Educate me on HK91’s and do they all commit Hate Crimes against brass?

[TheHorta]

NOT ACCEPTABLE- The Management

My question is… do all 91/G3’s do this?

And holy crap does this thing chuck brass a mile or what?! It’s like a lethal secondary projectile. Stuff was, no exaggeration, 25+ feet away!

This is my first HK91. It ain’t no wannabe PTR knockoff. It looks brand new inside and out, all original, with a matching S&B 3-12. It’s a piece or art, but why the hate?

It was LC M80 ball ammo. Included original ammo and photographic evidence of this HK’s crimes against Brassmanity.

Before and after. It literally beat the lip, the side, and the bottom, and scored the case circumference with groove marks.

I literally heard the cases crying and screaming “Why, God?!?!” as they flew through the air.

 

[MadDuner]

That’s what all of mine look like.

 

[TheHorta]

How the hell does it hit top, bottom and middle? It defies physics!

 

[bcrich]

Nature of the beast

 

[W54/XM-388]

Welcome to what everyone has experienced for the past 50 years.
Roller locked guns are very hard on brass due to the way everything works.
They were designed for military applications and brass was always considered single use from the get go.

Yes if you don't hit the enemy with the bullet you might still take them out with the ejected case.

The grove marks in the necks are from the gas flutes in the chamber.

Actually some of the PTR clones beat up the brass a bit less, but still it's not usually considered worth reloading after that.

It's the nature of the system.
If you want to reload your brass get an AR10

 

[isofahunter]

The short answer is yes.

 

[clcustom1911]

My PTR91 does the same with the 45⁰ standard locking piece. I switched to an HK21/23E #9 40⁰ locking piece and it made a significant difference because it slows down the bolt speed noticeably.

And now the brass only fucks off 15-20 feet away instead of the 30-40 feet away.

 

[Texascbr]

Totally normal. Wait till you try the HK belt feds. My HK21 sends brass into orbit. That being said, if it is bothersome you can change locking pieces and try keeping bolt gap on the lower end of the acceptable range.

 

[shoobe01]

I do not recall seeing the mid-case crease as well, but grooves and mouth dent: 100% of the time, intrinsic.

Flute marks are meaningless. People who load a LOT, and to failure for experiments, have never ever ever had a flute related failure. Works like any full power rifle, get 7-8 loads out of them if you do the rest of your process.

Case mouth will need to be opened before you can resize but that's trivial. Get an old pen or make a plastic or wood or metal flaring "tool". Inspect a bit then to make sure nothing creased (may not be able to do this till after resize, but do check) and be sure to lube to reduce the chances of creasing, but should work fine.

Official HK gave such advice when they sold mostly roller locks and had nice CS folks.

 

[Laseredge]

They used to sell a port buffer that clamped over the top of the receiver to help save the brass from dents. Don't know if they are still available. Had one on a 91 30 years ago, and reloaded for it, worked well.

 

[Mudburner]

CETME C also does this.

Anyway... super slow-motion footage of this type of rifle shows that the vigorous ejection actually spins the case so violently that it hits the receiver twice.

The first time, the brass hits the rear edge of the ejection port, making the diagonal shaped crease in mid case. Since the case is spinning, it continues along until it hits the case mouth somewhere aft of the ejection port. If you inspect carefully, you will see the yellow brass stain in that area.

Roller delayed blowback makes for very smooth shooting and pleasantly mild recoil, for 30 cal NATO. Also contributes to a "better than average" accuracy, if popular modern opinions are to be believed.

In my opinion, PTR did a VERY GOOD thing by welding an unmoveable picatinny rail to the top of the receiver for scope mounting. That claw thing didnt seem to stay put, and wandered around under recoil, on my first gun.

This was such a good proven design, it came in many different calibers. I would like to have the 7.62x39 variant, just for fun.

 

[MK20]

When I first shot my PTR I thought I picked up all my brass. I did roof work on my shop the next month and found 2 308 cases on the shop roof

 

[Dogtown]

Dude, this is 100% what the G3/HK91 is known for more than anything

 

[clcustom1911]

CETME C also does this.

Anyway... super slow-motion footage of this type of rifle shows that the vigorous ejection actually spins the case so violently that it hits the receiver twice.

The first time, the brass hits the rear edge of the ejection port, making the diagonal shaped crease in mid case. Since the case is spinning, it continues along until it hits the case mouth somewhere aft of the ejection port. If you inspect carefully, you will see the yellow brass stain in that area.

Roller delayed blowback makes for very smooth shooting and pleasantly mild recoil, for 30 cal NATO. Also contributes to a "better than average" accuracy, if popular modern opinions are to be believed.

In my opinion, PTR did a VERY GOOD thing by welding an unmoveable picatinny rail to the top of the receiver for scope mounting. That claw thing didnt seem to stay put, and wandered around under recoil, on my first gun.

This was such a good proven design, it came in many different calibers. I would like to have the 7.62x39 variant, just for fun.

Slow motion G3 cycling. Very impressive.

 

[Mudburner]

Now... here's the REST of the story. The good news part.

CETME C parts kits are easily available and still fairly inexpensive. A brief search just now showed in stock for $154.

A receiver flat is still available for about $80. A new barrel for $200. Weldment parts, add $50?

So... a guy who can buy a parts kit, de-mill it, bend a flat, press in a barrel, weld a few items correctly, cut the trigger pack for semi auto only... can build a .30 cal NATO Main Battle Rifle for about $500.

Adjusting bolt gap, cocking tube gap etc. and getting it to run right is the tricky part. Totally do-able.

 

[Kamerad]

The irony of it not having a gas system at all.

 

[Camelfilter]

They used to sell a port buffer that clamped over the top of the receiver to help save the brass from dents. Don't know if they are still available. Had one on a 91 30 years ago, and reloaded for it, worked well.
View attachment 8444371View attachment 8444372

Modified one to work with a railed PTR91. Dremel to fit & glued on.

Recommend, if they ever turn up again & someone wants to save brass.

 

[TheHorta]

I feel like I got me some edumacashun. You guys are special. So special.

There’s a song in there somewhere.

 

[TheHorta]

Quick question… spicy ammo, like M80A1 and M993 — should that be avoided, or OK in this gun?

 

[W54/XM-388]

Quick question… spicy ammo, like M80A1 and M993 — should that be avoided, or OK in this gun?

Personal suggestion if it's a mint perfect real H&K 91 all setup with the nice mount and such.
Treat it nice, shoot a bit of mild ammo, keep it really nice and perfect in your safe as an investment and collector model.

Then go get yourself a PTR clone and treat it like the red headed stepchild.

 

[Camelfilter]

Quick question… spicy ammo, like M80A1 and M993 — should that be avoided, or OK in this gun?

Should be fine, however may increase roller wear. Dunno tho.

Would seem wastefull in them tho.

 

[whatsupdoc]

Now you know why they dont make delayed roller lockup rifles. I find the slow motion video kind of odd, the case
ejection appears to be at 3:00 unlike the 91's I have fired that ejected the brass forward at around 1:30

Another thing in the video, it appears the rifle has almost zero recoil dont recall that at all.

 

[Cascade Hemi]

Quick question… spicy ammo, like M80A1 and M993 — should that be avoided, or OK in this gun?

It's fine, just turn the gas down. It's the drum at the back of the receiver on top.

 

[TheHorta]

It's fine, just turn the gas down. It's the drum at the back of the receiver on top.

That worked!