Help w/300 Winmag Build

[Depart123]

I need some advice. I have about 2,500 210 SMK's and I have been trying to shoot them out to a mile from a 300 Win.

Here is the tale of woe: First barrel was ordered as a 10 twist, it shot great to about 800-1000 yards...beyond that, went to hell. Turns out, it is an 11 twist instead of the 10 twist ordered.

Next barrel, different company...9.5 twist...won't shoot better than 2moa with any bullet or powder I try. I've used up about 300-400 bullets trying. Yes, every variable was checked and other accomplished shooters loaded for it and shot it as well. Bore is measured at .300" w/ groove of .3065", 28" MTU taper.

Ok, now l'm not here to bash barrel makers.

What I would like... is advice for a proven combo of barrel spec and reamer spec to shoot this pile of 210 SMK's to a mile.

Thank you for your replies.

 

[LA50SHOOTER]

Where either of those you tried barrels a 5R / 5C type rifling ?
I've shot them in a 32" 1.450 straight Krieger 5R in 10 twist in a 300 WSM Maxi-Tracker H.G. with a .270 throat with H-4350 and they grouped decent at 300 yds., just not as good as Bergers so I've not pursued them any further. - Also are we talking about the same 210 gr. (SKU:9240) or the older version that has been discontinued ?

 

[Depart123]

The first barrel was 3 groove 11 twist, 2nd barrel 5R rifled 9.5 twist.

Don't have the part# with me right now on the 210's but are in 500ct white boxes.

 

[LA50SHOOTER]

Approx 18-24 Months ago Sierra came out with a 210 (SKU:9240) & a 230 gr. (SKU: 2251) high B/C 30 cal bullet(s) that are pointed at the factory and were touted to be the new long-range competition advantage bullet(s) under their trade name.
- The older 210 gr "MatchKings" were a Tangent ogive bullet and have been discontinued for about 18 month now. - IMO the older version was a much user friendly to get to shoot well bullet than the newer version is. - The new 210 & 230's that Sierra has brought out have a very long nose on them and less bearing surface.

 

[Depart123]

These are indeed SKU: 9240.

 

[Depart123]

Bump

 

[XTR]

I didn’t try the 210 in that flavor, but I have tried the 200 in my FTR rifles. Pretty sure It isn’t your barrels. I dont know why, but nobody could get the 200s to shoot, and it wasn’t for lack of trying. There is some thing about those bullets, whether it’s the bearing surface is to short, or they over pointed them and damaged the bullet, I don’t know what it is ...but they will not shoot

Try Berger 215s and/or 230s

 

[poorboyr]

I shoot the 210 SMK out of a 1-9 28” Douglas barrel and they shoot lights out. I’ve taken it out to a mile with no issues. Standard chamber.