Re: Good Powder Choice for 308 Winchester in Semi-Auto
Posted: Thu Feb 11, 2010 11:56 am
Hmmm, something don't sound right. Check and see if a portion of the gas port is blocked off because the gas cylinder may be too far to the rear. Its easy;
1. Unload the weapon.
2. Lock the action to the rear. Insert a device of some sort to keep the bolt open.
3. Turn the weapon upside down and elevate the muzzle & listen for the piston to go all the way to the rear. On the bottom side of the gas cylinder there should be a small hole.
4. Shine a light and the "complete" gas port should be visible. If not, remove the gas plug and loosen the gas cylinder lock nut 1 turn at a time, reinstall the gas plug, tighten and check. You'll observe that as yo tightent the nut it will pull the gas cylinder toward the muzzle.
I don't remember the gas port size otherwise you could check it with the smooth end of the proper size drill bit. If its undersized it may be part of the problem.
One other thing to check is make sure the gas shut of valve is opened fully.
Ricks right, these things were designed around the 150 to 173 grain bullets with medium burning powder.
HTH
1. Unload the weapon.
2. Lock the action to the rear. Insert a device of some sort to keep the bolt open.
3. Turn the weapon upside down and elevate the muzzle & listen for the piston to go all the way to the rear. On the bottom side of the gas cylinder there should be a small hole.
4. Shine a light and the "complete" gas port should be visible. If not, remove the gas plug and loosen the gas cylinder lock nut 1 turn at a time, reinstall the gas plug, tighten and check. You'll observe that as yo tightent the nut it will pull the gas cylinder toward the muzzle.
I don't remember the gas port size otherwise you could check it with the smooth end of the proper size drill bit. If its undersized it may be part of the problem.
One other thing to check is make sure the gas shut of valve is opened fully.
Ricks right, these things were designed around the 150 to 173 grain bullets with medium burning powder.
HTH