6mm CM

I have a gen 1 rpr in 243 which is a 1:7.7 twist i believe, I think it was set up to run 115s but it shoots 107 smks extremely well. If I rebarrel however, I will go with 6mm creedmoor, less trimming brass which i hate being one factor.
 
Are used 6mm Creedmoore hunting rifles hard to come by?! i’m not seeing any in my price range everywhere i look, what you guys think? i want it for deer/coyote , want to do some hand loads

It is going to be a tougher row to hoe searching for a used 6mm Creedmoore. Its still new enough that the guys who have them knew what they wanted when they went after one and probably are not ready to part with them. Your more cost effective options would be settle for a .243 or pick up a cheap action (savage) and spin a barrel on.
 
It's too bad that Tikka doesn't smarten up and offer their long action T3 in 243 with a 3" magazine that allows for seating out and a fast twist bbl.

It wouldn't be a hard thing to do.
 
It's too bad that Tikka doesn't smarten up and offer their long action T3 in 243 with a 3" magazine that allows for seating out and a fast twist bbl.

It wouldn't be a hard thing to do.

I doubt they’d waste their time with that, but I bet they introduce a 6mm Creedmoor in the next couple years.
 
Does it bother anyone else that there seems to be a growing number of people shooting tiny bullets at deer-sized animals from half a kilometer away and thinking it's a good practice or is it just me?

Yes, yes it does, especially when the reasoning is "hardly any recoil"...probably has a brake on that vicious 6mm CM as well lol.
Not to mention all these long range "heavy for calibre" hunting (target really) bullets are pretty poorly constructed for hunting larger game.
Recoil sensitivity should not play a factor in choosing a game cartridge unless it's for a kid, and even then I don't think most considerate parents would let a kid shoot at a deer at 500m. Stalking use to be an actual skill that seems to be lacking these days,l. Why people feel the need to play risky sniper games with living food I'll never understand, I have too much respect for nature for that.
High BC should not even come into the equation when selecting a hunting bullet, bullet construction and caliber being adequate for the game is what should matter, put the time in on the range at ethical hunting ranges (just because my 7mm mag has 1000ft/lbs of energy at 1000m and I can hit targets doesn't mean I should be shooting deer with it at 1km for example).
Shoot enough and recoil doesn't even come into play, you get use to it off the bench (ditch the lead sleds lol), and you won't ever notice it in the field with the adrenaline.
 
I doubt they’d waste their time with that, but I bet they introduce a 6mm Creedmoor in the next couple years.

How much effort would that take? Change the ROT and adjust the magazine. Done! The T3 is perfect for this.

Sell some 6CMs as well. No big deal. I don't see the 6CM out selling the 243 or 6.5CM any day soon.
 
I own a .308 that i use for deer now. But like i said i want to get a 6mm/or.243 for a coyote/deer gun. I will most likely just get a .243 once i find one i like, i’m am learning stuff from these comments, Looks like i really need to pay attention to twist rate.

thnx for all the info guys cheers
 
I doubt they’d waste their time with that, but I bet they introduce a 6mm Creedmoor in the next couple years.

Out of all the new Hornady offerings, I don't think the 6mm CM will become that popular that all the bolt gun makers will jump on the bandwagon like the 6.5CM/PRC. Plus you negate one of the main selling features of the cartridge sticking it in a LONG ACTION Tikka, "it fits in a short action, ya know, which is better then a long action because I read that in the marketing materials".
In the target world there are better 6mm bolt gun cartridges that are being used, and have been used for decades, plus the yanks can use the 6mm in AR10 style rifles for PRS and hunting which is probably the vast majority of where the 6mm CM is seen. For hunting it doesn't separate itself enough from the other 6mm's to make any difference. The 6.5CM got a little lucky, as the American market never really clamored to the 6.5's prior to the CM version, 260Rem, 6.5x55, 264 Win were well respected, but always rolled closer to niche market status... people that used them new they were great, but they never reached super popularity.
 
I own a .308 that i use for deer now. But like i said i want to get a 6mm/or.243 for a coyote/deer gun. I will most likely just get a .243 once i find one i like, i’m am learning stuff from these comments, Looks like i really need to pay attention to twist rate.

thnx for all the info guys cheers


You are on the same path I took. I have a 308 for deer. Took at T3X 243 and rebarreled it with a 1:8 Krieger barrel for coyote and wolf. Loves 100 gr Sako ammo and just have not shot it with anything heavier. I think that is a win in my books as I do not reload yet.
 
Some more good information about the benefits of a more modern cartridge design below, of course this is info from Target Shooting World where they shoot 1000s of rounds competitively each year, again if your simply grabbing a 6mm cartridge to go deer hunting once or twice a year hardly matters and the 243 would be hard to beat as loads of factory ammo available on any shelf, but you can't deny the upside to a cartridge like the 6mm Creedmoor,

I have two 6mm Creedmoor rifles and both are very accurate with factory ammo and have been very easy to hand load for as well as lots of aftermarket brass available.


"There are a few modern cartridge attributes that are common to virtually every cartridge designed in the past 20 years:

1. Steeper shoulder slope (around 30°). Older cartridge designs have a more shallow shoulder, typically around 20°. Cartridge designers have found a 30 degree has a lot of benefits. One is that it slows case growth, which means less trimming and longer brass life. Another benefit is the difference of how pressure builds with steeper shoulders, which can allow you to get the same velocities with less powder.

