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Thread: Headspace and Walther KK300

  1. #1
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    Headspace and Walther KK300

    Hoping for some top quality advice again please guys..

    I've seen some comments online regarding the setting of head space on various different target rifles. Also a friend at my club has experienced some problems with cartridges sticking in his KK300.

    I'm wondering if getting a KK300 is going to limit my choice with regard to ammunition. I'm also wondering if head space can be easily adjusted on a KK300 and how and why this might be desirable.

    Sorry if I'm sounding a little vague...it's because I am. I've little experience of rim fire as yet nor familiarity with the mechanics of various systems.

    Simon

  2. #2
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    Simon,

    Headspace in a .22lr is the gap between the bolt face and barrel for the case rim. Target rifles have the headspace set at, or near, the permitted minimum (0.043in under CIP and SAAMI spec). This ensures the bolt pushes the rim flush against the barrel face, so when the case is struck by the firing pin the primer is detonated instantly. When there is excess headspace the case isn't chambered fully until hit by the pin, which saps energy, and can cause inconsistent ignition.

    Cases that stick are more likely to be caused by a tight match chamber, especially if the barel and bolt aren't regularly cleaned, than by headspace. Remember the bullet actually engages with the rifling, and is finally jammed in as the bolt locks. Unloading an unfired cartridge can be tricky if the chamber is very tight. A bolt that's set for minimum headspace will feel a little harder to close, because it meets the case a few thousands of an inch sooner tHan an okd and worn bolt with a little excess . However if headspace is set very tight to suit Eley, then the bolt may only just close on Lapua and RWS, as the rims are thicker. I would not expect a Walther ( or Anschutz, or FWB) to be this tight from the factory, as they seem to headspace to 0.043-44in. But it's not unknown when a gunsmith has replaced the barrel, as headspace is often set tight, at 0.041-42in.

    Headspace can be tightened with shims on some rifles. These slip over the bolt body, under the handle. Barry Nesom sells shims for 50p. When a rifle has excess headspace through wear, rather than when the owner wants it super-tight, a new bolt handle is a better long term solution. Opening headspace can be done with a chambering reamer, which relieves the barrel face, or by fettling the bolt handle. Both are jobs for a professional gunsmith, one who is experienced with smallbores. The KK300 has the barrel secured with epoxy, so it can't be moved unlike early KK200s and Anschutz 2013s where the barrel is clamped into a split receiver.
    Last edited by tim s; 17-04-2017 at 11:02 PM.

  3. #3
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    It would surprise me if a KK300 would limit yr ammo choice.
    I've never had ány issues whatsoever in ány matchrifle, be it Anschutz 54/1807/1808/2007, Walther KK100 or any hunting rifle (CZ 452 Krico..).
    Of course there is difference in accuracy and with some rifles (anschutz 54) some ammo is a bit harder to load (closing the bolt) but it doesnt really affect anything.
    Maybe 'exotic'ammo can cause issues, but those dont belong in a KK300 anyway
    ATB,
    yana

  4. #4
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    Thank you

    Again, thanks very much.

  5. #5
    RobinC's Avatar
    RobinC is offline Awesome Shooting Coach and Author.
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    KK300 headspacing

    I've never had nor heard of headspacing problems with a KK300, ours shoot superbly with RWS R50 or Eley Tenex, and I know people who shoot Lapua with them. They are designed as a very ammo tolerant rifle. We've had two, and I still have one, both before, and now the one I still have extracts and ejects each shot neatly into a 6 in square tupperware box if the bolt is lifted with the same effort each shot, (saves picking up empties!), try that with an Anschutz!

    The only time I've seen a KK300 not extract is with an unshot live round and that is because the bullet is stuck in the rifling, but that should be a very rare experience.

    We clean our rifles after every shoot with a few dry felts to remove carbon, and wipe out the breach and bolt face, perhaps once a year I give them a good scrub out to remove any lead build up, (whether they need it or not!) this is the recomended Walther cleaning regime.

    Walther use R50 for its new Rifle group testing. We have never bothered to batch test, and we both shoot RWS R50 exclusively, and have never had a misfire or failure to extract from either rifle in five years, and we both shoot 5K+ a year.
    Walther KK500 Alutec expert special - Barnard .223 "wilde" in a Walther KK500 Alutec stock, mmm...tasty!! - Keppeler 6 mmBR with Walther grip and wood! I may be a Walther-phile?

  6. #6
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    Does headspace affect extraction and ejection in any rifle? Wouldn't weak springs or claw shape be the likely culprits? Failure to eject an unfired cartridge us due to chamber dimension, which is entirely separate to headspace in .22LR firearms with a recessed bolt face.
    Last edited by tim s; 18-04-2017 at 09:04 PM.

  7. #7
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    Thanks

    I 'll relay this to my club colleague who has been having the round ejection problems. It's a relief to learn that this is not an inherent issue with this rifle.

    Many thanks for putting my mind at rest.

  8. #8
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    Quote Originally Posted by Sundance View Post
    I 'll relay this to my club colleague who has been having the round ejection problems. It's a relief to learn that this is not an inherent issue with this rifle.

    Many thanks for putting my mind at rest.
    A good clean out of the extractor slots in the breech with a toothpick, and cotton buds dipped in 009 won't hurt. Many shooters are surprised at how much crud builds up in there. As Robin noted, wiping away any crud from the breech and bolt, especially from around the claws, won't hurt.

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