AR Questions Mid Length and Adjustable gas blocks

[Centurian22]

Ok, I started off thinking I would be happy with a S&W M&P Sport basic entry level gun. Then I started doing more research and now I am convinced that won't meet what I want without significan modification. First off the role of this gun: mostly for target practice at the range, some for home/property defense, possibly to be used for hunting of coyote or maybe deer (though I have a .308 bolt and 12ga pump that fit this bill better), and possibly for casual competition (3-gun) if I can find a local club to get involved with. I also plan to buy and add a .300 blackout barrel at some point and MAY get a can way down the line.

So now the individual parts I'm looking for:
• 16" barrel, 1:7 or 1:8 to handle heavier bullets, govt/med/or possibly heavy. (To be clear this is 16" + muzzle device, not 14.5" + pinned flash hider).
• Mid length gas system for smoother function, reduced 'recoil', faster follow up and reduced wear.
• Free float smooth forward hand guard with optional rail sections.
• Adjustable gas block for tuning of factory or reloads to be smooth but reliable.
• Flat top (no interest in carry handles).
• 6 position buttstock
• Optics to be determined either scope or red dot possibly both on QD mounts with flip up irons mounted on 45 degree angle for backup to optics.
• Brake to stay on target / better follow up shots.

Not terribly concerned with weight (within reason), however would like to stay short for maneuverability in house / woods. It's primary role will be more Close Quarter, but I'm a stickler for accuracy. Range no more than 200yards 95% of the time with possibly paper punching out to 300ish.

So questions: is there any reason to think about an 18" vs my choice of 16"? I'm not to concerned with the 1-200fps difference.
Are there any downfalls to the mid length gas sys especialy in the 16" length?
Are there any downfalls to the adjustable gas block? Is it helpful to open up a wider range of loads / powders in reloading or is it really overrated?

I was tossing around the buy vs build idea for a long time but THINK I have settled on buying a S&W M&P15 MOE MID, then (after testing), adding a JPRifles free float hand guard (either 12.5" or 15.5") and JP low profile adjustable gas block. Any comments or input on any of these products separate or paired together? Is there anything difficult about swapping the front sight gas block for the low-pro adjustable? Especially the NON chrome lined 1:8 5R rifling barrel?

This purchase is not happening for a while but I want to put in the time and research to make sure I'll be happy with my final choice. I don't have the finances to just up and turn around and try again if I mess up. Speaking of budget: like I said I was originally trying to get away with an entry level for less than $800, then as I looked at mid gas and free float tubes I began to realize I'm realistically looking at probably $1500 when all is said and done. So that being said: any recommendations that anyone has under $1500 that meet what I'm looking for (or what you may think I SHOULD be looking for if my choices are misguided).

Sorry for being long winded, thanks for sticking it out, and thank you for ANY help you can offer.

 

[ugaarguy]

is there any reason to think about an 18" vs my choice of 16"? I'm not to concerned with the 1-200fps difference.

Nope, 16" is fine.

Are there any downfalls to the mid length gas sys especialy in the 16" length?

Not on a 16" bbl.

Are there any downfalls to the adjustable gas block? Is it helpful to open up a wider range of loads / powders in reloading or is it really overrated?

It's overrated. You don't need it.

I was tossing around the buy vs build idea for a long time but THINK I have settled on buying a S&W M&P15 MOE MID, then (after testing), adding a JPRifles free float hand guard (either 12.5" or 15.5") and JP low profile adjustable gas block. Any comments or input on any of these products separate or paired together? Is there anything difficult about swapping the front sight gas block for the low-pro adjustable? Especially the NON chrome lined 1:8 5R rifling barrel?

The 1:8 5R bbl is melonite treated rather than chrome lined. It's a great option. S&W uses (at least they used to) straight pins rather than taper pins, and they mushroom them out. You'll probably end up cutting off the factory gas block. From there it depends on if your new gas block pins on, or needs flats / dimples milled into the bbl for set screws.

This purchase is not happening for a while but I want to put in the time and research to make sure I'll be happy with my final choice. I don't have the finances to just up and turn around and try again if I mess up. Speaking of budget: like I said I was originally trying to get away with an entry level for less than $800, then as I looked at mid gas and free float tubes I began to realize I'm realistically looking at probably $1500 when all is said and done. So that being said: any recommendations that anyone has under $1500 that meet what I'm looking for (or what you may think I SHOULD be looking for if my choices are misguided).

