Planning out an 18 or 20 inch AR build

meth0d

meth0d

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18 inch AR ALMOST DONE!

I've been putting together an 18" AR-15 to be used for plinking, hunting, and informal medium to long range shooting since last December.

Thanks to everyone's helpful and much appreciated input, this is where I'm at so far:

- DS Arms M4 flat top upper
- Forward assist and Ejection port cover
- Young Mfg chrome BCG
- LMT charging handle
- 18" SPR White Oak Armament barrel, 1-7 twist
- Rifle length gas system
- Low profile Rainier Arms match grade gas block.
- BCE BattleComp 1.0 matte stainless
- JP Enterprises XL hand guard

- Smith and Wesson M&P lower

Pending:
- Daniel Defense LPK - installed
- Stag A2 stock with hardware
- Trijicon AccuPoint 1-4x24 (some day)
- Base/rings
 
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White Oak makes great barrels. The SPR barrel would be a good all around barrel, although you would need to permanently attach something to the muzzle, or have WOA not thread it. They will also sell you a bolt, and headspace your barrel to that bolt. I have a WOA 24" varmint barrel - longer than the 20" you're thinking about. Shoots great, but HEAVY - like, who put that truck axle on my rifle heavy. The 20" would be heavier than the SPR, and the only gain would be barrel mass and whatever muzzle velocity gain 2 inches gets you.

I'm not a hi-power competitor, but if you're looking at that, check the current rule book to see what class the rifle you're building will put you in. Probably not Service Rifle.....

The 1-12" twist available in the varmint barrel would be optimized for shooting light varmint bullets, the 1-7 for heavier bullets. What ammo are you planning on shooting?

Are you planning on optics? The MBUSes are excellent backups, but not what I would pick if they were the primary sighting system.

PRS stock would be an excellent choice with the varmint barrel, with the SPR I'm not sure. I can't figure out from your specs if you're looking to build something accurate, but heavy, or building a light rifle to be as accurate as possible. I'd be inclined to put an A1 or Ace stock on the SPR, myself.

Either way, if it's a WOA barrel it will be accurate - [smile].
 
Remsport has lowers for $98.00 and we are in Mass. Pick up and there is no transfer fee or shipping. This can save you as much as $40.00
Contact us at 413 579 1994
John
 
KMM696 said:
White Oak makes great barrels. The SPR barrel would be a good all around barrel, although you would need to permanently attach something to the muzzle, or have WOA not thread it. They will also sell you a bolt, and headspace your barrel to that bolt. I have a WOA 24" varmint barrel - longer than the 20" you're thinking about. Shoots great, but HEAVY - like, who put that truck axle on my rifle heavy. The 20" would be heavier than the SPR, and the only gain would be barrel mass and whatever muzzle velocity gain 2 inches gets you.

I'm not a hi-power competitor, but if you're looking at that, check the current rule book to see what class the rifle you're building will put you in. Probably not Service Rifle.....

The 1-12" twist available in the varmint barrel would be optimized for shooting light varmint bullets, the 1-7 for heavier bullets. What ammo are you planning on shooting?

Are you planning on optics? The MBUSes are excellent backups, but not what I would pick if they were the primary sighting system.

PRS stock would be an excellent choice with the varmint barrel, with the SPR I'm not sure. I can't figure out from your specs if you're looking to build something accurate, but heavy, or building a light rifle to be as accurate as possible. I'd be inclined to put an A1 or Ace stock on the SPR, myself.

Either way, if it's a WOA barrel it will be accurate - [smile].
Click to expand...

Great points and info here, thank you!

I think I will scrap the match rifle idea from this build as I'd rather have free reign to build it as I'd like. I'm leaning towards the 18" and I'll talk to WOA about not threading it. Probably shoot a lot of factory ammo while I save for a reloading setup, so I'm thinking 1-7 for the twist.

I'm going to scope it down the line, what would you suggest for irons over the Magpuls?
 
