Do all HK Rear Drum Sights Wobble ?

[rocketfish]

I recently picked up a G3 rifle (FMP parts kit). The rear drum sight has some wobble. Even when it's "locked in" to an aperture setting, it slightly rotates about its axis causing the aperture to move left to right. It's not much movement but it's enough to open up the groups horizontally at 100 yards.

I was at a gun shop yesterday and checked out an HK 93 (a real HK one but old/used) and some PTR 91's. Sure as ****, the rear sight on the HK 93 wobbled. I asked the clerk about the PTR 91's and he said they wobbled too.

What in the heck is going on? Do they all wobble? Are there just a lot of cheap surplus Portuguese sights going around that I'm seeing?

Here's a link to some video I made of the sight wobble:

http://www.youtube.com/watch?v=MsMImKB-GCQ

 

[86thecat]

The higher the drum is adjusted the worse it gets. Most of the wobble seems to be between threads of the rotating drum and the ring. Once elevation is set a couple dots of silicone adhesive inside the ring may help hold these parts in alignment, just don't glue everything solid.

 

[wideym]

My HK91s drum don't wobble. The rifle has see rough use and the only pet peave is the trigger/grip housing is a little loose. Maybe the screw is a little loose on the sight drum?

 

[Chipperman]

Mine don't wobble.
(HK91, MP5, V53)

 

[redneckrepairs]

Nope the ones epoxied down dont wobble at all LOL . Seriously tho the drum sight has to turn to rotate apatures for ranges into line to sight thro , a slight play in the sight is not uncommon.

 

[Chipperman]

Once it locks into the detent, though, it should not be wobbly.

 

[redneckrepairs]

Once it locks into the detent, though, it should not be wobbly.

true assuming both sides of the detent are to spec , the spring has proper tension , and there are no other " artifacts" on either side to cam things slightly out of alignment . My attempt at a humorous post was to more or less illustrate that this is a battle rifle expected to shoot into 4 to 6 moa at best . I am not saying that many wont do better , none the less even tolerance stack can degrade it to the loose end of that standard .

 

[HorseSoldier]

The HK firearms I've shot have not had wobbly sights, but then they were in fairly new condition. I could see how it might become an issue with worn weapons or kit builds. I'm kind of surprised that a new PTR-91 would be wobbly, though (they're new builds aren't they? do they use some surplus parts?).

 

[TexasRifleman]

I'm kind of surprised that a new PTR-91 would be wobbly, though

The otherwise good quality of the PTRs seems to have been left out of the sights. My rear sights suck, they are too far offset for windage to adjust to center and they wobble. This on a brand new PTR91

 

[waterhouse]

I just checked mine, both my PTR-91 and Greek Sar-8 rear sights seem to be fairly solid, meaning I can turn them easily enough to change elevation but they don't wobble once set.

 

[Kipling79]

Checked my G3 parts gun, which even has a Hesse reciever and it had no wobble at all.

But, that really doesn't surprise me, because my reciever (at least) has never fulfilled the the rumor that "Hesse" is horrible. Quite the contrary actually.

Sounds like a problem with the internals... maybe missing a ball-bearing? springs not tight? I dunno... never been inside the drum since I beleive I lack the tool required.

Jeremy

 

[MassMark]

HK 93 purchased 1985: Over 100,000 rounds through the gun - zero wobble
HK 91 purchased 1985: Over 50,000 rounds through the gun - zero wobble
HK 94 purchased 1986: Over 50,000 rounds through the gun - zero wobble

 

[rocketfish]

LMAO! This kind of crap always happens to me. :banghead:

I took it apart and could see nothing wrong. The spring was there and a shiny little detent ball was down in the little hole where it's supposed to be. The detent ball did not come out. Is the detent ball supposed to come out of the hole?

 

[rocketfish]

double post