Hi Folks,

I am moving away from the flat-wire Tubbs buffer springs I have been using in my AR-10s and AR-15s until recently for several reasons.  The first, and less important reason, is that they stopped making them out of chrome silicon and now just use stainless steel, which would likely have the short life of the standard generic buffer springs, despite their advertising claims that they will last a long time.

Second, and far more critical, is what I discovered the hard way that a flat-wire buffer spring does to receiver extensions.  When you remove the buffer and round-wire spring from a receiver extension, the round wire rolls over the buffer detent pretty smoothly without imparting much force to it.  However, when you do the same with a buffer on top of a flat wire spring, each coil of the flat-wire spring hits the buffer detent and takes a lot more force to slide off of it.  This causes the buffer detent to tilt forward and its side to strike the receiver extension each time a flat-wire coil slips over it.  I always take care to keep the buffer detent depressed with a tool when removing the buffer, but there is a point when withdrawing the spring that you can't hold it down and it hits the receiver extension.

I never worried too much about this, as I have had the Tubbs flat-wire springs in all my modern ARs, and have taken buffers out many times over the years with all of them.  These include 2 ARs with rifle receiver extensions and Cav Arms C1 stocks, and 2 with carbine receiver extensions with Rogers Super Stocs.  All 4 of those ARs use OEM Colt hammer-forged 7075T6 receiver extensions, and so the buffer detent problem never occurred to me.

However, I just a few weeks ago built an AR with a collapsible stock using a 7075T6 receiver extension from one of the premium AR manufacturers.  This receiver extension was not forged, but impact-extruded, but I didn't think it would make a difference.  Well, I used a Tubbs flat-wire buffer spring in it, and this weekend I took the buffer out for only the second time in the life of the rifle, and after I had depressed the detent, pulled the buffer out, removed it from the spring, and was withdrawing the spring carefully, the detent broke a hole in the lip of the receiver extension that holds it down.  I don't want to say what manufacturer made this receiver extension, as they advertise on this site and are universally considered a very premium outfit, but suffice it to say, I will never use either an impact-extruded receiver extension or anything made by them ever again.  

To see whether the flat-wire buffer springs did this to other rifles, I pulled both the rifle-length receiver extensions from my rifles wet up with C1 stocks, and lo and behold, they both had a noticable divot in the aluminum where the buffer detent is held in place.  These two rifles have had flat-wire springs in them for 7 years and have had the buffers removed likely 100 times, so they were much better-constructed, but it seems that the flat-wire spring is hard on any receiver extension.  

Therefore, I am getting round-wire buffer springs for the AR-15s in chrome silicon, but am not sure who makes a good round-wire chrome silicon spring for an AR-10 (mine is an ArmaLite) with a rifle-length extension.  It looks like Springco's RED and ORANGE springs are designed for carbine receiver extensions, and the only spring I have found made of chrome silicon that is listed specifically as for a rifle receiver extension is this one: https://www.bangswitchparts.com/products/ar10/buffer-spring-lr-308-rifle-chrome-silicon/

However, given the suspiciously-low price and the lack of identification for a manufacturer, I think this might be of very suspect quality.  Does anyone have any experience with this spring, or can anyone recommend a chrome silicon round-wire buffer spring designed specifically for .308 ARs with a rifle-length receiver extension?

Thanks in advance!

For my AR10's, I use the DPMS springs:

https://www.brownells.com/rifle-parts/receiver-parts/recoil-parts/recoil-springs/308-ar-buffer-springs-prod42988.aspx

Dont discount stainless springs.  They use a very special alloy now for stainless springs, 17-7 PH, which is very comparable to the life of CS.  

Simply replace every 5,000 rounds.  You are halfway through a .308 barrel's life by the time you need to swap the $9 spring.

Tubbs claims that their stainless springs last as long as the chrome silicon ones, but that is hard for me to believe, because back when I first got their springs in 2010, they spent almost the entire product description trashing stainless steel as a spring material, and making all these claims about how quickly they take a set, and how chrome silicon is the answer.  

Are you saying, also, that even chrome silicon springs only last about 5,000 rounds?  The whole reason I got them was because they are supposed to stay at the same strength essentially forever (at least far longer than any component but the receiver will last).

I have CS springs from Sprinco - that after less than 1000 rounds are shorter than brand new ones sitting in my parts drawer.

No springs last forever.  5000 rounds is quite good for a spring like that.  It doesn't mean it is toast or stops working, but it absolutely is affected to a degree.

I agree that I have had great performance with the Tubbs springs for 7 years, and while I am planning to use a Sprinco Green in the rifle receiver extension for my AR-15s, I have decided to keep the chrome silicon Tubbs spring in my AR-10.  The problem with the flat-wire spring (not unique to Tubbs products, just the nature of any flat-wire spring) is not that it broke the buffer detent, but that the force the spring hitting the detent imparted to the lip of the receiver extension actually broke the extension.  I do not doubt that most of the issue was a substandard receiver extension, but the flat-wire design is considerably harder on the extension.

The issues with Tubbs moving to stainless steel is basically because of how strongly they criticized stainless steel as a spring material in all their literature back in 2010 when I got my first sets of springs for them (2 for my AR-10 and 2 for my AR-15; 1 to use and 1 spare).  Also, the fact that they have moved away from using a different spring for the CAR and rifle-length extension makes me wary.  A carbine spring is shorter and stiffer, and that is not something I want in a rifle receiver extension.