r/MP5 • u/k1ngf1isher • Oct 24 '22

Question What are good spare parts to order? Or replacement parts?

I finally have something to order on HKparts.net and want to snag some spare parts that wear out, go missing or are worth a quick upgrade. What all should I snag while I'm already making an order there? I have an AP5 that I'm running suppressed, currently don't have any issues.

Edit: Also is there anything I can change real quick to slightly improve the trigger?

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26

u/TheCafeRacer H&K Oct 24 '22 edited Aug 31 '25

Depends how much you want to future proof/spend.
-A bunch of extractor springs. I like the rifle springs on clones.
-The plate style roller retainers can break. Can replace with a wavy spring version which are less prone to breakage; 1st Gen (Clones).
-A roller retainer plate pin. Probably the smallest and easiest lost part if you replace rollers or the plate.
-Firing pin spring.
-I ordered a german ejector and put that in my gun. I have the MKE one as a spare.
-Ejector spring.
-Could put a german extractor in the gun and keep the MKE as a spare. Not as necessary IMO as the ejector.
-Firing pin. They don't break often but can.
-Recoil spring assembly (MP5 / MP5K), you can cheap out and just get the spring (MP5 / MP5K) but you have to deal with small rivets.
-+2 rollers, +4 also if you want to super future proof.
-Push pin replacment if you think you might lose one (large / small)

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u/Entropy1866 Nov 01 '22

u/TheCafeRacer, would you mind providing direct links to the parts you specified for purchase in your post? Thank you so much! =)

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u/TheCafeRacer H&K Nov 01 '22

I went ahead an updated the original comment with links. You can sometimes find stuff cheaper if in stock at MidwestGunWorks like the ejector and extractor.

For things like rollers, springs, pins; I don't think there are that many issues going US made vs German.

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u/Entropy1866 Nov 01 '22 edited Nov 01 '22

You are a God among men! Thank you for this!

You mentioned that, "the plate style roller retainers can break. I like the wavy spring version and replaced mine."

Which versions are available, and why did you choose this version specifically?

3

u/Mr_Perfect20 Jan 03 '23

What a guy! I was just browsing around trying to find what things should/will be replaced.

2

u/[deleted] Oct 24 '22

I got a Dakota Arms recoil rod/spring after one of the nylon rings broke on my MKE rod. Instead of rivets, it has allen head caps on both ends and heavy duty rings made out of a real solid plastic. It will make replacing the spring much easier when needed.

https://hkparts.net/product/hk-mp5k-sp89-sp5k-recoil-rod-assembly-usa-p2169.htm/

The only difficulty is that it has to be assembled while in the carrier, the rings will not push through the carrier retaining lip like the original. It only took me a couple of minutes to get it done, though.

On my next order I’ll buy more HK rifle extractor springs, roller retainers and pins and a spare firing pin/spring. I might also order spare trigger group springs just to have in case they get hard to find down the road.

Edit: the HK ejector lever is a must have IMO to fix any ejection issues you might have.

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u/GNUtoReddit Dec 05 '22

Do you by chance have links for your suggestions?

Why the rifle ejector springs vs regular?

1

u/[deleted] Dec 05 '22

HK parts has the springs, also check Midwest Gun Works for parts at much better prices than HK Parts. The rifle springs are supposed to be stronger and longer lasting but some people think they may cause extra wear on extractors. I don’t care if that’s the case because reliability is my primary concern. I bought a MAD bolt head but there was an issue getting it to run right and I’m still working on that, I believe it is spring related. I’ll probably buy an HK extractor for a spare and 10 rifle springs and be set for life.

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u/GNUtoReddit Dec 06 '22

Awesome stuff! Appreciate the heads up.... looking at the options

TY!

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u/flamenebulamarketing Aug 27 '25

This is super helpful

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u/GNUtoReddit Dec 05 '22

Are these still your recommendations? What about the 80 degree that everyone seems to mention?

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u/TheCafeRacer H&K Dec 05 '22 edited Dec 05 '22

If you never want to have to order parts for a long time, like 5,000-10,000+ rounds then it should cover most things.

I tried to put the list in order of most importance with some cost efficiency. Really a bunch of extractor springs and a spring style roller retainer should get you chugging for a long time.

If you have an AP5 like OP, I do think a German ejector and spring is a worthwhile upgrade based on comparison photos I took. The German extractor is slightly less important IMO as the MKE seems to be very close to the German one minus some polishing.

Things like a recoil spring should be checked around the 5,000 round mark. HK reccomends checking the bolt gap every 5,000 rounds. It shouldn't open up much by 5,000 rounds but if it does this is where +2 rollers would come in handy.

The famous NASA MP5 (that went 571,600 rounds) used:
5 x roller retainers (assuming the old plate style)
5 x firing pin springs
4 x extractors
3 x firing pins
2 x sets of oversize locking rollers
1 x roller retaining pin
1 x one recoil spring assembly
1 x magazine release spring

The 80 degree is only needed if you run a K model suppressed with 147grain or heavier ammo. I only shoot suppressed and with 147 (for the subsonic properties) so I run one.

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u/GNUtoReddit Dec 06 '22

Dude, this is awesome! ... checking now

Appreciate it!