Question about Action Spring Replacement

AR/M4 AR Technical Discussion
1

I bought a new action spring for my Daniel Defense M4 Carbine from Midway, I got this one, the Wilson extra power spring.

It is 1.5 inches longer than the spring that came with my DD. I’ll put pics at the end of this post.

I cycled about fifteen rounds through the action, since I also installed this morning a new extractor. All worked fine, not when I tried to short-stroke the bolt, but when I yanked the CH back and let it fly and then pull it back sharply again, every round cycled in and out of the chamber fine.

[Not to worry, the firing pin was removed from the bolt during this test and the weapon was pointed in a safe direction].

My question is this, should I be concerned that my new spring is so much longer than the stock spring? Any problems I might experience? etc.

Here’s a pic.

2

You’re lucky you did not get your BGC stuck in your upper by removing the firing pin.

3

OK, thanks for that…

Now to my question.

4

Pulled right from the sticky ‘operator level’ thread at top of this subsection:
action spring (buffer spring) a carbine length spring should measure between 10 1/16 to 11 3/4 in length. A rifle spring should be 11 3/4 to 13 1/2

5

http://m4carbine.net/gtsearch.php?cx=003496919632624929056%3Adhiwgm0hbaa&cof=FORID%3A10&ie=UTF-8&q=spring+length&sa=Search&siteurl=m4carbine.net%2Fshowthread.php%3Ft%3D81484#1069 :confused:

6

Huh?
:confused:

To the OP,
Why did you feel the need to change out the action spring?
Especially for an extra power spring?

7

The firing pin keeps the cam pin from turning. If the cam pin turns when in the closed position the BCG is stuck. The cam pin will hit the carrier key not allow the bolt to unlock.

8

I was having some cycling issues.

9

OK. Something was learned today.
In my book it was a fruitful day!

But again to the OP:
Why did you change out your spring for an extra power spring?

10

I’ll try to answer your question again…

I shoot 62 grain 5.56 NATO.
I was having cycling issues with stock spring.
I read up on Wolf extra power springs.
I bought one.
I installed it.
If it does not work for me, I’ll put the older one back in, or get another one.

Any more questions?

: )

11

I don’t see where you posted the answer to begin with.
Unless the site is being wonky again.
Or perhaps you have a different thread on the subject?

How many rounds do you through the old spring?
Have you tried different buffers?

EDIT: Nevermind about the 1st paragraph. I thought you were talking about cycling problems from removing the firing pin! Derp-a-der!

12

Scroll up:

Quote:
Originally Posted by polymorpheous View Post
Huh?

To the OP,
Why did you feel the need to change out the action spring?
Especially for an extra power spring?

I was having some cycling issues.

13

Round count: Getting up to around 4.500 rounds.
Different buffer? No.

14

I got almost the same barrel set up as you, (mine is a 14.5"), I’m at about 5,000 on it.
I bought a new spring about a month ago.

15

Why did you replace your spring? Just preventive, or were you noticing performance issues.

16

I hadn’t replaced it yet.
I did notice my last range trip that on the last round, the carrier catches on the bolt catch, not the bolt.
So I will be toting the spring along for every range trip.

17

Yes, I was starting to have weird problems like that too a few times. I’ll see how it goes with this “extra power” spring.

18

Well I’m too broke for those springs!:o

$4.50 from BCM.

BTW: Jealous of your carbine.
I think the DD V1s are slick.

19

I bought my DDV1 before I knew anything about anything. I just had read good things about DD. If I had to do it all over again, I would have gone with a complete flat top, got BUIS, etc.

I run either my ACOG or Aimpoint most of the time anyway.

But I love my DD.

20

From your pic it appears that both springs are in spec, but at opposite ends of the spec.

I am curious why, if you are at the 4,500 round point, you didn’t buy another standard spring and just look at it as replacing an item that succumbed to normal wear. I don’t have any first hand experience with the extra power springs, maybe you’ll be fine.

But my first inclination would have been to replace the old spring with something I knew worked well. I’d only look at the extra power spring as a possible course of action if the new standard spring exhibited problems.