Armory Sponsor
Posted: 6/9/2007 6:17:41 AM EDT
|
My SW5 9mm works fine with quality factory ammo, but it has some trouble with cheap reload stuff. I guess that's ok because I'd never use that stuff in an emergency. Hell, I probably wouldn't even use the SW5 in an emergency. But I digress. So the SW5 has got an HK trigger pack which appears to have a .308 spring. Well I took my HK91 apart last night and compared the two. They look identical. I was looking at some online pictures of springs and it appears that the 9mm hammer springs are smaller diameter wire (for lack of a better term) which would imply that the resistence would be less, allowing the weaker ammo to cycle the bolt group further/better. Has anyone had any experience with changing out this sping (and only this spring) to correct problems with lesser quality ammo? And do real HK94s/MP5s have the lighter pull spring, allowing them to cycle further and use lesser quality ammo? Conversely, is this bigger spring going to help with high power ammo by absorbing some of the recoil? |
|
What kind of ammo are you having problems with? Mine will shoot even the cheap white box wins from Walmart. As to using it in an emergency, I would I haven't had any problems with reliability. I know I'm getting on my soap box here, but in the HK world is the only place where if you have a clone you're a lesser person and you get flamed if you say that you would use your clone for anything other than a range gun. In the 1911 or the AR world most guns are clones, hell in the AR, 1911 world if you have something other than a Colt or an Armalite you don't even have to call your gun a CLONE. 
|
Anyway, I was shooting some reloads. I've read several posts here and over at HKpro about the springs in the clones being the same as those used in the 91, which require more power to push them back. I was just wondering if anyone was having a problem with weak ammo and then fixed it with a different spring. I was looking through the MP5 Operator's Guide and it specifically stated "Do not use reloads" so maybe it's not just a clone thing. I just mentioned the clone thing because it's been a previously discussed issue. Sorry if I caused you to get any splinters in your feet. 
|
|
 Dude....you crack me up.
|
|
We'll good news and bad news! The 9mm hammer spring makes it run any ammo, the bad news is I need a pinned hammer strut as the shank of the hammer strut was popping off and jamming the trigger group. Now the question is can I figure out a way to pin the G3 hammer and strut or do I cough up the buck for a 9mm hammer and strut. JAs always YMMV. Jeff |
|
Ok, here's the deal. They used HK91 (.308) trigger packs with the stiffer spring. These do not have a pinned strut/hammer. Using a 9mm spring on this setup can cause the strut to disengage the hammer and cause jamming of the trigger pack. The real MP5 design incorporates a pinned connectiong between the strut and hammer, which keeps this from happeneing. So the options are: 1. Use powerful ammo, capable of cycling the action correctly. 2. Replacing the hammer/strut with a MP5 version (about $120) 3. Wait for the pending release of the US made version, estimated within the next few months but should be cheaper than the HK version. I might get a couple of 9mm hammers and try them out. But I'll probably just use some good ammo till the US made hammer/strut comes out and I can test it. Ah crap, who am I kidding... I'll probably get the HK parts and try that out. In any case, I'm looking forward to seeing if my (to be delivered) CA89k will have this combination or the pinless version. |
What kind of pin did you use? Did you friction fit it to the strut and then allow it to rotate in the hammer??? I've got a drill press with a cross vise so I might be playing machine shop in the near future. It seems that the optimal approach would be to get it close enough to perfect and then adjust the hole in the hammer to allow the original contact surfaces to continue to do their job, using the pinned contact just to keep the strut from jumping out of the groove. |
| I just drilled the strut center. Put the hammer and strut together and work them in your hand to get an idea of how they move together. Then as a unit (hammer and strut)center punch the strut and using a drill press ,drill them through and pin.I reamed the hammer slightly larger and used a small roll pin to hold them . |
Kinda what I thought. Thanx, Jeff |
|
Well I finally got my 9mm hammer springs. It was a little tricky installing one since they are longer than the .308 springs. But I did it without even removing the fire control box from the lower. Then it was off to the range... Well I started with some powerful S&B 115 grain stuff in a straight mag. It worked flawlessly, just like it was in a curved mag. Then I shot some Monarch 9mm ammo from Academy in a straight mag. It again worked flawlessly. So then I decided to go with the acid test: all the crappy 9mm ammo that has accumulated in the bottom of my shooting box, which is a mixture of reloads and cheap factory ammo. I put it all in a straight mag and shot it all easily. There doesn't seem to be a need for pinning the strut to the hammer, especially since there is more force holding them together when in the uncocked position. Not sure why H & K pinned these unless it was for full auto dependability. I got an extra hammer and strut though and might attempt to drill and pin them together. It looks like it might be a bit more direct to do that what I expected. Anyway, I just might be in HK clone nirvana now. The thing is cycling great and completely. And the fact that it appears to be able to operate well with the straight mags is a big plus. |
Armory Sponsor