6/6.5 AR

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Bluejazz

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Jun 8, 2009
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#1
I have a 223 RRA, and it is a great AR, but am interested in getting something between that and a 308 AR.
Looking at the 6 or 6.5 calibers.
In the 6cal, I am interested in shooting the 105 Berger or 115 DTAC, in the 6.5 cal looking at shooting the 140 Berger or 142 SMK.
I would like opinions on caliber choice and why you choose to shot what you are shooting. Discription of your build might be helpful as well.
Also, do you need to go to a AR10 platform for the 6.5?
 
#5
Re: 6/6.5 AR

6.5 Grendel is the best way to go in my opinion on the AR15 platform.
If you want to go to an AR10/LR308 size receiver you can't go wrong with the 6.5 Creedmoor.

I run the latter for POF-USA, but will be having Scott at Specialized Dynamics make me a 6.5 Grendel DI upper as soon as I can swing it.
 
#8
Re: 6/6.5 AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: armydog</div><div class="ubbcode-body">6.5X47 Lapua? </div></div>
Too long for the magwell.

BUT that new short .30 caliber for the 2.25-inch mag limit (was it Remington came out with that??) is one that I would neck down to 6.5mm to get something higher speed than the Grendel.

The ribs on .223 mags are too "deep", making the width of the space for cartridge bodies too narrow for Grendels (or 6.8 SPC). That makes stacking more than 5 rounds or so or Grendel in an unmodified mag a jammomatic proposition. I don't know anyone who can iron out those ribs.

If you really want to run 140-gr bullets, they are great on wind drift compared to anything else, but the Grendel can't safely drive them fast enough for my trajectory wants.
 
#9
Re: 6/6.5 AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bluejazz</div><div class="ubbcode-body">I have a 223 RRA, and it is a great AR, but am interested in getting something between that and a 308 AR.
Looking at the 6 or 6.5 calibers.
In the 6cal, I am interested in shooting the 105 Berger or 115 DTAC, in the 6.5 cal looking at shooting the 140 Berger or 142 SMK.
I would like opinions on caliber choice and why you choose to shot what you are shooting. Discription of your build might be helpful as well.
Also, do you need to go to a AR10 platform for the 6.5? </div></div>
If you want the longest bullets possible in both calibers you will need to step up to a AR10 size to get those bullets to fit in the mag without having .200" jump to the lands. IMO nothing in a AR15 is fast enough to push those bullets except a 6BR, 243 wssm or 6.5BR, 6.5 ARSM
 
#11
Re: 6/6.5 AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Grump</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: armydog</div><div class="ubbcode-body">6.5X47 Lapua? </div></div>
Too long for the magwell.

BUT that new short .30 caliber for the 2.25-inch mag limit (was it Remington came out with that??) is one that I would neck down to 6.5mm to get something higher speed than the Grendel.

The ribs on .223 mags are too "deep", making the width of the space for cartridge bodies too narrow for Grendels (or 6.8 SPC). That makes stacking more than 5 rounds or so or Grendel in an unmodified mag a jammomatic proposition. I don't know anyone who can iron out those ribs.

If you really want to run 140-gr bullets, they are great on wind drift compared to anything else, but the Grendel can't safely drive them fast enough for my trajectory wants. </div></div>

They make specific mags for the 6.8 and 6.5, not a good idea to try to use 5.56 mags for either one.
 
#12
Re: 6/6.5 AR

Modifying mags is not an issue what so ever, as long as you use mags worth modifying. I've been modifying PMAGS to run 243WSSM ammo with an OAL of 2.400" for over a year now with no hiccups.

If you can modify it to run WSSM ammo, then 6.5 Grendel or 6.8 SPC should be no issue at all. HOWEVER, it would still be easier to just buy a mag that's already built UNLESS you've already got excess PMAGs lying around.

Myself and others shoot 105 Bergers out of the .243WSSM but if you want to run 115's then you'd be better off going with something like the 6mm AR Turbo 40 Improved simply because the bullets are too long for the WSSM case length.

 
#13
Re: 6/6.5 AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bluejazz</div><div class="ubbcode-body">I have a 223 RRA, and it is a great AR, but am interested in getting something between that and a 308 AR.
Looking at the 6 or 6.5 calibers.
In the 6cal, I am interested in shooting the 105 Berger or 115 DTAC, in the 6.5 cal looking at shooting the 140 Berger or 142 SMK.
I would like opinions on caliber choice and why you choose to shot what you are shooting. Discription of your build might be helpful as well.
Also, do you need to go to a AR10 platform for the 6.5? </div></div>

FYI,I tried running 115 DTACS in my 6mmART40.With a 26" barrel I only got 2675 FPS as a max load.The long bullet eats up to much powder capacity at mag length so I abandoned the idea.With the 105Amax I'm getting 2915 FPS with .3" groups half the time.

I've thought about getting the 22AR and shooting the Berger 90 grain VLD's because the recoil would be less and the BC is .551 instead of .492 for the 105Amax.

http://6mmar.com/224_AR.html
 
#14
Re: 6/6.5 AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: c_bass16</div><div class="ubbcode-body">Modifying mags is not an issue what so ever, as long as you use mags worth modifying. I've been modifying PMAGS to run 243WSSM ammo with an OAL of 2.400" for over a year now with no hiccups.

If you can modify it to run WSSM ammo, then 6.5 Grendel or 6.8 SPC should be no issue at all. HOWEVER, it would still be easier to just buy a mag that's already built UNLESS you've already got excess PMAGs lying around.

Myself and others shoot 105 Bergers out of the .243WSSM but if you want to run 115's then you'd be better off going with something like the 6mm AR Turbo 40 Improved simply because the bullets are too long for the WSSM case length.

</div></div>
Anyone that has ever tried to use a 6.5 or 6.8 in a 556 mag knows it makes the sides bulge. WSSMs are single stack just like my ARSMs, the 458 Socom, .499 and Beowulf. Use the correct mag and they work fine, there are 4 different companies that make 6.8 mags.
 
#15
Re: 6/6.5 AR

A. In the 6cal, I am interested in shooting the 105 Berger or 115 DTAC,

Greg Krebaum, Lee Wells, Robert Whitley, and "Bustin" here on the hide build 6m/m rifles that shoot 105 Bergers extremely well and by the way they shoot 87vmax well too...up to 3000 but Bustin's 6m/m runs 105's that fast as I understand it. I shoot 6RAT. This is all in the small chassis AR; An AR15. The 115DTAC is too long to be properly seated in the case to run in the small chassis AR magazine. You'll have to chamber a 243, 6x47 or 6xc for three examples in a large chassis AR's to run 115's and get their benefit.

B. in the 6.5 cal looking at shooting the 140 Berger or 142 SMK.
I would like opinions on caliber choice and why you choose to shoot what you are shooting. Discription of your build might be helpful as well.
Also, do you need to go to a AR10 platform for the 6.5?

Yes. Taking advantage of those heavies will required 260 Rem., 6.5Creedmore, 6.5x47Lapua, and:
an Armalite bolt (because of its right sized firing pin hole),
RL 17 propellant,
Magnum primers (or CCI#41),
adjustable gas block (regulate over-gassing),
OCW load development method (stabilize RL17 but it should be used anyway).
I promise there is a special reason for all these....its a chain reaction. I know.
Built right it works well. This assumes you want to take full advantage of the round. But if you want to merely shoot factory ammo a factory rifle will do. Either way the DTAC bullet is the wat to go. Run it in a 6x47, 243 or 6xc. Get GAP, Madesha, or Sabreco to build it and let us see it when you do. These are all big chassis AR's.

I had a x47 Lapua using DPMS Lr308 receivers. Madesha did the bolt work. Wells built the barrel. Used a Clark Carbon fiber float tube. Giessele trigger. The gun shot .3 until a thug stole it.

My shooting buddy just gotta Grendel. We've loaded 107smk, 123 Hornady, and next 108 Skeenar. I'm impressed with its seemingly inherent accuracy, but its no x47 clearly.
 
#16
Re: 6/6.5 AR

Casey,
I did make 6 and 6.5 BRs and BRXs but I have put them on hold except the 25-20" 6.5BRs coming from Krieger. We're just too busy to build custom rifles now, they take about 8 times longer to build.
 
#17
Re: 6/6.5 AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bluejazz</div><div class="ubbcode-body">Grump,
So what are your recomendations? </div></div>
If you really want to stick with a standard 5.56-scale lower, the Grendel is the only decent choice.
 
#18
Re: 6/6.5 AR

I just finished putting together a 6BRX with a barrel and bolt from AR preformance. Not sure if they are doing custom work but you might be able to get the extension and bolt and have another smith put one together. You won't be able to run the 115 at mag length and get the velocity you want but the 105 should be no problem. 6.5 120-123 bullets max for ar 15 length magwell without eating up your powder capacity. Heres some load data for the 6brx with a 22 inch barrel.

Loads in Red are near max in the barrel I am using, so approach with caution. Be careful about sizing brass if they are sized too small they can show a flat primer because there is room for the primer to be blown partially out of the case
so try to set the dies to get .004 setback on the shoulder. Do NOT use that 34gr of H4895 load it is HOT. V550 is the best all around powder for the BRX and produces the best velocities with all bullets
if you just want accuracy then 32gr of Varget is a good place to start with 90-95gr bullets.
OAL/powder type/charge/velocity in the middle of the excel file kind of run together.
6BRX 1/2 MOA 105 amax touch at 2.320, 95smk not touching at 2.322, load to 2.3.
95 Berger hits the lands around 2.375 in a .100 leade chamber so will need to be a .020 freebore to load to 2.3"-should be a .080 chamber and a .020 to handle all bullets
95 berger is about .510 BC, 105 Lapua BC 530+ maybe better than Berger, Amax about .500, 107 about .527
95SMK NODE at 3070 H4895 34 3224-22" almost as fast as a 243!!! seems HOT
6/10d CCI41 2.298 varget 33.7 3050 33gr V produced 3/8 groups 33.6-1/2"
Varget 33 3075 1/4"
2.298 RE15 33 3075 .4" looks like 3075 is the node
6/10d CCI41 2.298 15 33.5 3050 1/4"
95SMK 2.3 RE15 34 3141 8-May Test with 95 Berger 95 Berger will out perform a 105
IMR4064 33.5 3156
33 3092 41s
6/10d CCI41 2.298 N550 36 3150
95SMK wolf 2.298 V550 36 3075 3182-cci41 ??? 0.2 2.295-2.298 CCI 41 primers 8x3 22" PacNor try 35.5gr 550
35.7 3087 41s try35.7
V550 37 3203 nice group, test again 36-550-3/4" 37 at 1 " Vert string
6/10d CCI41 2.298 17 35.3 3050 1/4"
95SMK 2.3 RE17 35.5 3066-22" .4 /35gr17 4-Mar 35-17 .4" groups
105Amax 4895 33 3059-22" 33 is too hot
CCI41 2.298 Varget 31.6 2850 1/4 group 1/2"
6/10d CCI41 2.298 Varget 32.7 2950
105 varget 33.1 3056-22" 33 is max, back dn a little
105Amax RE15 32.8 TRY 32.8 1/2" wolf primers on clean barrel
105Amax RE15 33.5 3047-22" 33.5 max
105 4064 32 2994-22" max

fireform load 204 33 34gr is too hot to fire form, use standard 6BR load

6/10d CCI41 2.298 v550 34.5 2950
NODE at 2970 CCI41 2.298 V550 34.8 2970 1/2" 1/4"

v550 35 2995 wolf 3045-cci41
105 V 550 35.5 3038-22" max
105Amax RE17 35 2997-wolf
6/10d CCI41 2.298 re17 34.8 2950
105amax RE17 35.5 3042-22" Max
105 4831SC 35.5 2667-22" too slow
107 SMK 550 35.9 3038 35is max load lousy 3"

105 lapua
Varget 32gr


Hits the lands atXXXXX with BRX .100 leade
75 Barnes 2.25
80 Nosler 2.245
90 Nosler 2.245
90 Scenar 2.325
105Amax 0.5 2.32

.050 leade needed to touch or jump .020 with these bullets
95 SMK 0.48 2.35
95 Berger 0.51 2.375 needs .020 leade to jam lands
105 Scenar 0.533
107 SMK 0.527 2.36


6mm bullets are much easier to find than 6.5 right now. Hope that helps.
 
#19
Re: 6/6.5 AR

I have 2 Whitley 6mmAR's. One is lighter and shorter for WT hunting, and the other is for distance. They are both very accurate, pleasant to shoot and boringly consistent. I would do it again in a heart beat:) Over the last 4 years alot of my rifles have come and gone, sometimes twice, but the 6mmAR's had stood the test of time.

As Steve123 stated above, Whitley's 22ar looks real good with the heavies.

Hope this helps,
Trilogymac
 
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