Grendel and 5R Rifling (Haters gonna Hate)

[XcountryRider]

Regardless the Liberty barrel 100fps boost changes the conversation a bit. Now we are at our near the same mv and enjoy the longer ranges at the same time.

[XcountryRider]

The mv for a 123gr amax in my 18in barrel is 2560fps. Now subtract 20fps per inch and i would get a 16in mv of 2520 with a liberty barrel.

[woohoo]

Regardless the Liberty barrel 100fps boost changes the conversation a bit. Now we are at our near the same mv and enjoy the longer ranges at the same time.

Ah, now what if you change the 6.8 to a 5R barrel too?
You can change every variable you want to get the answer you want. Do you look for the truth or something to make you feel better?
This kind of goes along with Cory's post. math, science, physics and engineering at Georgia Tech weren't taught to me like you guys think it was.
Compare a 1.5 ton bottle jack used by Mary Sue to lift her little BMW and a 8 ton bottle jack used by Phred to lift his tractor. Do you throw out the rated capacities of the jacks because one is used to lift a car and the other a tractor or do you accept the fact that the larger diameter hyd ram in the bottle jack will lift more?
I thought you guys were comparing 2 cartridges. If you want the real answer just look at Hornadys specs under ammo. if you want to use a 5R barrel in the 6.5 then use a 5R barrel in 6.8. If you want to use a 24" 6.5 barrel then use a 24" 6.8 barrel.

[LRRPF52]

Even still, guys have maxed out with the 120gr SST in the 6.8 SPC with the ARP chamber inside of 2500fps, like in the mid-2400's. Hornady's factory load is a very good velocity-producing load if it registers at 2460fps.

[woohoo]

Even still, guys have maxed out with the 120gr SST in the 6.8 SPC with the ARP chamber inside of 2500fps, like in the mid-2400's. Hornady's factory load is a very good velocity-producing load if it registers at 2460fps.

Did those guys use the best powder for that weight bullet or did they use what some say is the most popular powder? Everyone seems to think AA2200 is THE powder to use with every bullet. It works well with some but not so good with heavier bullets. I've run 115gr bullets to 2830fps out of a 16" barrel when the primer cratered enough for me to say it's max. I've pushed 130gr Sierras to 2530fps out of 16" barrels, 120s to over 2600 all with the same powder and it isn't AA2200, it's an old unpopular powder. Factory 110gr Hornady hits apx 2600 in the 16" 5R barrels. Do you want to compare handload to handload or factory to factory? Handload to handload in different barrels will get you a bunch of skewed data.
Hornady posted the info on their ammo, they aren't biased they posted the facts as they are.
I know this is about to turn into a party and I hate to miss the fun but I have work to do. I'll read the cliff notes later.

[hobbesgunner]

I have a 300 Blackout AR Stoner barrel. ...wasn't advertised as 5R but it is stamped 5R..when I got it I thought......"sweet... bonus!!!"...

[XcountryRider]

Someone with a AR stoner/Liberty barrel in the 6.8SPC caliber needs to shoot and chrony 120gr amax and film the results.

[Tedward]

Do they make one? Some people just get excited... I think there was a lot of research in the development of the Grendel and it speaks for itself. It's better than the 6.8 and if they want to argue it, oh well..

You can look on the 6.8 Forum for that info. Grendel and 5R Rifling was the topic....not comparing 6.5 and 6.8

[woohoo]

Someone with a AR stoner/Liberty barrel in the 6.8SPC caliber needs to shoot and chrony 120gr amax and film the results.

Why?

[LRRPF52]

Did those guys use the best powder for that weight bullet or did they use what some say is the most popular powder? Everyone seems to think AA2200 is THE powder to use with every bullet. It works well with some but not so good with heavier bullets. I've run 115gr bullets to 2830fps out of a 16" barrel when the primer cratered enough for me to say it's max. I've pushed 130gr Sierras to 2530fps out of 16" barrels, 120s to over 2600 all with the same powder and it isn't AA2200, it's an old unpopular powder. Factory 110gr Hornady hits apx 2600 in the 16" 5R barrels. Do you want to compare handload to handload or factory to factory? Handload to handload in different barrels will get you a bunch of skewed data.
Hornady posted the info on their ammo, they aren't biased they posted the facts as they are.
I know this is about to turn into a party and I hate to miss the fun but I have work to do. I'll read the cliff notes later.

RL 10X-not sure what the pressure are. I notice a lot of people using primer signs as a gauge of pressure, then ejector extrusion.

The 6.8 SPC II 18" WOA loads were with AA2200, which did 2450fps with the 6.8 120gr SST. I'm quite happy with the 16" Grendel at milder pressures and comparable velocities, with high BC pills from the same companies, whether it be Hornady, Nosler, Barnes, etc.

Hornady lists 2550fps from their 16" test barrel for the 110gr BTSP with a .360 BC, so that makes sense for another barrel to hit 2600fps, especially if it's melonited.

[XcountryRider]

Why?

To see if the 6.8SPC is enjoying the same results from the 5R button rifling.

[woohoo]

To see if the 6.8SPC is enjoying the same results from the 5R button rifling.

You're kind of jumping the gun with that post on arfcom aren't you?
Here's an offer for you. You take any Grendel barrel you can find, beg borrow or steal and I'll beat you with a 4" shorter but legal 6.8 barrel. Load it as hot as you dare with the same weight bullet. $1000 bet.

[cory]

You're kind of jumping the gun with that post on arfcom aren't you?
Here's an offer for you. You take any Grendel barrel you can find, beg borrow or steal and I'll beat you with a 4" shorter but legal 6.8 barrel. Load it as hot as you dare with the same weight bullet. $1000 bet.

Beat him at what exactly???

If you're talking about MV then I stand by my statements before. Now if you want to compare Kinetic Energy at 100 yds, 200 yds, etc... then yes take the best both have to offer for the job at hand and compare.

Yes Kinetic Energy is an inadequate way of determining terminal performance of a round, but I don't see a better way as long as we're making this comparison on paper.

[woohoo]

Beat him at what exactly???

If you're talking about MV then I stand by my statements before. Now if you want to compare Kinetic Energy at 100 yds, 200 yds, etc... then yes take the best both have to offer for the job at hand and compare.

Yes Kinetic Energy is an inadequate way of determining terminal performance of a round, but I don't see a better way as long as we're making this comparison on paper.

I don't know what you are talking about this time either. He is talking about velocity and I am too.

[XcountryRider]

You're kind of jumping the gun with that post on arfcom aren't you?
Here's an offer for you. You take any Grendel barrel you can find, beg borrow or steal and I'll beat you with a 4" shorter but legal 6.8 barrel. Load it as hot as you dare with the same weight bullet. $1000 bet.

Factory ammo not shoving it full of powder.

[woohoo]

Factory ammo not shoving it full of powder.

Factory ammo, same length barrel.

[XcountryRider]

Factory ammo, same length barrel.

I would really love that not for a bet but just to see. 18in barrel shooting 120 and 123gr Amax. Know any one in san diego?

[KentuckyBuddha]

Why try to learn something without turning it into a urinary olympics though?

[woohoo]

I would really love that not for a bet but just to see. 18in barrel shooting 120 and 123gr Amax. Know any one in san diego?

No I try my best to stay out of Ca. Believe me there is a way to get this done. Agree to the fair bet and lets do it.
Well maybe I do... Corona. There is a dealer there that uses my barrels in his builds.

[woohoo]

Why try to learn something without turning it into a urinary olympics though?

I say don't make a statement if you don't stand behind it, talk is cheap.