Who has a barrel faster than 8?

[Alleycat]

300 WTF or 308. 1 in 7.. 1 in 6.5..

[rsilvers]

I have a 1:4 coming.

[LouBoyd]

Pac-Nor offers barrel blanks and finished barrels for most bolt rifles in faster twists, including chambers in 300 Whisper and 300 Blackout. I don't believe Pac-Nor directly makes "drop in" barrels for ARs. (wish they did).

http://www.pac-nor.com/barrels/

300 bore (for 308 bullets) in 4", 6", 6.5" 7", 7.5" plus 8" and many longer.

[Alleycat]

I'm trying to find out how many people have faster than 8 guns. How common are they? If this sounds cryptic, there's a reason. :grin:

[LouBoyd]

I'm trying to find out how many people have faster than 8 guns. How common are they? If this sounds cryptic, there's a reason. :grin:

I have three rifles with faster than 8" twist barrel though none faster than 8" twist in 30 caliber.

A 7mm BR with a 7" twist, 16+" Pac-Nor barrel. It's designed to shoot Berger 180 VLD's either low supersonic or subsonic. It's on a Rem 700 SA. It's mostly for experimenting with subsonic and transonic ballistics.

A 5.56x45 Colt AR-15 with a 20" x 7" twist barrel. It's was designed use in arctic conditions. I use it for shooting VLD bullets.

A 1937 Carl Gustav 6.5x55 Swedish battle rifle It's approximately 1:7.5" twist.

Since I shoot at over a mile elevation and in the relatively warm weather of Arizona I don't need fast twists to achieve bullet stability for most practical shooting.

What's your reason?

[LouBoyd]

I have a 1:4 coming.

What bullets and what conditions can use a 4" twist 308 cal barrel?

That might be a fast enough twist to stabilize LRB J40 220 grain solids fired at about 1300 fps as they drop though the speed of sound from a 300 BLK. It would be an interesting test.

I wonder if there are any bullet designs which would be stable if fired into water with that twist rate. My guess is not.

[Alleycat]

Just looking for .30 cal guns. Come on Spook you got to have one.

[dick]

Mr. Silvers, what are you saying? Are you implying that 1 in 4 is the new 1 in 8
I guess that's one way to sell more barrels. LOL HA HA

[jimpa]

I have a 6.5, knew the minimum would be 8",,, talked to a tech at pacnor and he built a 300/221 with a 6.5 and was pleased.
He was right and I am happy with it.
Have only shot 220 and 240 Smk so far. Going to try some 125 noslers

[Spook]

Just looking for .30 cal guns. Come on Spook you got to have one.

Were over 7500 ft in elevation where I shoot.... 10's easily stabilize 240's here. You have a real long bullet you're trying?

[dksd39]

I have a 1:4 coming.

trying a new solid? otherwise you might be able to make dust out of most jacketed bullets

[rsilvers]

I want to shoot light jacketed bullets and see what rpm they come apart at, if any.

[Scoop]

I'm shooting a 7-twist Douglas on my Remmy bolt gun. Also had a Douglas 7-twist on a Howa bolt gun. Works well.

[rsilvers]

I am saying 1:10 is the new 1:12 and 1:8 is the new 1:10.

I got the 1:4 twist today.

[Alleycat]

The point of my question was to find out how common faster than 8 twist guns were. Outlaw sent me some 250s to try in my 16 and 10.5 guns to see if they would stabilize. 60% did @ 100 yards in the 16" gun. All of them were tail dragging in the 10.5" gun. Oddly enough I was getting 1.25" groups with them. They're going to need 1 in 7 or 1 in 6.5 to fully stabilize. At this point I don't believe they're going to produce them, but there may be a possibility of small batches for guys with faster twist barrels.

[snipecatcher]

The point of my question was to find out how common faster than 8 twist guns were. Outlaw sent me some 250s to try in my 16 and 10.5 guns to see if they would stabilize. 60% did @ 100 yards in the 16" gun. All of them were tail dragging in the 10.5" gun. Oddly enough I was getting 1.25" groups with them. They're going to need 1 in 7 or 1 in 6.5 to fully stabilize. At this point I don't believe they're going to produce them, but there may be a possibility of small batches for guys with faster twist barrels.

Interesting that you seemed to find a correlation between barrel length and stability too. People say it's twist rate vs. velocity, but there is more to it. Unless of course your 10.5 has a slightly slower twist, say 8.25. My best subsonic group so far with my 10" barrel has been 5 220 Prohunters into an inch. Funny thing is, they were 'taildragging' too.

[Alleycat]

My 10.5 shoots 240s into a clean hole. The 250 Outlaws are shorter than the 240 SMKs, but do not fully stabilize @ 100yds. At 30 yards I get perfect round holes. I've seen this before in a 308 and a heavy bullet. They were stable and round @ 100 yards and shooting good groups, but at 150 groups opened up and the bullets were unstable. I've come to the conclusion that the OAL of a bullet, altitude and RPM in subs are not the only factor that determines is stability. It seems that a bullets weight distribution is also a major factor. I have no explaination for the barrel length issue. I have seen this in more than one gun. Both are running as close to 1050 as possible in a 1 in 8 so theoretically both bullet should react the same. As always when dealing with subs "Think backwards"