Plenty of other Post about it.

Doesn't sound like theres much of a difference between the 110 and 100. But HK is shipping its PDW (Stocked) MP5ks with the 100 so that what I would use. The 80 degree is just what you put, its used when using a suppressor, it slows things down a bit to account for a Suppresor back pressure. Firearm could have cycle problems when using the 80 degree but no suppressor. Using a suppressor with the 100 or 110 will leaded to faster wearing on the internal parts of your firearm.

 

My question to you is, what configuration are you going to be using the MP5K clone? Personally, I don't see where using the plain (100 degree) or #16 will add more wear. The bolt group needs enough energy to function, without over function. As posted above there is quite a bit posted about LPs and there is an article about LPs in "The World of HK".

Scott

 

Thanks for the replies guys. This is for a PPRR mp5k-pdw that will sometimes be used with a can.

I just want to make sure I've got things "directionally correct" - smaller angles (like the 80 degree locking piece) result in less energy imparted to the bolt group, and therefore less "wear and tear" and a lower cyclic rate. Is that correct?

Thanks,
Joe

 

Personally, I don't think it is so much about "wear and tear" as about function. If you use a can and a shoulder stock with a #16 or even standard LP, you could get over function. The bolt group will go back so hard that the inertia of the bolt hitting the LP will drive the rollers out, beating on the inside rails of the receiver. Since you would be using a stock all the time, I'd try a standard LP without the can. If you have good function stay with the standard. With the can, definitely, a #28.

You are correct, the lower the angle of the LP, the more energy is transferred into the receiver. The firearm is a system. If you change one thing, you have changed the whole system. Especially with a market value well over $20,000, I'd use the lowest angled LP that would give proper function. YMMV.

Scott

 

Wondering which locking piece to use an in mp5k. There seem to be three in use:

1. Original 110 degree
2. Suppressor-oriented "#28 or 80 degree"
3. Standard mp5 "100 degree" locking piece, which is apparently now standard in the mp5k
I'd really like to get a sense of the pros/cons of each.

Thanks!

HK recommends the #28 when fired as a PDW and with a can. Forget your concerns about wear. This is about function. Bottom line is if you have failures using the 100 degree it will most likely be solved with the #28. I know that is how I solved the same issues with mine.

 

Thanks guys!

 

Um I could be wrong here, but I think some of the people who posted here have things backwards. The Lower the Angle of the Locking Pieces actually lowers the amount of reward force on the Bolt and Carrier. So your more likely to have function problems with the #28 Locking Piece (80 degree) than the 100 or even the 110 angled locking piece. Though using the 100 or 110 locking pieces with a Can, will probably cause over function and thus wear on parts.

 

You are of course entitled to your opinion, but I'm not following your post. I think that you do have the first part right. As I posted above: "the lower the angle of the LP, the more energy is transferred into the receiver" and you posted: "The Lower the Angle of the Locking Pieces actually lowers the amount of reward force on the Bolt and Carrier" which to me are the same thing. A #28 (80 degree) would be used in a K with a shoulder stock and a suppressor. The MP5K connected by a stock to your body would have much more resistance to movement (mass) compared to holding a K like a pistol. So with a stock, the K remains in place such that minimal recoil energy is lost in the whole firearm recoiling back. A suppressor acts like adding barrel length which increases dwell time. Again that adds more energy into the bolt group. Those two things would would make for greater total energy in the system. So a lower angled LP, as we both posted, would put a greater percentage of the energy of the cartridge into the receiver. The #28 is recommended by HK in the MP5 Armorer's Manual for use with both a stock and a can in a MP5K PDW. If you used a #28 in a configuration with out both a stock and a can there might not be enough energy in the bolt group for proper function. YMMV.

Scott