We have been machining "Switch Barrel" actions since 1981 here at Kelbly's. We make extra bolts for actions and hold headspace here to +/- .001" we also hold the shank and thread dimensions to minimum thread specs. This allows us to ship barrels all over the world that are chambered to a standard and they will screw on your action, headspace properly and the only things you need are an action wrench and a barrel vise. This also allows your local gunsmith to chamber a blank to our specifications, you walk in and he swaps the barrel and then you go out shooting. Super simple and incredibly effective.
After seeing all this new technology come out and it all has its place, the problem still is raw accuracy. So coming from the benchrest world, where all of this custom rifle technology came from ie. switch barrels, carbon fiber stocks, match grade barrels, 6BR, 6mm Dasher, 6x47 Lapua, etc. They still use a shouldered and torqued barrel, even though guys will swap barrels in a match! This is because they know that a hand tight barrel will not shoot consistently day after day. The issue becomes pressure and how threads work. A thread only works to its full potential if torqued properly, so that the threads stretch as intended and the barrel is shouldered to the face of the action. If a thread is not torqued properly than the "sloppiness" of the threads is still present, allowing the barrel shoulder to separate from the receiver face under pressure (ie. 60,000 psi) and then it slams back into the receiver face, once the pressure has dropped. This causes minor POI shifts on target.
The only way to have extreme consistent accuracy is to have a shouldered barrel that is torqued at 100-150 foot pounds of torque.
The best system we have seen to date is AI's switch platform, but it only serves the purpose for tactical and plinking applications. If it were as accurate as a shouldered barrel it would have made its way into benchrest, or F-Class, because it is so easy to change their barrels.
We supply actions, barrels, and rifles to over 44 countries and we developed our tolerances around being able to supply our international customers quality match barrels, chambered properly that really only can come from the USA in the past.
So our system you can buy one action (ie. a short action) and order two extra bolts and cover case rim sizes from .385", .480", and .532" in one action and just change out barrels and bolts. All you need is a rear entry action wrench, and a barrel vise. No need to remove the stock or any optics. It can all be done without removing anything but the bolt and barrel. you unscrew the old barrel, screw on the new one and torque to over 100 foot pounds, and install the proper bolt. Easy changes, no headspace gauges, no worries about anything coming loose, just a simple thread and torque. It's even accurate enough to set 80 records in competition since 1994.
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