anybody got an ar10 in 6.5-284

[spencerhenry]

i am thinking of building an ar10 in 6.5-284. i am trying to find out as much as i can about reliability, magazine issues and the like. i know it can be done, that they exist, i just dont want to build one and then find out that they have some kind of little quirk.

[mrfish83]

I have a DPMS LR-260 in 260 rem. What's the COAL for the 6.5-284? I always thought it was considered a long action. Most AR-10 mags limit COAL to around 2.810"

[spencerhenry]

6.5-284 does not need a long action. if you want to seat bullets way out then the short action is short. a 6.5-284 most certainly does fit in an ar10. question is whether it is a good choice.

[Hoser]

My gunsmith in Pueblo built one a few years back. Ran good with virgin brass. After that it got finicky. He said he would not build another.

I would go with a 260 in an AR-10 if you want a 6.5 something. He has built several of them and they are much lower maint and cheaper to shoot. When I rebarrel my OBR it will be in 260.

[spencerhenry]

that is exactly the kind of information i was looking for.

my idea was to build a long range coyote gun, get the flattest shooting caliber in the rifle as possible. but in further research, the trajectory of a 6.5-284 vs a 308 is not as great as one would think. at 700 yds with optimum components in each the difference is only about 16 to 20 inches, at 300yds it is only like an inch or so. lately i have been wondering about a 6.5-300saum, i have read that the saum case is better for use in an auto. but havent found much for ballistics yet.

[C Ward]

Any caliber in an AR10 platform is going to be a comprimise with other than a 308 based cartridge. All the odd ball caliber riifles are inherently finiky and even the 260's and 243's can be , form powder burn rates and how it affects the port pressure of the gun .

To get the most out a 6.5/284 it really needs to be a long action gun . To take advantage of the case capacity and the high BC bullets it needs to be loaded long . When loaded to SAMMI OAL it will not reach the 3000fps range with 140's , the highest BC's are in this weight range .

If the high BC bullets are not going to be used it makes no sense to go with a hot rod cartridge that will shorten barrel life and increase your loading head aches . If varmint bullets are going to be used I'd get a 243 and be done with it .

The wind drift is really the more important number to compare since the bullet path is a known value and is compensated for with the scope before the shot .

[spencerhenry]

while i agree with most of the previous post, i do not necessarily agree that any caliber other than 308 is going to be problematic. for example there are a slew of different calibers for ar15's and most run trouble free. i have a 9mm and it works flawlessly, also a 300 fireball and it runs flawlessly.
there is a good possibility that some of the non 308 based cases will not reliably feed, but it is not a given. that is why i asked for responses with firsthand knowledge. a 6.5-284 may not be up to its highest potential in a ar10 platform, but it still kicks but in the ballistics category. all the load data i have for a 6.5-284 is listed with oal that will fit in a ar10 mag, and the velocities are not too bad. as far as gas pressures for proper operation of the bolt, my first ar10 in factory configuration went back to armalite 2 times for that exact problem, they worked the right direction on it, but never fixed it. i finally made the gas block adjustable and now it not only cycles properly, but the brass is not destroyed. in other words the gas pressures are not an issue that cant be easily overcome.
if i wanted a 243 i would have bought a 243. that is NOT what i want.

[C Ward]

So in Your own experience with a stock AR10 that didn't run with the original caliber and the OEM tried twice to fix it and couldn't and it took a 3rd try from some else to fix it and that is what you define as a reliable system ?

In 15 years of shooting competitively in the action sports and have seen every flavor of AR10's from box stock to 3K dollar JP's and Larue OBR's choke and not run reliably in the original caliber .

AR10's are notoriously over gassed as they are . Trying to make a rifle something it isn't is a recipe for problems .

It is more than just port pressures the powders for the hot rod cartridges are all slower than typical 308 powders and it changes the pressure curve and dwell time which changes bolt speed and wierd things happen .

Seems like You have this all figured out and are looking for approval of Your idea and not advice , best of luck to You .

[spencerhenry]

seems like you think you know it all. maybe you shouldnt ASSume what other people are thinking?
i NEVER said my ar10 didnt "run". it has NEVER been a problem from a reliability standpoint.
i guess if you were around in the gun industry around 1860 you wouldnt have had any use for cartridge guns either, after all why try to change something that works.
it is posts like yours that have caused me to look elsewhere for intelligent educated opinions. you may have been around competitive shooting for years, that doesnt mean you know squat about the question i was asking. it is specifically the kind of generalization about ar10's that i didnt want.
next time you see a thread authored by me, move on i dont need your sarcasm.

[C Ward]

Your words ,

"as far as gas pressures for proper operation of the bolt, my first ar10 in factory configuration went back to armalite 2 times for that exact problem, they worked the right direction on it, but never fixed it. i finally made the gas block adjustable and now it not only cycles properly"

that sounds like a gun that doesn't run to me .

The answers you were given were exactly what you asked for , " i am trying to find out as much as i can about reliability, magazine issues and the like. i know it can be done, that they exist, i just dont want to build one and then find out that they have some kind of little quirk. " and when they didn't agree with what you thought you got defensive .

Comparing AR10's to AR15's is apples and oranges what works with one doesn't always transfer to the other system because of the exponentialy heavier bolt carrier on the 10's . Comparing a 9mm AR15 is also way out of the ballpark as it has a totally differant operating system than either rifle , being a straight blow back design .

Like I all ready said you got this figured out have fun with it .

[m*o*a]

WOW! Not trying to get in on the arguing, so I will just post my opinion. The AR10 is a great platform, but for a coyote gun, it is a little heavy. Personally when I go to my spot to call some song dogs, it can be a long way, and want lighter weight. I would, and do use a 6.5 Grendel, or 6.8 x 43 in an AR15 platform.

There is alot of discussion on the internet as to which is a better cartridge, and have seen arguments for both sides. Myself I prefer the 6.5 Grendel as I like the ballistics and performance better. On that note, you had better reload if you go with that cartridge as factory ammo is scarce, but the componants are abundant.

The 6.8 x 43 (SPC & SPCII) is also a great cartridge with easier to find factory loaded ammo.

I have built both calibers in the AR15 platform for my customers, and all are extremely happy with the performance of what they choose.

Here are some pics of my 6.5 Gendel (OD green one w/scope) and some pics of a 6.8 x 43 I built (Black one)

Hope this helps and doesn't add more confusion in your search for a coyote gun.

http://i712.photobucket.com/albums/ww121/frommycolddeadhands/100_0174-1.jpg



http://i712.photobucket.com/albums/ww121/frommycolddeadhands/100_0303.jpg