Compiled Buffer Spring Data

[Dewey Mack]

At the risk of releasing this too early, I think this might help everyone building or tuning their large frame "non-standard" rifles:

Tested Buffer Spring Data

I used this idea from Blowback9.com when I was building my PCC. He made a spring tester for testing various springs for the "gentle recoil system." He only tested the springs for M4 carbine bolt-open/bolt-closed positions because that was the only data he had to compare. So I was inspired and created my own spring tester with multiple positions marked for M4, A5, and Rifle Length compression for AR15 and LR308. So far, I have tested 24 different springs (all of which I purchased) and are new or otherwise noted. My brother-in-law has the Aero 308 carbine and rifle springs which I should be testing soon as well. Yes, I actually spent money on this because I'm SICK of the industry not helping out the average joe and tired of tacticool keyboard warriors recommending springs when there is ZERO ACTUAL DATA behind any of their recommendations--[not meaning this forum, but Reddit/AR15.com/etc]. I tried to provide links to most of the springs in the "All Springs Tested" tab. This can be very useful for not only large-frame but fine-tuning all AR platforms. Keep in mind, most are data points of ONE spring each.

I reference 7.2 lbs / 16.5 lbs as the standard for AR10/LR308 since this is what Tubbs reported on their website. I also highlighted the EA1095 which I purchased from HeavyBuffers; I'm unsure if it's an actual Armalite component or their copy of that spring.

I have also tested some of these springs in my carbine, A5, and rifle LR308 setups. Without going into detail on this post, I have these few conclusions:

The Sprinco Orange was massive overkill. Ejection pattern direction didn't change but ejection distance cut 1/3-1/2. Maybe only try if severely over-gassed; it's $20 so maybe getting an adjustable gas block is smarter if you already have a good spring, proper gas port size, and correct buffer weight.

The EA1095 is pretty much ideal for A5 and Rifle setups. There are some GOOD alternatives as well.

The Strike Industries flat wire was extremely weak; I think it's best served in the AR15.

The Griffin Armament +15% A2 spring was more like +35%! I'm not sure if that is a defect or not. I may call them.

The KM Tactical 308 Rifle spring is also very weak; also a possible defect or I was sent an AR15 rifle spring.

ALL M4-carbine tube springs were overkill (except the weak SI flat wire), and it does not seem like an efficient nor flexible setup.

I have both A5 VLTOR and BCM MkII tubes. They both measure 7.75" internal. I don't care they're not 7 5/8" and not going to argue; I just wanted to make a standard for my measurements. And honestly, I 3D print custom shims for my buffer tubes to make all my AR bolts have 0.060-0.080" bolt catch gap. Buffer-bottoming depth varies based on how far the tube is threaded into the lower receiver, and every tube is different.

Enjoy and pin if you think it will help. I'll update when I test new springs.

Cheers,

Dewey