Brassthrasher HK91

[Bulltipper]

Guys,
I have a HK91 that was a safe queen for decades and I recently started shooting her. This rifle is unbelievable to shoot, way up there on the fun factor and absolutely murders the brass during extraction. This is a well known feature of this particular rifle, but my question to any of you who may have one or know someone who does is, have you ever had any problems reloading those cases with the smiley face in the side from the ejection port??? FL sizing removes most of the ding but there is a little bit remaining and I shudder to think I could damage that baby by reloading that brass... I am reloading with a 147 FMJBT over 46g IMR 4895 to get 2750FPS. Any thoughts?

[Jack Stanley]

I used to pick up the H&K abused leftovers at the range . While they were a pain to get them through the sizer dies , the ammo produced worked just fine in my 788 rifle . I'm sure as long as the ammo passes a gauge it would function fine I can't comment on the powder charge though . With all the surplus that was available a few years ago , I'm pretty well spoiled by that now . :smile:

Jack

[MakeMineA10mm]

There's several aspects to HK-abused brass, such as the longitudinal flutes from the chamber, the "ejector-bend", etc. My recommendations are:

1. Use Citric Acid bath cleaning to get rid of most of the scorching from the fluted chambers. This is helpful to keep from scratching up your sizer die.

2. Check on GunBroker/AuctionArms for a "port buffer." HK used to sell these to address the over-active ejector that creates that ejection smiley. In my experience, it usually doesn't totally eliminate the problem, but it does make it a lot less prominant.

3. Try lighter loads. The nice thing about the HK action is that it is fairly forgiving on powder charge, burning speed, etc., and will work well with a less-vigorous load. Less vigor means less severe ejection and therefore a less severe smiley. I bet a load that goes about 2600-2650fps would be better and quite possibly more accurate.

4. I'm betting you've already learned this, as you say you've been loading these, but when you're resizing, be sure to lube the cases very well. Don't over-lube, but make sure to keep in mind that the fluted chamber lets the brass swell more than a smooth chamber.

Hope those ideas help.

[bohica2xo]

Check to see that you have the right locking piece in the bolt. HK made several variations with different angles. This controls the unlock timing / pressure - which determines the bolt speed on a roller locked gun.

Because 91's came from several sources over the years, and some were assembled from used parts it is possible to have a worn or just wrong locking piece. If you bought the gun new from an HK dealer in the US, then you probably have the correct locking piece - for nato spec ammo.

Try some of the DAG surplus ammo in it, it was made for that rifle.

B.

[MtGun44]

+1 on port buffer, helps a lot, but the design is inherently hard on brass. Mine are
mostly used with milsurp for that reason.

Bill

[Bulltipper]

I had tried the port buffer, (the made is USA one from HK parts.com) and it made type 2 malfunctions (stovepipe) every single time i pulled the trigger. i read that the german one is really hard on the finish so i decided to run without. I chose the 2750 FPS load so the Hensoldt z24's BDC would be as accurate as it was with the mil-spec NATO round. This rifle was purchased from a really good friend who had never fired it and had bought it new in 1982. A really good friend:-) I have been reloading the ones with less of a dent and have not had a problem yet...

[bohica2xo]

The dents are just ugly, reloading them is not an issue.

Sounds like you have a good 91, and it probably has the "right" locking piece - HK made probably 30 variants for the 7.62 guns.

Powder burn rate affects the roller delay. A big spike with faster powder will behave differently than a long burn with slow powder. The case floats on gas because of the flutes in the chamber, so it can eject a case while there is still serious pressure in the bore.

You might try 44 grains of IMR3031 to see how it acts with faster powder. Or 44 grains of BLc2 for slower powder. Those two extremes should give you an idea which way to go with this rifle to minimize bolt speed.

B.

[Bulltipper]

Thank you brother B.

[Bloodman14]

Would the dent cause premature case failure? My SKS will sometimes put a small dent in the cases that don't seem to affect the reloading too bad.

[MtGun44]

Probably not, if kept hitting it in the same spot and had the pressure blowing it
back out again each time, it would get hard from work hardening and may crack
eventually. IME the dent in a HK case doesn't go away 100% even after reloading
and firing, and neither do the flutes.

Ugly as heck but they seem to work fine the second time around. My biggest
concern is that the rim is pretty mangled on some.

Again, we are abusing the cases - the mil gun designers have no idea that some
idiot would try to salvage a case and REUSE IT! Not on their radar screen at all.

Bill

[Bulltipper]

Yeah, no kidding on the rimmangling! I can't believe what that rifle does to the sturdy end of the brass... I wonder if the HK engineers wanted to make the used brass unreloadable by the enemy?

[9.3X62AL]

No argument with any of the info posted above. The HK-fired brass was a MOTHER BEAR to resize, but it worked for 2-3 more refills before the rims would no longer go into shell holders.

A lot of owners run milsurp 147 grain FMJs in their rifles due to cost considerations. Know this--my HK-91 and those of friends were ALL natural-born TACKDRIVERS with good bullets. I used Sierra 150 Game Kings atop 46.0 grains of WW-748 and WLR primers in W-W brass--mine threatened 1.00" at 100 yards, and 1.25" was routine.

Time went on, and an M1A NatMatch joined the party. MUCH nicer to brass, and almost as accurate. The CA AWB was pending, and MANY people clamored for the HK. I sold it at a good profit, in spite of a low-order 'bid war' that broke out during the transfer. Young cops, OY VEY. That buyer still has it, too.