MP 15 Sport barrel change from 1/8 5r to 1/9 6 lands and grooves. Pro's & Cons'. Any

[jayp1978]

MP 15 Sport barrel change from 1/8 5r to 1/9 6 lands and grooves. Pro's & Cons'. Any

Hello all. First, let me say thanks to all of you like minded shooters for all the input you've all contributed to this great forum over the years. I have for some time now been looking for my first AR type rifle. Like many of you I have been doing a lot of research on the subject both online reading and shooting different models at ranges that rent them and friends weapons. Also like many I will be on a strict budget. I have to say I love the M&P line and I think after shooting the MP 15 Sport now on 2 different occasions I have made up my mind. Now the problem! I was at my LGS to pick one up when I noticed that they are not the same marked 5.56 NATO 1/8 R5 barrel like the one I shot and liked so much. Also from what I've read,they are no longer melonite treated. This has really put a wrinkle in the plan I was so sure would work for me. My question is have anyone of you had experience with the 5r 1/8 twist barrel and the now used 1/9 twist 6 L&G? If so what are your thoughts? Another concern is longevity. The range where I rented this rifle said he was amazed at how well the barrel of the mp 15 sport has held up and kept its accuracy compared with other much more expensive options they use. Another option would be to buy a more expensive model of the M&P 15 like the MOE version or Viking Tactical version that still use the 16 inch 1/8 twist 5r barrel. Do you think the barrel would constitute the spending of about 400 to 600 more to get the barrel? Just any feedback will be appreciated. Again thanks for your time. Jason


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[cyphertext]

Welcome to the forum. While it is true that the Sport no longer has the 1:8 twist with 5r rifling, the barrel is still Melonite treated. S&W no longer calls it Melonite, as they do not own the trademark, but call it "maximum corrosion resistant" or some other marketing buzzwords.

If you want the 1:8 barrel, it is still available on the 15T. The barrels on the MOE or VTAC II are different, as those are made from 4150 vs. 4140 on the Sport or 15T.

As far as accuracy, if you are not hand loading, you probably won't see much difference in accuracy. If you are going to shoot the 55 gr or 62 gr type ammo that is available, either barrel will work fine.

 

[JaPes]

My question is have anyone of you had experience with the 5r 1/8 twist barrel and the now used 1/9 twist 6 L&G?

I own an earlier 15-Sport with the 1:8 5R barrel. I also own an AR15 with a 1:9 CMV unlined barrel. I will give you my honest opinion. On this forum you will see many threads where the 1:8 5R v.s. 1:9 barrels are intellectually debated. I've participated in these threads. Technically the 1:8 5R Melonite treated barrel has the hardness, corrosion resistance, and wear resistance of chrome lining. Technically the the 1:8 5R barrel is gentler on the projectile, deforming it less, leading to increased accuracy. In intellectual discussions, the 1:8 5R barrel is the end-all-be-all of S&W's technical superiority.

Real world?

I shot this with a 14.5" 1:9 CMV, unlined, barrel AR-15 I put together myself. Distance to target 100 yards, open sights A2front/Carry handle rear, cheap steel case TulAmmo, off a wobbly bench and bags.

We like to intellectually discuss and bicker over the technical differences between the barrels. It's a fun pastime. In reality, the 1:9 v.s. 1:8 5R barrel are practically not different in my hands. What makes the difference is me, the marksman.

Another option would be to buy a more expensive model of the M&P 15 like the MOE version or Viking Tactical version that still use the 16 inch 1/8 twist 5r barrel. Do you think the barrel would constitute the spending of about 400 to 600 more to get the barrel? Just any feedback will be appreciated.

IMO, the only reason you would want to buy a model other than the 15-Sport you've been eyeballing is if you really want features that come on the other models.

The 15-MOE is a mid-length gas system. The mid-length gas system has slightly less perceived recoil than a carbine length system. You get more handguard space and a longer iron sight radius. You also get the cool Magpul furniture that you probably want.

