Thoughts on twist rate for 32 " barrel 300wm

The length does not govern what twist to use, it's the length of the intended bullet(S) that govern the twist rate.
I run 30" barrels in 300WM with 10" twists, haven't found a bullet that won't stabilise in it yet. A 1:9" twist is very fast for a 30 cal, but many will come on board toting the 9" to be the optimum for real heavy bullets. IMHO, the 300WM just can't push 230-245gr bullets fast enough to justify their use or the faster twists. Just my opinion after 31 years of shooting 300WM's in various forms and disciplines.

Cheers.
 
Welcome to LRH! That longer barrel would help with generating more speed but like MagMan was saying the twist rate determines the weight and length (bearing surface) of bullet to be stabilized.
The 1 in 10" twist with certainly stabilize all the normal projectiles for the .308 caliber but the trend these days for long range and extreme long range is longer barrels and faster than normal twist.
I tend to gravitate toward the 200-215gn range of bullets and am looking at a 28" PacNor 1-9 or 1-10", but may do something different. There is a reamer than I'm am wanting to try for my next barrel; "300 Win Mag Fin 55651 Rhian Mantha". It supposedly is great for the 215gn Bergers. There's an article on LongRangeOnly irt this. Good luck with your build, keep us up to date. JohnnyK.
 
ogre miller said:
I have been looking every where for twist rates in a longer barrel was thinking 1:9 in a 32" 300 win mag
Click to expand...

Welcome to LRH and enjoy! I too am a longtime .300 WM fan and agree with MagnumManiac and johnnyk. When it is time for a re-barrel in any of my three .300 WM, it is going to be 1:9". I think you'll be fine with either the 1:9" or 1:10". Good luck!

Ed
 
I comfortably get 3200 FPS with 230's and 3350 with 215's in a 30" barrel, 4 groove 1:10" twist. I am not running either hot according to my pressure trace.
Funny thing, my 3 groove 28" barrel gets almost identical velocities. I have ordered 3 Bartlein barrels, another 2-3 month wait and I will post results. Have gone with 3 groove 1:10" twist in 30 cal and 1:8" twist in 264 cal.

The 215 above surpasses the 230 by 1200yrds according to my app, Ballistic AE.
The RUM would be better suited for the extra heavies.

Cheers.
 
MagnumManiac said:
I comfortably get 3200 FPS with 230's and 3350 with 215's in a 30" barrel, 4 groove 1:10" twist. I am not running either hot according to my pressure trace.
Funny thing, my 3 groove 28" barrel gets almost identical velocities. I have ordered 3 Bartlein barrels, another 2-3 month wait and I will post results. Have gone with 3 groove 1:10" twist in 30 cal and 1:8" twist in 264 cal.

The 215 above surpasses the 230 by 1200yrds according to my app, Ballistic AE.
The RUM would be better suited for the extra heavies.

Cheers.
Click to expand...

If you're getting 150-200fps over the capabilities of a 300RUM with a 300WM, I wouldn't complain about its capabilities...Wow...
 
MagnumManiac said:
The length does not govern what twist to use, it's the length of the intended bullet(S) that govern the twist rate.
I run 30" barrels in 300WM with 10" twists, haven't found a bullet that won't stabilise in it yet. A 1:9" twist is very fast for a 30 cal, but many will come on board toting the 9" to be the optimum for real heavy bullets. IMHO, the 300WM just can't push 230-245gr bullets fast enough to justify their use or the faster twists. Just my opinion after 31 years of shooting 300WM's in various forms and disciplines.

Cheers.
Click to expand...
thank you I am kind of new at this long range stuff but was raised by an avid hunter gunman and have been a deep woods hunter my whole life.
 
MagnumManiac said:
I comfortably get 3200 FPS with 230's and 3350 with 215's in a 30" barrel, 4 groove 1:10" twist. I am not running either hot according to my pressure trace.
Funny thing, my 3 groove 28" barrel gets almost identical velocities. I have ordered 3 Bartlein barrels, another 2-3 month wait and I will post results. Have gone with 3 groove 1:10" twist in 30 cal and 1:8" twist in 264 cal.

The 215 above surpasses the 230 by 1200yrds according to my app, Ballistic AE.
The RUM would be better suited for the extra heavies.

Cheers.
Click to expand...

WOW, those are impressive velocities. I too have very good results with 3-grooves (.270 in 1:8" AI and .30 LARA in 1:9") by Lilja barrels. Will have to try the Bartlein one of this days. Currently building a .264 Win and trying a 1:7" 5R.
 
johnnyk said:
Welcome to LRH! That longer barrel would help with generating more speed but like MagMan was saying the twist rate determines the weight and length (bearing surface) of bullet to be stabilized.
The 1 in 10" twist with certainly stabilize all the normal projectiles for the .308 caliber but the trend these days for long range and extreme long range is longer barrels and faster than normal twist.
I tend to gravitate toward the 200-215gn range of bullets and am looking at a 28" PacNor 1-9 or 1-10", but may do something different. There is a reamer than I'm am wanting to try for my next barrel; "300 Win Mag Fin 55651 Rhian Mantha". It supposedly is great for the 215gn Bergers. There's an article on LongRangeOnly irt this. Good luck with your build, keep us up to date. JohnnyK.
Click to expand...
What are your thoughts on paragonal barrels. They are well regarded in European and Israeli sniper rifles. Pac Nor offers them. I have been thinking about building a 338 Edge +P using one from Pac Nor.
 
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