So I recently purchased a new Browning BAR Mk3 in 243 win that has a 1:10 twist barrel. What I got going on is horizontal spread when shooting groups. The vertical spread will typically be within a half inch but the vertical is 2" center to center. It does not change with the powder charge. I'm loading Speer 85 grain BTSP and OAL is 2.625 which is Speer's spec. I have not done any seating depth adjusting being this is the first auto loader that I've attempted to load for. I'm hoping some of you guys might be able to help me out with this. I've done work ups with Varget and H4350 and both had good vertical spread but horizontal stayed about 2" some were 1.5" but not what I was hoping for. All rounds shot at 100 yds and off a stable bench with sand bags. Factory Winchester 80 grain sp shoots a 3/4-1" group but it's more vertical than clover leaf. I've checked the forend screw torque and it is good. Any help is greatly appreciated.
Horizontal group spread
- Thread starter FlGunner
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sea2summit
Well-Known Member
What is your normal group size? Focus on breathing? What is the stock profile/smoothness (is it getting a grip on the sandbags or sliding all over)? Scope parallax and cheek-weld?
Normal group for me with my bolt guns and reloads is 3/8-1/2" depending the day and me doing my part with hand loads. And I have not adjusted seating depth. I don't have a way to measure the distance to lands being it's an automatic. But I have at least a quarter inch in the magazine to use just gonna need to be able to feed reliable.
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Deleted member 107796
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I'd guess it to be lateral movement when you're shooting. Sounds like the rear of the stock is supported well. The suggestion to time your breathing may help.
ShtrRdy
Well-Known Member
From the photo you're showing factory ammo giving you a vertical spread. Yet your loads are resulting in a horizontal spread? Is this correct?
sea2summit
Well-Known Member
Did not recognize as a semi auto, are you crimping your bullets?
sea2summit
Well-Known Member
Try loading one round at a time, see if your groups change. If they do, might look at crimping.
I tend to agree but I would think one could squeeze a little bit more tightness out of one of these BARs. The OP mentioned forend screw torque so that's out of the equation, although any rigid contact along the forearm/barrel interface could affect things. Nothin we can do about that.
I think I would focus on seating things out a bit more, as it looks like there is plenty of mag length to spare here. Then maybe try a powder change. I think H4350 is a winner in the .243 but the semi-automatic factor here might call for a bit faster of a powder?
cohunt
Well-Known Member
Yes, hornady does make an offset tool
As far as horr stringing-- semi auto rifles recoil differently than bolt actions which can affect both shooter and rifle. While practicing good breathing techniques, Try a firm/hard hold into your shoulder with downward pressure on front of rifle--- squeeze trigger to rear gradually and hold trigger all the way back after the shot untill you know the bullet has contacted the target--- many semi auto rifles will require this "hard hold" technique to group well.
The BAR can group well, but are not known for exceptional accuracy, I would say 3/4-1 moa are about the best to hope for (though there is always the occasional tack driver)
As far as horr stringing-- semi auto rifles recoil differently than bolt actions which can affect both shooter and rifle. While practicing good breathing techniques, Try a firm/hard hold into your shoulder with downward pressure on front of rifle--- squeeze trigger to rear gradually and hold trigger all the way back after the shot untill you know the bullet has contacted the target--- many semi auto rifles will require this "hard hold" technique to group well.
The BAR can group well, but are not known for exceptional accuracy, I would say 3/4-1 moa are about the best to hope for (though there is always the occasional tack driver)
