AR10 build in 7-08, 260 rem, or 6.5 creed

[B Man]

Few questions so bear with me. I have a large Frame AR in 308. Like all my 308’s, love it. But I want something in a large frame AR that will Buck the wind better and make it farther before going transonic. That leads me to the 3 calibers above. I’ll be reloading but I still want something easy to obtain components for, and run very reliable in a AR without a lot of testing. All of this probably points to the 6.5 creed, so I’ll start there. I have read several say that when you run the 147+ to get the really good BC that they have feeding issues. That it’s best suited to run 130-140’s? I won’t lie something about the 147’s at almost .7 bc is very welcoming to it. So that’s what I would prefer to run but I would like experienced opinions.

Next, can the 260 Rem run the high weight long high bc bullets at Mag length? I always liked this caliber.

How would a 7-08 run the high bc bullets in a AR at mag length and how would it compare ballistically? I’m not sure how hard it could push them.

I have a lot of imr7828 & H1000 for my magnum bolt rifles and I see the 260 with high weight for caliber bullets has data listing both of these.

Appreciate it

 

[bigjake83]

Few questions so bear with me. I have a large Frame AR in 308. Like all my 308’s, love it. But I want something in a large frame AR that will Buck the wind better and make it farther before going transonic. That leads me to the 3 calibers above. I’ll be reloading but I still want something easy to obtain components for, and run very reliable in a AR without a lot of testing. All of this probably points to the 6.5 creed, so I’ll start there. I have read several say that when you run the 147+ to get the really good BC that they have feeding issues. That it’s best suited to run 130-140’s? I won’t lie something about the 147’s at almost .7 bc is very welcoming to it. So that’s what I would prefer to run but I would like experienced opinions.

Next, can the 260 Rem run the high weight long high bc bullets at Mag length? I always liked this caliber.

How would a 7-08 run the high bc bullets in a AR at mag length and how would it compare ballistically? I’m not sure how hard it could push them.

I have a lot of imr7828 & H1000 for my magnum bolt rifles and I see the 260 with high weight for caliber bullets has data listing both of these.

Appreciate it

I shoot the 147's in all of my Creedmoor Gassers without issue.

If you're wanting to go with the 6.5CM or the .260 you'll want to pick up some H4350 or StaBall 6.5 powder.

There's no advantage to run .260 in a gasser over the 6.5CM because you can't push it as hard as you can in a bolt rifle and the COAL is a issue, also the Lapua Small Rifle Primer brass in the 6.5CM is a huge bonus.

 

[Aftermath]

.243

 

[msgriff]

I shoot the 147's in all of my Creedmoor Gassers with issue.

...snip

Typo?

 

[bigjake83]

Typo?

Lol... Yes damn fat fingers!

 

[B Man]

I shoot the 147's in all of my Creedmoor Gassers without issue.

If you're wanting to go with the 6.5CM or the .260 you'll want to pick up some H4350 or StaBall 6.5 powder.

There's no advantage to run .260 in a gasser over the 6.5CM because you can't push it as hard as you can in a bolt rifle and the COAL is a issue, also the Lapua Small Rifle Primer brass in the 6.5CM is a huge bonus.

What kind of velocity are you getting with the load your 6.5creed likes with the 147’s and barrel length?

 

[bigjake83]

What kind of velocity are you getting with the load your 6.5creed likes with the 147’s and barrel length?

24" Proof Research Carbon

147 ELD/ 40.8grs H4350 / Starline Brass / FGMM 210M

24" Proof Research Carbon

140 ELD / 41.0grs H4350 / Starline Brass/ FGMM 210M





I haven't chronographed my two new Bartlein 6.5 CM barrels yet, those are 18" and 22". I've just started load development on the 18" that's in my OBR and its showing promise for the first round of load development.

 

[B Man]

View attachment 8052984View attachment 8052985
24" Proof Research Carbon

147 ELD/ 40.8grs H4350 / Starline Brass / FGMM 210M



View attachment 8052993
View attachment 8052994

24" Proof Research Carbon

140 ELD / 41.0grs H4350 / Starline Brass/ FGMM 210M





I haven't chronographed my two new Bartlein 6.5 CM barrels yet, those are 18" and 22". I've just started load development on the 18" that's in my OBR and its showing promise for the first round of load development.


