AR-10 SBR - 56k death

[ctbreitwieser]

It's a little ruff. Not sure how it compares, but you feel the concussion for sure, and watch out for powder burn.

I weighed it tonight, It weighed in at 8 pounds 10 oz. Little heavier then I thought it would be, but still happy with the end result.

Loaded or unloaded?

 

[short308]

Loaded or unloaded?

Unloaded. It could be a high 7 pound rifle (unloaded) if I wanted it to be. The muzzle brake and the red dot weigh about 13 oz together, and the hand guard wasn't my lightest option.

A 20 round ar-10 mag, loaded weighs 1 pound 9 oz on my scale. I get 10 pounds 4 oz with the rifle as seen in the pictures, with a loaded 20 round mag.

 

[praff]

how does it run??? What length gas system did u use??? What gas block did u use??? Was any gas system tuning necessary??? I like it a lot and have often thought of doing this myself, but was always hesitant due to the questions above....and the cost as i'm cheap.

I also wondered if there was any addtional concern with baffle erosion on a 308 suppressor similar to what has been talked about for 223 sbr's.

Nice build

 

[short308]

how does it run??? What length gas system did u use??? What gas block did u use??? Was any gas system tuning necessary??? I like it a lot and have often thought of doing this myself, but was always hesitant due to the questions above....and the cost as i'm cheap.

I also wondered if there was any addtional concern with baffle erosion on a 308 suppressor similar to what has been talked about for 223 sbr's.

Nice build

Runs pretty good. Had to mess with it a little bit, but I figured I would. All the barrel work was done by adco out of Ohio, and I would highly reccomend them. Barrel I sent them a 24" heavy barrel on a Saturday, and had it back by the next Saturday. They reprofiled it, cut it down, set it up to run a standard ar-15 gas tube, and bead blasted it.

I put a pri adjustable gas block on it. It would have been fine without it. I just used it to keep the gas down to a minimum.

As far as erosion, only time will tell for sure, but I'm sure it will be present to a certain degree. Hopefully the muzzle brake will take most of the beating.

 

[subtlesixer03]

Its an awsome rifle and Ill bet a blast to shoot. My question is what other benifits does this have over a 300blk sbr? Cool factor and fun factor aside. Not trying to zing as it is awsome. Im just wondering if I missed something.

 

[Stainer]

I would guess the ballistics would be a little different. It would actually be cool to see what the actual ballistic difference is between this and the 300blk

 

[short308]

Its an awsome rifle and Ill bet a blast to shoot. My question is what other benifits does this have over a 300blk sbr? Cool factor and fun factor aside. Not trying to zing as it is awsome. Im just wondering if I missed something.

Still enough over the the 300blk to make it appealing. The other thing that made it appealing to me was the availability of ammo. That was probably the biggest thing that ruled out some of the other ar-15 rounds. The other thing that ruled out the rest of the rounds was the lack of energy after being cut down to 10.5".

Anyways, stumbled across numbers somewhere on the same subject.



150 gr HPBT Win 748 loaded to a chamber pressure of 56.4K PSI WARM load 45 gr NOT a starting load. I chose 748 as the powder as it is most like NATO powder.

26" = 2918 FPS MP= 6.6K PSI ––99.6 % powder burnt -2836 ft/lbs
24" = 2873 FPS MP= 7.4K PSI ––––––––––––––––––––––––––––2750 ft/lbs
22" = 2823 FPS MP= 8.2K PSI ––––––––––––––––––––––––––––2655 ft/lbs
20" = 2766 FPS MP= 9.2K PSI ––98.7 % powder burnt -2548 ft/lbs
18" = 2700 FPS MP= 10.5K PSI ––––––––––––––––––––––––––––2428 ft/lbs
16" = 2623 FPS MP= 12.0K PSI -97% powder burnt ––––2291 ft/lbs
14" = 2531 FPS MP= 14.0K PSI ––––––––––––––––––––––––––2133 ft/lbs
12" = 2417 FPS MP= 16.7K PSI -94% powder burnt ––1946 ft/lbs
10" = 2273 FPS MP= 20.5K PSI ––––––––––––––––––––––––––1721 ft/lbs
8.0"= 2080 FPS MP= 26.0K PSI -87% powder burnt. -1441 ft/lbs
6.0"= 1800 FPS MP= 34.1K PSI -79.4% powder burnt -1080 ft lbs

 

[iamaclone45]

I would be interested in watching a video of this rifle do a mag dump.

 

[HJezler]

I would be interested in watching a video of this rifle do a mag dump.

i second that!

 

[short308]

Throwing some lead at HillSide.

Yeah, yeah yeah. Glasses.

 

[wsenefeld]

How loud is it compared to a 5.56 SBR? I know my 11.5" 5.56 with AAC brake is uncomfortable to shoot with out the suppressor even with double ear pro.

Weird, my 11.5" 5.56 with AAC break is just as quiet as my 16". I wear ear plugs only and it's not bothersome at all.