Tikka 6x45 / 6mm-223

I'm not working today due to work being suspended because of the Cyclone happening here in Australia .
Perfect timing because my old T3 .223 Tikka is back from Trentech ( Gunsmith ) with a new 6x45 / 6mm - 223 barrel , so I started the fun job of putting stuff together .

I have over the last 6 months acquired bits and pieces for this old Tikka .
I found a GRS Stock recently secondhand at a price that I couldn't go past , so even though this was not my original idea , I have a Tikka Super Varmint Stock which I was going to use and still may if I don't " Jive " with the GRS . This Rifle is going to be used mainly for Targets , but will ride along in the Ute/Buggy at times and I'm not sure about the GRS stock for this application . It definitely isn't a walk around/hunting stock in my view .
From the research I've done it should launch a 85gn projectile in the region of 2750fps - 2900fps depending on how brave I am and powder choice .
I had purchased new Alloy bottom metal for it when it was a .223 , so that is being used instead of the crappy Factory plastic one .
A 6 round Waters .223 magazine that allows you to load out to 2.6 inches without any other modifications to the Rifle is being used so that the longer / bigger 6mm projectiles won't protrude down into the case robbing space for powder .
The Dummy rounds I sent to the Gunsmith ( the barrel was throated 20 thou jump for the dummy rounds I supplied using Sierra 85gn hpbt projectiles seated out reasonably long ) feed perfectly in the testing I have done this morning ( all dummy rounds , I don't like cycling live rounds at home :) )
https://i.imgur.com/vCdZFA2.jpg

https://i.imgur.com/RN76unO.jpg

https://i.imgur.com/mQHK4c6.jpg

https://i.imgur.com/hnm9FSa.jpg

https://i.imgur.com/d53pQrM.jpg

Here is a photo of a Factory 55gn round compared to what I'm going to be throwing now .

https://i.imgur.com/sHTIKis.jpg

@phillipo did you have one of these ?

She's purdy. Decently chunky barrel. What's it weigh all up?

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Originally Posted by Pommy

She's purdy. Decently chunky barrel. What's it weigh all up?

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That's a good question about the Weight .
I just put it on the Wife's electronic kitchen scales and it is to heavy for them , they max out at 5 kg :(
As I said in the first post it's basically going to be a fun informal Target gun , but if the Chambering shows promise I will be tempted to get a lighter barrel and put it into a lighter/more appropriate stock / lighter optics and mounts etc

you will love it.

I like it!

Now you could go with the 204 case and squeeze a bit more out of it, won't need to overload

Nicely thought out project. Do keep us posted on its performance!

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Originally Posted by SmokeyJason

Now you could go with the 204 case and squeeze a bit more out of it, won't need to overload

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Absolutely …….. but .223 Brass is overflowing in my cabinet and will never be an expense or problem to acquire.

I shoot Sierra 70gr hp projectiles out of mine

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Originally Posted by Tentman

Nicely thought out project. Do keep us posted on its performance!

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Cheers Mate :thumbsup:

The reality is that I had this old T3 .223 and really wanted to shoot the Hornady 80gn eldm’s after reading all about their greatness in the .223 Thread on this forum.
Well after many rounds down range and a bit of expense, they shot no where near the accuracy of the the Sierra 77gn TMK’s that my Howa 1500 is capable of .
The Howa is handicapped by magazine length, but with the Waters Magazine the Tikka can use the longer / sleeker Hornady 80’s seated out long ….. But they didn’t shoot no matter what I tried .
My thoughts were to just get rid of the Tikka because I already had to many .223’s .
Then I read an article about the 6x45 and the brain started whirling.
I basically had everything needed to maximise the 6x45 cartridge ( having to load them short OAL is a real performance killer ) except for a barrel and a set of Dies .
The rest is history :thumbsup:

This story isn’t all “ Blow Jobs and Party Pies “ though, I haven’t shot it yet , and the weather here means it won’t be for another week or so . :)
It might be another great big piece of “ Poo “ , but I have Sierra 85gn hpbt and Hornady 87gn hpbt projectiles to play with as well as 2206H , Benchmark, 2208 powders , CCi 400 , 450 , Br4 primers and Lapua / Starline / Fiocchi Brass .
Somewhere in amongst all of those combinations hopefully there will be an answer.

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Originally Posted by sportco62

I shoot Sierra 70gr hp projectiles out of mine

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How do they shoot ?
Do you know a velocity?
What barrel twist are you using?
How do you rate the chambering compared to the standard.223 ?
When comparing the 6x45 and the .223 research has shown that the 6x45 will have a slightly higher velocity when comparing the same bullet weights due to the efficiency of the larger bore/ case size scenario.

