I had a call yesterday from one of our customers out west and during the conversation the talk turned to guns and the 1000 yd match this spring. He said something that didn't quite sound right or maybe I misunderstood what he meant. He said that the regulars at the 1000 yarder had found that the 338's would tumble after about 600 yards (not just one gun, either, he assured me). Now I don't pretend to know a lot, but if a bullet is stable to 600 yds, and the spin imparted by the rifling for all intents and purposes, does not slow down, it seems to me that it should stay stable indefinitely or at least until it goes sub-sonic (Ah Hah, is that it? Do they slow down that much after 600 yds? Sounds hard to believe.) Could any of you set me straight on this?

Don't know. But, in the early days of testing M16's, we had a lot of problems with them and the 55-grain boat-tail at low temps in Alaska. The cold air was so dense, the bullets missed the 6'x6' target frames at 500 yards when the temp was -40 or colder!! Did they tumble? Probably. (1/14" twist in those days).

Well with a launch velocity of 2995fps the 250 grain Sierra SBT with .565 B.C is still going 2049fps at 600 and 1128fps at 1500 yards according to Load From A Disk.

So how do they "know" the bullets are tumbling? Did they shoot some into the targets and see sideways hits? You are correct about the bullets not slowing in spin.

The M-16 had some teething problems and at -40 the powder charges might not have been sufficient to acheive a good velocity. Also the early rifles had a slow spin so the bullets would tumble as soon as they hit something. The combination could have done the trick.

Perhaps they were shooting the 300gr Sierra MK bullets or similiar length bullets with standard twist barrels(1 in 10") Alot of the so-called VLD bullets in the heavier weights require faster twists to stabilize these longer bullets.

The 338 Lapua comes with a 1 in 12 twist and has no bullet stabilization problems in bullets up to 250grs at the longer ranges(500yds+) Maybe some of the 338 experts will comment. sure-shot

[This message has been edited by sure-shot (edited 04-13-2002).]

We are using the 300 Match King out to 1200 yards or so with no problems, 9 inch twist, some rifles have 8. And 250 Match King, 10 inch twist, also, with no problems.

I put 10 inch twist on the hunting rifles, 12 is too slow for long X bullets. And 210 to 250 grain bullets work fine with 10.

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