I thought I always heard 60?
Yep, I think I was just telling Keith a week or two ago that the change happened in 1960.
Now.. The answer is:
I'm not sure.
Before you all lynch me, though.. I can definitely say it is NOT 1960. I was reviewing some pictures of factory information that Fug kindly let me grab a snapshot of, and I ran across bore specifications for Savage 99's. The 250-3000 is listed as 1-10", and I didn't think much of it because there's a couple pages and the first one is 1980. Thought they were all postmil stuff.
I finally spotted up in one corner a line on one page... "DATA ON GUNS MADE AS OF 2-26-59"
. The 250-3000 is listed as 6 grooves of 0.090" with a right hand 1-10" twist
So it might be #2.. 1959. Maybe.. 1958?
But both Fug and I think the bigger question is, when did any of these barrels make it onto a 99 to be sold? They didn't seem to sell many 250-3000's in 1959. Might it be they were using in-stock 1-14" twist rate barrels throughout 1959, and the 1-10" twist barrels didn't get used until 1960?
If anybody has 1958-1959 rifles in 250-3000... feel free to check them. My latest is a 1957, and it was 1-14" twist, give or take 1/4".
But the barrel change to 250-3000 was at least at the beginning of 1959. Something new we didn't know before.