Need help with AR10 260rem reloading

[bender338]

Hey guys,

I picked up a custom AR10 upper in 260 rem. From the research I did so far, most people use h4350 and 123 grain bullets in semi auto.

Can someone please tell me where I should start with H4350 and 123 grain bullets in AR10?

Also, which buffer tube/spring should I use?

Thanks!

 

[Sniper338]

Id try 120gr bullets or 130 gr bullets. measure your seating depth, and you will probably have to settle for max mag length... H4350 is the powder.. very good brass prep is paramount...

Look up load data.. sounds like you need a load book... or go one a bullet or hogdons website and look at their data for reloading... bullet weight all depends on your twist though too... 130s are my recommendation as I have an opinion that a certain 260 chamber is needed to use 140 gr bergers which I have in my 260.
id personally start with 130gr berger hunting vlds and H4350.


If I had to throw out a starting point itd be 40 grs and work up from there.

 

[mac86951]

Hey guys,

I picked up a custom AR10 upper in 260 rem. From the research I did so far, most people use h4350 and 123 grain bullets in semi auto.

Can someone please tell me where I should start with H4350 and 123 grain bullets in AR10?

Also, which buffer tube/spring should I use?

Thanks!

Start at 2.800" COL, as listed above start at 40gr H4350 and work up from there.

Use a standard AR10 buffer, buffer spring, and appropriate buffer tube.

-Mac

 

[joejo]

I'd run 123 scenars or sierra. The ojive is more forward so at 2.8 oal your not a mile from the lands.

 

[bender338]

Id try 120gr bullets or 130 gr bullets. measure your seating depth, and you will probably have to settle for max mag length... H4350 is the powder.. very good brass prep is paramount...

Look up load data.. sounds like you need a load book... or go one a bullet or hogdons website and look at their data for reloading... bullet weight all depends on your twist though too... 130s are my recommendation as I have an opinion that a certain 260 chamber is needed to use 140 gr bergers which I have in my 260.
id personally start with 130gr berger hunting vlds and H4350.


If I had to throw out a starting point itd be 40 grs and work up from there.

Thank you. I will try that and get back with a range report.

 

[jlow]

I'd run 123 scenars or sierra. The ojive is more forward so at 2.8 oal your not a mile from the lands.

You do know that means they have a lower BC and that means less of an ability to buck the wind...

 

[bender338]

What is a realistic accuracy of AR 10 in 260 rem? Will any AR10 shoot .5 moa and under?

I feel that If I can't get .5 moa with semi auto, then I will just use my bolt gun and shoot .5moa and under.

 

[rogn]

A good one will amaze you.

 

[mac86951]

A good one will amaze you.

+1

 

[ebb]

Bender your about 20 years behind the times.

 

[Brians356]

I would start here:

http://www.hodgdonreloading.com/data/rifle

Note: 260 Rem: 24-inch, 1:9 barrel, and all loads for 95 - 142-gr bullets state COAL 2.780", so YMMV.

 

[Danattherock]

A good one will amaze you.

That's a fact. My Barnes Precision AR-15 with 20" Krieger shoots half MOA all day with 77 SMK molys and Varget and shot a 0.172". My next gun will be a AR in 6.5 CM. Folks that say autos don't shoot well are off base. I used to be one myself. Live and learn.


Dan

 

[Brians356]

My buddy shoots at least as well as me and my R-700 VS with his RR Coyote Carbine, when he skips the coffee. He gets 3/8 MOA no sweat using 40 to 55-gr varmint bullets like V-max and Varmageddon and careful load development. I see no reason why an AR-10 wouldn't hang with, or better, a typical bolt gun in the same chambering.

The only reason I don't have any ARs - yet - is I can't stomach the aesthetics, ergonomics and controls. But with the accuracy and rapid fire, I'm coming around, slowly.

 

[joejo]

I'd run 123 scenars or sierra. The ojive is more forward so at 2.8 oal your not a mile from the lands.

