Barrel twist question for 300wm.

I haven't seen a 1:9 option anywhere, just found that Browning changed their HC LR to 1:8 this past year. Hence why I've asked this question.

The HC Speed is still a 1:10 as are all the other x bolts in various models with the 300wm cal. I'd like to go to the speed for the weight savings.

I'm looking at the x bolt HC because of what all you get for the price. Cerakote, brake, etc.
if price wasn't a consideration, I'd just have Gunwerks or someone build me a ready to go rifle.
I'd take a 1:9 if they make it. 1:10 is close to being ok on heavy bullets. 1:8 isn't necessary and costs you some velocity. 215gr is my limit in the 300wm. If more is needed, the 338 edge comes out of the safe.
 
My 1:10 will blow up 110 gr V-Max bullets, 99% of the time. It also does just dandy with 200-212 grain bullets. Haven't tried anything heavier, but the stabilization calculators indicate it's just fine up to at least 220 grain bullets.

1:8 just seems fast to me, but on the other hand, aside from party tricks, who's using bullets less than 150 gr in a 300 WM?

I've had good luck throwing the 110 V-max out out my my 300WM. It IS a 1:11 though. Shoots the same size groups as the 180 TTSX.
 
I don't think your theory of overstabilization plays out in the elr crowd. They are running much faster than "needed" twist in order to pass the transonic range more cleanly.

From our shooting and testing we have seen no downside to running bullets in the range of 2.0 sg, and higher, calculated at sea level out to long range hunting ranges.

It was once thought that a bullet fired at marginal stability would be better for long range for the reason that you describe. So the nose will break over as the bullet trajectory does. I have hunted with bullets that are very accurate with marginal stability and have seen less than stellar results on game. Marginal stability will greatly increase the odds of bullet failure on game. Bullets tumbling on impact or not opening up due to yaw. The lower the rpm's the more quickly the bullet loses stability after impact causing the bullet to not track straight though an animal. This becomes ultimately important with quartering shots.

To the OP. As some others have said, your needs will most likely be met with any twist rate offered in factory rifles shooting factory ammo. I would recommend that you stay away from the 11" twist that are in some of the 30cal offerings. You should not rule out the faster twist that is available in the Browning. There is not a downside. Some have said that you will lose vel. Not enough to accurately measure or be noticeable from one rifle to the next. It may cost you ~25fps going from a 10" twist to an 8" twist. This is not enough to be noticed. You could get an 8" twist barrel that is faster than a 10" twist barrel just because of variation from one barrel to the next.

There is one effect of a faster twist compared to the slower twist than has not been mentioned, that actually happens. The faster twist will impart more spin drift than the slower twist with the same bullet. This is easily compensated for, so not really an issue.

My .02
I shoot elr to holy **** I need a map far most of the time. Now as far as hunting goes, your issue with the arch and it's effect on game sounds like a bullet design issue. My issue is there's no way to reliably quantify a danger space or having to be super tedious measuring swept space if belly up bullets are hulahuing in to instability.


Also the magnus effect will lead to instability and accuracy issues. It doesn't get better with more spin for sure.
 
I shoot elr to holy ---- I need a map far most of the time. Now as far as hunting goes, your issue with the arch and it's effect on game sounds like a bullet design issue. My issue is there's no way to reliably quantify a danger space or having to be super tedious measuring swept space if belly up bullets are hulahuing in to instability.


Also the magnus effect will lead to instability and accuracy issues. It doesn't get better with more spin for sure.
I'll take your word on it.
 
I shoot elr to holy ---- I need a map far most of the time. Now as far as hunting goes, your issue with the arch and it's effect on game sounds like a bullet design issue. My issue is there's no way to reliably quantify a danger space or having to be super tedious measuring swept space if belly up bullets are hulahuing in to instability.


Also the magnus effect will lead to instability and accuracy issues. It doesn't get better with more spin for sure.
I started a thread in the elr forum that you may find interesting.

https://www.longrangehunting.com/threads/twist-rates-for-elr.215510/#post-1589919
 
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