View attachment 8053012

That is all very impressive. That’s all from your gasser correct?

 

[bigjake83]

That is all very impressive. That’s all from your gasser correct?

Yes Sir..

 

[B Man]

Yes Sir..View attachment 8053016

Those seekins sets are solid! Question, have you noticed any POI shift when your barrel heats? I’ve read where the carbon barrel has a tendency to shift sone when it gets hot but I’ve read the opposite too…. Trust your opinion

 

[bigjake83]

Those seekins sets are solid! Question, have you noticed any POI shift when your barrel heats? I’ve read where the carbon barrel has a tendency to shift sone when it gets hot but I’ve read the opposite too…. Trust your opinion

I thought at one point there was definitely a thermo shift going on and it was causing my groups to open up more so compared to a stainless steel barrel, but it turns out that wasn't the case it was just the mirage. Now would I choose a carbon barrel for 3 Gun competition, no.. and it's too light for PRS. All the proof barrels I've seen for competition use are stainless steel.

 

[B Man]

I thought at one point there was definitely a thermo shift going on and it was causing my groups to open up more so compared to a stainless steel barrel, but it turns out that wasn't the case it was just the mirage. Now would I choose a carbon barrel for 3 Gun competition, no.. and it's too light for PRS. All the proof barrels I've seen for competition use are stainless steel.

Thanks Jake. I’ve just heard/read that they have had that issue with a wondering poi change with a longer string of fire. Not mag dump type shooting but 10 shot string then an immediate 10 shots behind it. Just trying to decide if I wanted stainless or carbon on this build if I went proof.

 

[bigjake83]

Thanks Jake. I’ve just heard/read that they have had that issue with a wondering poi change with a longer string of fire. Not mag dump type shooting but 10 shot string then an immediate 10 shots behind it. Just trying to decide if I wanted stainless or carbon on this build if I went proof.

What caliber are you doing?

 

[B Man]

What caliber are you doing?

Honestly haven’t decided yet…. Leaning to a 6.5 creed at the moment.

 

[bigjake83]

Honestly haven’t decided yet…. Leaning to a 6.5 creed at the moment.

If you're going 6.5CM I honestly wouldn't go with a proof barrel, the stainless steel PR has a contour that is too light IMO and the Carbon is just expensive and doesn't offer anything over a custom Bartlein you can get from CLE or Craddock for cheaper.

Don't get me wrong the PRCF Barrels are outstanding but unless saving weight is a priority I'd get a Bartlein or Krieger made to order.

 

[bobke]

Will agree with Jake, though I really like my 20” Proof CF barrels in both 6.5GR and CM. Have a 20”Bartlein 6.5CM as well as a CM spun up by Keystone Accuracy that manages to nudge both barrels by a small amount and is spot on for cold bore shots. They’re all levels of very good, but the Krieger is an absolute hammer.

 

[B Man]

If you're going 6.5CM I honestly wouldn't go with a proof barrel, the stainless steel PR has a contour that is too light IMO and the Carbon is just expensive and doesn't offer anything over a custom Bartlein you can get from CLE or Craddock for cheaper.

Don't get me wrong the PRCF Barrels are outstanding but unless saving weight is a priority I'd get a Bartlein or Krieger made to order.

I didn’t realize the Proof SS 6.5 creed was that smaller profile. After reading your comment I did look it up and seen it is.
Still thinking caliber over. I’m undecided now on 6.5 creed or sticking with 308. I know the obvious advantages the creed has especially for a mag fed AR, but I have a ton of 308 components and my range only goes to 800 yards. So I’m sitting on the fence….

 

[Peterpan]

i have a krieger barreled 260 that compass lake done up for me. couldn’t be happier. with the reamer they used the throat is perfect for the 142smk i shoot out of it. i’d rather shit a sideways brick than own a 6.5creed.