Ar-15 buffer springs and checking wear


#1

Buffer springs! Let’s talk about them.


#2

Any experience with the Geissele Super 42 Braided Spring?

Braided Wire Buffer


#3

I found a video made by geissele automatics.

In this video Mr.Geissele explains the importance of the buffer spring in your Ar-15 rifle. In the video he had mentioned that once your buffer spring is compressed to 10 and 1/16 of an inch it needs to be replaced. They also talk about the development of there super 42 braided buffer spring. They take you to there R&D department and show the difference in wear in a stock spring and there super 42 spring wear! It is very interesting.
So I went down to measure one of my buffer springs that has a huge amount of rounds through it, many, many thousands of rounds. The minimum length before replacement is in decimal is 10.0625”. I removed my spring and measured it.


When measuring remember that you want just the slightest bit touching, try rolling the spring. Close your eyes and try to feel the spring drag on the caliper.

I was pleasantly surprised that it measured 10.6565”! Still good at least measurement wise.
The rifle this spring came out of is a pre ban 16”, Carbine length gas AR.
Here are pictures of the buffer weight in the same rifle.

Like I said lots of rounds fired!
Now to be honest I love giessele’s products and I love over engineering too!
So what do you think?
What’s your experience?


#4

That’s exactly where I was going with this Brother!


#5

I love my JP Silent Capture spring.

It’s quite nice to have the buffer and spring as a self contained unit.


#6

JP really hit a home run with their captured buffer spring. But I may go with the Super 42 for my eventual AR10.


#7

I believe it is nice.
My only hang up on that is I have a friend that has had one come apart during firing. I wasn’t there when it happened, but when he told me he was let’s say animated!


#8

Loctite exists.

Too many people fail to use it when instructed and then blame the thing instead of their failure to use loctite…


#9

Maybe that’s exactly what happened. Like I said I wasn’t there.
What are some of the positive aspects of owning one? What are some of the negatives? You sound like you have experience with them, share it with the forum Brother.


#10

Multiple spring weights to tune your rifle. It’s easy to pair with an adjustable gas block and have a real nice shooting rifle.

The captured portion is real nice for disassembly. Minor thing, but handy to not have things flying all over the place.

Finally, it’s just smooth. It feels different and is real nice - it’s difficult to describe.

Oh yeah, if you’re shooting suppressed, it is nice as it gets rid of the twang in the buffer tube.


#11

Sounds like all good positives! I know JP makes quality parts and I have talked with a few reps being there made not far from my home.
Is there any negatives you can think of?
Do you know the life expectancy of the shorter springs in the system?
What does one cost?


#12

The negative is the cost. It isn’t cheap. There’s a lot of parts on your AR I would upgrade before getting one of these.

I don’t know about the life expectancy. I haven’t had to replace mine yet, but I have replaced a regular buffer spring before.

To my knowledge, the only downside to the JP spring is the cost.


#13

You need to be careful with buffers, springs and receiver extensions with 308 ARs. You pretty much cannot use an AR15 spring in a 308AR. There is no standard between manufacturers and this is frequently the cause of malfunctions (FTF, FTE, etc…) with new builds. There are 3 main “standards” that work well independant of each other: Armalite AR10, DPMS pattern and Rock River (used only with their rifle or early Bushmaster 308).
There are dozens of threads with examples of mismatched buffer systems with the corrections needed in the 308ar.com forums. This has gotten worse over the last couple of years with some low priced manufacturers producing things that they have not researched well. Their quality control is not always what it should be.
Two places to look for specifics are this thread and www.heavybuffers.com. There are plenty of people more knowledgeable than I am about this. @Robocop1051


#14

@USMCMahon

@ArmedEyeDoc is correct in this. To keep it simple… find a true Armalite AR10 system and use that, if you can.

• A5 receiver extension, which is also a 7 position 8” tube. This is about 3/4” longer than a standard AR15 Carbine receiver extension.

• 3.250” buffer

• Armalite AR10 RIFLE length buffer spring


#15

Tubbs flat wire springs are good shit! One size fits both rifle and carbine AR-15 and another size fits rifle and carbine 308AR platforms, including the AR-10 carbine tube. If his site is out of stock LaRue Tactical usually has them. He has another lighter spring for running low mass builds and 300 BO subsonic.
http://www.davidtubb.com/tubb-springs


#16

This is because most flat wire springs are only 2” long when fully compressed. This makes them usable on ANY buffer system.

I recently compressed an entire flatwire spring onto a DPMS LR308 2.5” Buffer. The plastic nub still protruded beyond the compressed spring.


#17

This is because most flat wire springs are only 2” long when fully compressed. This makes them usable on ANY buffer system.

I recently compressed an entire flatwire spring onto a DPMS LR308 2.5” Buffer. The plastic nub still protruded beyond the compressed spring.