Two different AR questions.

[SecuritySixShooter]

Alright so a couple of weeks ago I bought an AR-15. The first question I have is did I screw up by not getting a chrome lined barrel? I dont think its that big of a deal, I usually clean my weapons within a few days of firing them (no later than a week). It is a 16" 1x9 barrel. So the question is, did I do alright?

Second, I have a friend wanting to design a long range (400-500m max) AR. He is looking at a 20" AR and is needing suggestions on the barrel twist and any other info you might want to share.

 

[RNB65]

I prefer chrome lined barrels. They are easier to clean and last longer than unlined barrels.

The best twist to use is determined by the weight of bullet you plan to fire, not by distance. Lighter bullets work best with slower twist (1in12), heavy bullets work best with faster twist (1in8). Most AR's use a 1in9 twist in order to accomadate a wide range of bullet weights. For a long range varmint rifle, a heavier bullet with a faster twist is usually the preferred choice.

 

[dmftoy1]

I don't think you'll ever have a problem without the chrome lining. From my reading it's primarily something you want in a rifle you're going to be using in combat situations. (large round counts without cleaning in adverse situations . .eg, dirt, mud, etc.). It's just my opinion, but I think for the way that 99% of us shoot the AR's they will work perfectly well without the chrome lining.

I'm definately not an expert on AR's, but for my money if I was building an AR for 500-600 meters I'd go with a 1 in 8 twist (or 1 in 7) and a free floated handguard. I'd probably start with a 20 inch barrel and if I wasn't using it in a service rifle competition I'd think about one of those varminteer style uppers from RRA or Bushy. (this is assuming I wasn't going to be carrying the rifle around alot . . .as they get heavy. )

Just my .02

Regards,
Dave

 

[308win]

There is a good article in Shooting Times (Aug or Sept I think) on loading for AR that discusses bullet weight and twist.

 

[redneck2]

There are guys here that feel an AR without a chrome barrel isn't even good for a tomato stake

Uh....how many of your other guns have chrome bores???? I've got a pretty fair selection and the answer would be zero. Will it clean easier? Probably yes, but I can get my other rifles clean.

Your 1-9 should throw 69's OK. IMO, it depends mostly on cross winds. Once distances get beyond 300-400 yards every variable starts to add up a lot quicker.

 

[jem375]

Most shooters will never shoot enough rounds to shoot out a rifle barrel. Stainless Steel barrels are just as easy to clean as a chrome barrel and a shade more accurate. There is no need for a chrome barrel unless you are in a very harsh environment or shooting fully auto.
I have 2 ar's, one SS and the other non-chrome and I am not going to lose any sleep over not having a chrome barrel on either one and they both clean up pretty easy anyway..............

 

[Lebben-B]

Second, I have a friend wanting to design a long range (400-500m max) AR. He is looking at a 20" AR and is needing suggestions on the barrel twist and any other info you might want to share.

A 20" barrel should be more than enough for the given range. I agree that 1:7 or 1:8 would be fine for what your friend wants to do. While all my ARs have chrome linings, a precision AR would be better served with an unlined bore or stainless steel barrel since they tend to have slightly better intrinsic "accuracy" than a chrome-lined barrel. I would also say that your friend would want to go with a heavy barrel profile to increase the stiffness of the barrel, or a fluted barrel at the very least. While a heavy barrel will aid in accuracy, it also adds a substantial bit of weight to the system. As a previous poster stated, a precision rifle isn't light.

Mike

 

[Bartholomew Roberts]

I've owned both chrome-lined bores and unlined bores and have been a big supporter of chrome-lining in the past. Right now, I don't feel like chrome lining is a major issue one way or another.

From my own research looking at old military tests, following up on some very hard-use testing locally, and my own experiences, chrome-lining seems to offer the following:

1) A little better lubricity in a normal GI-type chamber that helps function (you can pretty much achieve the same effect in an unlined barrel just by having a nice polished chamber though).

2) A slight edge in barrel life if you are shooting a heavy firing schedule. Some have claimed chrome will double the barrel life; but in actual practice it seems to get you maybe 1-2k of extra useful life assuming accuracy standards of <7MOA at 300yds are acceptable to you. If you need higher accuracy/longer distance, then chrome offers even less of an advantage to longevity. If you need less accuracy or shoot at closer ranges, then you'll see more use than that.

3) It may offer a cleaning and maintenance advantage in very humid climates over an unlined Chrome-moly barrel. Stainless steel (SS) seems to be pretty competitive with chrome-lined though.

If your friend is only shooting out to 400-500m, I would even consider a 16" barrel. The amount of difference in drop and wind compared to a 20" is pretty insignificant and you can get a lot stiffer barrel for the same weight; but a 20" definitely wouldn't be a bad choice if weight isn't a consideration.

 

[SnakeEater]

Some of the best combat weapons ever did just fine without chrome lining. I recommend the 20" for anything other than strictly CQB. If your friend is using irons it will be noticably easier to make hits.

