8.5 twist, enough for 140gr bullets

[BlackHawk95]

I have a new 4 groove Krieger barrel in 6.5mm thats a 8.5 twist I was originally going to chamber in 6.5x47L to shoot 123gr Scenars. But now Im thinking of 6.5-284.

Do you think I would be able to stabilize the 139gr Scenars and 142gr SMK's?

Im trying to make sure befor ordering a 6.5-284 reamer.

Thanks,

Jerid

 

[jr600yd]

If your barrel is long enough 1/8.5 will o fine with the bullets you mentioned. I shoot a 30" Krieger 1/8.5 chambered in 6.5/06 and it shoots outstanding at 1K.

Good shooting, Jim

 

[BlackHawk95]

The barrel will be finished at 28"

What bullet are you shooting?

Jerid

 

[camac]

A true 8.5 (Kreiger) will do it easily
at 2950 fps Miller stability of 1.55 with either.
at 2650 1.497 so no worries.
A lot of guys shoot them well in 9 twist.
Cam

 

[BlackHawk95]

Thanks guys. I think Im going to pull the trigger on the 6.5-284.


Jerid

 

[jr600yd]

Jerid,

I shoot both the Berger 140VLD and the 142 SMK

Good shooting, Jim

 

[Rust]

Being a 6.5 X 284 shooter, I would caution you that it is expensive to shoot one. Barrels do not maintain match accuracy all that long, 1,200 rounds is considered very good. So unless you plan on shooting 1,000 yards on a regular basis the 6.5 X 47 with 130 gr Bergers would be a better option.

And a 1-8.5 will stabilize the heavy bullets. I've been using a 1-9 for years (in 6.5 X 284) and during initial load development the 139 Scenars printed fine at lower velocities around 2750 fps. Not that the 1-9 twist is for everyone as it's cutting things a little close. The other thing is sometimes a barrel that is supposed to be 1-9 might be a little off, or a lot off. A little faster twist is OK, a little less twist is not. So 1-8.5 twist is the more conservative choice, and thus more likely to avoid unstability.

 

[camac]

I also shoot a 6.5 * 284 and after chewing through some barrels am actually entertaining going back to a 6.5 * 47 for F class. Nothing against the 6.5 x 284 it is a fantastic round but I rarely shoot 1000yds and the 6.5*47 isn't that far behind anyway. Some of the guys are running the 140 gr class bullet at 2900+ fps in the 6.5*47 case. I run mine at 2920 in the 6.5*284 but burn a whole lot more powder and barrel life in doing it. REL 17 and 130-142 gr in 6.5*47 sounds amazingly efficient (Look at Erik Cortina on other 6mm post above)

 

[BlackHawk95]

Thanks for all the input, I have had a 6.5-284 and the 6.5x47Lap. both shot extremely well. And your right about the barrel life on the 6.5-284.

I have been thinking about having the barrel Melonited. Ive been reading about it lately, and it looks pretty promising in keeping throat erosion to a minimum and not affecting accuracy. If it werent for that I would ge 6.5x47Lap, as I allready have the reamer for that round.

Anyone tried the melonite with the 6.5-284?

Jerid

 

[Rust]

Been looking, haven't decided yet.

What I've been finding is that the barrels will maintain accuracy much longer, and that when they finally go, they go all at once. Other consideration is that it will not improve the basic characteristic of a barrel. The barrel has to be completely finished prior to the process as the surface hardness matches or exceeds that of most tooling. I'm also hearing that it does not treat/convert/coat very sharp corners quite as well as curves and flat surfaces, thus polygonal or gentler canted lands my be better candidates compared to very sharply profiled rifling.

I think I'll try a barrel or two when I have the time, maybe next year.

 

[skeetlee]

Yes an 8.5 twist will shoot the 140 just fine. And even if you go with the 6.5x47L shoot the 140's........................... There is no substitue for the 140's in a 6.5mm chambering. Higher BC will always win, in the 6.5mm Lee

 

[BlackHawk95]

Thanks again for all the suggestions.

The more I think about it, I dont want to do a 6.5x47Lap as this rifle is more of a tactical/plinking rifle.

Id rather build the 6.5x47 in a dedicated f-class type rifle.

Jerid

 

[camac]

Jerid, even more reason for choosing the 6.5*47Lap. Look at the the velocities guys are getting from the 140's (2900-2950) yet it is the perfect round to load high BC bullets in a 308 length magazine and action. Sure the 284 fits but you can't seat em long in the mag. Not to mention for plinking you will get more than twice the barrel life and burn 10 gr less powder every shot!!!