BRNO ZKK 600 gunsmithing options

Discussion in 'Gunsmithing Forum' started by Superoo, Aug 20, 2010.

  1. Superoo

    Superoo New Member

    Hi All,

    I own a BRNO ZKK 600 chambered in .270 cal. It's the model with the pop-up peep sights and has a factory two stage trigger.

    It also comes with a beautiful walnut stock complete with a thick rubber recoil pad. I use a Leupold Vari X II scope in 3-12 x 40.

    I never have any problems with recoil - can shoot this rifle all day long without flinching. Compared to my friends' .30-06 (pronounced, dirty-06!) it's so easy to shoot.

    Quite accurate at the moment - I have almost head shot a kangaroo at 300m from the window of a vehicle (rifle resting on the door trim).

    However, I'm trying to work out if I should take it to a decent gunsmith to improve the accuracy further, or sell it and buy something else (ie. maybe a .270 WSM 0.300 Win Ultramag).

    I find the Leupold pretty useless for long range. I like the .270 as a caliber because it's so flat, decent knockdown and not much recoil.

    Any ideas?

    I was thinking of glass bedding the barrel, lightening the trigger (although the 2-stage is pretty light on the second option) and floating the barrel. I imagine I would also need a good scope (any ideas there - Meopta, Doktor, Zeiss, or anything else?). I don't know much about what's involved in these, but I think the most important thing is that I want it to remain a good pig/deer rifle with extended long range capability for 'roos out to around 500 or 600m if possible.

    I've read some people saying they can get a good .270 to shoot out towards 800m, but I find that hard to believe. Not after a match grade rifle, or a show-pony one, but something decent for long range field shots.

    Appreciate any info you guys could add. Bought the rifle for around $1200 AUD (hardly used, almost new) and would like to improve it, not completely screw it up beyond recognition.


    Superoo! :D
  2. stalkingbear

    stalkingbear Well-Known Member

    First, you need to establish what the accuracy level is now and realistic expectations of what you want/will settle for. How tight does it group now?

    There's several things you can do to improve accuracy. Some may or may not improve it. If the trigger is smooth and light enough then I wouldn't touch it-you're already used to it. If you honestly feel the trigger is holding you back then by all means have a trigger job done on it.

    Glass bedding (action) and free floating the barrel don't automatically guarantee better accuracy. What glass bedding does is form a skin tight fit between the action and the stock. I ALWAYS recommend bedding the stock-either glass bedding, pillar bedding, or bedded with an aluminum bedding block in the stock. Free floating the barrel prevents the stock from putting pressure against the barrel, and letting it vibrate freely when a bullet goes down the bore. Some barrels perform better with some upwards forend pressure against the barrel but most will benefit from free floating.

    Hand lapping the bolt lugs will ensure full contact of all locking lugs. That means the bolt won't flex when the rifle is fired. If both lugs are not contacting the lug recesses in the receiver, the bolt WILL flex slightly until they do upon firing. That flexing may cause the bullet to start down the throat & bore to be cockeyed a very slight amount, causing the groups to be larger than necessary.

    You didn't mention whether you're handloading or shooting factory ammo. Careful handloading WILL improve your accuracy. Read this post on handloading.
    SWSinTN likes this.

  3. Superoo

    Superoo New Member

    Thanks for the info StalkingBear.

    I have made a single shot in over 2 and half years since I've been based overseas for the period (and my rifles are at home), but from memory I could get 5 shots within a 1inch spread at 200m. That was using factory Winchester 130 gr ammo I recall.

    I also mapped out the trajectory and it's the standard 270 ballistics - an inch high at 100m, dead on at 200m, and an inch low at 300m.

    As you've stated, custom loads always improve the accuracy, but I don't have a reloader yet (and I heard Lee re-loading gear was not great??) and have to buy my custom loads from the local firearms store. Never had the chance before moving o/s so can't tell ya how well it shoots with handloads.

    I'd like to be able to headshot a kangaroo at 500 or 600m if possible (I "shoot" as well as hunt, and there are some very large crop fields we try to control the local kangaroo populations on). That would be akin to hitting a 5 inch spread at 600m.

    Is that a realistic goal for this rifle, or would I need to re-chamber into another calibre?

    Also, what scope would you recommend?