+Peak Creedmoor Barrel

[ACHILLES]

In theory, what you said makes a lot of sense and is what I was thinking at first but:

- I ran the numbers in a recoil calculator. Leaving bullet weight (153gr), velocity, and gun weight all the same, and ONLY changing the powder charge, the CM was 19.4% less recoil than the PRC.

- Also, SAC released a short video of them necking down a 6.5 CM +Peak case to a 6 CM. They said these dies are coming out this summer.

Only time will tell, but I think there's a much larger conversation here with the barrel and case technology advancing this rapidly. I truly think the 6.5 CM could literally be a much less recoiling 6.5 PRC performance cartridge. Which brings me back to my original question, if we can push larger bullets faster without the recoil penalty, should the pendulum swing back toward the 6.5 (or 25) rather than the 6? Or are there still more advantages to staying with the 6mm that I'm not thinking of?

I appreciate everyone's responses and please keep the feedback and discussion going!

The recoil calculators I’ve used do not account for pressure. Now I could be wrong but I don’t see how it’s possible to run 6.5prc velocities without having 6.5prc recoil. Would be nice to see both tested in a recoil sled.
Good to know there are no issues necking down to 6mm.

 

[omicron1792]

The recoil calculators I’ve used do not account for pressure. Now I could be wrong but I don’t see how it’s possible to run 6.5prc velocities without having 6.5prc recoil. Would be nice to see both tested in a recoil sled.
Good to know there are no issues necking down to 6mm.

The people shooting have already said they recoil like a 6.5cm. The math checks out too.

 

[bnewt3]

Popularity by itself doesnt matter. But in the case of the 6.5C and 308 the popularity means we get MANY ammo options. From super cheap, to high end. Target, hunting, plinking......all of it.

*MAYBE* 25, 6, and 22 Creed will become as popular as 6.5......but none of them *need* +Peak the way 6.5 does so even if they do +Peak in those, they dont benefit as much. So I would consider other Creedmoors getting +Peak an IF, not a when.

Because of all of that, Im finding it very hard to look at anything other than 6.5C anymore. I *was* looking at a 6mm for a faster, flatter shooting option.

Now if they do 6ARC +Peak.....that will upset things IMO, because it is very similar to 6.5C in that its *a bit* on the slow side with excellent bullet selection and great potential.....some more speed and its right in that sweet spot.

Regardless, 6.5C now has the best of both worlds IMO. brass ammo when cost is a consideration, +Peak when you want/need the velocity/not kill a ton of velocity with a short barrel and/or running superheavys.

 

[bnewt3]

The recoil calculators I’ve used do not account for pressure. Now I could be wrong but I don’t see how it’s possible to run 6.5prc velocities without having 6.5prc recoil. Would be nice to see both tested in a recoil sled.
Good to know there are no issues necking down to 6mm.

Remember its basic physics "for every action there is an equal and opposite reaction"

In this case the "action" is WWWgr bullet pushed by XXgr of powder(because the powder is mass traveling down the barrel with the bullet) leaving the barrel at YYYYfps of a Zlbs rifle

If those variables are the same, you get the same "equal and opposite reaction", no matter if you achieved it through a short barrel and fast powder or a long barrel and slow powder.

The increased pressure results in more velocity, the velocity is where you get increased recoil over brass 6.5C. But because there is less mass from powder, +Peak is lower recoil than PRC.

The pressure by itself doesnt factor in for recoil, its the result of that pressure(velocity) that factors in.

If you were to tune barrel length of 6.5+Peak so that velocity is identical to 6.5PRC but kept rifle weight identical, 6.5PRC has more recoil due to more mass from powder.

 

[MoeFaux]

Popularity by itself doesnt matter. But in the case of the 6.5C and 308 the popularity means we get MANY ammo options. From super cheap, to high end. Target, hunting, plinking......all of it.

*MAYBE* 25, 6, and 22 Creed will become as popular as 6.5......but none of them *need* +Peak the way 6.5 does so even if they do +Peak in those, they dont benefit as much. So I would consider other Creedmoors getting +Peak an IF, not a when.

Because of all of that, Im finding it very hard to look at anything other than 6.5C anymore. I *was* looking at a 6mm for a faster, flatter shooting option.

Now if they do 6ARC +Peak.....that will upset things IMO, because it is very similar to 6.5C in that its *a bit* on the slow side with excellent bullet selection and great potential.....some more speed and its right in that sweet spot.

Regardless, 6.5C now has the best of both worlds IMO. brass ammo when cost is a consideration, +Peak when you want/need the velocity/not kill a ton of velocity with a short barrel and/or running superheavys.

Ammo selection is moot to someone who reloads, as the OP does.

I like your second point, though. It's logical for +peak to gravitate to the cartridges that benefit the most from it, and I REALLY like the idea of a 6 ARC +Peak!

 

[bnewt3]

I think reloading reduces, not negates, ammo selection and availability as a consideration.

