What twist for 300WM rebarrel

[Tatanka17]

Hey guys, I’m wanting to re-barrel my semi custom 300WM. The rifle is built off a tikka action with a Mesa Precision stock and a red snake tactical bottom metal. (Running AICS mags). It has a tikka sporter barrel with a 1:11 twist, cut down to 24 inches finished length with custom muzzle break. Currently the gun likes 165 and 180 grain Barnes TTSX bullets but I’m looking at going to a heavier bullet like a 208 grain LRX. I’d like a shorter carbon barrel because I primarily hunt suppressed. Was thinking of a proof sendero light at 22 or 20 inches however I think I can only get that in a 1:9 or 1:10 twist. Not sure if those would stabilize a heavier 200 grain bullet. Any recommendations would be appreciated.

 

[G8ters]

Are you limited by mag length. Longer bullets need long mag length. I have a tikka 300 wm 1/10 and wanted to do a 1/9 for heavier monos. But looking at bullet length there was no way for the cartidge to fit in mag. I’m running 175 lrx and 205 Berger’s seated at 3.4”. Not optimal as they can seat longer. Tikka is 3.4 mag length.

 

[madcalfe]

barnes website says you need a barrel twist of 1:8.5 or faster for the 208gr lrx
on bergers website they have a twist rate stability calculator and just putting the numbers in and a velocity of 2850fps that bullet will be marginally stable.

 

[ReddingArcher]

Monos have to be pushed fast for good expansion. A 208 grain lrx in a 20-22” barrel may not give you the velocity needed to expand at longer distances.

 

[Rock-o]

SAAMI recommendation is a 10 twist. I have an 11 twist Sako and it stabilizes 212 grain bullets.

 

[JakeSCH]

My recommendation would be 1-8" or even 1-7" twist for any 30 cal that wants to shoot copper.

That said, if you are wanting to buy what is in stock, get what is available and limit your bullet choices. 1-10" is great for most lead bullets that you want to shoot out of a 300 WM.

The 175 LRX is the best copper choice for your current setup.

 

[madcalfe]

SAAMI recommendation is a 10 twist. I have an 11 twist Sako and it stabilizes 212 grain bullets.

300wm also was introduced in 1963 and saami started in 1979..... a 10 twist would stabilize anything at that time...

 

[PanhandlePilgrim]

I'd do a 1-9 twist, it's going to get you well in to your stability window with most heavy bullets on the market. You don't really have anything to lose by going with a one inch faster twist, and there's plenty of info out there supporting that there isn't any significant loss in velocities if that's what you're concerned about.

 

[madcalfe]

id personally go 20" 1:9 twist and shoot 200gr eldx, 190gr LRX, 190gr NABLR, 200gr accubonds
should still be around that 2850+ fps in a 20" and 200's

 

[rifletuner]

I decided to use a 1/8" twist when I rebarrelled my 300WM. That way I am future proofed if I want to run heavier bullets. Since you can "over stabilise" a bullet, there really isnt a down side as long as you are using a good quality bullet.

 

[Tatanka17]

Are you limited by mag length. Longer bullets need long mag length. I have a tikka 300 wm 1/10 and wanted to do a 1/9 for heavier monos. But looking at bullet length there was no way for the cartidge to fit in mag. I’m running 175 lrx and 205 Berger’s seated at 3.4”. Not optimal as they can seat longer. Tikka is 3.4 mag length.

I’m running an aftermarket red snake tactical bottom metal with AICS mag. So my OAL is 3.5” or greater. The action cycles and feeds fine with longer bullets.

 

[G8ters]

Great to know. I ended up building a 300 PRC off of a weatherby mark 5 action rifle with 1/9 twist. Saving the tikka action for something else mid length.

 

[Rock-o]

300wm also was introduced in 1963 and saami started in 1979..... a 10 twist would stabilize anything at that time...

What do the dates matter? OP asked about stabilizing a 200 grain bullet and I simply gave an example.

 

[madcalfe]

What do the dates matter? OP asked about stabilizing a 200 grain bullet and I simply gave an example.

because you said SAAMI recommends a 1:10 twist.
i was just stating SAAMI is old and they didn't have long range high BC bullets back then. a 200gr Nosler partition is quite different from a 208gr LRX
even a 220gr nosler partition is only 1.370" and a 208gr LRX is 1.819"

 

[shax2lex]

I just posted this same type of question but for a 300WSM.

My Proof barrel is being chambered by Straight Jacket Armory. They said the barrel options for 20” was 1:10 and 22” at 1:9. Proof doesn’t cut a 20”, 1:9 in their new rifling style. I wanted to shoot 200gr ELDX bullets and I went with 1:10, 20”. I’m also attaching an TBAC Ultra 9, Gen 2. I also found a post but the a guy from Bartlein that said 1:10 is fine for that bullet.

I hope that helps.

 

[Tatanka17]

Another idea I’ve kicked around is to Re-barrel to a 7PRC…