The VTAC is optics ready (no iron sights), has the Troy rail, Viking tactics furniture, and the Geissele Super-V trigger. This bad boy is equipped with lots of aftermarket goodies out of the box.

If you want a full featured upper with a forward assist and dust cover, the 15-Sport isn't for you.

Regarding the latest run of 15-Sport barrels, I believe they're still Melonite treated. Melonite is a registered trademark and S&W can't use it. They use some other generic description to allude to the treatment. If you want to get confirmation whether or not the barrel is Melonite treated, send S&W CS an e-mail.

IMO, whether or not to spend the extra $$$ on something more than the 15-Sport is up to you and your budget. For me the 15-Sport:

• Was the gateway to AR-15's
• Left me $$$ for ammo
• Let me discover my preferences

 

[jayp1978]

Right now I can get the sport from a LGS for 699 and it comes with a case and 4 extra p mags. I won't be using hand loads only want something that is dependable and will last. I also was thinking in the accuracy department they would both shoot better than I can. Thanks JaPas and cyphertext for the input. I think I will run with the sport and let it lead me into the black rifle world. I'll post some of my first thoughts when I pick it up tomorrow.


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[ChattanoogaPhil]

Japes nailed it.

The words from a company that knows something about rifle barrels.

5-R Rifling


The Obermeyer 5-R™ style rifling is simply a different style of rifling that has a more 'ramped', or angled transition from the groove to the land and back down from the land to the next groove. Our conventional 4 groove rifling has nearly parallel sides to the groove. The internet is full of information describing perceived benefits to the 5-R™ rifling over conventional styles, but most of this is comparing "apples to oranges" as they are usually comparing one manufacturer's "non 5-R™" to a different manufacturer's "5-R™" barrels. We have honestly seen no significant differences in accuracy or performance between the two styles of rifling when comparing our barrels.

Thank you, Krieger Barrels

 

[JaPes]

Right now I can get the sport from a LGS for 699 and it comes with a case and 4 extra p mags. I won't be using hand loads only want something that is dependable and will last. I also was thinking in the accuracy department they would both shoot better than I can. Thanks JaPas and cyphertext for the input. I think I will run with the sport and let it lead me into the black rifle world. I'll post some of my first thoughts when I pick it up tomorrow.

The 15-Sport will take a licking and keep on ticking. The 15-Sport is the only brand-name AR-15 I own. The nice thing about the 15-Sport is that it has good bones: buffer tube, spring, lower receiver, upper receiver, and barrel. If you ever get the urge, you can build up your 15-Sport to no end.

Because I can anticipate the next few questions:

When you get your rifle home, I highly advise that you field strip the rifle & BCG to do an initial inspection, clean, and lube. There are tons of YouTube videos on the process.

Cleaning products & lube threads go wild. IMO, stick with the basics. One piece rod, tips, Breakfree CLP, patches, rags. I've guinea-pigged lots of cleaning products and tools. This thread may save you some $$$.

http://smith-wessonforum.com/smith-...8269-new-ars-here-some-tools-i-use-clean.html

Go shoot your rifle as it comes out of the box. Live fire will tell you what feels just right and what you may want to change out. For me, I wanted hand guards with heat shields.

AR Delta Ring Compression Tool - YouTube

I also wanted to swap out the stock for a Magpul MOE stock.

M4 Stock Removal. Install Magpul MOE. - YouTube

Those were the first two things I ever changed on my 15-Sport, and it's been all downhill from there.

 

[jayp1978]

Thanks so much. This forum rocks!


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[gunny4053]

Welcome to the forum. The Sport is a fine choice, and in the grand design of the universe, there probably isn't enough difference between the two barrels to worry about. I've shot 1/8s, 1/9s, and a 1/10, to be honest as long as you're shooting a bullet whose weight is appropriate to the twist rate, I doubt you'd notice the difference.

Good Luck and good shooting.