 

[possum]

chrome lined barrels do make cleanning easier, but sometimes take away from the accuracy a little. for me I get chrome lined barrels where i can, because they last longer, and are easier to clean-up but i would definetly own a non chrome lined barrel, that's not a great big deal to me. my bushmaster is a 1in 9" twist as well and is great form 55gr to 62gr, it will stabalize a good portion of the ammo that you will be shooting out of it.

if i was gonna build an ar for 400-500m, then i would have a SPR built. I would use an 18" heavy barrel,with a 1in7" twist, that would stabalize the larger grain rds like the 75, and 77 gr. which is great for those longer ranges. i would also have a free floating handguards (aluminum) put on there. i would put a bi-pod on it, collapsiable buttstock, pistoll grip that fits my hand which is the first samco grips, nice front and rear flip up sights, nice detachable scope rings, a flash suppresor. a scope but you really don't need much if 500m is as far as you are going. a nicer fixed power scope would be great, maybe even an acog if he has the money. hope that helps if you have any other questions let us know.

 

[ocabj]

You don't need a chrome lined barrel to have easy cleaning. You just need a quality barrel. The White Oak Armament CMP upper I recently purchased for Service Rifle highpower cleans very easily. And the amazing thing is that it does not copper foul at all. I get carbon and powder fouling and that's it. It is a stainless steel White Oak barrel (probably a Douglas blank, cut by White Oak), 1-7" twist.

As far as your friend goes, he can go with an 18" or 20" and be fine for up to 600. Definitely get a 1 in 7" twist so he can utilize 77gr Sierra Match Kings. If he is willing to single load, then he can go with 75gr (or the new 80gr) A-Max or the 80gr Sierra Match King. I developed a Mk262 mod 1 duplicate load using 25.3gr Varget, 77 SMK, Winchester SR, and LC brass which shoots at an average of 2787fps in an 18" SPR barrel. Although, I recommend switching to a different primer since Winchester primers have issues at high pressure loads.

Oh, and also make sure he gets a Wylde chamber. He'll be able to shoot high pressure loads but with a 'match' (longer) throat for longer bullets.

 

[taliv]

ocabj... that's very interesting. i recently got a ss WOA barrel and have cleaned it about 10 times now, and had noticed the total lack of copper fouling. it's like it doesn't foul at all. it was kind of freaking me out. i thought it might have been a fluke.

 

[SecuritySixShooter]

Two more questions

Ok so he found a floated SS barrel that he apparantly likes. He is going to go with a 1x8 twist on the barrel. My first question is actually about optics. I have an old Bushnel (dont know if the spelling is correct) 2.5 magnification scope that I inherited from my grandpa. It looks to be already set up for Picanny rails. Would this be a decent optic to start out with? I would loan it to him (we are roomates and best friends) if needed. Dont really have a use for it. Next he is going with a flattop upper and I was wondering if there were any advantages or disadvantages to a raised flattop? Thats all I can think of off the top of my head. Thanks again!

SSS

 

[Bartholomew Roberts]

I would avoid the raised flattop. The fact is that the normal height flattop is so popular that pretty much every accesory under the sun is made for that height. You actually limit what you can mount with a raised flattop.

A Bushnell 2.5 should do fine; but if he plans to use it for precision shooting at 500m, he will probably want something with greater magnification and a finer crosshair eventually.

 

[Critter183]

I have a M93 Spanish Mauser that was made in 1894 and went through the Spanish American war. First time to the range with it, it put 3 consecutive bullets through the same hole at 50 yards and consistently groups and inch or better at 100.

It has an unlined barrel.

I rest my case.

PS. None of my ARs have chromed barrels.

 

[SecuritySixShooter]

A Bushnell 2.5 should do fine; but if he plans to use it for precision shooting at 500m, he will probably want something with greater magnification and a finer crosshair eventually.

Its just something to get him started with. The upper he is looking at has no sights whatsoever.

 

[soul_rapier]

i was wondering the same thing when i was ordering my barrel they said add $50 for chrome lined and my gunsmith said he hasnt seen a ar / m16 barrel not chrome lined since the 60's and they told me it a 3 week wait on the barrel so i had they to ship it without chrome . but any way when i got it in and it was chrome lined

 

[Shawn 357]

I don't even know if my AR has a chrome lined barrel. I really don't care if it does.....the gun shoots more accurately than me (chrome or not)......it is extremely unlikely that I will get enough rounds through this gun to wear it out.
just my two pennies

 

[wanderinwalker]

For your friend, for a 400-500m rifle, I'd get one of those 18" SPR barrels, with a 1-7" twist and call it good. I'm sure he's found something else already, but just my opinion.

As for accuracy, it seems most match shooters see between 4-6000 rounds through a SS AR barrel before COMPETITIVE accuracy is gone. I tomato-staked the stock Wilson barrel from my Armalite with an estimated 5500+ rounds on it. If it wasn't a match rifle, but rather a coyote/woodchuck/informal stuff rifle, that barrel probably had another 3500+ good rounds in it. As it is, I swapped it out for a $200 WOA 1-7" Wilson barrel that looks to be a hammer so far.

Good luck, and don't worry about not having a chromed bore. You'll not likely notice the difference.

 

[Monkeybear]

18" or 20" stainless midlength free floated (insert brand here) with a regular non raised flat top.

At that distance youll likely want some heaiver bullets. Heavier bullets are typically longer and longer bullets need more spin to remain stable. More spin means faster twist. Id count on shooting 62gn - 77gn bullets. 1-7 to be safe but I wouldnt be suprised if you were able to make it work with your 1-9 upper. I wouldnt be suprised if you werent either.