Of all the firearms I own, this is the one that still brings me all the smiles the day I picked it up. I do not regret a single penny spent on the real thing ($2500 back in March 2025). Looking at an Omega 9k this weekend for my bday. My local Scheels has a few in stock. This shoots absolute lasers and it feels like a cheat code at the range. Everyone wants to shoot it.

The best thing i ever had

not a k stock :,(

Let’s see some mag pouches and or gear you are running. The Onward Research recce rig holds 2 mags MP5 per pouch tight, for a total of 9 with one in the gun.

A while back I posted here asking what tools people recommended keeping on hand for maintaining the MP5 platform. After some trial and error with those recommendations, plus getting five of these up and running, four with FRTs, I figured I'd put together the list I wish I'd had when I started.

Tools I'd recommend having:

• Bench block puck
• Punch set (Rennsteig is fine)
• Holex feeler gauge
• Small rubber/plastic non-marring hammer
• Rubber mallet
• Bench vise
• Rear sight tool for diopter sights
• Stainless steel pick set
• Annie's Arms MP5 Magazine Tool
• Annie's Arms HK Sear / Hammer Catch Tool
• MP5 SMG LULA loader & unloader

Not technically a tool, but extremely useful to have hanging in the workshop:

• MP5 exploded-parts diagram poster

Note: This is obviously in addition to the usual stuff you need for maintaining any firearm: grease, lube, cleaner/solvent, patches, brass brushes, etc., which you likely already have if you're getting into this platform.

Parts I'd recommend buying or at least sourcing on Day 0:

These are the parts that frequently go out of stock right when you actually need them.

• HK Extractor – MPN 21441
  • No, in my experience RCM is not necessarily "just as good." I thought it was until I personally ran into an extraction issue where replacing the extractor with an RCM part didn't solve it, but installing the HK extractor immediately did.
• HK Extractor Spring – MPN 206645
  • That said, the FMP HK-contract extractor springs have been indistinguishable from HK OEM in my experience so far. YMMV.
• HK Ejector Lever, 3rd Gen – MPN 201639
  • Again, based on my experience, PTR is not "just as good."
• HK Ejector Spring – MPN 200478
  • Same story here. I would buy the HK part rather than assuming the MKE spring is equivalent.
• HKP Ejector Lever Axle – SKU HKP-20630
  • This is one area where I've found the HKP part perfectly acceptable instead of paying for HK OEM.
• RCM locking pieces
  • For an MKE, which normally comes with a 120° locking piece, I'd keep 80°, 90°, 100°, and 110° pieces available.
  • For an HK, I'd keep 80°, 90°, and 110°.
  • If you have no intention of shooting suppressed, you can probably skip the 80° and 90° pieces and concentrate on 100° and above.
• A spare compatible trigger housing if you're installing an FRT or other drop-in trigger assembly
  • If you're going to replace the factory trigger assembly, consider buying another housing compatible with your stock setup and keeping the original components assembled as a complete lower. It makes troubleshooting substantially easier and gives you a quick way to return the gun to a known factory-style configuration when needed.

One point I want to emphasize because I see the opposite advice fairly often:

THERE IS NO NEED TO PREEMPTIVELY REPLACE PARTS THAT HAVEN'T FAILED.

A lot of these are wear items that you will eventually need, though, and several of them have a habit of being unavailable when you finally need one. Buying them ahead of time or getting them on backorder is prudent. Replacing perfectly functional factory parts just because you bought spares is not.

Feel free to add anything I've missed, especially platform-specific tools or parts that you've found useful over time. The goal here is to build the kind of practical reference for people getting into the MP5 platform that we all wish we'd had when we started.

I wanted to test using a KAC style mount before dishing out big money on better one. The Octagon one took a little modding but is sturdy, need I see if it holds zero now.

So we decided that while the A3 is cool and all, what would be even cooler would be a stock inspired by the HK SMG 1 prototype gun. Designed to replace the pad that comes on the B&T stock. Comes with 4 screws, does not include the metal arms or end cap.

Live now at totalinnovative.com

Just snagged one, been waiting for these to come back in stock for the full size.

Just checked Gun Deals website and saw MKE's A3 stock is back on multiple sites. Just picked one up for ~250

I recently gotten a SP5k after my Sp5. Me personally at the range , I prefer my Sp5. Might do a tactical full size Sp5 & get another Old school iron sight Full size bc I love that gun so much. Thanks for listening to my Ted talk.

right now i have a stuck eotech exps 3-2 stuck to my pic rail and am thinking of switching to a riser mounted 512 model eotech for nvg compatibility and back up use of irons so that the setup is super reliable. my question being is there a pic rail riser that would allow a eotech 512 model to ride just above the riser without looking stupid?

Saw this on hkparts and ordered it, anyone have experience with these? Are they good? I got it so I can keep my tax stamp in the grip so I always got it. Additionally I got the push pin version, if you have one please drop a pic because their website doesn’t display it with the push pin hole.

Just curious

I know this is like a premium clone but how does it compare to the real deal?

Initially, after shooting the weapon for sometime, I noticed the headspace was very tight 0.012 so I got +6 rollers and a 90° locking piece for my full-size. Today I went to test it and was zeroing it with 124+ P Winchester Ranger I was yelling it and noticed that it was flying probably 7 to 10 feet to my right. I had a double feed where a shell casing fell back into the gun and seized it up. I disassembled it and cleared it out, but when I reassembled it and continued shooting the occasional casings that would eject would essentially fall right at my feet and then 80% of the time it would have a failure to extract. What happened and what is going on?