In 1988 I bought a new Sako A-1 single shot bolt action, in 22PPC USA calibre. I had problems right from the start. Using Sako 22PPC USA factory ammunition extraction was very difficult. The shop where I bought the rifle was owned/operated by a gunsmith; I took it back and got him to fix it. He improved it some, but extraction is still difficult. I only fired the rifle a limited amount (factory ammo and reloads) and then stopped shooting it altogether. I'd like to start shooting this rifle again but I want to get it fixed properly. I'm curious to know if anyone else has had similar problems with this rifle, or did I just get a lemon?
22PPC difficult extraction
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Two basic possible causes come to mind. One is excess pressure, in which case you usually not only have stiff extraction, but the bolt is often difficult to lift, too. If you have both symptoms, I would get a chamber cast made to be sure the throat is normal, or have someone with a 22PPC reamer and a T-handle just ever so gently take a turn or two with it in the chamber to be sure the throat is OK, then check it with a headspace GO gauge. The smith likely already did these things, but if you have sticky lift it should be double-checked.
If you have sticky extraction alone, it is more likely just to be very rough tool marks in the the chamber, or, worst case, something created an expansion ring in the chamber during proofing. Do your cases come out with bright shiny marks that go around the case? If so, it is likely to be tool gouges or a ring. Typically such marks can be smoothed some with crocus cloth. However, the best quality solution is to remove the barrel and set the shoulder back a little and recut the chamber using a sharp reamer and adequate lubrication and clearing the chips frequently enough to keep the surface reasonably smooth.
Two basic possible causes come to mind. One is excess pressure, in which case you usually not only have stiff extraction, but the bolt is often difficult to lift, too. If you have both symptoms, I would get a chamber cast made to be sure the throat is normal, or have someone with a 22PPC reamer and a T-handle just ever so gently take a turn or two with it in the chamber to be sure the throat is OK, then check it with a headspace GO gauge. The smith likely already did these things, but if you have sticky lift it should be double-checked.
If you have sticky extraction alone, it is more likely just to be very rough tool marks in the the chamber, or, worst case, something created an expansion ring in the chamber during proofing. Do your cases come out with bright shiny marks that go around the case? If so, it is likely to be tool gouges or a ring. Typically such marks can be smoothed some with crocus cloth. However, the best quality solution is to remove the barrel and set the shoulder back a little and recut the chamber using a sharp reamer and adequate lubrication and clearing the chips frequently enough to keep the surface reasonably smooth.
The bolt lift is fine, the problem is with extraction only. Before the rifle went back to the gunsmith, fired cases had definite marks running around the case. Now fired cases only show a few miniscule scratches along the length of the case. Even though my bolt lift is OK, I will have the dimensions of the chamber checked. Thanks for the reply.
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Sounds like the gunsmith got the toolmarks worked down, so that's the main issue. You could still have some gradual ones that now have rounded and polished edges that are still grabbing. Unfortunately, cutting a chamber with continuous through-barrel pressurized chlorinated cutting fluid is the only way I know to completely rid yourself of those toolmarks and get a smooth chamber.
Short of that, it also tends to be the case that those marks smooth some more with firing. You could also polish the chamber. As long as you don't also oil it or let any kind of dry lube get into it that will not, contrary to popular wisdom, raise bolt pressure to any appreciable degree. A shotgun bore mop with Flitz or MAAS or even Brasso on a variable speed drill will do the job through the bolt way (you remove the bold, of course). Just be sure to use some carb cleaner afterward to remove the waxes the polishes leave behind.
Short of that, it also tends to be the case that those marks smooth some more with firing. You could also polish the chamber. As long as you don't also oil it or let any kind of dry lube get into it that will not, contrary to popular wisdom, raise bolt pressure to any appreciable degree. A shotgun bore mop with Flitz or MAAS or even Brasso on a variable speed drill will do the job through the bolt way (you remove the bold, of course). Just be sure to use some carb cleaner afterward to remove the waxes the polishes leave behind.
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MAAS is just another brand of polish in a tube. It is flesh tone color instead of blue, like Flitz, so I think cerium oxide is the main polish in it. Gunbrite, made by Iosso, is another one. The choice isn't critical. White automotive polishing compound would work, too.
The problem is with both factory ammo (Sako brand 22PPC USA) and handloads. As I mentioned in my first post, the rifle was purchased over 20 years ago and handloads were worked up using then current data (Hornady Third Edition). Velocities were very consistent with what the Hornady handbook showed, so I don't think I was shooting proof loads.
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