Thread: Tikka 6x45 / 6mm-223

Originally Posted by Mathias

https://www.nzhuntingandshooting.co....-barrel-56502/
19 pages here of reading material.

I have no idea how the search function works on this forum, but I have searched 6x45 on here and have never been directed to that Thread
Thanks for posting that up , I read it from start to finish

Found some old pic's of my 6mm 204 from a trip to Kurow & Tekapo with Jakewire, was a great few days, I miss my bunny - Wallaby shooting mate

Was running it in a GRS stock at this time, Those 87 Vmax are great killers

Finally got down to the Property today ( Weather and Work has just got in the way ) and shot the Tikka for the first time .
These groups were shot prone , Harris Bi-Pod , rear Bag at 100m ( laser Range Finder )
The first 3 shots were to get it on paper and I cleaned between each shot and adjusted scope .
I'm very happy with the results and just sent a text to Lee at Trentech to say he is now my favourite Gunsmith
I didn't bother using the Chronograph today , because all I was interested in was knowing that the Rifle went " Bang " and that it could hit the side of a Beer Carton at 100m
I'm going to load up 100 rounds of the 25.8gn load and just shoot it .
After that the barrel will probably speed up a bit and the real load development will begin ( different powders , seating depths , projectiles etc )
I know 3 shot groups aren't exactly conclusive but when my first 21 shots ( 7 x 3 shot groups ) average under 12mm with three different powder charges , I'm not unhappy .

Nice!

@Ground Control
Good stuff. That's pretty typical accuracy from the 6x45, mine were the same straight up with 85gr & under. Good case/ powder volume / bullet combination, it was a popular BR round until the PPC came along.

Just a bit of an update .

I chornographed the 6x45 the other day .
The barrel had 95 rounds through it up to that point , so the last 5 rounds of the 100 cases I had loaded were tested for velocity .

edit - should mention the load

85gn Sierra hpbt
Starline brass
CCI 450
2206H 25.8gn

2865fps AV / SD of 11fps .

This load is basically the first one tried without any development or Fecking around . After 75 Rounds of shooting groups at 200m it is averaging 30.4mm / 200m = 0.522moa ( that average is all shots and includes the odd shot that was my fault etc that ruin an otherwise great group , shot in my paddock prone with Harris Bipod and Rear Bag )
It shows no signs of pressure and the primers etc are fine .
The powder weight of 25.8gn of 2206H is the max I can cram into the case , so have reached the limit of velocity with this load .
But to be honest this has exceeded my expectations and I'm very happy .
I will be playing with other Powders / Projectiles / seating depths but for now it's fun to shoot what I've got .

Originally Posted by Bagheera

@Philipo sorry about the spelling.

Can people tell me whats the difference betweeen .223 and 6mm ? ( .04 mm I know)
Is it heavier bullet weights are easier to find ? Or shorter for COAL ?
On better barrel twists available ?
Or just opening up the calibre gives a smidgeonmore kinetic energy ?

@Bagheera here are my observations having owned both a 6x45 and .223.

The 6x45 made heaps of sense when .223s were twisted 1-12 as standard. These days a 1-8” .223 will eclipse a 6x45. Example:

My .223 20” barrel launches an 80gr ELD-M at 2750fps. I accept 1800fps impact velocity as absolute minimum (2000 better) and that gets me out to 585yds. Further than I shoot at deer.
The 85gr Sierra out of the 6x45 at 2850fps (shown in this thread) will reach 1800fps at 370yds. Totally agree that is far enough, however the wind drift is DOUBLE of the ELD-M at that range. That gives the real opportunity for a miss or wounding.

Don’t want to get into an ethical debate here, but what I’m saying is the .223 is slicker and will give you less drift and better hits. Energy is irrelevant.

Don’t get me wrong, the 6x45 is cool, and I have mates that use and love them. I just chose the efficient route now that the .223 is geared up for tight twist.