The Berger twist rate calculater shows the 180 .288” Woodleigh bullet (.513 B.C.) to be “marginally stabilized”
at 2500fps from a .270 1-10 twist rate.
You rely on a hypothetical Berger calculator instead of what Woodleigh the designer/manufacturer tested in the real world?
do you feel like contacting WL to tell them about what the Berger calculator tells you?
btw: achievable velocities are closer to 2700 fps
Haven’t seen what the original designer tested or what velocities were achieved and in any case prefer multiple sources rather than what a single manufacturer may say. I have problems reaching Nosler maximum velocities, for example, and find Hornady and other vendor data more consistent and reliable, even after adjusting for similar barrel lengths.
2700fps may be reachable but I have not seen any pressure test results for 180g loads other than Hodgdon, who lists 2540fps maximum at 50,600 CUP with a 24” barrel.
Re: "marginal stability"
For shorter ranges, marginal stability isn’t really an issue,( especially a high borerline case 180 WL stability factor of 1.45)
I agree. But high B.C. bullets are not needed for most ranges, either.
A marginal stability project. can still travel with good accuracy and precision, even though BC performance is less than ideal.
people interested in max. LR performance would need a slightly better twist to fully stabilise a projectile for best BC performance...
which is not imperative for the vast majority of hunters.
your Berger calc gives 180 WL a factor of 1.45
original BC of .513 is compromised to .505
minimum twist recommended is 9.75
Agreed that a high B.C. is not needed for the (vast) majority of hunters. But arguing that a bullet is best because of it’s B.C. and then saying that B.C. is compromised is trying to have it both ways.
Thanks, I’ll stick with my .280 Rem and 7mm RM, both with 1-9.5 twist rates, rates that stabilize the .510 B.C. 175g Woodley, not that I’ll ever use them. (I use 140g an 160g bullets exclusively in them these days, some with club-like B.C. values and am quite content to shoot them to 600 yards.) If higher velocity, flatter shooting and more energy downrange is how you measure it, a faster, stabilized .510 B.C. bullet is “better” than a slower 180g bullet with an effective B.C. of .505.
it doesn't sound anything like a worrysome situation in practical real world terms, but those who obsess with number crunching model
ideals could sure invent something to worry about.... Berger does not say its wrong to hunt with a factor of 1.45,
http://www.bergerbullets.com/twist-rate-calculator/GSC bullet site indicates a stability factor of 1.4 or greater is adequate for a projectile if 'general hunting out to 500 metres'.
considering GSC are made in Africa and used in Africa, I gather they know what they are talking about in their technical advice
to hunters.
I agree – for most hunters and most situations, arguing over which bullet or cartridge is “better” based on B.C. is foolish. Most bullets will work for most situations most of the time. And for those times they don’t, a higher B.C. bullet is rarely the answer.
It also shows a 175g Woodleigh (.510 B.C.) as “stabilized” from a 7mm RM 1-9.5 twist at 2800 fps.
Thanks, but I’ll take the 7mm RM and the "BC club" 175. Fully stabilized, flatter shooting and higher velocity and energy downrange.
how about you put your calculator down ....and in relation to the OP, just tell people what is going to 'go wrong' if a .270win owner
loads a WL 180....?....How much real world effect worse off are they going to be (vs) using .280AI 175 Woodleigh.....?
The OP is “not really a long range guy at all” that typically hunts at 300 yards or less and is interested in something with higher B.C. and velocity “just in case“. You admit that the 180g Woodley might not be the best past 500 yards. It really isn’t necessary at shorter ranges, though.
The real question for me is “How much better off would he be if using the 180g Woodley?” The answer I come up with is “Probably not at all.”
The “super duper BC pills and xtra long monometals” are “out of the game for most” factory rifles, regardless of chambering.
Yep.
most people use common twists with common bullet weights and get the job done at most common ranges.
Im a 7mm fan , but the hype about 280 AI and better bullet choices is exaggerated, as are some muzzle velocity claims.
ie; I doubt some are based on 'safe' loads or common length barrels.
I don’t know which claims you are talking about but both Hodgdon and Nosler list 2800fps for 175g bullets in the .280AI. The Hodgdon pressure is 61,100psi, well below the 65,000psi limit for the .270 Win and well within the safety margins for modern rifles.
I’m not arguing that a 7mm is “better”, just pointing out that that a .270 isn’t necessarily better. I have no real use for the heaviest bullets in either caliber. “More” is not synonymous with “better”.
When I asked you to show me a better deer/elk/both cartridge it was in reference to the 7mm RM, not the .280AI. ...
Hmmm.... you didn't ask me that, you asked TRYSTAN.
My bad. Hey, memory is one of the first things to go.
