Hi Horseman,
Shortening the back end of the extractor will make no difference what-so-ever. The spring pushes the extractor forward, not backwards.
The aim is to hold the case more tightly against the bolt face and the only way to achieve this is by moving the 'claw' of the extractor closer to the bolt face.
I don't believe the sako design is flawed - I believe it was probably designed with the Sako high standard of precision, but has just been implemented poorly, most likely in an effort to save production / assembly costs (i.e. perhaps the bean-counters got involved).
The extractor and ejector design needs to be accurately adjusted for EACH CARTRIDGE rim thickness in order to work well. Most of the time the factory rifle will work well (think of it in terms of a bell curve distribution with those beyond 2 theta causing the problems), however, for cartridge cases that have a thinner rim thickness there is a greater chance of an extraction issues. When the cartridge is loosely held by the extractor, then the greater the radial distance between the extractor and the ejector the more likely this is to be an issue i.e. cartridges like 300WM, 7mmRM, 338WM are more likely to have issues. Here is a limited list of selected rim C.I.P approved rim thickness (essentially identical to SAAMI specs - data from wikipedia). I suspect that during manufacturing sako did not discriminate between the bolt face - extractor distance for a .30-06 and a 6.5x55 and took a 'one size fits all' approach.
30-06 1.24mm
270 1.24mm
7mm RM 1.27mm
300 WM 1.27mm
338 WM 1.27mm
9.3x62 1.30mm
375H&H 1.30mm
7mm SAUM 1.30mm
7-08 1.37mm
308 1.37mm
300 WSM 1.37mm
6.5x55 1.5mm
7.62x39 1.5mm
Please note: I do not aim to disrespect Sako, they make quality rifles ....but sometimes need a little adjusting to work to our expectations.
Hope this helps
