating depth which is exactly the same effect moving the boss provides. Notice how the group changes size and location with each change in seating depth.
All my bullet seating is measured from the ogive, a .020 seat depth means the ogive is .020 from the lands. I never use OAL for any rifle work. Group2 (2) (800x614).jpg landscape.png
 

Lilly001

Senior Member
Wow Darkhorse, you realy get down to The bone.
Good write up.
 
Thread starter #7

DeweyDuck

Senior Member
Great tip Darkhorse. I also use ogive to lands for seating depth and I use a bucket of ice water and a towel to cool down my barrel in this hot weather. I also keep my ammo in the shade to avoid overheating issues. I have copied this whole thread to keep in the 30 06 notebook that goes with me every time. I number and record the results of every shot for later brainstorming. I list distances high or low and right or left for every bullet. I prep the brass to the exact lenght and headspace, I weigh the powder to within 1 particle, and I seat the bullets to within .001 maybe even .0005 of whatever jump I'm trying that day. My next goal is to buy a neck sizer and neck trimmer because I can measure about .001 variation in the a few of the necks. Better new brass might be the answer because I'm using a mixture of factory once fired brass I've saved up.
All of you guys are real sports for sharing your experience. My BOSS has now attained a longer life.
 
These guys ^^ have covered the Boss ...

just a tip about cooling down a barrel .... I use a 12 volt air mattress pump (Coleman) that has a flexible piece of tube that fits in many chambers ...

Since my range is in my back yard ...I use my JD Gator to haul all my stuff to the bench ...it has a 12 volt plug on the dash... plug the long cord of the pump in and it will cool a barrel quick ...
 
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