No English book published with this information.
I have a sako L461 serial no 97578. This was purchased in 1968 , so, I guess no 86302 would be somewhat older.
No known published sn data in the US
62 or so
Another Sako barrel
You will have to contact Sako. Falls outside published data.
Someone at the Sako collector club might know.
The twist rate is 14"
It's a high-quality, bolt action rifle, which apparently comes in .223 rem, .222, and a few other high-velocity, small-bore calibers. Sako is a Finnish firearms manufacturer. You can find more information buy searching for Sako L461 on Gunbroker, or reading the Sako article on Wikipedia. A blue book of gun values can help you find the appropriate price value if you're looking to sell or insure your L461.
1-8 or 1-12
1/14 IIRC. Have it verified by a gunsmith
Need a DETAILED DESCRIPTION OF ALL MARKINGS to answer.