You do know that means they have a lower BC and that means less of an ability to buck the wind...

Ummmm. Yeah. But if you have to jam .090 more bullet in the case you lose alot of capacity and you aren't gaining anything in BC with 140's vs 123 because you have to shoot them so much slower.

run a .547 bc 123 grain bullet at 3080 fps, which is no problem with a 260, and a 140 .615 bullet at 2850, which is typical velocity, and see what you get on any ballistic program. I bet the 123 wins or is equal.

 

[Brians356]

While it deals with 308 Win, I highly recommend reading the article Lane Pearce wrote for the Hodgdon 2014 Annual Reloading Manual: "Reloading the 308 Winchester for ARs". He discusses problems encountered and solved in tuning loads and preparing cases to ensure proper functioning in the direct-impingement AR-10 (as well as getting good accuracy.) Apparently the AR-10 is not quite as slap-dash easy to reload for as the AR-15 in 223 Rem. I wouldn't know, but I did find the article to be comprehensive and very informative. FWIW.

 

[bender338]

While it deals with 308 Win, I highly recommend reading the article Lane Pearce wrote for the Hodgdon 2014 Annual Reloading Manual: "Reloading the 308 Winchester for ARs". He discusses problems encountered and solved in tuning loads and preparing cases to ensure proper functioning in the direct-impingement AR-10 (as well as getting good accuracy.) Apparently the AR-10 is not quite as slap-dash easy to reload for as the AR-15 in 223 Rem. I wouldn't know, but I did find the article to be comprehensive and very informative. FWIW.

Thank you. Will take a look at the article.

 

[hogan]

Want the down & dirty?

You spent Big Bucks, if you got any kind of precision AR-10 upper. Now you're looking for "advice" on the cheap... What's more, there ain't that many AR-10 shooters on this board.

Got an adjustable gas block?
Really gonna use "internet load data" and jump to conclusion that H4350 is "the powder".... It isn't.
Too slow. Don't use Slow Powders in semi-auto rifles.

Glen Zediker has a lot of loading info for AR-10 and has a book devoted to handloading for AR rifles.
Might cost you some real money though. $30. Why the hell don't you have a Sierra loading manual? Might call their 800 number and get answers from people who KNOW. Maybe even Hornady techs can advise you?

Loading manuals are not obsolete. Really ought buy every resource you can to learn about loading for semi-auto precision rifles. Not like you want to use Federal 210M primers either.

Pretty damn easy to damage a fine rifle if you don't understand the variables and just dive-in and go a shooting. Might try the National Match boards. Sniperscountry used to be a great board with a section on semi-auto tactical rifles, with emphasis on precision. Maybe their old board is still active? AR-15.com has a precision rifles forum these days.

If you look at this forum, there are very few articles or discussion topics geared to AR-10 or AR-15 rifles.

 

[Brians356]

Edited:

I'd like to second hogan's warm welcome! But don't feel too cozy, bender338, we're not all as easygoing and pleasant as he is.

 

[jonbearman]

I don't think he is meaning to put you down he is telling you what you need to know and buy. I buy almost every type of reloading books I can get my hands on to just gain knowledge. I have an armalite ar-10 and was very careful working up loads because I didn't want to blow up a 1500.00 rifle or my face. By zedikers book on amazon is it is probably cheaper. Even though the powder companys show loads doesn't mean that they are tailored to a gas gun. Books are worth their weight in ammo and components wasted by trying this and that till maybe you stumble onto something that works.

 

[mac86951]

I'll go ahead and toss in my experience, my lr-308 loves H4350 and I don't have an adjustable gas block, and I use federal 210M (6.5 creedmoor). My 308 load development for a different -10 platform was very different. Your mileage may vary, and expect to try multiple variations and allow your data to point you in the correct direction. Gas guns show different signs than bolt guns, so more information on what to expect is a good thing.

-Mac