Ok -- should I be using black Colt inserts with Wolff extra-power extractor springs? Or D-fenders with a specific spring?

I really feel like the extractor spring is a weak area of the M16 design and want to really figure out what is best.

Rifles are Colt M4 14.5", Colt 10.5 inch, and 20" M16A1s.

If you use the D-Fender, you only need the standard spring.
D-Fender increases extractor force 4x.

With the D-fender, do you leave the other insert in place? And does it matter if the other insert if black or blue?

And also, does the new black D-Fender have the same properties as the older blue one?

I have a registered full-auto M4 carbine, and I use the Wolff HD spring. I have never had an extraction problem.

As for the insert colors, the inserts themselves are identical. They are included with the spring to indicate various tensions so that armorers can tell them apart. Factory Colt springs with red, blue, and black inserts all have different spring tensions.

BTW, I am using the old red insert with my Wolff extractor spring.

Interesting.

I thought black was firmer because Brownell's catalog says to use the Woff spring with a black insert:

"Stronger spring prevents "extractor bounce" during rapid semi-auto or full-auto fire. Provides extra force against case rim to give AR-15 rifles and carbines reliable extraction from a dirty chamber; ensures fired case is completely extracted and ejected from gun. Recommended for use with black, carbine, extractor spring insert. "

Wolff Xtra Power Extractor Sping ....I"ve been running them in all my AR's for years and have had ZERO problems!!!!!!!



Semper Fi
Jeff

I run Ken Elmore's Specialized Armament green springs in my carbine bolts.

What do people all think of the LMT bolt with the dual springs? Any evidence it is better than a D-Fender or Wolf high-power spring?

Screw the D-fender and the other overpriced rubber bits. Just go to the hardware store and get a suitable o-ring. $0.25 if your local store rips you off.

Maybe the D-Fender is 700 degree Silicon. Rubber is rubber.

When my wife said that movie-theater popcorn is too expensive, I said she should open a movie theater and sell popcorn and get rich.

lol

rsilvers, you rock.

Quoted: Wolff Xtra Power Extractor Sping ....I"ve been running them in all my AR's for years and have had ZERO problems!!!!!!! Semper Fi Jeff

I'm hoping for the same results that Jeff has.  I just bought 20 Wolff Xtra Extractor Springs and they came packaged with NO inserts.  Don't know if this is normal or not, but I have a few dozen blue inserts and if they don't mean squat, then the blue will go in there.

Quoted: I'm hoping for the same results that Jeff has.  I just bought 20 Wolff Xtra Extractor Springs and they came packaged with NO inserts.  Don't know if this is normal or not, but I have a few dozen blue inserts and if they don't mean squat, then the blue will go in there.

You just use your current insert.  

Quoted: You just use your current insert.

But does the 'current insert' wear out? I mean, should it be replaced when the new spring goes in?

I think they get lost more than wornout.  Never heard of one wearing out.

Quoted: Quoted: Wolff Xtra Power Extractor Sping ....I"ve been running them in all my AR's for years and have had ZERO problems!!!!!!! Semper Fi Jeff I'm hoping for the same results that Jeff has.  I just bought 20 Wolff Xtra Extractor Springs and they came packaged with NO inserts.  Don't know if this is normal or not, but I have a few dozen blue inserts and if they don't mean squat, then the blue will go in there.

Sounds like you are ready to go.  As always, Troy is 100% right on this.

I have used the Wolff, SAW Sales, Colt M4 and Model 1 Sales " extra-power" extractor springs on 16" carbines.  The Wolff is the strongest, the Colt M4 only slightly stiffer than the stock spring. They have all worked with 100% reliability. The color of the insert doesn't matter.
What is the best setup? Why the Model 1 of course, it only costs $1.00.

Quoted: I run Ken Elmore's Specialized Armament green springs in my carbine bolts.

+1. I have used these in my 11.5" RR for 2 years with zero problems.

Another satisfied Wolff Extra Power Extrator Spring user here.  The Wolff springs have worked flawlessly witout the need for o-rings or Defender rings.

