MSR – Lower Assembly, Lower Receiver, Stock & Buffer Tube
Don’t have a MSR (Modern Sporting Rifle), but would like to get one?
Intimidated by all the terminology?
Stay tuned for a series of posts explaining simple MSR terms and functionality.
Today’s terms – “Lower Assembly”, “Lower Receiver”, “Collapsible Stock” & “Buffer Tube”
The MSR can be separated into two main elements: The complete “Upper” assembly, and the complete “Lower” assembly. Both the complete upper and lower assemblies can be further separated, stripped down to their discrete components.
Image “1” shows the two main assemblies of a MSR – the complete “Upper” assembly, and the complete “Lower” assembly.
Image “2” shows the just the complete lower assembly, also known as the “Lower”.
Image “3” shows the lower assembly further divided into three components or sub-assemblies: The collapsible buttstock sub-assembly, the lower receiver sub-assembly, and the grip.
The collapsible buttstock & buffer tube sub-assembly: The collapsible buttstock is slide-adjustable so the user can adjust the rifle’s length-of-pull. It can also be fully collapsed to make the rifle more compact while carrying. The buffer tube has approximately 6 detents allowing the stock to be positioned to one of six extended positions.
The lower receiver sub-assembly: The lower receiver is the “frame” upon which the MSR is built. This is the serialized component that the ATF considers the “firearm” and therefore regulates. Purchasing only the lower receiver requires one to follow the same process as if purchasing a complete firearm. The lower receiver – in this example – also includes the components to lock & release the magazine, to lock & release the bolt assembly, and the trigger sub-assembly. A lower receiver which does NOT contain any additional components is referred to as a “stripped” lower receiver.
The grip: Last but not least, is the grip. Obvious in function and simple in installation.
That’s it! Another handful of intimidating terms explained!