I’ve asked a few off this forum this question directly. Thought I would post on here.

I’ve been wanting a Browning hells canyon long range in 300 win mag for awhile. I just saw on their site in 2018 they changed from a 1:10 twist to a 1:8. I called browning and was told it was due to demand for long range and stabilizing larger bullets. Searching other forum discussions, the 1:8 twist does seem to be catching on for 215 grain plus bullets. I’m wanting to use the 175 grain Barnes LRX.

Any opinions or thoughts on the matter?

1:8 twist is faster than needed for a 175 gr. bullet. But it certainly shouldn’t hurt any. Especially being a copper solid.

Is that because copper bullets are longer?

I think he many have meant that a solid copper bullet is less likely to spin apart under the fast twist. Whereas, a conventional lead-and-copper-jacketed bullet might separate and shed its jacket as it leaves the barrel. This is probably only of concern in the lighter bullets, in the cartridge you're considering.

Jim

Heavier bullets are longer. Longer bullets need a faster twist to stabilize.




Charlie

Good James, good

Stabilization is a product of bullet length vs RPM.

RPM is governed by velocity and rifling twist rate. A certain RPM is required to stabilize any given bullet, with shorter, lighter bullets being easier to stabilize.

A .300 WinMag, with it's higher muzzle velocity, will develop greater spin rates with the same twist rate when compared to most other 30 calibers.

A .308 with 1:10 or 1:12 rifling will stabilize a conventional lead core bullet of 175 grains just fine at 2,600 fps. If we drop the muzzle velocity, stability is compromised. If we increase velocity, we can get away with an even heavier bullet with the same spin rate.

When talking bullets of conventional construction (jacketed lead core), as we increase weight, the length also increases and velocity declines. Because we lose velocity AND gain bullet length, we must make it up in a faster twist rate.

When we go to monolithic bullets like the Barnes, the material used (solid copper alloy) is less dense than lead, so for any given weight, the bullet will be longer, thus requiring a faster twist to stabilize.

1:8 is extremely fast for a .30 caliber bore and there will be no problems with stabilizing your 175 Barnes bullets. Because it is a .300 WinMag, the velocity should be high enough to stabilize a Barnes even heavier than the 175.

Here is a spin rate calculator that can be manipulated to see the behavior I posted above:
http://www.bergerbullets.com/twist-rate-calculator/

James, your point regarding jacket thickness and bullet durability is a good one, but most game bullets will not spin fast enough to rupture the jacket, especially 30 cal and larger. I have been able to disintegrate many varmint bullets by combining thin jackets with high velocity. My .22-250 with blow up 40 & 45 grain bullets designed for the .22 Hornet. My 6.5-300 Weatherby will blow up 87 grain Sierras meant for much lower velocities. Another thing that will compromise bullet jackets at higher velocities is a rough, work throat.

Barnes bullets, with their monolithic construction, are not prone to this sort of damage and have been driven to amazing speeds. Roy Weatherby and Fred Barnes had teamed up at one time to try for highest possible velocities and reached almost 5,000 FPs and their limit was not the bullet. Absolute muzzle velocity was limited by the rate of gas expansion available in the smokeless powders available to reloaders,

I run a 1 in 8 on my 30-338, Sub MOA with 165s through 210s. My bullet of choice is the 180 accubond at 3150 fps and it stabilizes perfectly.

Here's an article i read one time that quotes Dan Lilja of Lilja barrels. Dan has lots of good info on his barrel site and is good reading concerning barrels.

For me, i'd like a little slower but as this article states, at hunting distances you probably won't notice it.

http://www.shootingtimes.com/ammo/ammunition_st_twistrates_200809/

Lot's of great information, thanks.

It sounds like I'll be ok with a 1:10 or a 1:8 twist.

companies are catering to very long range shooters to get them to buy their rifles.

to the normal hunter you will likely never know the difference

but 1:8 barrel will sell more to the people who need to ring steel or hit targets at 1000 yards and want to use the very high Ballistic coefficient ELD bullets that are longer and heavy.

the new game of Precision Rifle is driving a lot of sales , and it is not uncommon for a competitor to have 1500-2500 in rifle with 1500-2500 more in optics mounted on it firing hand-loaded rounds 40-50 rounds in a day at ranges out to 1750 yards

even if a shooter might never shoot past 400 yards they want the toys like the competitors run

This is exactly what I was thinking of. Guess I should have mentioned that. Sorry.

we see cup and core bullets leaving 1:9 twist barrels in .243 at 3800fps all the time without coming apart in air.

a 110 gr bullet from a 1:8 at 3600fps isn't all that likly to be an issue.

but at 2900 to 3200 fps these 168 to 205 grain bullets should get the same kind of stability that we see from the heavy for bore bullets that are taking the long range matches

300win is not a well suited cartridge for long bullets. They must be seated deeply and its short neck means the base of the bullet is occupying space in the case body where powder is needed.

Chose another case for bullets over 180 grains.

Definitely has a short neck, but plenty long enough for a good grip on the bullet. Seating depth has more influence over intrusion into the powder space than neck length. Seating depth is usually governed by throat and magazine clearances.

FWIW, I run 210 Bergers and 208 A-Maxes at 3,005 fps with an SD of 5 using Hornady brass, Federal 215Ms and H-1000 from a 26" Krieger barrel and they feed through a standard Rem 700 magazine box. Good brass life, no excessive pressures, 1/2 moa... I am having a hard time seeing where this is not working.