Here is how David Tubb describes some of these benefits for the 6XC (source): “The 6XC’s 30-degree case shoulder retards case growth (less trimming required). I have found that velocities attainable with the 6XC are equivalent to those attainable using .243 Win. Barrel life is much better than .243 Win. due to the fact that the 6XC has about 7 grains less powder capacity.” This may also reduce barrel wear, because of where the “turbulence point” is on the cartridge (either inside or outside the case). In another article, David says “Pressure data indicates higher attainable velocities compared to a standard .243 Winchester cartridge.

The 6XC attains these higher velocities with less propellant and lower pressures (superior case design is the reason). The Turbulence Point (TP) is situated inside the case neck so increased barrel life over case designs such as the .243 Win. where the TP point is down the barrel.”
Longer case neck (around 0.30″). Modern cartridges are designed with a longer neck to better support the bullet. This can promote concentricity and ensure the bullet is more perfectly aligned with the bore."
 
Tubbs 6xc never really caught on. Neither will the 6 Creedmoor, with manufacturers originally chambering it, now dropping it.

This is what happens when you try to fix things that aren’t broke. Tall marketing tales can only get you so far.
 
Well put. Yeah, you probably get flamed. ;)

Oh boy, I’m sure I’ll get all kinds of flamed for this, but here it goes: I wouldn’t say that 6cm and 243win shoot the same bullets. I’d say they shoot the same diameter bullets, and in some (many) cases are capable of shooting the exact same bullets. But in factory form what they are capable of shooting best is different. Don’t believe me? I guess ask Hornady then. Why do they offer a 6mm 80gr gmx and a 90gr gmx. The 90 has a much better bc, it also says minimum of 1 in 8 twist required. How about the 90gr eldx and the 103gr eldx, same story. Based on that I would say they do, or are designed to, shoot different bullets. Or perhaps different bullets are designed to be fired from each cartridge? I know I know, it doesn’t say anywhere on the box of projectiles when you purchase them that they MUST ONLY be loaded in xyz cartridge, but you can see the implications here. Also, see factory loaded ammo for each cartridge, kinda reinforces what I’m saying here.

I like both cartridges (have owned both), makes sense, they’re very similar. But 243 does tap out with heavy long bullets, due to most factory twist rates. Granted, Ruger and garbageton do have decent factory twist rates, savage is okay and browning / Winchester are terrible. So for most factory rifles the 6cm is going to do better with (as in stabilizing) long heavy high bc bullets than 243win.

Nothing wrong with a custom fast twist 243win barrel either, evens the playing field in terms of bullet stabilization. Cartridge oal and max magazine length can become an issue with some actions though. Could always AI the 243 for a little extra power room.
 
Tubbs 6xc never really caught on. Neither will the 6 Creedmoor, with manufacturers originally chambering it, now dropping it.

This is what happens when you try to fix things that aren’t broke. Tall marketing tales can only get you so far.

Of course but the point I was trying to bring to light is the benefits cartridge design not the 6XC cartridge, that just happen to be his baby and the one he uses for an example.

If a person want to go through life with the blinders on that their right, :bangHead:
 
How much effort would that take? Change the ROT and adjust the magazine. Done! The T3 is perfect for this.

Sell some 6CMs as well. No big deal. I don't see the 6CM out selling the 243 or 6.5CM any day soon.
I like your thinking, but expect most manufacters would see the two chamberings as too similar.
 
Of course but the point I was trying to bring to light is the benefits cartridge design not the 6XC cartridge, that just happen to be his baby and the one he uses for an example.

If a person want to go through life with the blinders on that their right, :bangHead:

Ackley was doing 30 and 40 degree shoulders and blowing case bodies straight long before the Creedmore was ever thought up. It allowed more powder for a little extra velocity and extended case life, that's pretty much all it does.
This whole notion that you can go faster with less powder capacity due to case design is a myth, velocity is a result of pressure generated by ### amount of powder.
Otherwise we would see Weatherby cartridges winning long range target matches as they have the most efficient sharpest shoulder angle, and they would also be considerably faster then their similar capacity cartridges like the 7mm Weatherby vs the 7mm Rem. We don't see either of those.
 
Whidden shot the 105’s in his 243 win 8T target rifle to 1000 yrds. Found no need for the 115’s.
Same 105 gr bullets shoot out of a factory Remington 700 243 Winchester and fit nicely in a SA mag box.
 
Not sure why people get so fussed about short action cartridges in a tikka. They’re the same people that are happy as pie to shoot 223 out of a 2.8” short action.
 
Another benefit to these newer cartridges is the throat design. Many older cartridges' SAAMI chamber design specifies a tapered throat that starts out much larger diameter than the bullet. This is a major reason why we usually had to load close to the lands for good accuracy.

These newer designs specify a parallel throat that is only 1/2 a thou over bullet diameter. This keeps the bullet more concentric to the bore even when you aren't loading to the lands.

BTW, to those folks who like to compare identical bullets in the 243 and 6mm Creedmoor to "prove" that the 243 is just as good, why don't you shoot a 103 ELD-X from a factory 243 and a factory 6mm CM and see which works the best? Apples to apples, right? ;-)

And to those who say ballistic coefficient doesn't matter for hunting... Your bullet starts slowing down and losing energy the instant it leaves the barrel. Muzzle energy is irrelevant, impact energy matters. Why use a bullet that loses more energy than necessary? Some people step up to magnum cartridges for more energy. Why not step up to a high-BC bullet for more energy? Same result, different way of getting there.
 
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