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Tikka 270 wsm and 300 wsm Reloades ???

fordtractorfordtractor Member Posts: 10 ✭✭
edited March 2004 in Ask the Experts
Anyone herd of the T-3 being reamed 0.200 over SAAMI spec's for the 300 WSM and the 270 wsm which presents problems for a reloader. Recent Shooting Times article even noted the Tikka chamber was about 0.200 and the velocity was about 150 fps slower than a Savage that was tested alongside of it in same bullet weights etc.
Has anyone had problems reloading ???[?][?][?]
The rifle quality and value sound great , but I would eventualy like to try some reloads in it , so I would appriciate your experiences before I buy one...
fordtractor.....

Comments

  • nononsensenononsense Member Posts: 10,928 ✭✭✭✭
    edited November -1
    fordtractor,

    Another good question to clear up a mis-understanding from gunwriters.

    The actual chamber for the piece of brass is NOT cut 0.200" longer. The writer is referring to the 2 areas in front of that part of the chamber which are named the leade(also called 'freebore') and the throat. In cartridges that run at the upper end of the pressure scale, a longer leade and throat can be cut which acts to reduce the intial pressure of the cartridge when fired. It is the length of this leade that they are usually referring to. The bullet has room (length) to leave the neck of the brass and travel forward without immediately contacting the throat. The leade or freebore is cut to be approximately 0.0005" larger in diameter than the bullet. This allows the plasma or gases to 'blow by' the bullet, effectively reducing the pressure. The blowby is also responsible for the reduction in velocity since part of the gas driving the bullet is allowed to exit without acting on the bullet. This process has been used by Weatherby since day one. More recently, we saw it crop up in the original chambers for the 300 Rem. Ultra Mags. at their introduction.

    This freebore, as it is most commonly referred to, is good only from the standpoint of reducing pressure. The plasma or gaseous blowby has been proven to cause a couple of different problems with the bullet, most notably, gas cutting, which causes the bullet to be inaccurate due to the removal of material at the base of the bullet. Think of it like a cutting torch used to cut metal. The other is bullet upset. Since the diameter of the leade is bigger than the bullet, the bullet can and does get pushed off center and is wobbling as it enters the bore. Now it's not spinning around it's own center line and it leaves the bore off center and is inaccurate.

    It's long but I hope that it's clear.

    Best.

    29 MAR 04

    My response above answers the why part of your question but not the main reason for the question. I apologize. Here is the rest.

    The main problem with a long leade in a chamber is the inability to reach the lands with short and medium length (weight) bullets or even sometimes, the longer and heavier bullets. Shooters looking to use short, light varmint bullets at high velocities might see problems reaching the lands. This is only a problem if you deem it necessary to touch the lands in order to achieve accurate loads. This concept stems from the benchrest folks who have found this set up promotes very fine accuracy in their rifles. But this is not always true in the hunting world, Barnes-X bullets being a good example. Generally speaking, they are more accurate when loaded 0.050" or there abouts, OFF of the lands. Loading Barnes-X bullets off of the lands also serves to reduce the pressure associated with shooting monometal bullets. Other bullets function accurately off of the lands as well, but it requires testing in your particular rifle to see where it is happy.

    I can only guess as to the 'why' of Tikka using the longer leade. But I think that it stems from the initial reports on the Winchester 300 WSM ammunition being a bit hot in some of the first rifles released. Reports of extremely flat primers and some blown primers were posted to sites on the internet. Some shooters returned rifles that showed signs of high pressure, as they should. So I would also guess that Tikka took this and the possibility of reloaders looking for more velocity, into consideration and had their reamer maker grind a longer leade onto their reamers for the WSM's. The T3's are a hunting type rifle and therefore the longer, heavier hunting bullets would be used the most and most certainly with regard to the 300 WSM. So the length of the leade wouldn't be as much of a problem for reloaders anyway. Factories do use more than one reamer per cartridge but they are all ground the same. The decision for a longer leade would affect all of the reamers for that cartridge.
    The T3's are availble in a Varmint model but not chambered standard in the WSM's. They have to be special ordered if available at all. So says their website: http://www.tikka.fi/rifles_varmint_stainless.php#

    The longer leade is not a safety issue as tembler correctly points out, but it can, as the benchrest people have demonstrated, have an affect on accuracy. The Tikkas that I have fired were all more than reasonably accurate in cartridges other than the WSM's. Everything that I have read indicates that Tikkas are an exceptional rifle especially for the price.

    Best of luck!
  • temblortemblor Member Posts: 2,153 ✭✭✭✭✭
    edited November -1
    All of the reloading data in the available reloading manuals(Hornady #6, Nosler#5, etc.) is compiled to function safely in SAAMI spec chambers. Anything like the small extra leade or freebore would only serve to lower pressure slightly and would not present any safety problems, unless it was a custom built gun that had a tight chamber cut by a custom reamer or just a gunsmithing mistake that might serve to raise pressures to unsafe levels. -- I've had no problems loading for the WSMs................. // PS = The Tikka rifle in that article may have just been one that got by that way. It doesn't mean the one you might buy will be that way. There are lots of variations in mass produced things, and I'm sure Tikka has more than one reamer in the fray..............good luck............[8D]
  • temblortemblor Member Posts: 2,153 ✭✭✭✭✭
    edited November -1
    I agree with everything that nononsense has mentioned but would like to point out one thing worth mentioning. I also read that same article in Shooting Times that you mentioned above. I found it interesting that the Savage clocked so much faster with identical ammo in essentially the same length barrels, but in the case of the Tikka it was exceptionally accurate for a lightweight gun and if memory serves me well it shot over 70% of the loads tested to almost the same point of impact in the bullseye regardless of bullet weight and the author noted it was a "Keeper" with that type of accuracy.-- Go Figure --. Sometimes out in the real world things don't always follow accepted practices.................[8D]
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