22LR Magazine Fed Rifle, Match Chamber Reamer Info

[Johnny Boom]

With all the interest in CRPS/PRS/NRL style rimfire, I am curious as to which reamers are being used to chamber barrels.

Please note, this applies specifically to magazine fed, bolt action rifles that are shot in all conditions in "practical" competition. I respect and admire the skill of the shooters and the accuracy of the equipment in many of the other rimfire disciplines, but a chamber that works well in a single shot BR rig may not necessarily be the best for field competition.

Also, for many PRS shooters, the 22LR is a trainer version of their match gun, so it may seem oddly large and impractical for a rimfire, with 24 inch+ heavy barrels and the like.

I've done a bit of lurking on rimfirecentral.com and snipseshide.com as well. Seems like the Calfee 4 and Lilja 2 chambers come up a lot.

If someone has actual experience, that would be a plus.

 

[Shooter1971]

Calfee 4 on my 457, accurate and never ever failed to feed or extract sk rifle or cci standard

 

[grauhanen]

The most recent table I've seen of chamber reamer specifications is shown below.

In general, sporting repeaters have larger chambers than match rifles. Match chambers, which themselves vary in dimensions, are usually tighter and shorter than most .22LR chambers. European sporter rifles made to CIP specifications will typically have smaller chamber dimensions than North American sporter rifles made to SAAMI specifications.

It should be noted that many match rifle users with match-type chambers report that it can be difficult to extract live rounds. They often have to push them out of the chamber with a cleaning rod from the muzzle. As a result, shooters who need to be able to reliably and safely extract unfired rounds should avoid chambers with the smallest dimensions. Whether extracting live rounds from match chambers is more difficult because of tighter chamber diameters or because shorter chambers result in more engagement between the bullet and rifling, or both, is not clear.

 

[allan harris]

It should be noted that many match rifle users with match-type chambers report that it can be difficult to extract live rounds.

My experience too! Not only does it depend on chamber length/bullet/land engagement but not all extractor designs are created equally!

 

[tiriaq]

Thanks for posting that chamber dimension chart.

 

[Johnny Boom]

The most recent table I've seen of chamber reamer specifications is shown below...

@grauhanen, thank you, this is very helpful and exactly the kind of information I was hoping to discuss. You make some very good points.

I have read that most, if not all, match chambers will engrave the bullet upon chambering to various degrees.

 

[Johnny Boom]

@Shooter1971, are you getting engraving on your 457 when you chamber?

 

[Shooter1971]

Yes