If you're going to scope down the line, the Magpuls will work fine. I have a rear Magpul on a scoped rifle (standard front sight base) that works great. My personal preference is for standard front sight bases instead of fold downs anyway, and if I'm not putting optics on, I really like standard A2 rear sights. If your plan is to scope once your budget recovers from building the rifle, stick with the Magpul. Troy builds great sights, with one minor i$$ue......

If you end up needing a brake to attach, check out Primary Weapon Systems FSC556. It's not cheap, but works really well. I've shot the FSC556 on other people's rifles, and have an FSC30 on a 308 AR. Another option I like is this style brake. The company that made mine is now extinct, and that's the closest to what I have. Doesn't reduce recoil as much as other designs, but also isn't noticiably noisier than a bare muzzle - that, I really like.

Plotting out the build is almost as much fun as building, isn't it? I'm currently putting together a 16" midlength, and am in a bit of a snit over Magpul's inability to ship midlength MOE handguards on time. I know they're busy and all, but the handguard is the only thing I don't have. Maybe I could just shoot it without handguards until the end of September - where's that oven mitt?
 
I have a WOA SPR barrel, its a nice barrel, little heavy if you have to hold it up for awhile. 1/7 1/8 is the way to go. as is rifle length over a middy. If you are just plinking at the range, I would either not have it threaded, or have it capped. It you plan on any 3gun type shooting, I would put a brake on it.
 
YHM rail with the WOA SPR barrel make for a very heavy combo! It's also a pain to set up requiring a special tool to lock the lockring and it's difficult to line up the 12 o'clock rail with the upper receiver. If you got the coin, get the PRI free float tube that is found on MK12 Mod 0s. It's carbon fiber and it's indexed so it lines up in a snap with the upper receiver.
 
Thanks again to everyone who's contributed.

I'm gonna go with the 18" SPR and I'm thinking the Medieval muzzle brake from Troy, pinned/welded in compliance with the laws of course! [rolleyes]
 
if you're planning on shooting highpower, build an upper for the task. unfortunately muzzle brakes arent allowed whether its a service rifle, or a match rifle (i'm not aware of any particular classification that allows them). if ya wanna try it out before you invest a dime, shoot me a PM. there are still a few matches left this year to attend.

for what you're building, the only organized matches youd be able to shoot are IDPA/USPSA rifle stuff, and the any/any's that a few clubs put on. sounds like an excellent plinker, but a long range precision paper puncher for highpower it isnt.


just tell John H that you dont want the barrel threaded if it's a concern. he'd be more than happy to do it (makes his job easier if anything).
 
Jasper said:
if you're planning on shooting highpower, build an upper for the task. unfortunately muzzle brakes arent allowed whether its a service rifle, or a match rifle (i'm not aware of any particular classification that allows them). if ya wanna try it out before you invest a dime, shoot me a PM. there are still a few matches left this year to attend.

for what you're building, the only organized matches youd be able to shoot are IDPA/USPSA rifle stuff, and the any/any's that a few clubs put on. sounds like an excellent plinker, but a long range precision paper puncher for highpower it isnt.


just tell John H that you dont want the barrel threaded if it's a concern. he'd be more than happy to do it (makes his job easier if anything).
Click to expand...

I'm going to abandon the match rifle idea for this build, since I want to be able to mix it up. I just may take you up on that offer to try it out though, thank you!
 
meth0d said:
Thanks again to everyone who's contributed.

I'm gonna go with the 18" SPR and I'm thinking the Medieval muzzle brake from Troy, pinned/welded in compliance with the laws of course! [rolleyes]
Click to expand...

