Many folks want to handload short action rounds longer than their magazines will allow and I recently came across this issue with my 7mm08 and decided to convert it over to allow for loading close to the lands. There is a little information on the internet(several threads about this on 24hrcampfire) but I figured this information may help someone out. All tikka T-3 rifles are built on long action platform. The only difference between the SA and LA rifles is that the magazines for SA have a spacer built into the magazine effectively limiting how far back a cartridge can travel in the mag. In addition, the bolt stop is different between LA and SA rifles with more rearward bolt travel allowed in the LA rifles.
To convert my rifle, to LA, I simply purchased a LA magazine. I have seen an example of people modifying their SA mags to accommodate LA. This process seemed a bit tedious for my skill level and resulting function could be less than ideal with cartridges porpoising or other feeding issues resulting. The mags seem to run at least $50 so someone who is handy or motivated could give this a go to save some dough.
As far as the bolt stop goes, these can be purchased from beretta, and instead of selling just one bolt stop for a reasonable price the kit comes with both LA and SA bolt stops and runs$65 from brownells.
http://www.brownells.com/userdocs/products/p_913400677_3.jpgAs you can see in the pictures the bolt stops are almost identical except that the LA stop has a longer "cutout" section. I decided to do some hacking on mine and the results have worked perfectly, with good bolt retention, cycling , etc. I used a dremel cut off wheel #409 i believe and to keep the bolt stop still i used some small tack nails, and a piece of wood.
