Need help with 308

[poke_53]

OK here is what I have. Terry Cross (KMW) built 308 with about 3000 rounds through it. I pruchased it with about 2500 rounds fired. I have always loaded my loads to 2.820 and not measured to the ogive. So I got a gauge to measure to the ogive and i started out by seating a bullet softly in a piece of brass to see where the bullet makes contact with the lans. So I got an overall measurement of 2.952 and an Ogive measurement of 2.288. This seems a little long but I am not sure. I am loading 155gr Sierra Palma. Does this seem right or do I need to have the barrel set back for better accuracy or should I shoot at maximum mag length. With 175gr pulled SMK I am getting .6" 10 shot groups at 100yds. But I am switching to 155gr now. Any opinions or advice would be greatly appreciated.

Thanks

 

[7stw]

OK here is what I have. Terry Cross (KMW) built 308 with about 3000 rounds through it. I pruchased it with about 2500 rounds fired. I have always loaded my loads to 2.820 and not measured to the ogive. So I got a gauge to measure to the ogive and i started out by seating a bullet softly in a piece of brass to see where the bullet makes contact with the lans. So I got an overall measurement of 2.952 and an Ogive measurement of 2.288. This seems a little long but I am not sure. I am loading 155gr Sierra Palma. Does this seem right or do I need to have the barrel set back for better accuracy or should I shoot at maximum mag length. With 175gr pulled SMK I am getting .6" 10 shot groups at 100yds. But I am switching to 155gr now. Any opinions or advice would be greatly appreciated.

Thanks

From what I can tell, if you are looking to kiss the riflings, you probably will have to st it back. The 155's are much shorter. If the rifle has 3000 rounds thru it, the throat is more than likely receded, not to a point that it will not shoot, but most .308's shoot better when close to or kissing the throat. Particularly if you are going to a lighter bullet. My coal with 168 smk is 2.820, and it is close to, but not touching the throat. Hope this helps!
AIM SMALL, MISS SMALL. 7 STW

 

[Greyfox]

I don't think I would get too hung up on the long bullet jump yet, particularly after hearing the level of accuracy you're getting with the 175 SMK's. I have a couple of Remington Mil Specs that have very long leads, in excess of .180" and they are .25-.5MOA shooters when loaded to the standard COAL of 2.8". The Palmas are shorter, but I would test them for accuracy in your rifle before making any major changes. My experience is that this bullet design is not as finicky about seating depth as other designs such as the VLD styles. iMHO

 

[runshort]

We have a Rem 700 (factory) in .308 Win. that we shoot the 168 Hor. Amax SMK in 168 and 175's. It's throated long like your set up. These listed bullets all shoot well loaded to the magazine. They seem to be very tolerant to the jump.
It wouldn't hurt to load some of the 155 Palma to mag lenght and shoot them to see what they will do. Just something to try before you start changing things.

 

[7stw]

We have a Rem 700 (factory) in .308 Win. that we shoot the 168 Hor. Amax SMK in 168 and 175's. It's throated long like your set up. These listed bullets all shoot well loaded to the magazine. They seem to be very tolerant to the jump.
It wouldn't hurt to load some of the 155 Palma to mag lenght and shoot them to see what they will do. Just something to try before you start changing things.

I have to agree on this approach. In my original thread above, I was commenting on if he wanted to put the bullet into the throat, using the 155's. That being said, they WILL shoot WITHOUT being into the riflings, and even if it has to jump, they will still shoot. I would at least try them first.
AIM SMALL, MISS SMALLlightbulb 7 STW.

 

[poke_53]

Thanks for the input all. I have loaded up some at about 2.85 which is gonna be MSG length for me. I am gonna do an OCW test at this length and go from there.

 

[backwoods83]

At 2.952" the 155 palmas have barely more than the boattail left in the case, there isn't enough bearing surface in the neck and it would not be safe.