My .308 Winchester / PDC Chassis Build Just Arrived

[rkittine]

My PDC Chassis finally showed up all complete. Krieger 26" Heavy Contour 26" Barrel, 1:10 Twist and optimized for the 155-175 grain projectiles. Re-worked Timney 520CE Trigger set at 8 ounces. Burris Signature Zee rings with 0 MOA inserts currently installed, a Night Force 8x32 Benchrest graces the top of the Picatinny Rail and a custom mussel break and Harris bipod and una-pod finish off the build. I have a box of 50 Lapua factory 165 grain match rounds, which I plan to feed it next week. Three fired cases and a copy of the Pacific Tool and Die reamer print, will then be off to Whidden for a sets of Custom Full Length / Neck Bushing and Micrometer Seating Dies

 

[CMaier]

1/10 for 155-175 is not what i would call optimum...more like old school.

 

[rkittine]

I am very new to this (and 67 so pretty Old School myself) and you might be right, or maybe the input I got was based on my lack of experience to make things easier for me. I was more referring to the amount of FreeBore than the twist, but I had been told to use everything from a 1:8 to a 1:12 and I settled in the middle. Since this is really neither a bench rest rifle or an F-Class, I am only going to shoot it to 300 yards most of the time.

What twist would you have recommended for these bullet weights? I am probably staying toward the lower weight projectiles, 155 - 165 grains, then maybe 175 as I get more throat wear.

Bob

 

[CMaier]

If i was limited to 300 yards, i would have built based on that.
and skipped the 175's. excellent bullets, but for 300 you could probably shoot
125 to 150.
300 yard score benchrest is shot with light bullets....112...118 maybe a 125 , 135 not sure anyone shot a 150.

That would put you at 1/12 or less ( 30 br, a 1.5" 308 case, use 1/17,1/18 with 112=118 bullets).

I think i would look at 135 match bullets and see how it does, then go up to 150's.


If the chamber is cut for 168's and 175's...oh well go shoot them.

 

[WSnyder]

For the type of rifle you have built a 10 twist will suit you just fine. Yes a 12 might have been more optimal for your choice of bullet weights but a 10 won't limit you or anybody else (if you sell it) from trying a heavier bullet. If you ever choose to get rid of it a 10 twist in 30 cal always seems easier to sell to the masses than anything else.