 

[jayp1978]

The whole thing with particular ammo was another reason I was drawn in so much for the 1/8 r5. From what I understand it's a lot more capable of firing a wider range of bullet types. Where I live I'm lucky to find ANY ammo of a certain caliber much less a certain grain ect. It just would be nice to know that if the ammo was in stock theirs a better chance the gun would properly fire it. I know from my handgun experience individual guns like a certain ammo that it likes and shoots well where my buddy's same gun may hate it.


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[pgamboa]

Right now I can get the sport from a LGS for 699 and it comes with a case and 4 extra p mags. I won't be using hand loads only want something that is dependable and will last. I also was thinking in the accuracy department they would both shoot better than I can. Thanks JaPas and cyphertext for the input. I think I will run with the sport and let it lead me into the black rifle world. I'll post some of my first thoughts when I pick it up tomorrow.


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Since you are on a strict budget, there are online places where you can get this Sport for just under $600. And in most cases, free shipping and no tax. I know many of us like to support our LGS but when when there is a $150 savings and a tight budget, online is where I will go. I was in the same situation as you as well with a strict budget, but decided to wait and save for the MOE/FDE version. Mainly because I wanted to goodies and the barrel was a plus for me (I'm new to AR so I won't be able differentiate the barrels just yet). I found the MOE for $899, no tax, free shipping. $10 FFL Transfer. Couldn't be happier. In my case, it was a $300 difference than the Sport. You can't go wrong either way you go. Good Luck!

 

[pgamboa]

$579 from Grabagun. No tax if you are outside of Texas. $5.99 shipping.

Smith and Wesson M&P 15 Sport 811036 Rifle 5.56 NATO 16 inch 30rd Black Online Gun Store

 

[red dragon]

Welcome to the forum. A 1/9 barrel will have no problem stabilizing a bullet from 45-70g. Most 223 ammo available falls in that weight range,so finding a particular weight shouldn't be a problem. A lot of us run steal cased tula ammo(55g). Its cheap and great for practice out to 100yds.

 

[WR Moore]

JaPes has pretty much hit the nail on the head. There's a lot of angst over theoretical differences that might, maybe make a difference. Rarely is there a significant difference. The 5R rifling profile allegedly reduces friction and reduces distortion of the bullet jacket. Again, this allegedly and theoretically increases velocity and accuracy while reducing bore wear. Note the words 'allegedly' and 'theoretically'.

1-9 twist will stabilize up to 75 gr Hornaday HPBTM bullets. It's the length of the bullet more than the weight, the VLD (very low drag-for extremely long range shooting) bullets may be too long to stabilize.

1-8 twist will stabilize possibly up to 90 grain bullets. Will certainly do the Sierra 77 gr HPBT and the 80 gr HPBT. These are match bullets intended for very long range work.

If you want long life and can't get the Melonite coated bore, get chromed bore and chamber. The hard chrome is about twice as hard as the steel and greatly improved resistance to gas and friction erosion. The premium for the plated bore/chamber is generally around $40. You can't buy a barrel for that. On the other hand, if you're reasonable in your rates of fire and how many rounds at a time, it may not make much difference. I bought a Mini-14 (un-plated bore/chamber) 34 years ago and used it for competition and other uses. It's gone from a 1 1/4 MOA rifle to about a 2 MOA rifle in roughly 4000-5000 rounds. I've never indulged in 'how fast can I empty a magazine' exercises.