The only reason I contemplated the 6x45 is because in theory it can throw an 80gn plus projectile efficiently and effectively.
I already have a Howa .223 that shoots 77gn TMK bullets and lighter into small groups .
This is an experiment of how much of a bigger projectile weight can I practically use ( my threshold is 2700fps ) out of a .223 case / Rifle.

I have had 6.5TCU chambered rifle for years ( 6.5-223 Improved if you prefer) as I also have heaps of once fired .223 brass
a good charge of Power Pro Varmint or 8208XBR throws a 123sst @ 2500fps + so I would expect you would get faster velocity with the 6mm bullets.

You guys are far too technical for me . My one has a Mini mauser action , a Kimber of Oregon barrel , chambering done by Nelson Collie , laminated stock fitted by an old guy in Helensville - all done years ago.

Seriously - I dont recall any of that load information beyond "I loaded a bunch of rounds , found the ones that shot most accurately . and just stuck with those"

Sorry - I have way too many rifles , and too much load data to wade through to find any of it. But it shoots minute of goat and minute of fallow deer and thats all I need

My 23" 1:10 6x45 chucks out Sierra 85gr HPBT @ 2918fps using CFE223.
Same load in my 20" 1:8 6x45 does 2834fps. The CFE223 is the slowest powder I've used and most suited to 80gr + bullets.
I regularly run 75gr Sierra HP with H335 for about 3000fps in the 20" rifle.

By having a longer throat you'll achieve pretty much the same velocity but burn more powder to do it. This I have proven in another caliber. A long throat is great for those 80gr+ bullets when using something like CFE223, as it's a high density load.

Sent from my SM-S906E using Tapatalk

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Originally Posted by Bagheera

@phillipo did you have one of these ?

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Yeah mate close, I had a 6mm 204 ruger built by KG. Fuck it was a great gun n caliber, 87 grainers @ 3000fps like a laser & sacked everything from bunnies to big SI roos out to 600 yards, farken loved that gun was such a great alrounder from doing Gilly field events to bowling things

Just spent 30min's trying to find some of those pics but fuk knows where in my puta or the cyber they have disappeared too

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Originally Posted by Mathias

My 23" 1:10 6x45 chucks out Sierra 85gr HPBT @ 2918fps using CFE223.
Same load in my 20" 1:8 6x45 does 2834fps. The CFE223 is the slowest powder I've used and most suited to 80gr + bullets.
I regularly run 75gr Sierra HP with H335 for about 3000fps in the 20" rifle.

By having a longer throat you'll achieve pretty much the same velocity but burn more powder to do it. This I have proven in another caliber. A long throat is great for those 80gr+ bullets when using something like CFE223, as it's a high density load.

Sent from my SM-S906E using Tapatalk

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What's the OAL of your 1:8 20" 85 grn load? Wondering what mag it would fit into of the .223's Ive got if I was to re-barrel.

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Originally Posted by Tahr

What's the OAL of your 1:8 20" 85 grn load? Wondering what mag it would fit into of the .223's Ive got if I was to re-barrel.

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I would also be interested in knowing this :thumbsup:

I spent 30 minutes yesterday sizing 50 new Starline cases for initial testing , and I'll reload them today with a few different combinations of Powder/Projectiles .
This is my first time playing with expanding/altering a Cartridge and I can't believe how easy it is .
Lube the case , a single stroke of the Press and they are ready to load .

https://i.imgur.com/xu9JwgW.jpg

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Originally Posted by Tahr

What's the OAL of your 1:8 20" 85 grn load? Wondering what mag it would fit into of the .223's Ive got if I was to re-barrel.

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58.08mm OAL for both rifles, but for the 20" gun I have to pull it back to 56.9mm to eject a loaded round, due to it not clearing the port. I could fix this with a minor mod to the ejector / bolt stop but just left as is for now. Have over 200 75gr loaded to that OAL.
These Sierra 85gr HPBT are a stubby nosed little bullet, just like the 75gr HP, they lend themselves well to short mags and OAL.

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Originally Posted by Mathias

58.08mm OAL for both rifles, but for the 20" gun I have to pull it back to 56.9mm to eject a loaded round, due to it not clearing the port. I could fix this with a minor mod to the ejector / bolt stop but just left as is for now. Have over 200 75gr loaded to that OAL.
These Sierra 85gr HPBT are a stubby nosed little bullet, just like the 75gr HP, they lend themselves well to short mags and OAL.

