AusVarmint

Right , i thought it would be best to get out of the other post ,re Light Gun ability's and start a new one .. The reasons for the success or not of the VLDs is square at the feet of the exterior shape consistency and very little else .. If you want a very boring read then go to *Tip Off Rate* in the Ballistics write ups , but this is where the problems are .. It is in effect a bunch easier to produce a FB bullet with the same Exterior shape than it is to make one that is shaped like a javelin , period.. The success of your Consistent bullet placement at the further distances lies with how much each bullet cants or Tips Off just as it leaves the muzzle .. If the overall dimensions of the bullet from the position on it's land engagement point through to the meplat are all over the place then the cant will be different .. Dave T has not only been employed by some of the large Bullet company's to design new projectiles but has made his own for a big bunch of years , his tests with doppler chrono's and spark photo work at the Govt facility's prove the bullet with a predominance of mismatch on the front part of the projectile can and will start off it's flight differently but will also arrive at a different speed because of the total time of flight .. In effect what you can get is is one projectile arriving at more than 100 fps that another which gives you the vertical and because it has tipped to the right or left then you get induced windage .. The problem is in the 1st 50yds and if you have conflicting wind effects in that 1st 50 then the problems already induced are compounded .. Ever had a VLD that goes the opposite way to what you thought the wind flags said it should , now you know why ... Speeds that the bullets travel at or nodes are IMO more to do with case capacity/ gunpowder burn rate than the actual all out speed ,this is highlighted by the 300wsm vers the 300ack with the 210s .. Both can set world records at 1K but everyone will tell you that the wsm has to run at 2850 BUT the 300Ack guys will say it has to be at 3050 fps , the bullet is not determining the speed , the case/ powder is .. As far as i know i am the only fool in this county to run the 187 BIB flat base bullets and have had some reasonable successes even though they have only a BC of .520, and quiet frankly i like it that way.. JR..Jeff Rogers

Thanks Jeff. Your post got me searching and i've found a few articles that have really changed the way I look at bullet flight and accuracy including the articles here http://www.thewellguidedbullet.com/inte ... istics.htm

I have a headache now, but it is sinking in.

Hi all ,another consideration about Flat Base Bullets for longrange is that the twist rate can be taken from say a 210 Ber at 10 or 11 twist to what i run at 13.5 ins with the 187..No doubt in my mind this helps when your gettin winds coming from multi directions .. I run the bullet at a brisk pace so i do not suffer too much when the wind blows .. A 300wsm at 2850fps with most of the available 210s drops about 27 moa with a 10 mph drift of 70.2 ins.. My redneck with 187s is a drop of 21 moa (buy the charts only for comparison ) and a drift of 70.8ins and there time of flight is way less .. The 300ack is well in front at 63 ins windage .. One thing i will say even at 11 twist in the Ack if those bullets are not real goody's the accuracy will be worth as much as a icecold pussy is.. In qualifying different projectiles over the last 15 years the best of some of the brands bullets are still way worse than the ones i reject to barrel warmers in sorting a box of the FBs i currently use .. If there ever was a bullet u could just pull from the box and shoot then it's them..JR..Jeff Rogers

Jeff,

If I get you correctly you are saying that bullets are changing direction as they exit the barrel due to distortion of the frontal area of the proj? I seam to recall some info on this in "Rifle accuracy facts".

If so, Barrel design, ie lans etc would also have an impact on this would it not, could this be a pointer toward some of the winning barrels that have 5 lans or less?

Or in some of these cases is barrel design changes an R&D path forced on some of us due to the lack of quality projectiles on the market?