Thread: Tikka 6x45 / 6mm-223

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

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

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.

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.

I would also be interested in knowing this

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 .

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.

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.

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.

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

Originally Posted by Tahr

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

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 .

@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 ?

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 ?

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.

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 ?

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 )

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.

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.

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.

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

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