Tikka 6cm vs factory 243

[JoeK]

Echo, Echo , Echo....
You specified reloading so Unless your wanting to really push the longest bullets and find yourself at the edge of stability with 1:8 twist, or run out of throat there's little reason to rebarrel. No reason to do it before you work with the factory barrel and see ho wit treats you. Or after you burn it out. Factory ammo is really the main advantage to 6CM vs 243 given a 1:8 factory tikka. and less case trimming.

 

[kblewis4]

Go factory in 243 then re-barrel to the 6CM. I am digging the 6CM though! Thinking of picking one up. Good luck!

 

[huntsd]

If you want an easy button without messing with barrels etc, just get the factory 243. Hog the barrel channel out, vertical grip, degrease, nail polish and crank action screws to 65. Good to go.

If you're inclined to do so, rent or borrow a 6mm uni throater. It can be rented for like .. $40-70? I did mine, never used one, bore scope pictures looked like ass after I did it, but got the throat length right and it hammers. Concerned about factory ammo? Maybe that matters if you really want to shoot 108s. But there's lots of 90-100gr options.

First rounds through barrel. Throated it before shooting at all.
View attachment 951045

Just getting it broke in
View attachment 951046

Probably 300ish rounds in.
View attachment 951047

Newbie question… but what is a throater? I assume it just bores out the throat a bit? Is this done a lathe

 

[huntsd]

Another option is buy the 243 and then have a smith rechamber it to 6CM. Cheaper than buying a new barrel. This is what I did with my tikka and it’s now my favorite gun.

How is this done?

 

[pods8 (Rugged Stitching)]

I'm a mile high so I doubt that's the case. I have read that others find the 109 picky also.

There isn't a lot of margin depending on velocity/temp before it starts crossing under <1.5SG with a 8 twist (berger calc) but as you've noted it could just be picky. Not advocating for it, esp. with the 108s being the easy button, just mentioned the stability because the longer bullet takes a little more than the 108 is all despite only the 1gr difference.

 

[wind gypsy]

Newbie question… but what is a throater? I assume it just bores out the throat a bit? Is this done a lathe

How is this done?

a 6 cm reamer cuts a chamber deeper into the barrel than the current chamber. The barrel shoulder and tennon needs to be machined to make the new chamber headspace correctly.

 

[passinggas33]

How is this done?

I’m not a gunsmith so take this with a grain of salt. But my understanding is they set the barrel back (cut out the old) and then ream it to a 6CM. It did shorten the barrel length a little bit not enough to matter.

 

[pods8 (Rugged Stitching)]

a 6 cm reamer cuts a chamber deeper into the barrel than the current chamber. The barrel shoulder and tennon needs to be machined to make the new chamber headspace correctly.

You worded this a little weird for someone unfamiliar. The new reamer needs to ream in deep enough to clear out the old chamber (where it differs) which in the case of the 6cm reaming a 243win means the barrel will need to get set back (some larger cartridges you don't need to set back the barrel).

 

[Nine Banger]

No measurable difference on average. If you happen to get a poor or great example of one or the other, it may skew your experience or expectations.

I agree.

The factory barrel should shoot the same as a prefit.

If you shoot out the 243 and then switch to 6CM you will get to answer your own question the hard way but get an extra 1500 shots in.

They are functionally the same thing in this very specific instance.

 

[nm.otter]

Can't speak to Tikka chambers per se, but SAAMI minimum chamber specs (to bottom of neck, which seems to be the short pole) indicate at least 0.1497" will need to be lopped off the tenon.

 

[Big_wals]

Sample size of one, but my 243 shoots both 108 and 109 eldms around 1.25 moa for 10 shots with h4350.

If youre going to have to buy a Tikka to get a donor action for a 6 creed, just pick up a 243 and shoot it first. Tikka barrels are easy to sell on here if you put 50 rounds through it and then decide you’d rather have a custom barrel.

 

[HighUintas]

Newbie question… but what is a throater? I assume it just bores out the throat a bit? Is this done a lathe

It can be done by hand with the PTG uni throater with a T handle. These are available to rent from 4d rentals. Or, just buy one and sell it after ass needed. It is very easy to use. Don't have to remove barrel from action. Just remove action from stock. Look up vids for how to use them on Google or YouTube. There's a few good ones.

 

[ztc92]

Get the 243, shoot it out, then get a 6cm barrel. My Tikka 243 shoots fine.

This is exactly what I did. I’m just breaking in my barrel but it’s shooting the $0.50/round norma 100g ammo I bought to about 1”, 10-shot groups. I just bought it to get some good brass and break in the barrel but it’s shooting so well I’ve enjoyed using the factory ammo to practice with.

 

[Brontosaurus]

ass needed.

No thanks. Im good.

 

[Q_Sertorius]

This is exactly what I did. I’m just breaking in my barrel but it’s shooting the $0.50/round norma 100g ammo I bought to about 1”, 10-shot groups. I just bought it to get some good brass and break in the barrel but it’s shooting so well I’ve enjoyed using the factory ammo to practice with.

How far are you shooting when you hunt with that rifle? Are you a competitive shooter?

I’m curious because - apart from following Douglas’s specific barrel break in instructions for a brand new barrel, which were minimal and mostly just required cleaning at stated intervals between shots I would take anyway - I have never bothered to break in a barrel. The whole idea just seems strange to me. The barrel geometry will change slightly over time until it gets too poor to shoot well. Along that path, it may get slightly better. But for a hunting rifle, I am personally not in any hurry to get into some perceived sweet spot.

 

[pods8 (Rugged Stitching)]

How far are you shooting when you hunt with that rifle? Are you a competitive shooter?

I’m curious because - apart from following Douglas’s specific barrel break in instructions for a brand new barrel, which were minimal and mostly just required cleaning at stated intervals between shots I would take anyway - I have never bothered to break in a barrel. The whole idea just seems strange to me. The barrel geometry will change slightly over time until it gets too poor to shoot well. Along that path, it may get slightly better. But for a hunting rifle, I am personally not in any hurry to get into some perceived sweet spot.

Semantics may be in play here. There is the Shoot/Clean/Shoot traditional break in. And there is shooting 100rds or so before starting load development for reloading to let the barrel settle in (break in) and speed up first before honing in on a powder charge.