6mm PPC factory loads

[Webphut]

Doesn't anyone have any thoughts about bullet weights in a Sako 6mm PPC????

I just within the past couple of months started loading for my Sako 6PPC. It is not the Sako factory reamed barrel though, its a .262 neck diameter. Not knowing exactly where to start...go with the masses 68 grain Berger or just try the factory choice, 70 grain, so I went the factory weight. I am just getting my feet wet though. I munched up a lot of brass just trying to figure out how to turn necks. I through away about 25 cases trying learn how to turn necks. Now I have me a really sweet quiet neck turning system. Also now that I'm actually getting not so embarrassing groups, I ordered some new brass from Norma to give that a shot as I started with Lapua brass. I know what everyone thinks about the two, but I'm the kid that touched the side of the weber bbq grill after being told it was hot. I chose 70 grain Nosler ballistic tips because that's the weight that Sako chose. I went the Nosler route because those are all I have ever shot in my rifles, so why change right. But now I'm starting to explore a little bit here and there. First different brand bullets, being Sierra. Next Norma brass instead of Lapua. In the end though, Im probably going to just call Bruno Shooting supply up and order 45 cases that are pre turned. I have not tried any other weight bullets though. My tightest group is with RL10X and it is a .278" 5 shot group. I'm hearing alot of "ditch the RL" and "try N133 , Benchmark, and H322 if you want to extend my barrel life". So I made up 3 batches of each for the next trip out to the range. When I first got started someone posted in a thread I had started "welcome to wildcats". That takes on a whole new meaning every time I poke around my 6mm ppc. LOL But the darnedest thing is I cant stop reading about them, loading for it and shooting it. It gets better and better and more and more fun as my knowledge and experience grows.

 

[South Pender]

How long is the throat in that Shilen barrel? In other words I'm asking how long a 'jump' does the bullet have to make before it engages the rifling? Wouldn't the factory throat designed for a 70 gr bullet be much longer than the throat designed for a 62 grain bullet? Doesn't 'free bore' have a serious bearing on accuracy? Some of the benchrest people want their bullets jammed

I think I can add something here. First, the chamber neck in the Sako 6 PPC-USA is, as others have noted, of greater diameter than what we've seen with the usual benchrest 6 PPC guns. Although I haven't made a chamber cast, I'd estimate that it is something on the order of .270", possibly larger. As for the throat length in the factory Sako 6 PPCs, it is quite long. As an example, for me to seat the Bart's or Watson 68-gr. benchrest bullets to touch the rifling, the base of the bullet protrudes only about .12" into the case neck. This is not ideal, but this does seem to be enough bullet/neck contact for the rounds to be functional.

With this throat length, the 70-gr. Sako bullets may have allowed deeper seating to achieve contact with the lands. As has been mentioned, most rifles shoot most accurately with the bullets just touching, or even jammed into the lands by .01"-.03". Deeper seating, resulting in bullet jump, may result in good accuracy, but typically not as good as with the bullets in contact with the rifling on chambering.

Finally, a difference of 8 gr.--as between a 62-gr. and a 70-gr. bullet--doesn't necessarily mean that throat designed for the 70-grainer needs to be much longer than for the 62-grainer. The shape of the bullet's ogive determines this as much as anything. A bullet with a long, streamlined ogive that doesn't reaching the bearing-surface diameter until quite far back on the bullet will require quite shallow seating to allow the bullet to touch the lands.