Mounts
Two piece scope mounts are definitely the most common mounts available. They can be recognized by separated front and rear mounting elements.
Personally, I like the idea of the open upper part of the receiver; it is easier to load cartridges in the chamber if there is no obstacle, like rail or other mounting element between bases. This type of mount is easy to produce and is usually quite affordable.
Firstly, we have to understand two different possibilities of two piece scope mounts:
single part design and
two-part design.
Single part design where ring and base are made of one piece, is quite common.
It means that you have two different pieces of scope mounts – front and rear and each of them is made only from one part of raw material.
Two part design is common as well, especially for mounts with separated bases and great advantage can be achieved that way in the terms of windage adjustability.
Each of them (front and rear piece) have separated base and ring that have to be joined together (normally with screws). Of course, higher number of parts means also higher possibilities of failures.
There are also two piece scope mounts that can be screwed directly on the receiver (even if the rifle does not have dovetail) available.
Talley is one of the most-well known manufacturers of these mounts. Mounting of all of the two piece scope mounts by gunsmith is absolutely advisable. They are quite hard to adjust and to mount without flexing or damaging the scope in some other way.
All of two-piece scope mounts (single and two-part design) are normally lightweight, elegant design can be easily achieved and they are also affordable (in most cases).
Because of separated design and a general need for great rings alignment, these mounts are usually difficult to mount.
Proper alignment of front and rear part might be hard to attain. This is the reason why experienced gunsmith is normally needed. It is also important and should not be forgotten that two part designed mounts have many joints and these joints could potentially fail.
Lapping process with two-piece scope mounts is normally needed or at least advisable. If lapping is not done, there is a huge possibility of flexing the scope during mounting or at least making stress and deformations in the material.
If there is no lapping done during mounting process of two-piece scope mounts, there is still bedding possible to correct imperfections.
Bedding scope bases is a process of making hard bonds between receiver and bases with epoxy, Loctite blue glue or any other bedding liquid that can assure solid bond and precise connection of parts. It is good to know that bedding can be done also between scope tube and rings, not just between the rifle and bases of the mount.
Two piece scope mounts appear light and elegant and there are many available mounts of this kind on the market.
They are popular also because of their affordable price, but on the other hand – they might be a nightmare to mount, even for experienced gunsmiths.