What weight bullet for 1-9" twist 6.5MM

[Twmaster]

Hi gang,

I've got an old Japanese Type 38 Arisaka rifle chambered in 6.5-257 Roberts. This barrel has a 1-9" twist rate.

I see a wide range of bullets ranging from 85 grain Varmint pills all the way up to 160 grain pills.

Considering the twist rate what range of bullets might work best for this rifle?

I'd like to do some 'Yote and Prairie Dog hunting so I'm leaning toward a lighter varmint round.

Since I'll be reloading for this rifle I'd like to hear some suggestions.

Thank you.

 

[longdayjake]

depending on the length of the barrel you should be good up to 140 grains. If you have a shorter barrel it may not do the 140 grainers very well. Anything under that will be fine.

 

[GooseGestapo]

My .260Rem (Rem Mod7 w/20"bbl) has a 1/9" twist.

The only bullet it hasn't shot well is the Hornady 140gr SST. This bullet is very long for weight and shot ~4" groups at 100yds with some showing yawing.

All the flat-based and round nosed bullets up to 160gr shoot well. In fact, some 160gr Sierra RN have shot under 1moa for 5-shots with several different powders. They do however impact several inches lower at 100yds.

The least expensive "hunting" bullets are the Speer 120 and 140gr "Hotcor" soft points. These are excellent deer bullets and are also very accurate. My gun wants them seated to touch the grooves, but isn't an issue as they will still fit and feed from the magazine. (ie: Speer 140gr Soft point at 2.810" touches, and with 41.5gr of IMR4350 gives 2,650fps and occasional 1-hole groups..... Good enough....!!!).

Most any of the "hunting" type bullets will shoot ok from the 1/9" twist. Only the very long bullets such as the 140gr and 142gr VLD's or A-max or SST type bullets will give you trouble. These are in fact somewhat longer than the blunt 160gr bullets. It's the length of the bullet that determines the requisit twist, not just weight alone.

 

[Twmaster]

Thanks Jake, dangit. I knew I forgot to mention barrel length.

It's barrel is like 30". Not a carbine.

That's good news. Thanks again.