In our SBR Episode I: Short Barreled Rifles – A Short Crash Course article, we outlined a brief history of rifle development and touched on the U.S. National Firearms Act (NFA) and NFA Firearms.
In SBR Episdode II: Short Barreled Rifles – Worth the Work, we discussed the pros and cons of an SBR and why we think it’s worth the investment – the process, wait, and cost involved to become a legal SBR owner.
We started with the wildly popular Springfield SAINT rifle with the free float handguard. We then reduced its barrel length from the unrestricted 16-inch length to 11.5 inches, applied the proper gas system “magic” and of course put on an appropriately fitted, shorter hand guard. The SAINT SBR also fires the same ammunition (as the original SAINT) with the same magazines, it’s just much more compact.
Engineering an SBR is a little more involved than just cutting off 4.5 inches of barrel.
Removing approximately 1/3 of the barrel of a perfectly timed “machine” does require some tuning. Primarily a revision of the gas system – to optimize the rifle to function with a different port position in the barrel.
A lot of engineering talk could be included here by someone far smarter than I am, but the base design concern is with the different gas port pressures and the reduced dwell time of those pressures, both which are caused by locating the gas port closer to both the chamber and the muzzle.
But don’t worry, at Springfield we certainly know what we are doing!
We learned a lot about short-barreled gas systems when we developed the 7.5 inch-barreled SAINT pistol. While a little tricky to perfect, when it IS right, the reward is reliable, consistent function. #MissionAccomplished
Therefore when we (Springfield Armory) got into the SBR market, we already had a lot of knowledge, reliable data and current, valuable experience.
The end result with the SAINT SBR is reliability and durability, the same features you have come to expect from all of the models in the Springfield Armory product line.