If you like the looks of the Troy brake, then go for it, if you are actually looking for an effective brake, look elsewhere

If you are in the Dedham area, you are welcome to try my 18" WOA
 
Supermoto said:
If you like the looks of the Troy brake, then go for it, if you are actually looking for an effective brake, look elsewhere

If you are in the Dedham area, you are welcome to try my 18" WOA
Click to expand...

haha, well I do like the looks of the Troy, but I'd prefer a functioning brake. What else would you suggest? Is the FSC556 any good?
 
I have a FSC556 pinned on my 14.5" spikes. I like it, it works well but like most comp's, it is LOUD. The website has some cool videos of it being fired at night, it seems (they claim anyways) to reduce the flash. That is a nice feature. It is kind of long if you are worried about adding length to your barrel.

If you want a comp that reduces felt recoil and does not pound the guy next to you with concussion and flash, check out http://www.battlecomp.com/. It is about the same size as an A2 flash hider looks similar to the KAC triple tap, and is A LOT cheaper, although it is 50 bucks more then the FSC556. I have one sitting at home waiting for a new project.
 
I actually just ordered a cooley for my WOA SPR, I am just stuck trying to pick a fore end. I really want the JP tube, but I also want to the gas block covered, I wish the JP tube was a little bit longer. I am considering the VTAC take off of the Troy since that one is long enough to cover the block.

Do you run a 1 o'clock iron on yours? I like the idea, but with a 1-4 scope it seems kind of redundant if you can just dial down to 1x.
 
JP is making a XL forearm that will cover the gas block
http://www.brianenos.com/forums/index.php?showtopic=107596

Firebird also makes one.

Depending on what kind of match I am shooting, I will run a 2nd red dot at the 45*, usually a c-more. This puts me in Open, which my shotgun and handgun are in anyways
The reason I do, even with a 1-4x is hold over. On close range tight shots. I don't have to worry about hold over. I sight the scope in at 100 yards, the 2nd red dot at 25'.
 
meth0d, sorry for the thread hijack.

Supermoto said:
JP is making a XL forearm that will cover the gas block
http://www.brianenos.com/forums/index.php?showtopic=107596

Firebird also makes one.

Depending on what kind of match I am shooting, I will run a 2nd red dot at the 45*, usually a c-more. This puts me in Open, which my shotgun and handgun are in anyways
The reason I do, even with a 1-4x is hold over. On close range tight shots. I don't have to worry about hold over. I sight the scope in at 100 yards, the 2nd red dot at 25'.
Click to expand...

This makes sense, I wasn't thinking about the close range hold over. Thanks for the tip!

And that XL forearm might be in my future, I like it!
 
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edmorseiii said:
Do you run a 1 o'clock iron on yours? I like the idea, but with a 1-4 scope it seems kind of redundant if you can just dial down to 1x.
Click to expand...


I would say that it depends on your equipment as well as the match. Around here (NH, MA) 80%+ of your shots are 35 yards or less. You'll have some out to 50, random at 100 and punch out further even less. I actually sight my 1x4 in at 25 yards. Personal preference but this puts me dead on for 90% of the shots I need to make. No hold over and no tilting the gun for another sight picture. Even at 50 or 100 its a minor adjustment if needed. Using the Burris XTR, holding 1 line above center on target is dead on at 200 yards. If your scope has holdovers and you know your POI, you can turn and burn with just a the scope, no additional irons needed.


Method - One thing you may want to consider is weight. For a range/plinking gun this sounds great and will be a lot of fun. For hunting you may find that its a little on the heavy side. You may want to consider trying to add up the weight for all the components and see where you end up. The PRS is a heavy stock. Depending on the weight of the barrel, it could be ass heavy or well balanced - I don't really know. But, all said and done it could be a 10lb gun. That may or may not be heavy in your eyes. Going with something like a ACE or even A2 could shed a lb or 2 and drop it down more towards the 8lb mark which is about the same as a good bolt action with wood stock. Just some food for thought.
 
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Go with the unthreaded barrel, if you have spent any time at the range shooting a comped AR or especially standing next to one you will know that it's nice to be directing that noise downrange.
 

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