Ar15 caliber that uses large rifle primers

[cohunt]

Here this is from hornady's website
Both are the hornady custom line of ammo.
The 6.8 is loaded with the 120gr sst
The 6.5 is loaded with the 123gr sst.
Pretty close comparison. This was as far out of a distance as i could get. But we all know that the farther out the better the 6.5 is gonna do for the same weight bullet.
I choose the 123 over day the 100 gr as it was more common and you shoot 130 which I'm sure is common out of the 6.8.
First one on the left os the Grendel which has a slightly faster starting speed.

I just noticed you didn't play fair with these 2 charts-- if you look at the factory specs on hornadys web pag, the 6.5g is using a 24" barrel to hit 2580fps, where the 6.8spc is only using a 16" barrel. I like to see real world numbers with equal length barrels so people can compare numbers for themselves. This is usually what happens when people compare cartridges is they skew numbers in favor of 1 over the other

 

[cohunt]

So your bullet starts to beat my 97 at 650 yards in drop. This is applied app. But boy are they close.
Yours is in the left mine is on the right. Hope I did those right as I did them fast.

The wind drift on the 130 will be better than the 97 at distance.

I do think in general, the 6.5g beats the 6.8 at distance-- but this combo we found for the 6.8 just really works well -- but a guy still has to shoot well to make any round work at those distances .

Normal weights for the 6.8 are 90, 95, 110, and 120-- but there are 85 up to 130 that work. I think the 6.5 has slightly lighter options if one likes to run those too.

I think the real thing that shines in both of these cartridges is they work well for normal hunting distances with little felt recoil in gas guns. They really are close to each other, each has had its shortcomings in the past that has been overcome and they both shine at what they do....they really do seem to hit a sweet spot for hunting with an ar15 chassis.

 

[snox801]

I just noticed you didn't play fair with these 2 charts-- if you look at the factory specs on hornadys web pag, the 6.5g is using a 24" barrel to hit 2580fps, where the 6.8spc is only using a 16" barrel. I like to see real world numbers with equal length barrels so people can compare numbers for themselves. This is usually what happens when people compare cartridges is they skew numbers in favor of 1 over the other

Oh man I did not even look. My bad most of that stuff always uses a 24". So yes you would gain some speed or drop off the Grendel making them very close.

 

[snox801]

Also gotta say. Not sure about you but I don't trust the bullet to open correct and do enough damage out past say 400 yards. They may hit the target but I won't shoot mine on game that far. So they are basically both great but Great rounds for the most common distance we all shoot.
Most common weight fro the Grendel is 123gr but I prefer to add some speed for my hunting. Especially thermal.
Mike from Texas on here has a real smoking 6.5 grendel with a 20" tube. Would be cool to see how they stack up with the same barrel. I think he plays with 109g also.

 

[cohunt]

Also gotta say. Not sure about you but I don't trust the bullet to open correct and do enough damage out past say 400 yards. They may hit the target but I won't shoot mine on game that far. So they are basically both great but Great rounds for the most common distance we all shoot.
Most common weight fro the Grendel is 123gr but I prefer to add some speed for my hunting. Especially thermal.
Mike from Texas on here has a real smoking 6.5 grendel with a 20" tube. Would be cool to see how they stack up with the same barrel. I think he plays with 109g also.

Agree, wouldn't hunt past 300-400 depending on the bullet construction and speed. I might push my 20" with the 140 fusion/gold dot out to 450 on deer/lope as its still above 1800fps with over 1000 ftlbs -- but my 16" stops around 350-400 depending on bullet

My 110ab load from my 16" still has 1800fps at 500, but the energy is down to around 800 ftlbs-- getting pretty marginal for my likes . I'd say 400ax for deer sized and 300 and inside for elk sized woth good shot placement.

There have been some pretty stellar shots performed out way past where I'd be comfortable shooting elk with either cartridge, but those would be exceptions to the rule-- I generally take my 308, -06, 7rm, or 300wsm for elk hunting.

 

[Schroedernd]

Another vote for 6.5 grendel. Easy to load for, wide array of bullet choices, accurate, and fun to shoot to 1k at steel!

 

[javman]

Got both the 6.5Gr and 6.8. If your needing LRP look for PPU brass when available. Now in my experience with the 6.8 and 95gr ttsx I'm getting 2988fps out of mine and shoots clover leaf groups.

 

[DDWing]

How fast do you push a 130 grain in the Grendel with a 20" barrel?

I'm running around 2550 with AR-Comp, and 130 gr Bergers.

 

[snox801]

I hunt have you tried any lighter hammer bullets in your 6.8?
That's what made me choose them when I ran the numbers about the time the bc started to make a difference the FPS dropped off to where I didn't feel comfortable.

 

[cohunt]

I'm running around 2550 with AR-Comp, and 130 gr Bergers.

I hunt have you tried any lighter hammer bullets in your 6.8?
That's what made me choose them when I ran the numbers about the time the bc started to make a difference the FPS dropped off to where I didn't feel comfortable.

Nope, the 116/117 grain are 1.2" so it's about the same length as the 130 lead core-- definitely need to run a "faster " powder as you'd loose case capacity. The 85gr is a shock hammer design so I'm not really interested

It's something I might try in the future but haven't done yet. I'd like to see something in the 100-105 gr range

I wonder what powder Steve would suggest? He hasn't done much work with gas guns though last time I checked

 

[snox801]

My guess would be xbr 8208. Just based on the case and maybe Rl10x

 

[DDWing]

My guess would be xbr 8208. Just based on the case and maybe Rl10x

Good luck finding any 8208. I haven't seen any of that in over a year.

 

[Mike D Texas]

Good luck finding any 8208. I haven't seen any of that in over a year.

It's been coming around. I managed to snag a couple of pounds from powder valley recently.

 

[cohunt]

My guess would be xbr 8208. Just based on the case and maybe Rl10x

Aa2200 is one of the best for 95-110 gr
Reloader 7 works well for the 95 and under...I'd have to look at a burn rate chart but it's gotta have the right gas impulse for the di system too.
Cfe blk to 1680 burn rate maybe for the ahh?