Tikka 300WM - want longer OAL

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by DND, Feb 12, 2013.

  1. DND

    DND Member

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    Looking to the brain trust of the board, hoping I've missed something.

    I'm working with a Tikka Tactical 300 Win Mag in a Manners T4 stock. Load development indicates a longer OAL would be beneficial. My goal is whatever that length turns out to be, is capable of feeding from the magazine.

    Research indicates this to be a common hurdle, for which I have yet to locate a solution.

    Aftermarket bottom metal for the Tikka long action is limited to CDI as far as I can find. While this allows the use of AI mags, it doesn't help with OAL increases beyond the factory Tikka set up due to internal design limitations. No fault of CDI, but perhaps potential to expand on the offering if possible. The challenge as I understand it is, there's not much room to move the magazine back as it will quickly interfere with the trigger.

    Users of short actions have been successful in working with longer OALs by modifying the bolt stop to long action specs, thus allowing the bolt to move further rearward and pick up the fresh cartridge. This works because the short action has room to move further rearward.

    Has anyone, with greater knowledge than I, explored the potential for a similar modification for long actions? Is there enough room to be gained as to make the effort worthwhile?

    A thread on another board indicated Dave Kiff was looking in to developing a DBM that would address exactly this, but that thread has gone silent for almost a year now.

    Beyond that, has anyone come up with anything I've missed? I believe this rifle has potential but is being held back by this limitation.

    Thanks,
    Dave
     
  2. Marble

    Marble Well-Known Member

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    How much further out do you want to push the bullet?

    Have you tested with the longer OAL cartridge?
     

  3. phorwath

    phorwath Well-Known Member

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    I researched aftermarket bottom metal options for my Tikka T3, 7mm Rem Mag, and I learned that same things you've just noted. I was simply looking for an aluminum aftermarket bottom metal that would duplicate the factory bottom plastic. The only one I could find was manufactured in Sweden or some such place and was costing more than $200. Even then, it wasn't clear that they were available for purchase. Dunno if the company continued in business with that item.

    But while Google searching, I also learned that the trigger on the Tikkas prevents any extension of the back of the magazine on the long action calibers. It is what it is. I don't see how that restriction can be overcome unless a new trigger is designed that allows the rear edge of the magazine to be shifted back further.

    I load my Tikka single shot style for LR shots. I carry shorter length controlled expansion bullets in the magazine for bears while hiking, around camp, or for short range shots on game.
     
  4. .284

    .284 Well-Known Member

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    I wish you luck as I'd like to play the tacticals from tikka but why they make the mags like that and use a 24 inch tube is beyond me
     
  5. DND

    DND Member

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    @Marble

    Exact figures are at home.

    I've been testing with single feeding and getting tighter groups with OALs beyond what the factory mag will accept, but inside what the AI will handle. Load development is still on-going but so far indicates I could work within the OAL available with the AI mags.

    For me this would cover both a target (208gr AMax) and big game hunting load (200gr LRX)
     
  6. 6point5x284

    6point5x284 Well-Known Member

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    DND,

    I too have this same struggle. I'm trying to launch my Berger 185 VLD's just off the lands and can't with the magazine restrictions.

    I'm also looking to fit in a Manners T4 stock for the Tikka, and lastly, I'm looking to use the CDI bottom metal with AI mags for the 3.65 COAL like you are.

    Since there are 2 action lengths restricted purely by the bolt release (everything is actually on a long action) my thought process is this.

    If I sell my 300 Win Mag and buy a 300 Win Short Mag...I'll keep the same ballistics which is fine. But in theory, I will achieve what I'm looking for. The ability to seat my bullets to the lands.

    If I use a 300 WSM, (medium action) I can file down the bolt release (or you can buy the full length for $65) so I have the full length of the long action at my disposal but with a much shorter brass length (300 WSM vs the long 300 WM). I'll have the full length of the long action CDI bottom metal and mags to seat out my bullets to whatever length I want.

    Do a web search for "Tikka T3 Bolt Stop Modification" and click on the first YT link and watch it.

    Am I missing anything? It's quite possible I am, but as long as I purchased a long action mag for my medium length caliber (now working in a long action due to the bolt stop fix) it will give us our desired overall length.

    Please let me know if this makes sense...it makes sense in my head but that doesn't mean anything!

    -6point5x284
     
  7. DND

    DND Member

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    Bringing this thread back to life as I've found a solution that is working for me and may help others.

    Installed the CDI DBM which in turn allows the use of AI mags. This set up feeds fine with COAL up to the SAAMI standard. I was looking to go beyond that so began working with a local gunsmith who has proven to be a good outside the box thinker. Together we've modified the AI mags such that my rifle now feeds consistently 300WM rounds with a COAL out to the max the AI mag can fit, 3.65" from memory.

    Our solution was two step.

    1. Using hand pliers we adjusted upward the follower retaining tabs at the front of the mag. This allows the front of the follower to rise to a higher point before maxing out. This results in the follower being front high compared to stock. At most 1/16" - 1/8" increase in height was achieved.

