Hi! New the board, and to AR's, could use some advice.

[Rossignol]

Hey folks!

While familiar with firearms, I'm only just beginnning to look at AR's and I mostly have no idea where to begin.

I know what I want, but dont know how to get there. I guess the biggest questions I have are these; If I like a lower from say Bushmaster, and an upper from somewhere else, are they all compatible? And is the 6.8mm/.270 compatible with all 5.56mm lowers? Also, are fore arms/hand gaurds interchangable, providing the caliber is the same? I'd like to have a one piece rail forend and reciever rail if possible. I bit confused also with Carbine/gas blowback/... whatever. I'll be honest and just say for the record I dont know the difference, but can look these up pretty easily I bet. And Carbine Length?

I'm willing to take the time to build the rifle, and really want the 6.8mm.

My ideal build at this point would be a 6.8mm mil-spec construction as much as possible, heavy wall barrel, cold hammer forged, chrome lined, quad rail forend with Magpul AFG, folding BUIS, hydraulic recoil buffer tube like the Enidine, and Magpul stock, maybe the UBR.

I'm really open to advice here, and realize I sound like I have little idea what I'm talking about.

Thanks folks,
brad.

[Paulo_Santos]

Welcome aboard. I'm very familiar with the 6.8. Check out:
http://www.weaponevolution.com/forum/showthread.php?1598-Remington-6.8-SPC-Guide.

From what you wrote, I'd say, the Daniel Defense 6.8 would fit your needs and is really the only one, unless you want to go with a stainless barrel. What do you plan on using the 6.8 for? It makes for an excellent hunting cartridge, but it is expensive to shoot. The 6.8 upper is compatible with any 5.56 lower. The only difference is the barrel, bolt and mags.

[willardcw4]

paul - the 6.8 SPC guide you put together is phenomenal... I don't see how I missed it!!!

To the OP. If you want to shoot 6.8, are you planning to reload? Rounds are pretty expensive and reloading will make the investment in a 6.8 caliber weapon a bit more affordable.

+1 to the DD 6.8.

[Rossignol]

Yeah, I prefer the 6.8 as a hunting round, and no, I wont likely be reloading. I know the 5.56 is less expensive all around, and I do target shoot as well, which may make the 5.56 the better choice. I'm not dead set on the 6.8.

No, I dont really want stainless.

Whats prefered here as far as piston vs. gas blowback vs. etc?

[willardcw4]

There are pro's and con's to both systems. The standard AR-15 gas impingement system is what the weapon was originally designed for, meaning gas from the barrel is fed back into the upper receiver which moves the carrier group back to chamber a new round. My only 'issue' is that carbon buildup occurs really fast on the bolt and carrier, as well as inside the upper itself... All AR-15 owners have to deal with this (that is if they maintain they weapons ;) ). There are plenty of tools and easy ways to keep your AR clean, however.

The piston systems operate on the same theory as an AK-47, where a rod / spring assembly will push the carrier to the rear or the receiver to chamber a round, so no gas is going directly into the chamber. These guns are heavier (for the most part) than a standard AR, but the BCG stays cleaner! =D From what some people say (don't flame me for this! I don't own a piston rifle and thus have no personal comparison) piston rifles tend to lack some accuracy when compared to other gas impingement ARs in the same price range.

It really depends on your use / preference as far as which one is "better". What barrel length were you considering? How much money are you wanting to spend?

There are tons of threads on here that will give you a good idea as to what kind of weapon you might want based on your needs/use.

I don't know jack squat about hunting >.< so hopefully some others can give you insight into the choice in caliber.

[Paulo_Santos]

Yeah, I prefer the 6.8 as a hunting round, and no, I wont likely be reloading. I know the 5.56 is less expensive all around, and I do target shoot as well, which may make the 5.56 the better choice. I'm not dead set on the 6.8.

No, I dont really want stainless.

Whats prefered here as far as piston vs. gas blowback vs. etc?

I have the LMT piston and it is my favorite AR. If you don't lile cleaning ARs, pistons are the way to go. That is the one main advantage.

[Rossignol]

Well, I was kinda planning on a 20" and I'm less concerned about the cost, I'm planning on a cold hammer forged barrel anyway. I'll have to do some diggin on the forum for the other threads...

[Vise]

I'm less concerned about the cost

Build a 5.56 and a 6.8. Train with the 5.56 and then use the 6.8 to do real work.

[Rossignol]

Build a 5.56 and a 6.8. Train with the 5.56 and then use the 6.8 to do real work.

Thats just crazy enough to work! Or, if the 6.8 upper works with a 5.56 lower, I can alternate between uppers? Keep the 5.56 for the target shooting/practice and would even work for smaller game like coyote...

