School me on buffer tubes

[Sniffer]

I have a couple of projects that will involve buffer tubes and I always assumed that there was simply one size / style.

One of those projects is swapping the standard buttstock on my RPR for a Magpul PRS. I watched a Youtube video where they swapped the buffer from standard to a longer (rifle length?) version so that got me thinking "why?"

I had a quick look today and saw "Commercial", "Milspec", "Carbine" length and "Rifle" length. What are the differences? I don't understand as I was under the impression all BCGs are standard (same dimensions) so why would different lengths of buffer be required?

I also plan to use a JP Silent Capture Spring system for the other project I have going on - does it matter which buffer this gets mated with?

 

[Rebel Rouser]

 

[jiffx2781]

I also plan to use a JP Silent Capture Spring system for the other project I have going on - does it matter which buffer this gets mated with?

The JP SCS system will work with both the carbine length receiver extension and the rifle length receiver extension. The kit comes with a spacer. If you install it in a carbine length tube you don't use the spacer. If you install it in a rifle length tube you slide the spacer into the tube first and then slide in the SCS system.

 

[chillyrabbit]

Commercial and milspec buffer tubes differs in just the outside diameter of the tube, due to the different ways they are manufactured (Extruded vs milled I believe). I think commercial spec tubes are a developmental dead end as nearly everyone only makes milspec sized stocks.

Carbine vs Rifle buffer tubes are completely different and can't be mixed up part wise.

The M16 family was obviously designed to use a rifle length buffer tube/spring. The rifle tube and spring are longer meaning that after you fire when the BCG starts going backwards it takes a longer amount of time to compress the spring, then go forward resulting is a longer felt recoil impulse since the backwards forces are more spread out. The downside is you are usually limited to longer fixed stocks to contain the rifle buffer system.

The carbine length buffer tube/spring were obviously designed for the M16 family carbines using a shorter buffer tube and spring to enable the installation of a shorter collapsible stock allowing a solider to keep the rifle as compact as possible. Because of this after you fire, when the BCG goes backwards it has to complete the same amount of work as the rifle buffer in a shorter carbine system. This tends to result in a shorter sharper recoil impulse as all the work needs to be completed in a smaller space.

A newer development is the VLTOR A5 buffer system which is a proprietary system but tries to strike the balance between the smoother recoil of a rifle length buffer system while still retaining the ability to use collapsible stocks. The tube is slightly longer than the carbine buffer tube so you get the longer rifle like recoil impulse but short enough that you can install most collapsible stocks allowing you to adjust them to your personal preference.

TL;DR

Rifle buffer = smooth recoil fixed stocks
Carbine buffer = sharper recoil collapsible stocks
A5 buffer = Inbetween rifle/carbine recoil collapsible stocks