It is awfully nice to have the option to run in any store and have a wide selection of ammo.

 

[nm.otter]

if they do 6ARC +Peak.....that will upset things IMO, because it is very similar to 6.5C in that its *a bit* on the slow side with excellent bullet selection and great potential.....some more speed and its right in that sweet spot.

FWIW, the closest analog to 6.5mm Creedmoor in case capacity to bore area ratio is 6mm GT (less than 1% difference).

The ratio for .22 ARC is 7% lower.

6mm ARC has a 25% lower ratio -- slightly below that of .223 Remington.

 

[Huntnpack 2]

Ammo selection is moot to someone who reloads, as the OP does.

I like your second point, though. It's logical for +peak to gravitate to the cartridges that benefit the most from it, and I REALLY like the idea of a 6 ARC +Peak!

Don’t discount the fact that Federal Premium Ammunition is in the business of selling ammunition. The Gravitational pull in the most recent offering seems to be somewhat influenced partly by potential market analysis. But companies do develop their own flight paths.

 

[bnewt3]

FWIW, the closest analog to 6.5mm Creedmoor in case capacity to bore area ratio is 6mm GT (less than 1% difference).

The ratio for .22 ARC is 7% lower.

6mm ARC has a 25% lower ratio -- slightly below that of .223 Remington.

I take that to mean that 6ARC could benefit more from increased pressure because its powder capacity limited?
Is that not how you see it?

 

[KeepHammering]

I've had very similar thoughts on the 6 ARC getting a significant boost from a +Peak case. The 6.5 CM goes from good to great (IMHO). And a 6 ARC gets up into 6 CM territory assuming the same 200 to 300 fps boost that the 6.5 CM is getting. That's an unbelievably low recoil out of a 6 ARC while still doing 6 CM things at distance. Sign me up!

I'm primarily a bolt gun guy, but think of the benefits all of the AR shooters would be getting from the 6 ARC +Peak assuming they could keep things safe and cycling rounds well. I'm not sure if it would need a different gas system, or if it's similar enough to a standard cartridge from a gas and cycling standpoint. Reference @bnewt3 post above with the physics comments. It could be all good regardless of pressure changes on the case wall.

The rest of the world may be falling apart, but it's a great day to be alive in the rifle shooting world!

 

[Huntnpack 2]

6 CM + Peak would be interesting

Sales of 6CM ammunition is on the rise.

 

[nm.otter]

I take that to mean that 6ARC could benefit more from increased pressure because its powder capacity limited?
Is that not how you see it?

Time will tell on the respective improvements in MV, but barrel life should be better (as it is with brass cases) for cartridges having lower ratios.

 

[Treelineasassin]

I take that to mean that 6ARC could benefit more from increased pressure because its powder capacity limited?
Is that not how you see it?

The guys who've been hand loading the peak cases in 65/6cm are using faster than traditional powders for bullet weight. Heavy charges of varget area burn powders. Since the 6arc is already using high case fill quantities of varget area powders, you'll be needing faster powders to get the pressure elevated, before running out of case volume.

 

[Treelineasassin]

6 CM + Peak would be interesting

Sales of 6CM ammunition is on the rise.

Guys already doing it. 120 Bergers have been pushed to 3300 from a 24in barrel. Who knows psi on this, but its been done for "science" purposes.

 

[omicron1792]

Guys already doing it. 120 Bergers have been pushed to 3300 from a 24in barrel. Who knows psi on this, but its been done for "science" purposes.

His accuracy looked pretty dang good too

 

[Treelineasassin]

His accuracy looked pretty dang good too

3100fps with a 328 g7 BC @ 1/4 moa precision is pretty dreamy!

 

[Huntnpack 2]

Guys already doing it. 120 Bergers have been pushed to 3300 from a 24in barrel. Who knows psi on this, but its been done for "science" purposes.

Exactly !! C’Mon Federal !!!

 

[ACHILLES]

I've had very similar thoughts on the 6 ARC getting a significant boost from a +Peak case. The 6.5 CM goes from good to great (IMHO). And a 6 ARC gets up into 6 CM territory assuming the same 200 to 300 fps boost that the 6.5 CM is getting. That's an unbelievably low recoil out of a 6 ARC while still doing 6 CM things at distance. Sign me up!

I'm primarily a bolt gun guy, but think of the benefits all of the AR shooters would be getting from the 6 ARC +Peak assuming they could keep things safe and cycling rounds well. I'm not sure if it would need a different gas system, or if it's similar enough to a standard cartridge from a gas and cycling standpoint. Reference @bnewt3 post above with the physics comments. It could be all good regardless of pressure changes on the case wall.

The rest of the world may be falling apart, but it's a great day to be alive in the rifle shooting world!

I’ve never seen it in stock but they had a 6ARC nas3 option for a year or two now.

 

[KeepHammering]

@MoeFaux, maybe I get my marshmallow now with a 6.5CM and also another one later with a 6 ARC +Peak. It really is a great analogy.