It seems like whenever I post about a weight saving strategy or carbine part, some Tactical Internet Adonis drops into the comments section to shame all potential buyers of said part with comments like “Just lift more bro!” Meanwhile, people who can think their way out of wet paper bags realize that lightweight gear is less about building a carbine that our puny little arms can hold and more about common sense.
The easiest to grasp reason to be at least a little weight conscious when it comes to your gear is that lighter gear is easier to carry for a long time. Certainly, soldiers all over the world have proven that you can carry heavy rifles day in and day out but I suspect that many would choose lighter if they could. Carrying a light carbine just simply sucks less than carrying a heavy one. I can’t speak to being a soldier but this principle comes into play if you are hiking or during 3+ day carbine courses too.
One of the best reasons to be a bit weight conscious and the one that I have never heard anyone talk about is to deal with injury. It is easier to use a lightweight carbine when you are injured. Certainly that applies to hardcore scenarios like your support arm getting disabled by a knife wielding meth-head. It applies equally to far more mundane injuries – the type that happen in your every day life and can have very real effect on your ability to use a firearm in defense.
I’ll give you an example from my own experience. My family processes firewood in late summer and into fall. Last fall, I found myself spending a lot of time swinging a splitting maul in preparation for our first year heating with wood. My elbows were becoming more and more sore every day but there was work to be done so I pushed through. By the time everything was cut and stacked, I had a rip-roaring case of tendinitis in both elbows.
I have since figured out what was wrong with my form but the elbow and forearm pain during that time was no joke. There were days where I was physically incapable of extending a handgun out in front of me. The weight was too much and my hands would basically just open involuntarily to drop what ever weight I was trying to push out at arms length (side note: grip strength was also effected in a big way so I found that aggressively textured grips were a must during this time). The only firearm that I could still operate effectively was a lightweight carbine. Heavy carbines were better than handguns thanks to the way the shoulder takes some of the weight of a rifle but they were still pretty rough. That was one of impetuses for the Sub 6 with a Twist project. That carbine was lightweight enough that, when anchored to my shoulder, I could actually use it unencumbered.
There are definitely cases where strange, unnecessary, and expensive things are done to carbines in the name of saving weight. There can be value in the exercise of shedding all those ounces but you don’t need to go crazy. I think that the wise shooter is more than a little concerned about the weight of their carbine. Reliability and accuracy are probably the two most important factors in choosing a firearm for defense but neither of those matter if injury renders you incapable of lifting it so the mundane ability to live with the carbine you choose is pretty important too.