r/MP5

Bought a MAC 5, slightly on impulse, Saturday. Welds looked decent, bolt gap was okay. Got home and took it apart to clean and lube and noticed it was a complete smooth bore. I’ve sent an email to the warranty for an RMA, now we wait.

MAC 5k first range trip.

I’m not gonna lie, I read A LOT of bad stuff from MAC after buying it on impulse. Read people did this , you have to do that, u need to replace this, you need to break it in 500 rounds with nato 124gr etc etc.

I didn’t clean my gun after purchase, just dumped a bunch of lube in it. I ignored the break in, I believe a gun should run out of the box. My confidence was low about this gun after reading so many negatives.

I fired 50 rounds of 115gr 1150 fps. Fire smoothed with no issues. I then ran a mix of 115 and 124gr super sonic suppressed for 250 more rounds. This thing was smoooooooth! It ran fine with MAC mags. I wish I didn’t get spooked and wasted $80 on a hk mag because it wasn’t needed.

I love it, maybe one day I’ll get a hk but for now I am happy!

ZF5 shooshed by an obsidian 9, topped with a Midwest industries lam + t2 mount, SMS trinity laser, MAC handguard light, and fed via an ibex applications placard. Applesauce standard cocking handle and magwell, completed with a quicksling.

Anybody use their foregrips? I bought one to put on my build with the UTG pro rail and it has an extra m lok notch for no reason. This extra notch makes it so you can’t split the m lok slots it has to go in one, thus making it not useable on my ap5-p.. it cannot mount in the rail closest to the mag well because the rail doesn’t sit flush with the body.. i contacted them waiting to hear back now.

In the mean time i was wondering if it was a one off or mistake.. none of their pictures online show the notch so that’s what makes me think that.. personally I’ve never seen this on anything this small, only long rail scales.. there is no need for it i don’t think, no benefit..

I decided to buy the Century Arms Ap5-p a month or so ago. I wanted to use the gun with a can, of course, so I changed the LP to a 90 degree to get the best of both worlds. Immediately the trouble began. I had double feeds or FTE with every mag, especially while unsuppressed. I began scouring the subreddit for solutions. Changed the extractor and the spring, which didn't help. If anything, I was jamming every 2-3 shots. I changed the ejector lever. Bought HK mags. Nothing. I tried both 115 grain and 124 grain ammo. No difference. I disassembled, cleaned and oiled the gun many times, checked the pic rail clamp, checked bolt gap. I reviewed armorer videos on YT trying to find the small detail that I was missing.

Yesterday, I was at the range with an engineer friend. He wanted to shoot the AP5, but I told him it was a lemon. We tried it regardless, with many jams ensuing. He did notice one thing: Using the suppressor with the factory locking piece, it did seem to cycle better for a few shots. I jumped back online and realized a piece I missed: Breaking the gun in with 9mm 124gr NATO ammo. I didn't know Nato ammo was spicier. I startes paying attention to my ammo's FPS. My 124 gr was rated 1090 FPS, too weak to cycle a new stiff MKE spring. I went out and bought Winchester 9mm NATO fmj, rated at 1200 fps and went to the range.

It worked. I had about 300 rounds through the gun, but plagued by failures. I ran 150 rounds of 9mm NATO ammo through it in an hour. I had 2 jams on the first 50 shots, but the latter 100 went without issues, and that's with both MKE and HK mags. It even began cycling 115 grain 1100 fps rounds with one or two FTE in a whole box. The gun started shooting softer and straighter. It's like a switch flipped to make it work. Trying the previous 124 gr 1090 fps ammo resulted in constant jams again.

Moral of the story: Break the gun in with the correct ammunition. Most posters here do the same thing I did. Have a few jams, and then run to change every lever and spring available. It seems dumb in retrospect, but I rarely saw specific ammo types discussed. I hope this helps other new owners.

I’ve never own any mp5. I bought a ap5p and put about 1000 rounds in it so far. Gun hasn’t given me any problems but for the outer rim of the barrel is it meant to be this rough. Or is this just normal wear