[Paulo_Santos]

Well, I was kinda planning on a 20" and I'm less concerned about the cost, I'm planning on a cold hammer forged barrel anyway. I'll have to do some diggin on the forum for the other threads...

I don't know of any 20" 6.8 hammer forged barrels. Matter of fact, the Daniel Defense is the only cold hammer forged 6.8 barrels that I know of. For most uses, the 16" barrels are the ideal length for the 6.8, unless you want an 18" SPR type.

[Rossignol]

Ahhh, ok. 16 it will be then.

[TehLlama]

16" 6.8 will be adequate, that's a solid choice.
It would work very well to have a pair of similar uppers, or as mentionted a single MRP Upper with a pair of barrels and bolts (more expensive rifle hardware, but can save some cash on the optic if you don't mind the zero being off between calibers).
IMHO, the piston offers very little in the way of advantage for a hunting setup - in an SBR, especially a part-time suppressed one, there are some advantages. With the MRP, you could swap it both ways.

[Fred_G]

Another vote for getting a 5.56 for shooting, and the 6.8 for hunting. That is my current AR setup, will be looking for another lower in the future so I can have 2 complete guns. It only takes a few seconds to swap the uppers, I just want 2 guns. I might have the EBG disease...

[Rossignol]

I'm likin the idea of 2 uppers for now, will likely stick with gas operation. Am I understanding correctly a carbine length forearm is just a shorter forearm, like say a 7" "carbine length" vs. a "mid-length"? Carbine not refering to the operation of the firearm?

Thanks for the insight and advice folks. It helps me to refine what I'm focussing on.

[Fred_G]

I think I have this right. A mid length is an 8" forearm. My 5.56 is 6", so I assume carbine. But, the location of the front gas block is at the end of each forearm, so the Mid length one has the front site farther down the barrel. If prefer the Mid length, but the smaller one might have some weight savings.

And down the road, you can just buy another lower receiver and have 2 AR's...

[Paulo_Santos]

The carbine length is 7", while the midlength is 9". I recommend getting a 16" midlength if they have that option over the 16" carbine length.

[Fred_G]

Thanks for the info paulosantos. How are the measurements made, If I might thread hijack a bit? My old forearm is 8.5" total length, 8" for the part you actually grab. Plus or minus a few mm.

[Paulo_Santos]

A typical midlength handguard is going to be around 9". All you have to do is measure them from one side to the other.

[Fred_G]

On mine, the handguard is right at 8.5". The .5" fits under the Delta ring and the front part. I am just asking for clarification, as once I obtain a new lower, I want to change out the handguard on my 5.56 upper. Keep the info coming.

[sangria7]

Piston driven is the 'new technology' however any old school M4 / AR15 will do the trick. Depends on your budget as well. Back in the 'sandbox' we used standard M4 Carbines with no compensator, piston, special barrel, or bolt assembly group. We used standard broom handle style VFG's and slings. However, optics was everything. ACOG's were pretty standard issue.

My point is a rifle is an extension of you and your skills. Find one that best fits your needs and become one with the weapon; and she will treat you well.

[Paulo_Santos]

On mine, the handguard is right at 8.5". The .5" fits under the Delta ring and the front part. I am just asking for clarification, as once I obtain a new lower, I want to change out the handguard on my 5.56 upper. Keep the info coming.

Your handguards are the non free float, so they are slightly shorter. Free float handguards are slightly longer.

[Fred_G]

Your handguards are the non free float, so they are slightly shorter. Free float handguards are slightly longer.

And there is my answer! Thanks! Was getting confused. Well, actually, I stay that way.

[Rossignol]

Lots of good info! Thanks, that clarifies much for me! Sangria, I totally agree on your point about the rifle being an extension of the individual and skills. Some time ago, I was told no ammount of upgrading a firearm would make me a better wing shooter, I just needed to learn to be a better shot!!! Very true words, thanks! Def keep the info coming!

[rob_s]

I like threads like these, seeing the lightbulb go on over guy's heads! Cool to watch the progression.

IMHO use is everything. There are forums out there dedicated to the owners that primarily want an AR to say they have one,post pictures on the internut, tell the guys at work how cool it is, and to scare old Aunt Edna once a year at the family BBQ. Fortunately you're not at one of those, you're at WEVO where there is a much higher concentration of actual shooters with varied backgrounds from LE, .mil, as well as recreational and competition shooters and training junkies.