Your choices are good. I'd also consider a Daniel Defense M4V7 since that's what you seem to want out of the box. Also, heavy bbls are overrated on ARs. You'd also be fine with a light weight bbl for anything you want to do (and the DD M4V7 comes in a LW version too).

 

[Centurian22]

Ugaarguy: thanks for the very detailed reply! I looked into the DDm4v7 after reading about it in a gun magazine. I never thought I would consider a $1500 AR but as mentioned in my post I'm starting to realize and trying to accept that it may be worth it to "have it all" if I determine that what I think I want is what I really want.

Do you feel the DD is a higher quality or significantly better product than the S&W? My only nit pick with the v7 as well as one of my nit picks with the RRA Operator 3, is the full length top rail. I don't plan to run irons at the 12 o'clock and (think) I would prefer a smooth tube for an extended off hand far forward grip to manipulate the rifle. It is nice that it comes with three rail sections which can be moved, though not having sights at the high price point is a bit of a put off. I don't know how much (if any) the DD's sell under MSRP or if they can even be found in stock? Though I guess where I have time before this purchase that's not as much a concern. I just don't want to narrow in on my "perfect choice" just to find that it remains to be unobtainium.

Edit: I answered part of my own question. DD lists them as out of stock, gallery of guns didn't even list DD, but with a little more google foo, or in this case 'bing foo' I found a DDM4v7 supposedly in stock for $1349! (Edit again found on Buds for $1272!!!) I think at that price point I would take it over the S&W pending further input from people with actual experience with them.

Also after some tactical couch imaginary rifle mounting I'm beginning to think that the top rail may not be a problem. I don't know if I would ever try to modify my muscle memory rifle hold of my left hand. As it stands now I keep my thumb and fingers clear of the top either to avoid the barrel or stay out of the way of sights / optics. I don't see that I would intentionally change that even if I had a completely round tube, unless it would make a significant practical difference for tactics or competition. Even then I suppose I could always try and find a rail cover that wouldn't look horribly stupid to slap on there if I really wanted to.

 

[ugaarguy]

Centurian, you're welcome. I'll try to answer your other questions.

If you're going for Mil-Spec then DD is better with their 4150 steel barrels that are cold hammer forged. I'm in the minority here, but I actually like S&W's 1:8 5R melonite 4140 bbls over any chrome lined bbl - even if that chrome lined bbl is CHF 4150. On the other hand, Daniel Defense got their start by making rails. They still make some of the strongest and lightest rails available. If you want max accuracy the S&W bbl is one of the best you're going to get on a factory rifle.

Yes, $1350 is expensive, but compare that to an $1150 Colt M4. The DD M4V7 is built as well as, if not better than, the Colt M4. The extra $200 gets you the modular FF tube, and the CHF bbl.

The DD M4V7 gets you close to what you want out of the box. The S&W gets you a good base that's going to need a little work.

A more cost effective alternative might be to just buy a complete upper and lower and put them together. That's not really assembling anything because the upper and lower are held together by two pins.

You can get a complete lower for anywhere from $160 for an Andersen lower from Karri's Guns to just under $300 for a PSA lower with MagPul furniture. You'll just have towatch to see what's in stock in either place.

From there look at the Noveske Rogue Hunter 16" Upper (in stock at Midway for $1134 complete), and various stainless steel bbl uppers at Bravo Company ($760 and up plus BCG and charging handle). Their $915 (plus BCG & CH) SS416 upper with PRI round carbon fiber handguard is one option you should strongly consider - http://www.bravocompanyusa.com/BCM-...er-Group-p/bcm-urg-mid16 ss410 pri12black.htm.

 

[justice06rr]

I would speculate that the DD is actually better than a basic Colt6920 (unless you get the Colt M4A1 SOCOM).

I would still get the DD over the Colt for the $1300-ish price tag. IIRC the Colt SOCOM is around $1400 so you may save a bit and put that towards a good optic or other accesories/ammo.

 

[oldpapps]

So many ways to go.....

IF (and I wouldn't) I were to buy an AR/M4 type, I would buy a Colt. Know product for resale and I know that I wouldn't be happy with it long. They are nice, I don't have one.