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Ta. So they will fit into pretty much any .223 mag then (Tikka is 2.3"/58.42mm).

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Originally Posted by Tahr

Ta. So they will fit into pretty much any .223 mag then (Tikka is 2.3"/58.42mm).

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None off my 6x45 reloads smallest being 70gn mk will not fit in a standard tikka 223 mag, I run aics mags notiched with a dremel.

Here is a photo of the Dummy round that was sent to the Gunsmith so he could throat the barrel 20 thou jump .

This has an OAL of 60.6mm , the 6x45 in theory is designed to have the same OAL as the standard .223 which is 57.4mm so it will function in AR15 type Rifles/Magazines .
As you can see from the photo if I was to seat those Sierra 85gn bullets to 57.4mm then there would be an extra 3.2mm of projectile protruding into the case and that of course means less room for powder .
My research strongly suggests if you can ( Bolt Gun / Magazine length etc ) to set the Sierra 85gn up at an approx OAL of 2.4 inch (60.96mm) .
I chose to go a fraction shorter so that the Rifle is throated in a way that will allow some other projectiles to work better ( in theory ) both longer and shorter .

https://i.imgur.com/1WLOgxU.jpg

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Originally Posted by Doon

None off my 6x45 reloads smallest being 70gn mk will not fit in a standard tikka 223 mag, I run aics mags notiched with a dremel.

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Attachment 242618

left to right 75 gn sierria hp 59.2 mm,85 Gameking 59mm,95 gn Targex 62.6 mm 90gn sierria gamechanger 64mm. 223 accurate mag. ruger aics mag, standard tikka 223 mag

@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 ?

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Originally Posted by Doon

Attachment 242618

left to right 75 gn sierria hp 59.2 mm,85 Gameking 59mm,95 gn Targex 62.6 mm 90gn sierria gamechanger 64mm. 223 accurate mag. ruger aics mag, standard tikka 223 mag

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Do you know how fast the 90gn Sierra's are going ?
I have a 200 of them to play with , but thought I'd start with the 85gn Sierras because of the great reports from overseas about their on target performance

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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 ?

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Dunno. I just keep looking at all the 6mm projectiles Ive got and wonder what Im going to do with them. I could plant them into wallaby with one of these.

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Originally Posted by Ground Control

Do you know how fast the 90gn Sierra's are going ?
I have a 200 of them to play with , but thought I'd start with the 85gn Sierras because of the great reports from overseas about their on target performance

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90GN Sierria gamechanger 2800fps. the 95gn targex are 3 shots touching.stillworking on the 90 GC as they are not as accurate as the targex (still under moa though)

Im running a 1/8 twist throated 30 thou.

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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 ?

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There aren't many .223 Rifles that can throw a 80gn plus Projectile at the velocities that a 6x45 can with barrel lengths of 20 inches - 24 inches .
As a few respondents have already mentioned here they are achieving results/performance with heavier bullets that a .223 just can't match ( not easily anyway , 28-30 inch barrels and really pushing the limit's of safety )

I have got a cooper 6x45, with 20” tube, i am running 85 gr serria soft points or partions, to 2880 fps with CFE.223, and 75 gr serria HP to over 3000 again with CFE.223, benchmark was the best powder for light bullets, BLC2 and CFE game me best results with 80 gr up, i think the 90 gr ELDX might be a great bullet to try.
I load to 60 mm, as i have a bit more room, in the cooper than say a sako or CZ action,
Great we rifle,
Pitty the old hunting and fishing forum is gone, was a brilliant thread on there for the 6x45.

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Originally Posted by southernman

I have got a cooper 6x45, with 20” tube, i am running 85 gr serria soft points or partions, to 2880 fps with CFE.223, and 75 gr serria HP to over 3000 again with CFE.223, benchmark was the best powder for light bullets, BLC2 and CFE game me best results with 80 gr up, i think the 90 gr ELDX might be a great bullet to try.
I load to 60 mm, as i have a bit more room, in the cooper than say a sako or CZ action,
Great we rifle,
Pitty the old hunting and fishing forum is gone, was a brilliant thread on there for the 6x45.

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

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Originally Posted by Mathias

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

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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 :thumbsup:

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


Attachment 242677



Attachment 242678



Attachment 242679



Attachment 242680

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 .

https://i.imgur.com/UFP1oYv.jpg

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 .

https://i.imgur.com/pOsLGPw.jpg

https://i.imgur.com/KyExnwB.jpg

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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 ?

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@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.