JP Rifles’ Silent Captured Spring (SCS) is one of those things that I can’t imagine living without. This captured buffer weight plus recoil spring system for the AR-15 and AR-10 completely eliminates the Mattel-like “SPROING” sound and grating, scratchy-squeaky feel of a standard buffer and spring setup. Additionally, it’s highly tunable and ever so convenient . . .
I don’t know about you, but it’s fair to say that I detest the sound of a standard AR-15 buffer and spring setup. Not just the sound, actually, but that jankey, toy-like, scratchy feel that conducts through the receiver extension (buffer tube) and/or stock and right into my face and shoulder. That chintzy clang and springy sproing and rebarbative rattle can be heard and felt both when manually cycling the charging handle and when firing.
Add a suppressor and it’s even worse. Shoot a suppressed, 9mm AR-15 or a subsonic .300 BLK AR-15 and it’s enough to be distracting. Sure, maybe I’m a little OCD, but the freaking spring noise is louder than the gunfire and it’s f’ing annoying! And it’s a real firearm, dagnabbit, so why does it sound and feel like a spring-powered airsoft toy?
Unfortunately I pretty much completely failed at capturing the audible difference between a factory buffer setup and the JP SCS. Getting a microphone to pick up what the human ear picks up in addition to what’s conducted through the bones of the jaw, plus getting that to play back in an equivalent fashion over speakers or headphones proved highly difficult (plus, your specific speakers/headphones will affect your ability to hear what’s in the video below). This quick clip is as close as I got, with an external microphone placed on top of the buffer tube.
Although some of the difference is audible in that video — maybe 10% of what you hear/feel in real life — and sounds to me like the slamming of palms against a loose, chain-link fence (audible only with the standard setup), you’re unfortunately just going to have to take my word for the fact that it’s a massive difference in real life. Night and day. Toy sproing and scratch and fence rattle noise vs. complete and total silence from the buffer area.
And, if I haven’t made it clear enough already, it’s not just noise but feel as well. Now, whether pulling the charging handle or firing the rifle, it’s smooth and nice. Gone is the vibration and spring binding, scratchy sorts of things that can be felt through the cheek, jaw, shoulder, hands, etc. It’s just oh-so-smooth.
Now if sound and feel seem a bit nitpicky, and improving just those things maybe isn’t worth the cost of entry, the SCS has other benefits as well. Least important, probably, is that convenience factor I mentioned above. As the SCS is a self-contained unit that’s just about the exact length of the buffer tube, the buffer retainer (the pin that sticks up in front of a normal buffer and prevents it from shooting out under spring power) is no longer needed:
Not a huge deal, but since the SCS is over a hundred bucks it’s pretty nice to be able to remove it from one rifle and drop it into another in about 10 seconds. No buffer retainer also makes swapping and adjusting receiver extensions faster and easier.
Also very convenient is the fact that the same SCS can be used in carbine- or rifle-length receiver extensions. The SCS itself is carbine-length, but it ships with a spacer that allows it to be run in a rifle tube. More bang-for-the-buck with the ability to quickly swap it between all of my lowers.
More importantly, the SCS smooths out the actual operation of the firearm, minimizes bolt bounce, and can be tuned to suit a rifle’s specific operating system. JP offers different weights to allow for changes to the mass of the buffer and also offers five different spring weights for selecting the perfect recoil spring power. That said, I’ve put multiple thousands of rounds through the standard AR-15 setup through a handful of rifles without a hitch of any sort, but the option to custom-tune it is great if you’re looking to really dial things in and end up with the smoothest, lightest-recoiling action possible.
One item of note is that the center “guide rod” of the JP SCS does not compress, and remains full-length while the buffer weight is compressing the spring:
On nearly all AR-15 and AR-10 rifles, this is a non-issue. The bolt carrier is hollow in the middle and it simply surrounds that guide rod as it cycles into the receiver extension. The notable exceptions are bolt carriers from PWS, as the extra mass added at the rear of PWS’ carriers restricts the diameter of the opening too much.
Additionally, most 9mm AR-15 bolts have an extra weight that’s pinned inside of the hollow channel. That weight will have to be removed in order to use the JP 9mm SCS, which is the one seen on top in the lead photograph. The weight in my CMMG carrier came out fairly easily, and the 9mm SCS has run flawlessly in that setup. There’s more than enough weight in the SCS buffer to make up for removing the pinned-in carrier weight, and the entire blowback action feels smoother and more solid. Some 9mm bolt carriers are solid at the rear or have a welded-in weight and, in those cases, the SCS isn’t an option.
For those on a budget, JP’s Custom Centerless Ground and Polished Operating Springs (bottom of this page) offer a shockingly large reduction in spring noise and feel compared to any other recoil spring that I’ve tried — and I’ve definitely shot plenty of parts kit and other generic ones plus a couple Brownell’s, DPMS, and otherwise-branded springs. Apparently just getting the diameter exactly perfect and polishing the springs to a mirror finish is worth the time and effort. If $139 for an SCS isn’t in the cards, or isn’t for the entire AR collection, the $19 cost of entry for the centerless ground springs is fully worth it.
Ratings (out of five stars):
Fit: * * * * *
Spot on. Universal for carbine and rifle. No buffer retainer needed.
Functionality: * * * * *
Improved over the standard recoil system in every last way. Plus it’s fully tunable.
Overall: * * * * *
5-stars. I love the SCS. Even if you haven’t been bothered by the grating twang of a standard recoil system, the SCS is one of those things that, once you try it, there’s no looking back. That sproingy twang will be torturous in comparison to the smooth sounds of silence.