Results 1 to 7 of 7
  1. #1
    User
    Join Date
    Sep 2011
    Location
    Western Cape
    Age
    32
    Posts
    4

    Default . 260 Rem long action conversion

    Good day.

    I'm reloading 129gr sst in my Tikka 260 rem. However my coal is restricted by the mag length. Loading at maximum mag length, im still 3.6mm off the lands. And I'd like to get closer.

    I've done some searching and found that replacing the bolt stop to that of a long action and getting a 25-06 mag will then allow the additional space to load much longer coal to get close to the lands.

    Can someone help with sourcing the boltstop and magazine locally. Before I try importing.

    Thanks

    Sent from my SM-G960F using Tapatalk

  2. #2
    User
    Join Date
    Aug 2017
    Location
    Jo'burg.
    Age
    47
    Posts
    168

    Default Re: . 260 Rem long action conversion

    Forrest, allow me a somewhat differing opinion, but I doubt seating the bullet "on the lands" has any magical properties.

    Many calibers - 7x57, 7x64 - have long throats, and never seat a bullet anywhere near the lands. They are just as accurate, though. My rifle's current pet load (also limited by magazine length) is close to 9mm "off the lands", and shoots sub moa if i do my bit.

    Coal has a massive effect on pressure and speed, but there is no real benefit to "seat just off the lands", imo. Tweaking coal allows you to control muzzle speed, and once an exit node is found, you are good to go.

    However, what is important is that a projectile jammed into the lands can spike starting pressure. A bit of a lead seems to have the benefit of smoothing any potential spike out, and manages starting pressure. In my opinion a 4mm lead is probably beneficial, not detrimental.

  3. #3
    User
    Join Date
    Sep 2011
    Location
    Western Cape
    Age
    32
    Posts
    4

    Default Re: . 260 Rem long action conversion

    Hi AJR

    Thank you for the feedback. I am new to reloading and have only been reloading for a year now so I welcome such feedback. I can only learn from.

    I am aware of the pressure spike of seating up to the lands.

    My .223 performs best very close to lands with 55gr vmax. Sub moa groups and so far hitting 6inch gong at 500m.

    For my .260 129gr Hornady interlock, I'm 0.5mm off the lands. Sub moa groups but lacking consistently past 600m on 6inch gong.

    So I'm trying a Hornady 129gr sst load with varget and have seated to the cannelure (max allowable for mag length). Im yet to get to the range to do load develop.

    Was looking at the long action conversion as an option should I not get good grouping with the sst.

    Sent from my SM-G960F using Tapatalk

  4. #4
    User
    Join Date
    Aug 2017
    Location
    Jo'burg.
    Age
    47
    Posts
    168

    Default Re: . 260 Rem long action conversion

    A boattail design - such as the sst - could probably work a bit better beyond 500m. Also check your bullet's stabilisation: is the bullet suited to your barrel's twist rate.

    In any event, lekker skiet!

  5. #5
    User
    Join Date
    Apr 2011
    Location
    Republic of Texas
    Posts
    1,742

    Default Re: . 260 Rem long action conversion

    Try a Sierra 140 or 142 grain HPBT matching. Set the COL to the Sierra manual specs. Make a 20 round batch starting with the min. Load. Do another batch with + .4 grains of powder. Do that until you get close to the max. Load. Take them out and bench shoot them at 100 or 200 meters. You will find one batch that groups really good. It took many batches before I hit the right settings on my 6.5x55. I never could get Honadys to group well. Their bullets seem to be designed more for hunting.

    Iam just starting this process on my new Tikka CTR 308. If it would stop raining.

  6. #6
    User
    Join Date
    Nov 2011
    Location
    Kempton Park
    Age
    33
    Posts
    2,480

    Default Re: . 260 Rem long action conversion

    Only reason I would like to load with a larger COL is to not have the heavier bullets take up too much case capacity. That is a problem with the standard magazines. I shoot a .260 CTR.

    See http://www.watersrifleman.com/magazines/

  7. #7
    User
    Join Date
    Oct 2012
    Location
    Under the Jackalberry.
    Age
    53
    Posts
    7,646

    Default Re: . 260 Rem long action conversion

    The real reason one would need a longer mag in a Tikka 260 is to be able to load the efficient 140gn+ bullets without the ogive reaching into the case mouth. Being able to play with the "jump" is a bonus, but not always a prerequisite to extracting the full accuracy potential from these rifles.

    Generally, the Secant Ogive bullets (Hornady etc.) are somewhat sensitive to "jump". The Tangential Ogive bullets (older Sierra etc.) are generally much less sensitive. Then there are the Berger "Hybrids" that offer the best of both worlds, but at a price. Look for a type that your rifle likes.

    The bolt stop can just be shortened, no need to find a new one. Measure twice, cut once.

    The longer mags for the 30-06 length cartridges should fit and function perfectly. I have seen a few at gunshops, priced around R1k. Somewhat steep for a flimsy plastic mag, but if it works, it works.

    There are various after-market mags made worldwide for the T3 rifles. Check out Waters Rifleman from Australia, for example. I got a Waters for a T3 in 223 from G&G Varminting in Bloem. Maybe they, or someone else, could bring in the required part. Don't expect any of these machined metal parts to be cheap.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •