AR-15 Long Distance Caliber

[Graham Smith]

Over the weekend, a fellow and I got to talking about alternative calibers that will work in an AR-15 frame. The question we posed was, if you bought/built a separate top end for an AR-15, what available caliber would make for the "best" long distance (600+) round. And immediately it got complicated.

He knows alot more about this than I do and I learned that there is quite a list of calibers available. But it also quickly became clear that "best" was going to be a relative term because some of the calibers are so difficult/expensive to get/build ammo for that the cost was going to be prohibitive.

My conclusion in all of this is that it's just not worth the money. But since this is basically a theoretical discussion anyway, why not pursue it. After all, I might learn something.

So, what are your suggestions and why?

[cyburg]

Personally I am going with the 308. I have been shooting a buddies POF in 223 and 308. What a smooth rifle. Heaveyer buller more power sweet and accurate.

[Graham Smith]

Personally I am going with the 308.

Unfortunately a .308 upper cannot go on an AR-15 lower.

[ShooterSteve]

Check out the Grendle. I'm not sure if 6mmbr.com has info on it, but it is worth looking at for sure.

[Graham Smith]

Check out the Grendle. I'm not sure if 6mmbr.com has info on it, but it is worth looking at for sure.

That was my first thought and one I've looked at. It's expensive to load for but not as bad as some.

[iainmcphersn]

Carl Bernosky won the 2007 Camp Perry High Power with his 6mm Hagar.

http://6mmhagar.com/

http://www.6mmbr.com/6BRBlog.html

At New Holland, Carl shot alongside Robert Whitley. Carl said he was impressed by Robert's new 6mmAR Turbo round. The 6mmAR Turbo is based on 6.5 Grendel cases necked to 6mm with the shoulder blown forward slightly. Carl told us: "If Robert's 6mmAR Turbo can really shoot the 105s at 2880+ fps, then it should be competitive with the 6mm Hagar, and the brass is available right now. Whitley's cartridge looks like it has great potential."

More info on the 6mm AR Turbo here:

http://6mmar.com/6mmAR_Turbo.html

Also look at the 6mmAR Turbo 40° Improved

http://6mmar.com/6mmAR_Turbo_40_Improved.html

The 6mmAR Turbo 40° Improved (left) has a significantly larger powder capacity than the 6mmAR (right) and can easily drive the larger 105-108 gr bullets in the 2900 fps range.

Edited April 20, 2010 by iainmcphersn

[GentlemanJim]

Just go look at the ballistics for 6.5

Hypersonic over 1000yards,

Jim

[Graham Smith]

Hypersonic over 1000yards

The Grendel? I don't think I knew that. More interesting all the time.

[M ammo]

I still went with a DPMS in .308,,, I can find .308 everything. brass, bullets. small base re-loading dies...

I got the gun for $1300

and it will reach out for the 3 Gun distances I need to shoot. 600 is the longest,, 3 gun shot I have ever made,,,,

but the gun shoots .5 inch at 200 if I do my part,,, so the gun can do the job.

for me .308 was a better solution.

Jim M ammo

[TeamGE]

Shooting the much higher BC 107g 6mm bullets, compared to the same weight 6.5mm bullets makes a lot of sense to me. I think the 6mmAR (or one of its other fire formed wildcat forms) is a good call. I have already started my build. Should be a fun project.

[rma_38sup]

You can find a great deal of info on the Grendel at:

http://www.65grendel.com/

Grendels are more expensive to shoot than .308.

Others will need to weigh in as to the cost of some of the more exotic calibers.

Robert

L2723

[Middle Man]

.264 LBC-AR may have better component prices than 6.5 Grendel^TM...they do have near identical ballistics. Les Baer is a bit more "mass market" than some of the other 6.5mm wildcats.

[kgunz11]

.264 LBC-AR may have better component prices than 6.5 Grendel^TM...they do have near identical ballistics. Les Baer is a bit more "mass market" than some of the other 6.5mm wildcats.

It's just another name for the Grendel to avoid paying anyone any royalties. Black Hills will be loading ammo for the .264 LBC.

The 6mmAR offerings are pretty neat. I'm going to build one of Robert's other variants, the 6 Super in the near future.

6.5 Grendel with 123gr Scenar @ 2650 fps

1000 yards 33.0 MOA up with 7.8 MOA in the wind

6mmAR

1000 yards 29.2 MOA up with 7.3 MOA in the wind

The 6AR has a slight advantage to the Grendel, but reloading costs are comparable as the 6AR uses necked down Grendel brass.

[buzzworm]

Anyone have an experience with Olympic's .243 WSSM or .25 WSSM? I've been considering a longer range upper, but there are so many variations. I would like to get something that is not a complete wildcat, so that I can get brass, dies, etc. without going the custom route on everything.

[Graham Smith]

I would like to get something that is not a complete wildcat, so that I can get brass, dies, etc. without going the custom route on everything.

That's the rub. It would be interesting to look at a few if the different calibers and figure out the loading cost per round (it's actually an interesting problem just figuring out how to calculate that by itself).

If 6mmAR is a bit better than 6.5 Grendel and costs and availability of supplies the are about the same, then the 6mmAR is the better choice. But what if 6mmAR costs 20% more to reload? What about 30% more?

Of course, all this ignores the cost of the gun and the reloading dies. Even if the supply cost for the 6mmAR is about equal to the 6.5 Grendel, if it costs 50% more to build the gun and setup for reloading, then...

[Religious Shooter]

Anyone have an experience with Olympic's .243 WSSM or .25 WSSM? I've been considering a longer range upper, but there are so many variations. I would like to get something that is not a complete wildcat, so that I can get brass, dies, etc. without going the custom route on everything.

I was looking at the .243 WSSM for the AR15. Because of case-length and the AR mags you are limited to 80/90's. 105's and 115's are too long for mag length.

In addition the available mags for it was like 8 rounds.

For the games I intended it for... those restrictions were too limiting.

I was going to use it for MGM Ironman and for the various precision rifle matches.

You need capacity better than 8+1 rounds for both type of venues. And you are limited to 3000-3100 fps in most PR matches (to conserve their steel). If you have that velocity limitiation the 80/90's can't match the 105. Right now I don't know of any AR calibers that will run a 115 at mag length.

So I said screw it to the .243 WSSM.

[Graham Smith]

For the games I intended it for... those restrictions were too limiting.

Good points. You have to factor in mags and purpose.

As I said in the original post, I'm theorizing about shooting an AR-15 at 600+ yards so I'm not sure that velocity limits would be an issue since they would have dropped off quite a bit at that distance.

Edited April 30, 2010 by Graham Smith

[fl3gun]

Anyone have an experience with Olympic's .243 WSSM or .25 WSSM? I've been considering a longer range upper, but there are so many variations. I would like to get something that is not a complete wildcat, so that I can get brass, dies, etc. without going the custom route on everything.

I have a rifle i use for NRA Cross the Course High Power built with the Oly parts for the wssm line. Mine is chambered in 6BR. the rifle shoots 1/2 moa out to 600 with ease, but the quailty of the Oly parts sux.

[Graham Smith]

Has anyone looked at the .224 AR round? It's a necked down .65 Grendel case firing heavy .224 bullets. Here are some results from the creator:

Berger 82gr BT

27.0 grains Varget w/ Berger 82gr BT, MV = 2865 fps, ES = 29, SD = 14

27.0 grains RL-15 w/ Berger 82gr BT, MV = 2920 fps, ES = 15, SD = 7

Berger 90gr BT

27.0 grains Varget w/ Berger 90gr BT, MV = 2792 fps, ES = 26, SD = 12

27.0 grains RL-15 w/ Berger 90gr BT, MV = 2857 fps, ES = 12, SD = 6

[Jaxshooter]

Daniel Horner and Robbie Johnson of the AMU shot Grendels necked up to 30 caliber to make major power factor. There may be something there. I don't know how much testing they did with it at long range since 3 gun matches don't shoot 600 + yards.

[kgunz11]

They also did that with a propellant they say is not commercially available.

[Patrick Sweeney]

I think with any inquiry in this area you have to keep one thing firmly in mind: there's no cheap way to do it.

Anything that will put bullets in a small cluster way the heck past Ft. Mudge is going to cost. So, it is more a matter of figuring what costs matter most to you.

Do you want relatively soft recoil, relatively common components, relatively easy reloading process or top-end performance?

You'll get different combinations of those with one or another cartridge. Pick what matters, and let the others go.

[Tom D.]

Would like to add that to accomplish your objective, any cartridge will likely be too long to feed from the magazine. And, FWIW, the Farr Match at Camp Perry has been won with M-16 more often than not in the last several years. I believe the AMU shoots 90 gr. bullets in 6 1/2" twist barrels for that.

[M118LR]

I myself have been using the 6.5 Grendel in the AR-15 platform. Ammo is available from WOLF and also there is talk that Hornady is going to make brass and ammo for the Grendel. I currently load my ammo for the Grendel. Lapua brass is high, but you can find it. I am still waiting on the Hornady brass. Maybe it will not be as expensive as Lapua.

[Chris Conley]

The Hornady 6.5 Grendel ammo was suppose to be released in the March/April time frame but here it is May and no ammo yet. The wait continues.....

Chris C.