What model year did the.250-3000 switch its rate of twist from 1/14 to the newer rate? Which factory loaded bullet weight runs best through both different rot's? I have read here (I believe) that the old rate of twist does well with 87's but that is a bad fit for newer rate of twist.
When Savage introduced the tang safety 99 actions and changed the barrel threads for a square-thread style to a V-thread style in 1960/61. IOW, you're unlikely to find a V-thread Savage 99 barrel in 250-3000 that isn't cut 1 in 10" ROT and you're equally unlikely to find a square-thread Savage 99 barrel in 250-3000 cut with anything but a 1 in 14" ROT.
Savage used leftover square-thread 1 in 14" ROT barrels on the E, EG, and R receivers until those receivers were gone, but the 250-3000 was cataloged as a 1 in 10" ROT starting in 1961. That said, although Savage cataloged the tang safety 99DL and 99F in 250-3000 with a 1 in 10" ROT, they are quite uncommon. By far, the most common 1 in 10" ROT Savage 99 in 250-3000 are the 1970s vintage 99As with 20" and 22" barrels. The less common 99CD with 22" barrels comes in a distant 2nd, at least that has been my experience. AFAIK, all Remington 700s and Ruger 77s have 1 in 10" ROT barrels and all Winchester 70s have 1 in 14" ROT barrels.
The key to a bullet working in the slower twist barrel is the length, not the weight. For years, Remington offered a 100 grain round nose core-lokt (RNCL) bullet in the 250-3000 that was generally considered more accurate in the 1 in 14" ROT barrels then the 100 grain Pointed Soft Point (PSP) bullet. Likewise, Winchester/Olin loaded a rather rounded Silver Tip bullet in both the 250-3000 and 257 Roberts that was shorter than most component 100 grain .257" bore bullets.
In general, the 1 in 14" ROT 250-3000s do their best work with bullets under 100 grains, while the 1 in 10" ROT barrels will handle bullets up to 120 grains. I put together a 1 in 14" ROT varmint rifle in 25 WSSM a couple of years ago, as I intended to shoot the 75 grain VMax. If I was going to pick a single bullet weight to shoot varmints and medium game in a .257" bore rifle, regardless of the barrel's ROT, it would be the 87 grain Speer HotCore for medium game and the 87 grain TNT for varmints, as those bullets shoot to the same approximate POA in my .257" bore rifles.
Bottom line, for me, is that I've had good success using the 87 grain Speer HotCore for deer and the 75 grain VMax for varmints in a variety of rifles with 1 in 14" ROT barrels. Since these bullets do whatever I need done with a 1 in 14" ROT 250-3000 rifle, they are the bullets that I frequently use in my own rifles and recommend to others.
Jeff
Excellent post, Jeff... very clear and informative.
Ron T.
Welcome back, Jeff. Missed ya there for a couple of months.
+1 to everything Jeff said, but you might also try the factory loadings for 100gr bullets if you don't reload. None of them are very long bullets, and they've shot acceptably well out of some of my 99's. Not as accurate as shorter 87gr bullets, but plenty accurate for normal hunting.
That being said, they also shoot like crap out of some of my other 99's. It varies.
John, I have a 1960 99 F with a 1-10 ROT. It has a Chicopee Falls barrel address so it was before they moved to the Westfield plant. I don't know if all post mill 250s are 1-10 ROT but mine is very early post mill, sn#10060xx.
I hope this helps narrow it down a bit.
Lee
ALL post-mil SNs SHOULD have 1 in 10" ROT barrels, just as ALL pre-mil SNs SHOULD have 1 in 14" ROT barrels. Your post-mil 99F would be a tang safety style with a v-thread barrel, an uncommon rifle to be sure.
Jeff
This answers the ROT of 1/14 for my 99F. If the theory holds, then my 1955 dated 99F is a ROT 1/14...simple see!