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Actually the barrel has a match chamber (subject to varying opinions by others). The action is exactly the same at the cheapest 457 (American synthetic).Are bolt shims really necessary in a MTR since it has a match grade action to begin with?
Drop-in barrels do not require any special gunsmithing. Directions for installing the barrel are furnished with each barrel. These instructions can also be found directly below. If you do not feel qualified to install your new drop-in barrel we can do so for a $50 charge. Here is a link to our Facebook page with a video helping explain the process of measuring your headspace. https://www.facebook.com/580697272005364/videos/338760933509372/
Installation Instructions
(1.235 – .043 = 1.192)
- First you will need to measure your headspace. The most accurate way to do this is by using a depth gauge, and measuring from the receiver face, to the bolt face recess while the action is cocked. Let’s say you get a measurement of 1.235” and you want your headspace at .043”. That means you need a shank length of 1.192”.
(1.200 – 1.192 = .008)
- Every barrel will have a shank length of 1.200”. So now we know to shim the barrel .008” to obtain proper headspace.
- Now that we know how much we need to shim the barrel, we can use a .005” shim and a .003” shim stacked together to obtain headspace. You can use any combination you’d like, but try to use the least amount possible.
- Slide the .005” and .003” shim onto the barrel shank, making sure they are fit up tight against the shoulder of the barrel.
The receiver stock screws are a T-27 Torx HeadNote: We turn the barrel shanks slightly larger than the original CZ dimensions on this diameter. We’ve seen a couple of receivers that had a slight burr where the angled tapped holes break out into the receiver bore. This little burr prevented the barrel from sliding into the receiver with our close fit shank. So if you find the barrel difficult to slide in place initially, check for these burrs.We offer a .043” Go Gauge made by Pacific Tool and Gauge. Please note that it is not necessary to use a Go Gauge to get correct headspace using this method.
- Slide the new barrel, with shims up firmly against the shoulder into the new action, being careful to align the ridge of the cuts for the set screws at the 6:00 position. Tighten the two set screws equally, pulling the barrel into the receiver. Recommended Torque is 35-40 Inch Pounds.
Yep! Agree!Before shimming a bolt you must identify if a problem exists and if so, what is the problem and what is needed to correct it?
Just arbitrarily placing shims in a bolt can create more problems than it solves.