MPX after market extractor spring wear

[Chillywig]

Today at a match a friend/fellow MPX shooter raised some concerns about the SSI extractor causing premature extractor spring wear. I just changed a few parts on my gun thinking it was about time for things to start breaking and the extractor was one item I replaced. I test fired the gun last night and shot a match today so I have about 400ish rounds on the new extractor and spring that came with it. After examining the new extractor spring compared to the extractor spring I just removed with the factory extractor;  the new spring does seem more compressed than a sig spring that has many more rounds on it. Any one else seen the SSI cause the extractor spring to wear quickly and have extraction/ejection issues?

 

[SergioSF]

You mean like this?

 

[Chillywig]

Its not that bad yet - but damn!

 

Just measured my springs for comparison.

Sig factory spring used in sig factory extractor for ~1500 rounds 0.176"

SSI spring used in SSi extractor <400 rounds 0.155"

 

So whats the weak link. The SSI extractor or spring?

[Chillywig]

[SergioSF]

1 hour ago, Chillywig said:

So whats the weak link. The SSI extractor or spring?

 

In my MPX, it didn't matter whether it was the SSI or OEM extractor. My MPX chewed up springs within 200 rounds, as various malfunctions ensued.

The culprit was a worn out Raptor charging handle. 

I never suspected it. A friend witnessed the CH flying in and out as I was firing. (like a reciprocating CH!)

Swapped back to the OEM CH and it immediately solved the issue. I also went back to the OEM extractor, as I was advised by Rob @ ILWT that some MPXs just don't jive with it.

[Chillywig]

14 hours ago, SergioSF said:

 

In my MPX, it didn't matter whether it was the SSI or OEM extractor. My MPX chewed up springs within 200 rounds, as various malfunctions ensued.

The culprit was a worn out Raptor charging handle. 

I never suspected it. A friend witnessed the CH flying in and out as I was firing. (like a reciprocating CH!)

Swapped back to the OEM CH and it immediately solved the issue. I also went back to the OEM extractor, as I was advised by Rob @ ILWT that some MPXs just don't jive with it.

I read about your charging handle issue on a previous post. I am pretty sure mine is not doing that. Just had lunch with another MPX shooter that had ejection issues with the SSI extractor and went back to an OEM and his problems went away. Anyone else out there have ejection issues due to faster than expected wear on the extractor spring using the SSI?

[2011BLDR]

The extractor spring and insert is the weak link.  I was having spring failure issues with the stock extractors. Adding the  SSI extractors with the same spring and insert  didn't change anything.  I now use AR extractor springs with the  correct black insert:

https://www.brownells.com/rifle-parts/bolt-parts/extractor-parts/extractor-hardware/ar-15-m16-extractor-buffer-prod20892.aspx?avs|Make_3=AR-15

either Wolf XP with 1-1.5 coils cut off :

https://www.brownells.com/rifle-parts/bolt-parts/extractor-parts/extractor-springs/ar-15-m16-extra-power-extractor-spring-prod16488.aspx?avs|Make_3=AR-15

OR

The current colt with .5-.75 coils cut off:

https://www.brownells.com/rifle-parts/bolt-parts/extractor-parts/extractor-springs/ar15a4-extractor-spring-assembly-prod4840.aspx?avs|Make_3=AR-15

 

I cut coils until I get:

1. Proper tension against the extractor pin

2. Chabmering of the top round off of a 48 round mag from bolt lock

 

 your results might varry, I am running restricted gas plugs with the MBX comps that increase back pressure, and 13% reduced recoil springs to reduce dot movement. Load is115 gr bullets @1400 fps.....

Edited May 28, 2019 by 2011BLDR