 

[jayp1978]

Well, this site has been a great tool in helping inform me in what is important and what is hype. I don't know if I mentioned it but this is my first ar-15 type rifle. If I go by how I felt when I was shooting this thing at the range it's a first in many to come. I just wanted something quality but lower price range to get me started. I ended up getting one today. I went with the S&W M&P sport with the 1/9 twist. I normally don't have enough cash at one time to get big purchases so I end up paying a little extra using layaway feature at LGS and sometimes Gander Mountain. It paid off today though because Gander ran a 699.99 special that came with the gun,hard case and 4 extra p mags. I won a 100 gift card in a giveaway they had a couple months back so only ended up paying 599 really. I know they have this cheaper at other places but without extras I got not to mention 100 off. I am pleased and plan on stretching its legs tomorrow at a friends place. I will report back and let everyone know what I think. And thanks again. Jason


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[JaPes]

You got your factory complete rifle. Next level in the AR madness is to buy a stripped lower receiver and assemble a rifle yourself. Shoot the snot out of your 15-Sport, discover your preferences, then build you own just the way you want.

 

[moe smith]

If you want the 1:8 barrel, it is still available on the 15T. The barrels on the MOE or VTAC II are different, as those are made from 4150 vs. 4140 on the Sport or 15T.

Yes and no. I can't speak for the VTAC but I do have the MOE MID and it's barrel is still being produced in 1:8R.

 

[cyphertext]

Yes and no. I can't speak for the VTAC but I do have the MOE MID and it's barrel is still being produced in 1:8R.

It is not "Yes and no". The barrel on the VTAC and the MOE mid are made from 4150 or CMV... Marketing lists it as 4150 CMV, but there is no such alloy, it is one or the other. At either rate though, it is a different alloy than what the 1:8 barrel on the old Sport and the current 15T are made from.

We can debate back and forth if the MOE mid barrel is better as far as performance or barrel life, but there is no debate about it being a different barrel. There is more to a barrel than just twist rate.

 

[moe smith]

It is not "Yes and no". The barrel on the VTAC and the MOE mid are made from 4150 or CMV... Marketing lists it as 4150 CMV, but there is no such alloy, it is one or the other. At either rate though, it is a different alloy than what the 1:8 barrel on the old Sport and the current 15T are made from.

We can debate back and forth if the MOE mid barrel is better as far as performance or barrel life, but there is no debate about it being a different barrel. There is more to a barrel than just twist rate.

Yes, it is. Your post to the OP inadvertently suggests that the MOE doesn't have the 1:8 5r barrel. My post simply was to clear up a statement that could easily be misinterpreted. It wasn't an attempt to debate the merits or pitfalls of 4140 vs, 4150 barrels.

 

[Pinger5.56]

When I got my sport, I took it as is to the range and shot it, first thing that got change was the pistol grip, couldn't stand that GI style grip, went Magpul MOE+. Then I found out the hand guard had no heat shields and went with the Magpul Carbine MOE hand guard. Shot it again, then decided I could put up with that annoying butt stock rattle so you guessed it Magpul MOE CTR butt stock. Then shot it again, that day shot another AR that had a BAD lever and loved it so I got a BAD lever Magpul of course.
So shot it again, one day saw a extended quad rail on sale and purchased it was made by Global Military Group a drop in style carbine extended hand guard, liked it but went back to the Magpul, then tried the Magpul SL edition and like it but found out that most of my old MOE rails wouldn't work and would have to repurchase more m-lok rails to use it and didn't want to spend the money so returned it went back to the regular MOE that is still on there.
I have tried lights, scopes, and red dots and still haven't found anything that I liked, after my Mbus sight broke I got a carry handle for nothing (long story) tried it but was a non Mil-spec junk and couldn't get it to hold zero at all. I would get it sighted in and one little bump it would be way off.
So now I have a sport with no rear sigh and all Magpul furniture. I cannot wait to get that pop up sight back. I hope S&W sends it out to me today.

 

[AGoyette]

I am one of the people who went ahead on the M&P VTAC II AR. The 1:8 5R barrel did factor into my buying it. The fact that it is a mid length gas system also played into it. The final Coupe De Grace was the Geissele trigger that came with it stock. From everything I have read, the Sport is a great rifle, especially for the money. But for me, it was not "the one". BTW, I love love love shooting both my M&P AR's (I have the 15-22 and the VTAC II). I am sure you will love yours as much as the rest of us do.