...what will determine the "stability factor"...that is...the gyroscopic stability of the projectile in flight "primarily" are bullet length and to some degree weight...the projectile's configuration and it's center of gravity...the twist rate and exit velosity...the twist rate and actual exit velosity will determine the projectiles rotational speed...there are other factors such as air temperature and air density which will affect this relationship...SkyPup said:The reason I wanted to get the barrel in the first place was for long range heavy 75 grain handloaded bullets, not a varmit rifle for 35-55 grain bullets.
Does anyone know off hand what weight of bullets a 1:12" twist maximum is good for?twist rate?
...the longer barrels "generally" produce greater muzzle velosities and therefore greater rotational speed for any given twist rate...up to a point...before "barrel drag" becomes a factor...a 1 / 7 or 1 / 6.5 twist rate coupled with a 24 to 26 inch barrel will work "relatively" well with the longer 80 to 100 grain .224 inch diameter lead projectiles...however...for your purposes i would go with a 1 / 8 twist rate...a twist rate faster than 1 / 8 out or a barrel longer than 18 / 20 inches may be too fast for the 75 / 77 grain projectiles...especially in hot...humid...thin air...SkyPup said:From what I understand, since the barrel is much longer, that a 1:7 maybe too much for the heavier hunting bullets and that a 1:8 would be preferred.
Thanks so much for that excellent link, that is exactly what I want.Gremlin said:
SkyPup said:I ordered a 20" barrel with 1:8" twist drilled and tapped with a scope base.
...hey SkyPupSkyPup said:The good man from UPS showed up right when I got home from work to deliver my custom Match Grade Machine Thompson Center Contender barrel in .223 Remington with a 20" crowned barrel and a 1:7" twist rate.