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Old 12-13-2018, 11:54 AM
  #24  
waimahana
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Location: Golden Bay, New Zealand
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I know this is now an old thread, however, I can share how I resolved the Sako ejection issue that seems to plauge a number of 75 and 85 model Sako rifles and hope others may find this useful.

How I fixed my Sako 75 ejection issue:
I resolved this problem in about 1 hour and at no cost.


In my experience, long actions (30-06, 270, etc) seem more commonly affected whereas short actions (.308, .243) appear to be less affected. My Sako 75 .308 has give many years of service without ever failing to eject cases perfectly.

In contrast, my Sako 75 .30-06 used to eject the case vertically upwards into the base of the scope and occasionally it would come to rest in the magazine on top of the next round which was really frustrating. I searched the internet for a solution without success. So I decided to do something about it myself.

I tried .30-06 cases in my Sako 75 .308 rifle and still had the same ejection issues whereas it works perfectly with .308 cases.
I tried 9.3x62 cases in my Sako 75 .30-06 rifle and only occasionally had ejection issues.
I tried .308 cases in my Sako 75 .30-06 rifle and had no ejection issues, so I knew it must be something to do with the cartridge.

The rim thickness of a .308 case is 1.37mm
The rim thickness of a 9.3x62 case is 1.30mm
The rim thickness of a .30-06 case is 1.2mm

There seems to be a relationship between the rim thickness and ejection issues i.e. thinner rims lead to ejection issues. If you seat a case in the bolt face you will see there is more slop for cases with a thinner rim. Seems Sako has gone for the 'one extractor size fits all' approach - presumably to save costs.

So..... I needed to reduce the amount of slop that the extractor held the .30-06 case so the extractor would have a tighter grip on the case (at least as tight as it holds a .308 case). My options were:
1) either build up the under-side lip of the extractor;
2) seat the extractor deeper in the bolt somehow, or,
3) compress the extractor to reduce its overall length.
Options 1 and 2 seemed very difficult, so I chose option 3.

I removed the extractor from the bolt face of my .30-06 and with all the skill of a high-precision swiss watch maker.....I beat it with a hammer! Actually, I placed the extractor vertically with the flat near the round bit on the sharp right-angle edge of an anvil and used a hammer to very carefully slightly compress the extractor so when fitted back into the bolt, the extractor had a tight grip on the cartridge case.

If you do this make sure to closely monitor the amount you compress the extractor with a good set of calipers and repeatedly try the extractor in the bolt. If you overdo it the cartridge will not align straight with the chamber, and.....you will need to buy a new extractor - not cheap. Also make sure the hammer impacts the extractor square on - not on an angle. Hammering may create a very small burr on the top of the claw and you may need to gently file a small amount off the inner top edge of the extractor claw so the case slides easily into the bolt face.

Actually this is a really easy process and can be done by anyone with basic handyman abilities (i.e. anyone who can use a hammer). The extractor does not look any different compared to an unaltered extractor - it's just compressed a by a couple of hundred microns.

My .30-06 now extracts and ejects cases perfectly EVERY time. Cases eject horizontally rather than vertically and NEVER hit the scope anymore.

Essential tools for this task are: a hammer, a vice or anvil with a sharp right angle edge, a set of calipers, and a bandaid for when you hit your thumb.

Caveat: this worked very well for my rifle but may not work for everyone - attempt it at your own risk. Good luck.

I wonder if the variability between rifles comes from the process they use to put the rifles together (I don't know, but food for thought):

If the bolt extractor hole and channel is milled into the bolt head and THEN the barrelled action is correctly head-spaced by milling material out of the bolt face. This would account for the variability in how well the extractor holds the cartridge case, and the variability between rifles.
i.e. good design with incorrect implementation. Some Sako 75 rifles a have this ejection problem, however, the issue is allegedly more prevalent with sako 85 rifles. Beretta acquired Sako in 2000. The Sako model 75 persisted until introduction of the model 85 in 2006, so later model 75's might be affected by the ejection issue.
In my experience the first thing you do after taking over a rival company is look at way to cut costs and improve profitability.

Hence what I believe should be done is adjustment of the extractor to each rifle. This could be achieved by my method (crude but effective - see above), or better still, having a range of extractor sizes and fitting the correct size extractor to each bolt AFTER it is head-spaced, or even better, drill/mill the extractor hole and channel after the barrelled action has been head-spaced.
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