    2. Again using pliers we opened up the first two thirds of the mag lips, which allows the round to sit tip high on an increased angle over stock. Again, the lips were opened about 1/16" per side. The back 1/3 of the mag lips were left in the stock position so the shoulder of the case is still retained in the original orientation relative to the bolt.

    End result for my setup is consistent feeding of rounds with OAL beyond the SAAMI standard and all the way out to the maximum dimension the AI mag will accept.

    Load development is once again underway with this new variable. No conclusions yet, but results are indicating this was worth the effort.

    Hope this helps members chasing the option of longer OAL on the LA Tikkas.

    If pics would help, I'll tackle that too. Only thing is both my AI mags are now modded so there's currently no control piece for comparison.

    Cheers,
    Dave
     
  8. phorwath

    phorwath Well-Known Member

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    What's the purchase cost in materials for your modifications? Pictures would be very nice. Thanks for updating your Thread with your solution!
     
  9. DND

    DND Member

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    Keep in mind I'm in Canada so your costs may vary, probably in your favor.

    CDI DBM was roughly $240 - $250

    AI 5rd mags were roughly $100 each

    Install is smith dependant, took my guy about two hours of effort between machining and test fitting for the DBM, but he's a retired German perfectionist. I know Manners stocks can be ordered with inletting for the CDI DBM now so no increased cost is an option if your already going for a new stock.

    My smith and I took about an hour to wrap our heads around what we wanted to accomplish and to make the necessary adjustments to the first mag. I did the second mag at home in less than 15 minutes.

    I'll get pics happening.
     
  10. DND

    DND Member

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    Okay, pics and a hopefully explanatory tutorial -

    The overall goal is to raise the shoulder and neck of the case in order to facilitate chambering instead of jamming a longer than SAAMI OAL 300WM round in a Tikka T3 action. Image 1 depicts me holding a casing in roughly the stock orientation of an un-modified AI mag on the left. Note how the body of the casing is roughly parallel with the magazine lips. The mag on the right shows how the casing now sits shoulder and neck high and will feed reliably in my action.

    Image 1 -
    [​IMG]

    The front (directly under bullet) of the stock AI magazine follower is limited in the height it can reach by two small tabs as depicted in image 2.

    Image 2-
    [​IMG]

    With these tabs bent up approximately 1/8" on mine, the front of the follower is now visibly higher than stock. In image 3 I am holding the follower on the left mag in roughly the stock position while the mag on the right is at the new raised height. Note the notch at the front of the follower on the right mag is visible for reference. No notch showing on the left mag.

    Image 3 -
    [​IMG]

    Now that the follower is allowed to travel to the height we want it, the new limiting factor for rounds is the magazine lips that retain the casing. By bending the leading 2/3 of the two lips outward approximately 1/16" each side the casing is now allowed to travel to the height the follower will go to under spring tension. This is harder to see, but in image 4 I am pointing with the screwdriver to the point where the lips start being bent outward, all the way to the front or upward in the image. The rear 1/3 of the lips are not changed which holds the case head in the stock position and properly oriented with the bolt.

    Image 4-
    [​IMG]

    Image 5 includes a casing to help see where the tapered bend of the lips begins.

    Image 5-
    [​IMG]

    All bends were accomplished with hand tools, specifically lineman's pliers while holding the magazine by hand.

    I hope this helps anyone looking to run longer OAL in their Tikka T3 and I'll gladly address any questions to the best of my ability.

    Cheers,
    Dave
     
  11. phorwath

    phorwath Well-Known Member

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    Dave,
    Thanks for taking the time to provide the photos and description of your methods and modifications to gain increase overall cartridge lengths. That gives us at least this one option to ponder.

    I just received a Manners Elite Hunter Tikka T3 stock for my Tikka. My rifles are 7mm Rem Mags, so I'm not as limited as you would be with the longer casing 300 Win Mag.

    I'd simply like to use aluminum bottom metal to replace the Tikka plastic bottom metal. I thought someone would have produced aluminum aftermarket BM for the T3s by now, which will accept the Tikka factory magazines. But to my knowledge, there are still no aftermarket options available.
     
  12. Varberger757

    Varberger757 Well-Known Member

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    Maybe I can help you out. Just read a report about customized Tikkas in a Swedish journal. Concerning aluminium bottoms, AICS - and standard magazines take a look at:
    Welcome to AluTek
    BTW, have you ever had issues realted to the recoil - lug in your Tikkas? That seems to be something quite common today. Calibres stronger than 308W and often used (like we do)
     
  13. phorwath

    phorwath Well-Known Member

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    757,
    Thanks for the link to the source of Tikka bottom metal. These look like high quality units. Best as I can determine, the cost for the bottom metal that accepts the Tikka factory magazines is 1800 sek, and that's the equivalent of $280.25 US dollars? Does that monetary conversion sound about right?
    I see you're from Noway, so you may not be familiar with the sek currency either...
     
  14. Varberger757

    Varberger757 Well-Known Member

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    Since Norway and Sweden are direct neighbours it's no real problem. :) The actual valuta exchange is 1 SEK = 0,15 USD. Means 270 bucks for you. :D Yes, and take away the 25% VAT, that might make it even more tasty.