16 inch versus 18 inch barrel. If you like the longer look, go for it. The few feet per second velocity difference isn't a concern, change your load a little if you think you must have that 10/20 FPS. But, that 2 inches does make a little noticed difference in maneuvering. The 'mid length gas system supposedly gives longer/less jarring life. I don't think I will ever notice but I went with one on one of my builds. Balanced loads smooth them out anyway.

Heavy barrel. They are heavy! Unless shooting pin point shots at 2/3/4 hundred yards or planning on extended firings of a hundred rounds and more, not worth the weight.

Twist.... Lots of turns here. What are you going to shoot (bullet wise)? 55s do great with most any twist currently available. Heavy/er bullets like tighter twists. I just can't get away from SS barrels with 1 in 8 twist and Wylde chambers (I run 75 grain AMax quite well). Here I will stick my views of chrome. Chrome is great, easier to clean, doesn't rust as easy. I clean my weapons and don't have any problems doing it. Guess I don't need chrome. But then, I'm not in a war zone.

Adjustable gas blocks. It works or it doesn't. A lot of expense for what? IF that's what you want, get it. Hopefully you reload and your loading abilities are more than these 'give me a set recipe' to load mind sets. Load for the weapon, find the range (in loads) that your weapons runs best, then search out the best accuracy. A variable gas block becomes a redundant expense.

Look at as many suppliers as you can find, study the products, make your own determinations. One of the great things about AR/M4 type weapons is the interchangeability of so much.

You mentioned the 300 AAC BlackOut. Bad news, build a .223/5.56 and want to used the lower with your 300 Black and very soon you will be building a lower just for the Black, I did. The 300 BlackOut upper should run a Carbine length gas system and shows little if any benefit of a longer barrel.

Look at 'Palmetto State Armory' for uppers and lower kits. 'Rock River' too. Heck, there are so many good places to look and buy.

Oh, unless you have access to those special tools or plan on building lots of uppers, think hard about buying your upper/s pre-assembled. The process isn't all that difficult (with the proper tools) but... Building your lower/s, only odd thing I see is two or three inches of tape to prevent scratching.

And you thought that you babbled a lot.

Be safe,

 

[wally]

It's overrated. You don't need it.

Yup, ts mostly only needed if your gun is horribly over-gassed. If under-gassed it won't help, as the barrel port will need to be made larger unless the gas tube is kinked or the gas block installed cockeyed to the port, and then the standard gas block will work once the problem is corrected.

I like the midlength on a 16" barrel as the bayonet lug is in the right place relative to the original 20" barrel so to be it just looks "right". The down side is it reduces your had guard options as lots of stuff in not made in midlength.

Building your lower/s, only odd thing I see is two or three inches of tape to prevent scratching.

Proper sets of "starter punches" and "roll pin punches" helps a lot more than tape to prevent finish dings. The front takedown pin installation tool will save a lot of time searching for the small parts that go "sprong!" when you slip A castle nut wrench is pretty much required for a collapsible stock unless you don't mind dinging up the nut -- a single AR multi-tool will do the castle nut and upper assembly if you have a decent bench vice and some scrap wood. If you do a lot of uppers its worthwhile to get the more specialized tools to speed things up.

First time lower build, pay particular attention to the trigger guard roll pin installation if the tabs are not properly supported you can break one off, ruining the lower while trying to drive in the pin.

 

[G.barnes]

Buy what you really want and don't pay as much attention to price. If you buy a cheap model to save some money you'll just end up spending more to get a better on later on after you take a loss selling the cheap one. If accuracy is important to you look into a stainless barrel. Bcm offers rifles with stainless uppers and they're a top notch rifle and still in the same ballpark as DD price wise. The rifle is the cheap part shooting it is what gets expensive.

 

[hatt]

I fail to see where the Sport won't give you good service for your current activities. You didn't mention where it was inaccurate or unreliable. You can certainly use it to start off in competition as well, and then use your experience to build YOUR competition gun if you got serious.

 

[ugaarguy]

hatt, S&W has switched the M&P Sport to a 1:9 twist bbl. That's where it now falls short for those who want to shoot 77gr lead core bullets or 70 gr copper solids which require a 1:8 or faster twist.

