Building An Ar15 From Scratch

[David]

Anyone have any experience with building an AR platform rifle from scratch? I bought my first one already assembled, so I'm thinking my next one I want to build as it goes.


I'm also thinking something a little bigger caliber I know I can go with a .308 but are there any other options.

 

[Dirtbike]

Hard to go wrong with a 6.5 Grendel, that's one flat shooting round imo @Chris Timmerman this sounds right up your alley!

 

[Dirtbike]

I was browsing gunbroker the other day and saw an AR platform in 300 Win Mag too damn rich for my blood though, I'd be happier with that caliber in a bolt gun

 

[RangerTim]

I've built them from scratch but have always stuck to 5.56. I can't imagine a larger caliber would be too different from the build perspective. The parts are pretty much the same, just bigger!


6.5 Grendel is good. All depends what you want to do with it. Heavy hitting at close/medium like a 6.8SPC or flat and fast for long range? You could look at some of the short ultra mag rounds. I'll have to do some research. I went with a SCAR 17 for my heavy hitter so I didn't dig alot into other options.

 

[Shawn Agne]

You have all kids of options in the AR15 and AR10. The AR10 can do any of the 308 family cases (243, 260, 7mm-08) along with the 6.5 Creedmore, 6XC, 6mm-250, etc. Just need to get a barrel chambered for what you want and you're off and running. AR-15s same way. The 6mm variants are better off than the 6.5 Grendel such as the 6mm HAGAR, 6mmAR cartridges. Another cartridge that works nicely and you don't have to buy brass for is the 6mm-223 just expand the neck to 6mm. It doesn't have the horsepower of the Hagar or the 6mmAR variants It can take the 105/107s to around 2620ish which is quite nice performance being able to use regular 223 brass. Don't do the big magnums in an AR style rifle. You won't get the most out of the cartridge. Here are some smiths that do some different cartridges.


http://www.keystoneaccuracy.com/


http://www.6mmar.com/


One of my course rifles is an AR-10 in .260 Rem. First year I shot matches I used it for across the course and for Long Range. Probably the all around best cartridge for an AR-10 IMHO. Nice thing is you can form brass from 308 cases or any of the 308 family cases, where as you can't with the 6.5 Creedmore.

 

[OhAggie98]

I went the 6.5 grendel route on my from scratch build. Main purpose for it is for mule deer hunting in West Texas. I wanted something in the AR15 platform, so I could buy an inexpensive 5.56 upper for play and use them both on the same lower. If you do swap different caliber uppers on the same lower, build your custom with an adjustable gas block so you can tune it to the buffer in the lower. This will help from having to potentially swap buffers for the different calibers and gas system lengths.


Be careful about the AR10 platform, as parts are not all made mil-spec like on the AR15 platform. Many manufacturers parts for the AR10 are not easily interchangeable with other manufacturers.