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The case for Heavy Bullets and H-I-G-H B.C. bullets..

I have often wondered just how much a "Heavy-for-Caliber" bullet with a VERY high B.C. ACTUALLY makes over a "normal" high B.C. bullet running at a pretty good clip. Well I got my answer today. Listen to this:

I am sure everyone knows about the flooding in Texas. Well it caused our monthly 1000 yard match to be cancelled this past Sunday. Well I was all prepared to shoot and really wanted to give my new .260A.I. a run for it's money. So another Forum member Tom Holbrook and I decided to go to the range today (Tuesday) and shoot a fun match with just the two of us. We would shoot, go pull, shoot, go pull etc..etc. I was shooting my NEW .260A.I. barrel that truly is a HAMMER! I shoot the Berger 140 L.R.B.T. at 2910f.p.s. It's 'waterline" at 1000 is VERY tight indeed.. Tom was shooting his NEW 7mm RSAUM using the 195 Hunting Hybrid at 2845f.p.s.

We had winds that were blowing at about a 45 degree towards our face and from right to left. We both had "no-wind" Zeros out there at 1000. The wind was not bad at all, somewhere about 5 m.p.h. with "mild" pick-ups and let-offs.. My point of aim was somewhere, depending on the wind, between the NUMBER "9" and to the right of the NUMBER "8" almost to the 7 ring. I was dropping them into the 10 and "X" ring pretty good and only missed 8 for the 60 shots. I also lost more than a few "X"'s due to the head-wind causing a bit of "vertical". Tom had another thing going altogether! When I asked him where he was holding, he stated he was holding, to either the right "edge" of the "X" ring or on the number 10 itself. On one or two shots, when the wind picked up, he had to hold on the right edge of the 10 ring! He never had to waiver OUTSIDE of the 10 ring! His variation in his hold was no more than 1/3 m.o.a. INSIDE the 10 ring! AND his vertical, in the head-wind, was tight with none going way high or low in the 10 ring!
Mine was right at 1 m.o.a. variation(s) but 2.5 minutes AWAY from the 10 ring! It is incredible the difference! Now I don't plan on using the .260A.I. for very many 1000 yard matches, however, it 'taint no slouch neither! But the "mechanical advantage" of the 195 at 2845 over the 140 at 2910 was as far as the east is from the west! What a difference!
 
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I for sure saw that too Ben. I moved from a 300 winnie shooting a 230 berger target at 2765 fps to a 6.5mm 123 at 2900 fps. I literally had to learn how to read wind...lol. And it's even better now that I moved to the 140 hybrid at 2800 fps. I never left the 10 ring at 600 with the big 300.
 
I for sure saw that too Ben. I moved from a 300 winnie shooting a 230 berger target at 2765 fps to a 6.5mm 123 at 2900 fps. I literally had to learn how to read wind...lol. And it's even better now that I moved to the 140 hybrid at 2800 fps. I never left the 10 ring at 600 with the big 300.
As the old adage goes, "there are no free lunches".. That really goes for "magnum"itis" and the punishment dealt out over long shot strings in competition. You get better ability for bucking the wind, BUT you pay for it with constant heavy recoil. However, according to Tom, his 7 SAUM, shooting the 195's, recoil is so close to the Shehane, shooting 180's, as to be unnoticeable in the difference! So the "trade-off" for great ballistics is minimal, compared to a .300WSM (or larger) shooting 230's! OUCH! But I really had my eyes opened today. WOW! It amazed me...
 
Ouch is correct. It would leave a hematoma on my shoulder.... Good thing I was not recoil sensitive, but I'll never forget the feeling before the first shot on the second day of a 2 day match. Brings chills....lol
 
Using the ballistic data you provided and generic atmospheric inputs, JBM predicts 6.0 MOA wind deflection and 4.6 MOA deflection for the 140 and 195, respectively, in a full value 10 mph wind at 1000 yd. According to the POAs you described, the difference between your maximum right hold POAs was well under 2 MOA, not 2.5 MOA, i.e. outside 10-ring (his) to 7-ring (yours). An inside 7 would be 1.0 MOA difference, an outside 7 up to about 1.7 MOA difference. That fits just about perfectly with the wind conditions you described above. Nothing wrong with seeing the difference firsthand by actually shooting, but ballistic programs work pretty well if you use them.
 

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