We can chime in on one of your questions, but we'll leave the other 3 alone.
DISCLAIMER: WE DON'T CHAMBER BARRELS. WE HAVE A VERY BASIC AMOUNT OF INFORMATION ON CHAMBER SPECIFICATIONS THAT HAS BEEN COLLECTED FROM A RELATIVELY SMALL AMOUNT OF EXPERIENCE IN THE RIMFIRE GAME. OUR INFORMATION IS WHAT WE FEEL TO BE VALUABLE INFORMATION FOR THE SUCCESS OF OUR PLATFORM. PRACTICAL LEVELS OF ACCURACY AND SMOOTH FEEDING ARE OUR PRIMARY GOALS.
2 - Any variant of the Win 52D has shown to be the best feeding and performing chamber from our experience. There are a couple of important things to consider when choosing a chamber for this platform. The first being that it prefers a larger chamber "mouth" with a shorter chamber "throat." The reason we believe in those factors is from results of feeding reliability and accuracy potential.
Feeding reliability has been a problem for some people and we believe the reason behind that is tighter than necessary chamber mouths. There's a lot of conversation on using a chamfer or radius on the chamber mouth and how large that should be. We believe you can go either route but we recommend using between .005" and .010" of either shape. Too small of either and you can potentially have a rough feeding cycle. Too large and you can potentially run into ignition inconsistencies. One thing is for certain, the chamber needs to be cleanly machined or well polished. Polishing isn't a bad option and it's also not discouraged. We've had a handful of issues come through and 9 times out of 10, the issues are helped with a little bit of polishing in and around the chamber. That's also been the case with some other barrels that we haven't had our hands on. If the chamber is wonderfully machined (free of tool marks and things of that nature), there seems to be almost no limitation to the tightness of the chamber. Any inconsistency in the machining and that almost goes completely out the window. This is why we recommend the 52D or a variant with similar chamber mouth and throat dimensions. We leave the chamber decision up to the end user and gunsmith to specify. Some are working very well and others not so much. Trust in someone with lots of experience across a multitude of platforms.
Accuracy potential has a LOT to do with the chamber as well. I'm going to take a stab at a very basic example for the sake of this post. If you establish a baseline for chamber depth at 3 out of 5 (easy for this example), we've seen the following in our testing:
-Chambering to a depth of 4 out of 5 can create a very smooth bolt close but, a loss of accuracy potential can occur from the happy medium of 3 out of 5.
-If you stretch that out to 5 out of 5, the accuracy potential can decrease rather rapidly.
-If you chamber to a depth of 2 out of 5, the bolt can get a little stiffer than the happy medium of 3 but accuracy potential can (
not a certainty) increase.
-If you close up depth to 1, you are likely to experience a tighter than desirable bolt close but you may
(again, not a certainty) see an increase in accuracy potential.
I know that may take a couple of readings to follow completely, but it's about as basic as we can make it without getting into exact numbers of different reamers of which there are thousands. Basically, use the Win 52D as a baseline and most development from there will give you the best potential.
Most of our testing has been on PROOF Research and Lothar-Walther barrels with a couple of smiths in the mix. We'd be happy to give you a private recommendation via direct message if you'd like. Just send us a message here or an email to
[email protected] and we'll get you on the path we feel to be the most productive.
Thanks - Ray
