For the record, Winchester said the "official" sweet spot on a M-70 .308 with a BOSS-CR is 3.6 for 165-grain bullets -- then you work from there.
For a 165-grain Light Magnum .308 BTSP, the "dead-on" BOSS-CR setting is 4.1. That round was leaving the barrel at 2,880 fps.
Hornady said the load I'm considering, 165-grain Superformance SST, should be close to that -- as it's moving at 2,840 -- just 40 fps slower.
The Hornady rep said it'd be best to dial BOSS down -- as opposed to up -- initially.
Hornady said Winchester and Browning had sent them some rifles years ago with BOSSs on them to work up standardized BOSS settings. I was fortunate to call while that testing was going on -- and that's how I got the setting so exact from the lab tech.
Here's a valuable tip for those with a BOSS. Don't try to set the BOSS at 100 yards. Rather, set your target up at 25 yards. (Heck, 10 yards might even work.)
Find what the "official" sweet spot setting is, dial it properly, then crank your scope up to the maximum setting.
At that short distance, with the scope up high, you should hold steadier and see movement easier. Thus, it's easier to get the BOSS shooting through one hole faster and with fewer rounds.
Once you get it going through one hole, then sight the rifle in at distance.
Be aware that Winchester and Browning both have videos out on how to set the BOSS.
I deeply, deeply, deeply regret that Winchester discontinued the BOSS on the M-70. Maybe now that production has resumed at the FN plant in Columbia, SC after Winchester closed the Connecticut plant, the BOSS is something they'd consider bringing back.
In my view, it makes M-70 the most accurate rifle I've ever seen or shot -- and that's saying something.
(Also, be sure to use Gun-Tite on the BOSS once you get it set -- and make sure the trigger and magazine screws are secured at the right tension.)
Years ago, BOSS came out with fabulous groups -- then for some reason, the groups got bigger.
It was because the BOSS was shooting loose -- and so were the trigger and magazine screws.
Gun-Tite keeps that from happening.
For a 165-grain Light Magnum .308 BTSP, the "dead-on" BOSS-CR setting is 4.1. That round was leaving the barrel at 2,880 fps.
Hornady said the load I'm considering, 165-grain Superformance SST, should be close to that -- as it's moving at 2,840 -- just 40 fps slower.
The Hornady rep said it'd be best to dial BOSS down -- as opposed to up -- initially.
Hornady said Winchester and Browning had sent them some rifles years ago with BOSSs on them to work up standardized BOSS settings. I was fortunate to call while that testing was going on -- and that's how I got the setting so exact from the lab tech.
Here's a valuable tip for those with a BOSS. Don't try to set the BOSS at 100 yards. Rather, set your target up at 25 yards. (Heck, 10 yards might even work.)
Find what the "official" sweet spot setting is, dial it properly, then crank your scope up to the maximum setting.
At that short distance, with the scope up high, you should hold steadier and see movement easier. Thus, it's easier to get the BOSS shooting through one hole faster and with fewer rounds.
Once you get it going through one hole, then sight the rifle in at distance.
Be aware that Winchester and Browning both have videos out on how to set the BOSS.
I deeply, deeply, deeply regret that Winchester discontinued the BOSS on the M-70. Maybe now that production has resumed at the FN plant in Columbia, SC after Winchester closed the Connecticut plant, the BOSS is something they'd consider bringing back.
In my view, it makes M-70 the most accurate rifle I've ever seen or shot -- and that's saying something.
(Also, be sure to use Gun-Tite on the BOSS once you get it set -- and make sure the trigger and magazine screws are secured at the right tension.)
Years ago, BOSS came out with fabulous groups -- then for some reason, the groups got bigger.
It was because the BOSS was shooting loose -- and so were the trigger and magazine screws.
Gun-Tite keeps that from happening.
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