I'm no expert but wouldn't a projectile with a rearward center of gravity fly with the tip tending to pointed slightly upward? The spin should keep it from tumbling and at the point when the bullet peaks the weighted end would be pushed slightly farther than the lighter end, this would give the bullet a more driving effect, and a position that was more in line with the path of flight (instead of nose up) on the downward path.
This is probably not correct but if it is, then this may be the problem Kirby is seeing with the changing BC at longer ranges. The BC is actually changing because the bullet is no longer nose up to the flight path, it is actually in line with the path.
Do any of the experts see anything of value in my wandering train of thought.
What data do you have to support your comments that all bullets fired into fluid will land tail first?
Please re-read what I wrote. I was only describing FMJ bullets. Non- expanding.
Clearly expanding bullets prevent tumbling due to several mechanisms, shoulder stabilization, mass shifting, and becoming a cylinder with weight forward properties.
Data on FMJ bullets has been described in many places, here is one:
If I gave the impression that all bullets tumble I apologise, and that was never my intent. I think that were you to drop a bullet nose down from a reasonable distance that it would hit the ground in a general base down manner, this overturning moment is one reason for the need for twist.
I would say that your FMJ comments again have more to do with retained bullet length after impact then anything else.
I do not shoot solids or FMJ at long range for paper punching, varmint hunting or big game hunting so I have no experience there but I have read about african big bore rifles using far faster twist then needed to keep solid bullets on point as they penetrate.
Allen Precision Shooting
Home of the Allen Magnum, Allen Xpress and Allen Tactical Wildcats and the Painkiller Muzzle brakes.
Flat point solids are shoulder stabilized after impact and stay on track when penetrating..... Round nose solids will tumble at some point usally after penetrating a long way... Every round nose soild that I have fired or seen fired into wet news print tumbled,never have I seen a flat point solid tumble in game or wet news print.............I do not have any experience with pointed solids and my above comments do not include pointed solids.....
range it,check the wind, dial in correction, aim and only one shot
I may be 100% off, but I can often find problems at night.
If you can shoot the 300SMK and the 265 WC in the dark, either with a friend or better yet using a camera. You know that the SMK's are accurate, so use that as a baseline, and if the muzzle flash is noticeably exaggerated with the 265's, then try a different load.
This may not work for you, but I have found that when the muzzle flash is much more than my baseline loads that I might as well move to something different.
I was out shooting last night and it was particularly dark outside and I noticed something like this. I was shooting a 300 ultra mag with RL25 with 180 grain bullets and 200 grain bullets. With similiar charge weights, the 180 grain bullets dang near blinded me with muzzle flash. It was super bright, and went far enought out to the sides to blind my non-shooting eye as well. Then the 200 grain bullets hardly had a spark behind them. Shows pretty well in my mind that the 180 grain bullets were either too light, or the powder was too slow burning or both. In other words, the expansion ratio was much too low with the 180's.
goodgrouper, thanks for the feedback.
With my limited shooting, it has been reliable. I'm sure that you can find loads that are reliable that show a lot of flash, but I would think that there should not be a lot of powder burning after the bullet leaves the muzzle.....at least not more than with your best loads.