What's the difference between the "Crane" O ring and a generic O ring? Is one made out of 'unobtanium'?

It's a simple, normal o-ring. Just go to the hardware store with your extractor and find an o-ring that works.

Quoted: What do people all think of the LMT bolt with the dual springs? Any evidence it is better than a D-Fender or Wolf high-power spring?

Not worth it.  I would take a Colt with an enhanced spring over the LMT any day.  In fact, I have, because of problems with the LMT.

Rsilvers wrote:
With the D-fender, do you leave the other insert in place? And does it matter if the other insert if black or blue?

And also, does the new black D-Fender have the same properties as the older blue one?

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AFAIK, the insert is an attempt to do what the D-Fender does, in a different way, so I think having both would be a duplication, and possibly not good.  I never tried shooting with both of those items in place.

The black D-Fender and the older blue D-Fender are the same material, just different colors. All of them come black now.

Regarding the O-ring "replacements" instead of D-Fenders, the D-Fender is "wedge-shaped" in profile, and is designed to provide the needed shape that interacts with the tension of the spring being stronger on one side than another(due to the inherent forces provided by a coil). It does not get "squashed" like the O-ring does. When the O-ring gets squashed, it ties up the gun. The D-Fender has never had a malfunction due to being "squashed" like the O-ring does. I can't believe that with a $10k M16, a $12.95(shipped) part that enhances reliability is even a cost issue. It's not like there's a question about it. It has an outstanding reliability and performance record. That being said, if you want to put the $1 O-ring into your $10k M16, it's fine with me. But, let it be said that I warned about what will happen. We tested these things, and if the wedge shape wasn't needed, we wouldn't have gone to the trouble of making it that way.  We made it that way, because we saw in testing what happened when it was "just an O-ring". Our designs are patented, and that's why you see all these other "methods" of improving extractors that are NOT like ours.

Just another data point: on my 11.5" SBR for years and several thousand rounds I used a stock spring/blue insert/D-fender with very good success. Recently I started having problems. The old D-fender was looking a little flat. I replaced it with a new stock spring/same old insert/new Olympic "X-ring" and 1K rounds later still having great performance. The X-ring is a lot less expensive, I think I paid $2. I was going to cheap-out on a bag of Viton O-rings, but the O-ring shipping was more than the X-ring from my local parts guy.

IMHO, a good fresh stock spring with any kind of appropriately O/X/D-ring will work great. As long as it's made out of heat resistant material (e.g. Viton) go with what you've got handy. There's really nothing special about anyone's O-ring, Crane or otherwise. Nor is there anything special about the X-ring (my roadracing motorcycle chain has 100's of them inside it). The D-fender is only special because of its (uneccesary) shape and high price.

aa777888-2 wrote:
The D-fender is only special because of its (uneccesary) shape and high price.
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Okay, now for a little history.
Years ago, when Mack Gwinn and Jim Sullivan were working on the Counterpoise System, they found that the extraction problem on shorties would have to be dealt with, to have a fully reliable system. They were the first ones who even attempted to deal with it. Every conceivable O-Ring was tried, before the intial run of D-Fenders was made. All the O-ring failures and causes were identified and proven before the D-Fender was developed. The D-Fender shape and material was based upon these tests which showed what was needed to be a correct product for curing these extraction difficulties in carbines and SBR's. All of the other methods now currently being sold by other manufacturers came after our work, and they do not address the key issues related with the correct design for a part of this type.

It does cost more than others, but it is properly designed, and battle proven for thousands of rounds. If correct design and execution means anything to you, the small amount of money that the D-Fender costs shouldn't be an impediment to getting the best from your carbine.

No disrespect meant to any other manufacturer, but we were the first, and are still the ones with the most experience in this area. We know what works, and why. We were the first discoverers to find out something like this would cure extraction problems. We tested, tried, and designed the answer. Now there are alot of people saying that an O-ring will work just as well for 50 cents.

It's your gun.  
We can only build the D-Fender, we can't make anyone buy it.
It's the best.
Only you can decide what your life is worth.