Sub-Caliber on 700 SA Question?

[Freestate101]

Would like to have a sub-caliber barrel for my 700SA switch barrel rifle. Here are some considerations:
1) Rimless Case with 308 or 39MM head dimensions.
2) Low case capacity, i.e. 20 grs. powder charge or less.
3) Longer barrel life than 22BR/PPC.
4) Available brass and ease of creating cases.
5) Low 3's @ 100 yds. and enough RE for GH's to 250 Yds.
6) Prefer to stay somewhere from .18 to .22 cal.,Big Meathooks)

How about it guys, any ideas come to mind? I'm really not asking for too much am I? "Grin"

Thanks Guys!
Jim B.

 

[tightneck]

Using a 308 boltface, I can't think of anything without a lot of case forming. Further, if you wish to shoot consitently in the low 3's, you will need to shoot over wind flags,if you dont already). If you wish to run bullets slow enough to really help barrel life, wind will be a much larger factor.

 

[Freestate101]

Thanks Tightneck, however most of my shooting will be for 4 legged varmits so not much chance of using wind flags. After more research, the 22PPC does seem to fill the bill the best. I had been worried about short barrel life, but find repeated claims of over 8K rounds and continued .2 groups! I haven't considered the 22BR due to the difficulties of forming the brass and the increased powder capacity and noise levels.
Jim B.

 

[SF340Driver]

I don't think the PPC will work with the 308 boltface.

I'm surprised you think the 22BR is a lot of work to form. All I do is run 6BR brass thru my FL 22BR die -- load and shoot.

You don't have to push it up to the velocities a lot of us are running in order to extend the barrel life. 75g A-max is fantastic on varmints BTW. You can run them in the 3000 fps range and get pretty good barrel life.

 

[Freestate101]

SF340Driver, thanks for the post. I have 2 bolts for my 700SA, one for the 260AI and 308 barrels and one that has been bushed for cartridges based on the 220 Russian line of cartridges. Just how many rounds have you been able to get through a match grade barrel running around 3200 fps? I was under the impression the 22BR brass had to be formed from .308 X 1-1/2" Barnes brass. Since both the 22PPC & 22BR offer ease of case formation, almost identical ballistics and accuracy, the question now boils down to barrel longevity and case capacity per fps using the identical bullet. What to do, what to do???? Since the barrel/chamber work hasn't been started yet, I will entertain all positive and negative factors that members have to offer,who knows, this may be a great excuse for two barrels, one in each caliber...Hummmmm, Grin). Keep the replies coming in guys!!!
Jim B.

 

[tightneck]

I have no issues running ppc brass on a 308 bolthead but I'm not worried about ejection either. Based on your post I came to a thought, why not just go with a straight 220 russian. Several BR competitors shoot it and can attest to its accuracy. Matter of fact, it has an almost identical case capacity to the 22ppc .100 short, which if it wasn't for the Sporter class,.23 caliber minimum) at the big matches, might dethrone the 6ppc as the most used cartidge in the game. It wont get you under 20 grs capacity, but it will certainly get you closer and wear the barrel less.