So you need to define your use. Just as you aren't going to buy a Corvette to haul firewood, or a ball-peen hammer to build a house, or flip-flops to run a marathon, AR configuration tends to be use-specific. The good news is that even if you screw it up the first time or if your purposes or use evolve the modular nature means it's easily corrected or changed. So if you buy the wrong stock out of the gate you can always change it out later and sell the "wrong" one. Also, as mentioned already in this thread, intelligent lower configuration can allow you to buy two completely different upper but have a lower that works well for each. So you could have a lightweight mid-length 16" 5.56 with standard plastic handguards and an RDS for plinking and training, and a 16" medium contour6.8 with a FF rail system, bipod, and magnified optic for long-range use and hunting. I don't know of any other firearm where this kind of modularity is possible, and available.

The tendency, however, is for shooters to attempt to identify their use without any actual hands-on prior to this. They are often egged on by other owners that say things like "the great thing about building your own is you can start out with exactly what you want!" The logical followup is "how does anyone know exactly what they want without any experience on which to draw?"

Because of this I always suggest people start with a basic 16" AR with M4 stock, A2 grip (change that almost immediately) and plastic handguards, in 5.56. What this allows you to do is get out to the range with the least amount of cash invested, put the balance towards ammo and magazines and some training, and start to really work the gun and get an idea of where it's letting you down. Think it's not accurate enough at distance? Get some quality ammo and a real good shooter, borrow a magnified optic and go see. Most people wind up surprised (ammo and shooter ability are the most common weak links in the AR system, not free-floating and barrel diameter or the two-stage trigger). Think the 5.56 isn't hitting hard enough? Go hod hunting with some quality 75-77 grain ammo and see what it does.

I have a BCM standard 16" mid-length with Cavarms handguards and a MOE stock and grip. I have mounted a bipod to the bottom of the handguard with a short piece of rail, topped it with a Euro Leupold 3-9x in Larue mount, and turned in 1/2" groups at 50 yards with 75 grain ammo. and I am NOT a precision shooter. When I hear people start down a path of accessorizing and spending on a rifle I can't help but think of that gun. Similarly I have rung the 6" gong at 200 yards with an 11.5" skinny barrel Colt shooting XM193 and using a 4 MOA Aimpoint. According to the internut this is not possible, yet there the gong sits going "bong" more often than not.

IMHO start out somewhere like this, push it to it's limits, and change out parts as they start to hold you back only after honest evaluation to see if it's really the hardware or the software.

http://i134.photobucket.com/albums/q111/rob_s/gun%20stuff/BCM/TYPICAL-STARBOARD.jpg

[Rossignol]

Rob, good advice. Thank you.

[rob_s]

Ironically I came to the above conclusions the wrong-way-round. I did what everyone else does and bought the latest and greatest parts and pieces and anxiously awaited the sunset of the ban so I could assemble them all. Took the whole mess to the range and hated the damn thing! I had all the coolest parts at the time, Magpul M93 stock, Larue 12.0 rail, LMT 14.5" upper with pinned Gemtech suppressor mount, Tango Down pistol and foregrips, Aimpoint, Surefire light, etc. The gun above, and a similar SBR, are what I shoot now when I'm not working on T&E guns for articles.

Hopefully my experience can save someone else some money in the long run.

[Paulo_Santos]

INTERNUT? [BD][BD]

[Fred_G]

Ironically I came to the above conclusions the wrong-way-round. I did what everyone else does and bought the latest and greatest parts and pieces and anxiously awaited the sunset of the ban so I could assemble them all. Took the whole mess to the range and hated the damn thing! I had all the coolest parts at the time, Magpul M93 stock, Larue 12.0 rail, LMT 14.5" upper with pinned Gemtech suppressor mount, Tango Down pistol and foregrips, Aimpoint, Surefire light, etc. The gun above, and a similar SBR, are what I shoot now when I'm not working on T&E guns for articles.

Hopefully my experience can save someone else some money in the long run.

I tried not to go to far overboard on my 6.8 gun. Want to add a scope for deer season, a 5 shot magazine, and a sling. I would not want to use this in an active class, it is a bit heavy. Got my stock 5.56 upper for that. Great point about the application you want to use the gun for. Can't figure out why the 5 shot mags cost almost as much as the 30 round ones...



http://i756.photobucket.com/albums/xx206/FredG_album/FredG_2010/DSCN0487ARf.jpg

[Rossignol]

I appreciate the perspective and have long said why learn from your own mistakes when you can learn from someone elses! :)

[8'Duece]

I own an LWRC M6A2 Gen III. 6.8 SPC with Spec II chamber. 14.7" barrel.

I like the operating system, but if I had it to do over I'd purchase an LMT top end piston. Easier dissasemble for cleaning.

[Rossignol]

I really like the LMT uppers!