View Full Version : Sako L579 Bolt

02-02-2008, 08:49 PM
G'day all

I'm doing some truing work on one of my Sako L579 actions. I have rebored the action and now have to bush the bolt to get a nice fit.
As i had to open the bore out by almost 20 thow to get it to clean up (Yeah, 20 THOW!) the bolt is very sloppy. I was thinking of having the entire bolt metal sprayed and then i will re machine to the right size. My problem is the metal spray process will likely effect the heat treatment of the bolt steel especialy arround the bolt head.
I can have it re-heat treated after metal spraying but the heat treatment company won't even talk to me unless i can tell them the grade of steel.
Does anyone know what grade of steel sako used for the L579 Forester bolts?

I was also considering bushing the entire length of the bolt using the usual split and epoxyed sleeve. Has anyone bushed an entire bolt like this before?


02-04-2008, 09:00 AM
This may sound a little nasty, but if you took that much material out of the bolt raceway you were a bit too agressive. I seriously think you have a junk receiver. Sell the bolt and the other parts to recoup some loss.

02-07-2008, 01:02 AM
You can have the composition of the bolt tested by a Metal testing company. How much it w'll cost or how much material they need to have I don't know. Once you know the composition, you can take it as a reference and match it to a variety of steels in the same family group. (chrome/moly,,,4140, chrome/nickel/moly ,,,4340 and so on) Steels from different companies have the same compositions but listed under different mames. 4140 is the same as V320 from Bohler or 709 from ASSAB, 4340 is the same as V155 from Bohler or 705 from ASSAB for an instance. Even the composition may be nearly the same the individual mechanical properties of each steel are unique to the steel itself. The same goes for the heat treatment, it may be close, similar but not exactly the same. The boys in the USA would reheat treat your bolt regardless, but I wouldn't touch it. Good luck with it.

Shoot well

02-09-2008, 02:43 PM
Sorry to add this... Whom ever the testing lab is make sure you get a Certified lab with traceability back to the Govt certification. You might really kill the job by asking for a copy of their insurance liability. What you are undertaking relieves the manufacturer of liability and puts it all on anyone who has tinkered with it since. Why not send it back to the manufacturer and have them get you a replacement bolt?

02-10-2008, 12:28 PM
Bobhe is right. It's definitely much safer to contact the manufacturer, than is to try reharden a steel of unknown. You'll never know, unless you have a go.

Shoot well