Edit to add: even the 62gr Barnes TTSX requires a 1:8 or faster twist.

 

[hatt]

That's still a want. Plenty of suitable offerings that are ideal for his intended applications without the need to spend $1300 on a new gun. And some 1/9 barrels will shoot 77gr.

Edit. Does the OP have a Sport or was looking at a Sport?

 

[ugaarguy]

Some 1:9 twist bbls might stabilize 77gr bullets under ideal conditions. Most manufacturers recommend a 1:8 or faster for anything 75 grains or heavier (Hornady being the one exception with a single 75 gr bullet that's short enough to reliably stabilize in a 1:9 twist).

The OP has no AR. He states that he thought about a Sport, but decided he wants a 1:8 or 1:7 twist bbl and mid length gas, so he switched to wanting a S&W MOE mid as a base to be further modified. The carbine length gas on the Sport is also a short coming on his wants.


Also, a little back ground: I own a first gen M&P-15 Sport with the 1:8 twist 5R bbl. Even with the conventionally rifled 1:9 twist bbl that S&W has switched to on the Sport I still think it's a great value. However, I understand that the Sport doesn't fit every need.

 

[hatt]

I misread the OP and thought he already had the Sport. I'd get on Palmetto's e-mail list and save some money.

 

[Centurian22]

Wow! Thanks for all the replied I appreciate all the input! To address some of the questions and continue the conversation: I've never owned anything .223 / 5.56 before and as I mentioned this gun will be used in many roles so I expect to use a wide range of bullet weights including the "heavies". I do reload which is another reason I want the gun to be versatile in terms of what it can shoot for bullets; I've seen the shortages of components and if I find myself in a position where all I can get is some 62, 75, 80 grain whatever, I want to be able to make use of them.

On to the gas block: I appreciate the consensus on "it's not needed" that will save me some money and hassle. I didn't know / hadn't thought about the fact that it would only be useful in over-gassed situations not under due to the barrel gas port size. My original thought on the AGB was similar to the barrel twist. If all I can get is Powder XYZ and that powder works but is over gassed the AGB would allow me to tune it down. Maybe I'm creating an unnecessary problem to justify a solution, I'm not sure. I've just seen availability go to crap and I do not have the finances to stock up on 8lbs (or more) of all the powders during the 'good times' like some have the luxury of.

I'll have to look more into the 1:8 5R S&W barrel vs the 1:7 CHF Chrome lined 4150 DD barrel. I'm looking at a very close price point to get the S&W M&P15MOE MID, and add a low pro gas block, free float tube, and flip up front sight, compared to getting the DDM4v7 which has the low pro and free float already and would just need flip up sights.

Speaking of sights: is there any problem with using flip up sights like the magpuls both mounted on short rails on the free float forend aside from having a shorter sight radius? Or is it 'required' to get a 45 degree rail adapter to keep the rear sight back towards the rear of the receiver?

Thanks again for all the help!

 

[greyling22]

lots of folks have different opinions on this, but for me, a 16" barrel was just unbearable with a 223 AR. So much noise and muzzle blast. Maybe it was the birdcage, maybe it was the 4" lopped off the barrel, but when I started shooting a buddy's 20" flash hider-less gun it was SO much more pleasant. I sold my 16" upper that day.

I also would pass on any hbar or bull barrel.

 

[Centurian22]

Greyling: Very good point! I have only fired a couple rounds through a friends AR, but I have been at the range and noticed major differences in report of 5.56/.223 AR's even without brakes. I still think that maneuverability is more important to me than report but I will definitely keep a long barrel in mind for a future option.

 

[hatt]

Speaking of sights: is there any problem with using flip up sights like the magpuls both mounted on short rails on the free float forend aside from having a shorter sight radius? Or is it 'required' to get a 45 degree rail adapter to keep the rear sight back towards the rear of the receiver?

Thanks again for all the help!

Why are you contemplating such a setup? I don't know what you're talking about with this 45 degree rail adapter that does something with the rear sight. You've never owned an AR and have already come up with a million gimmicks and unnecessary needs. Go buy a basic gun like the MOE, Colt 6920, etc and shoot it, a lot. You'll figure out what you need, if anything.

