22 rimfire extraction

[GUNMETALDESIGNS]

I am midway in the design and construction of a 22 benchrest rifle. I have stumbled on a simple question? On a rimfire, the extractor is cammed out of the way of the cartridge as the bolt moves home (at least on a semi auto). Is this also a standard practice on a bolt gun as well? It seems it should be.

Any input appreciated

Joe Rich

[GeneT]

Yes, but differently - let's see if I can describe this:
If you look at the chamber end 'O' (hopefully your chamber is more round) the barrel has a bevel cut from 12o'clock to 3o'clock around the chamber. The bevel is such that it forces the extractor away from the chamber (leaving sharp edge at chamber mouth and deepest point of bevel farthest from chamber mouth). So, when the bolt is pushed forward the extractor is at 12'oclock and is forced away from the chamber (and rim). As the bolt is turned, the extractor rides along this bevel to the 3o'clock position, where the bevel is cut away, allowing the extractor to clip in, in front of the rim of the chambered cartridge.
Did that make sense?
GsT

[kurt]

All the ones i have done work the same as an auto.

[Al_Messer]

The Winchester Model 69-A is not a target rifle, per se, but the front part of its bolts does not rotate at all, only the section containing the bolt handle rotates. It has two slots milled in the breech end of the barrel at 9 and 3 o'clock for the extractors to set while the breech bolt is closed.

[Al_Messer]

Re: Winchester 69-A: I don't think that the extractors are cammed out of the way when the breech bolt is closed. If memory serves me correctly, that part of the cartridge case is supported by the extractors themselves. If'n I'm wrong, somebody please tell me!!

[jcbgunsmith]

Every 22RF I have ever worked on that has a flat bolt face has some type of extractor cut that is a bevel. The bevel cams the extracor outward so that the round can move forward into the chamber and headspace on the rim. Some benchrest guns that have adjustible headspace via the barrel just cone the end of the barrel so that no matter were the barrel ends up there is a bevel. IE: Time Precision actions. Recessed bolt faces only need an extractor clearence cut so that the extractor that protrudes from the face of the bolt has some place to go as the bolt comes up against the back of the barrel. Extractors need to be very sharp on rimfires so that they can grab that tiny rim. If you ever have extractor problem with a single extractor gun, IE: Ruger 10/22 try replacing it with a new or after market sharp extractor.