Opinions on best suited twist rate ?

[Die Judicii]

Just interested in what opinions are, on the best suited twist rate for 185 gr sub sonic hollow points in the 308 cal ?

And, where would 1:11 fit in ?

[deye243]

How long is a piece of string as 185g pills come in different lengths.
Twist rate requirements has more to do with length than any other factor.

[Die Judicii]

How long is a piece of string as 185g pills come in different lengths.
Twist rate requirements has more to do with length than any other factor.

I suspected as much, (not being a reloader) all I can supply is, Winchester SuperX Power-Point Subsonic 185gr
Intended rifle of use is Sako III 75 with 1:11 twist.

I have sifted through a heap of forums where this question arises, and the so called "answers" are all over the road like a mad womans sh!t.
They all seem to contradict each other,,,,, so I'm still none the wiser.

[bladeracer]

Just interested in what opinions are, on the best suited twist rate for 185 gr sub sonic hollow points in the 308 cal ?

And, where would 1:11 fit in ?

As already mentioned it will depend on the length of the bullet. 11"-twist in .308 should stabilise bullets up to around 1.500" so measure one first. Then load one up and see if it puts a circular hole in paper at 50m.

[bigpete]

I've had good results with hornady 199gn sib x handholds and sierra 170gn flat nose handholds in 2 different 1 in 10 twist 308w rifles. I do find the subsonic rounds a little lacking in killing power,they tend to pencil through,even the sub x ones.

[Blr243]

Blackout barrels are usually 1/7. But I guess that’s to help with 220 weight bullets … is it just the length of longer bullets that cause instability or is it the slower speed of the sub bullet a contributing factor when useing long bullets ? I have a stack of 308 subs made up that I’ll probably never use. I should give u some next time I see u

[Wyliecoyote]

Just been through this exercise with 8.6 Blackout and 375 Raptor. It's not so much a stabilisation issue but more an issue with bullets and rotational speed. The 8.6 hype says to run a 1 in 3 twist which at a 1000 fps the pills are spinning at around 500,000 rpm. With the Raptor it is a 7 twist barrel at way less RPM. The 8.6 has a poor reputation for accuracy where traditional copper jacketed lead bullets come apart so it is monolithics only whereas the Raptor shoots sub MOA with just about any type of bullet up to 450 grains and that is from sub to supersonic speeds.

An 11 twist 308 will stabilise up to 200 grain spitzer bullets and 220 grain round nose bullets at 308 speeds. At 1000 fps the weight is limited to 180 grains from my experience and that is more dependant on bullet shape and length. As stated at that speed the likelihood of pencilling through using spitzer style bullets is high so it is preferable to use a faster twist rate to help with centrifugal force deforming the bullet on impact. The best option at 11 twist is bullets designed specifically for 30/30s. Trajectory of a 22lr but at least the flat nose helps with bullet deformation. Failing that my bullet of choice was the 125 Speer TNT. Super accurate and the thin jacket helps with expansion at those slow speeds.

[Die Judicii]

Thank you,,,,,,, one and all for experiences, opinions & facts.
Much appreciated.

[Oldbloke]

This is very simple to use.

https://bergerbullets.com/twist-rate-calculator/