 

[Robert]

I tend to agree with hatt on this one. Either build or buy the basic rifle first, shoot the heck out of it and then see what you may want or need to add. A friend I shoot competition with had a set of off set irons on his AR. Used them a few times in competition and got rid of them. They just did not live up to the hype, at least for him. No reason to spend a pile of cash only to rind that you don't like or need half of what you bought.

Either way, I whole heartedly support you in your quest. It is your money and your rifle, build it the way that makes you happy.

 

[Centurian22]

I plan to get something and go shoot the heck out of it trust me. I have no intention of decking it out with a "million gimmicks" before shooting the basic gun. However as stated I do not have the finances to try something not like it, try something else, buy this sell that and settle on something. I will have a hard enough time getting the "OK" from the wife to spend $800-$1400 on the gun in the first place. Much less then turning around and telling her "oops I don't really like this one I need to buy a different upper for another $400-$800, or this or that accessory". So the closer I can get to getting it all right the first time with one big purchase the better for me and my marriage.

You make very good points that its just as bad to spend a pile of cash from the get go on stuff that I may not like. As to the offset sights: I want this gun to be my "no matter what happens I will be able to use it" gun. So I want it to have back up iron sights since I plan to run some type of an optic on it (red dot or scope). Also as mentioned it is seen used in competition, scope for long distance, cant the rifle and use irons for up close. If the scope gets damaged I would like to be able to transition to irons relatively quickly. The options for this are either have flip up back up iron sights in the usual position and have the scope on a quick detach mount that I can "pop off" or have the irons mounted offset. As I work away from home for a month at a time I have a lot of time on my hands to research and read reviews and ask people for their person experience with things that I have interest in. I don't have very much time for going to gun stores and spending time at the range (though I love it when I do get the time) to get hands on experience with things before I consider buying them.

I apologize if I came across as a mall ninja couch commando with asking about all these gimmicks, I'm just trying to learn from anyone with real first hand experience with them compared to just advertisements in gun mags and on the manufacturers web pages.

 

[hatt]

A scope has no business on a self defense AR. One of your primary stated purposes. You're not going to be shooting way out there. I think trying to get a competition gun has messed up your whole train of thought. A basic gun with traditional BUIS and an Aimpoint or EOTech is going to do most of the things you want well. Including getting your feet wet in the competitive side.

 

[greyling22]

addendum to my post on muzzle blast: if it bothers you, you could look into some of those linear compensators that supposedly send it all downrange. levang, kies, noveske, there are others.

 

[Robert]

A well made red dot, like an Aim Point, is more than able to take anything you'd be able to throw at it. A good set of back up irons that co witness with the red dot and you are set.

Or, just a good set of iron sights and skip the optic altogether. You'd be surprised what one can do with iron sights and practice.

 

[Centurian22]

Hatt: Exactly. One of my stated purposes (home/property defense). You are correct, a scope has no place on a home defense firearm. I should have been more clear. I have other firearms to fill closer roles within the house, so it would have been better stated as property defense. I am somewhat near-sighted. I do ok with irons but better with scopes. Maybe because of that I am putting too much emphasis on the optic. It does sound like a red dot with flip up sights may meet my overall purpose better. Having not shot a red dot before I guess it is "outside my comfort zone" and I'm trying to cling more to what I know.

It sounds like a good place to start (with flip irons and maybe a red dot). I have an extra scope and can always try out some Quick Detach mounts if I want to throw it on at the range to see how I like it.

Muzzle blast hasn't bothered me so far, but I also haven't spent hundreds of rounds behind a 16" AR either. I appreciate the product names to look into if it becomes a problem.

 

[hatt]

You don't even have to have flip up BUIS. I had a flip up rear sight and EOTech. Noticed that I usually kept it deployed for some reason. It sure wasn't hurting anything. Next gun I built got a fixed Troy battlesight and I saved $70 and the thing is built like a brick outhouse. You learn what works for you and build around it.

 

[ugaarguy]

Centurion, when you get some time, look into the Recce Rifle and the MK12 SPR. Those might give you some better ideas on barrels for the match rifle-esque precision you want. You'd also be surprised at how far you can get solid hits with a good red dot. If you get something nice like an Aimpoint, EoTech, Trijicon RMR, Meprolight Reflex, etc; you should be able to get most of your money back out of it if you end up not liking it.