Thinking about building an AR-15

[scooter123]

Never done this but have a co-worker who has built a bunch of them. What I'm considering could probably be best described as a Tactical Varmint Rifle and it may actually end up New York Compliant if I were to limit the magazine selection. Seems a bit odd to work out that way but I have some particular wants that are driving the selection of components in this direction.

First, I want to put together something with long range accuracy potential and that will utilize a full charge of a slower rifle powder efficiently. So, the barrels being considered are an 18 inch DPMS stainless SASS and a Shilen 20 inch Stainless with matching bolt. Right now I'm leaning towards the Shillen and oddly enough this particular barrel is unthreaded with a recessed crown. So, no Flash Hider if I go with the Shilen barrel. With that length barrel I don't think a flash hider will provide any benefit but if I am wrong about that feel free to speak up. I could have my co-worker chuck the barrel up in a lathe and thread it for me.

The Upper and Forward Handguard will be GIBBZARMS G4 side charging set with a mid length handguard. As for why, Hickok 45 has a video of this upper in action and it's totally COOL and there are some real advantages to a side charging upper if you want to use a reduced sight offset. The only downside to this choice no forward assist and no dust cover. Both of which I've been told aren't really even close to being essential unless you are actually in Combat.

Finally because I'm an Old Fart and because of the reduced sight offset my butt stock choice is a solid A2 version. This should allow a good cheek weld with either Ghost Ring sights or a forward mounted Scout Scope. Plus I'll end up with a rifle that sort of loosely pays tribute to the M16-A2 with some 21st century features.

Anyhow, that's the rough outline right now. I would appreciate some comments and suggestions for items like sights, gas blocks with or without front sights, trigger options, and basic lower parts kits.

 

[ColumbusJBR]

If you're looking for long range use, I think most would agree a nice 2 stage trigger would be ideal. Rock River makes a good one for a modest price, although most seem to think Geissele is tops. As far as parts kits, if you know you're going to upgrade triggers anyway, probably get one without the Fire control group. I think CMMG makes an inexpensive one that should be fine.

These are just suggestions, there are dozens of options out there.

Happy hunting!

 

[Ματθιας]

Have you decided on a bullet weight and twist rate for your barrel to extract the best accuracy?

 

[dwf6666]

You may want to contact Frank White at Compass Lake Engineering. I had him build a service match upper with a Douglas air gauge barrel. He installed one of his triggers in my lower. It's a 1 in 7 twist and I use the Sierra 70 gr match bullets. It's one of the most accurate rifles that I've ever owned. Do a Google search to see what they offer. Frank has built many rifles for Camp Perry matches.

 

[scooter123]

I've started gathering parts. Earlier in the week it was a Lower Builders Kit that has all the small parts required except those for the Trigger Group. Also ordered was a rubber Hogue grip and a KNS Anti Rotate trigger pin set. Today I placed an order for a DPMS A2 stock, a 3 lbs. Timney single stage trigger, and a Lee Deluxe Die set in .223 Remington.

As for the drop in trigger choice, Timney is a know quantity in top notch trigger groups and it was on sale at Midway. As for the weight, I was initially going to get the 4 lbs. version but the co-worker who is advising me on this build said to get the 3 lbs. trigger and if I didn't like it he would swap it for a 4 lbs. Timney he has in his spare parts stash.

So, once I pick up a stripped lower locally I'll have everything in hand to assemble my lower. Then it will be a matter of gathering together everything needed for the upper. One plus to the AR15 down the road will be the option to put together multiple uppers so if I want to do a 300 blackout it's just a simple matter of building a new basic upper in that caliber. Think I may end up really enjoying the AR platform.

 

[scooter123]

Finished up on my AR build and am very pleased with the results, function and accuracy are everything I was looking for.

Basically, it's a Varmint or Sniper's AR15. The Barrel is a 1:8 20 inch Shilen with a Wylde chamber and a matched bolt. Bolt Carrier Group is a Spikes Tactical Nickel Boron. The Side Charging Upper Receiver and forward handguard are by Gibbz Arms. The lower is a Detroit Gun Works because I live in the Detroit area. Trigger is a 3 1/2 lbs. Timney single stage. Handgrip is a Hogue rubber finger groove grip because I like Hogue rubber grips. The trigger reach is a bit short with this grip so I may try a beavertail style grip to get more reach. Buttstock is a DPMS A2 because I'm an old fart and don't need no tacticool sliding stock. In addition every sliding stock I've ever handled rattled. Right now the scope is a 38 dollar 6x42 gun show special but when the budget recovers a Nikon M223 3-12x42 is on the wish list.

Note, anyone interested in a Side Charging AR should take a look at the Gibbz Arms setup. Not only is the non reciprocating upper very well executed but the setup for mounting their free floating handguard makes mounting the barrel about as dead simple as it could be. What you do is screw the mounting adaptor to the receiver after sliding the barrel in place. Once the handguard mount is about 1/2 turn from tightening fully to the receiver you slide a 3/16 drill bit into the gas tube notch and port to lock the rotation in. Then you use the special castle nut tool for the internal castle nut in the mount and use a crowfoot and torque wrench to tighten everything up. Once that is done all you have to do is remove that drill bit, mount a low profile gas block and gas tube, then slide the handguard in place and secure it with 4 socket head screws. The end result is the gas tube doesn't touch the receiver anywhere at all and it "rattles" as some say they need to in order to get the best accuracy. BTW, not sure I buy into that bit but having the gas tube in full float can't hurt anything and with this setup it was very easy to achieve.

Something else I picked up in my shopping foray's was a Caldwell Brass Catcher that mounts to the forward handguard with a velcro strap. You have to bend the frame a bit into a v shape to get it to conform to the upper receiver but once that is done it works superbly. For 9.99 from Midway I have to say it's actually a very good bargain.

Range report and pic. First, the final weight with scope is 9 lbs. 14 ounces so it's not feather weight. However the recoil is almost as light as a 22 rimfire and it's surprisingly quiet without any birdcage on the barrel. Accuracy is also superb and my groups could likely shrink by at least 50% with a sled and better scope. Best group shot was 5 rounds into a 0.550 inch span on the left at 50 yards. Middle target was while I was refining the sights and the right was 10 rounds of a load using 0.3 more grains of Varget. I can also say the Timney trigger I installed is absolutely PERFECT, it breaks just as cleanly as a S&W revolver in single action with about the same degree of creep and over travel.