Uppers, twist and length AR

I am trying to start investigating uppers to complete my AR build this winter (or snap purchase prior to the election).

I've heard that 1:7 and 1:8 are best, but do they have problems with lighter bullets? Can 1:9 stabilize 70gr and under? I am looking at mostly plinking, but I'd like to be able to stabilize things like Nosler Partition ~65gr (I forget the exact weight) for things like deer and hog hunting, though I don't plan to use it much for either.

On Uppers, two that jump out on price and customizability are Del-tron and Stag arms. Any thoughts on either? My accuracy requirements are not super high, 2 MOA off bags with good hunting ammo would make me happy.

Barrel length, I'd like to go longer to get as much velocity as possible, especially since I am considering at some point using this for deer hunting, and plan on this being 5.56/.223 wylde. Any ideas on who makes 18" or 20" uppers? From Del-tron direct they are out of 20" and very few seem to make them, or are very expensive. I do see a few have Del-tron 20" uppers in stock though.

Chrome lined barrel? Bolt carrier group? Better coatings? Yes I'd like it to last awhile, but I also recognize the nice thing about an AR is how modular it is and if I need to rebarrel it at 5,000rnds instead of 10,000 that isn't really that huge an issue.

For uppers with the A2 front sight, I assume those are removable? I'd prefer a flat top with flip up BUIS front and rear and something like a 1.5-4.5x28 or 32mm scope on it. A future build or spare upper I'll go with fixed irons and a red dot.

Should I just consider a 16" upper and worry about getting a 20" later, or rebarrel it some day? Is there a big difference between mid length and rifle gas block (if I had a 18/20" upper to accommodate a rifle length upper).

I assume all fore grip furniture is replaceable? Del-tron has the option of MOE, which is the direction I'd like to go (MOE OD green, looking at a PSA MOE kit for the LPK), but if there was a option that doesn't come with an MOE front or wrong color, I don't mind it mismatching for a few months).

Ideally I'd like to spend less than $500 on the upper. Thanks!

Like you, I want a plinker and a sometimes low-end comp gun. I've been going 'round and 'round with the twist rate issue. People look at me when I say I had an upper, (a 1/7 that I got rid of), that would not shoot any factory ammo worth a damn that wasn't 75gr. Googled it and came across other boards where the discussion said 1/7 was ideal for longer bullets but was fine with 55gr. out to 200 yds. Every once in a while someone would chime in that they had the same issues as I did with 1/7.

I can only take from that, that it depends on the brand of barrel, material of the barrel, individual barrels and ammo...BUT most of the time 1/7 and 1/8 will shoot the 55gr ok.

Good luck.

So many options. As many have done, including myself, you can research this so much that a purchase takes months. These are all general rules. I would use the info available and purchase an upper that seems ideal and get out and shoot. It may be a perfect combination or not. It may shoot everything you put in it accurately or be finicky and like a few loads.

With a Noveske SS 16" I can shoot 55gr ball 3/4 high, 55gr Hornady varmint 1/2 low and some 69gr match center. It took some time and trial and error to find that.

White Oak Arms. A 1-8 twist barrel will do what you want. The quality of White Oak is hard to beat or even equal, especially for the money, unless you go to a premium barreled custom upper. For one of those, White Oak Precision is top notch.

Different barrels from different manufacturers, rifled with the same twist, will shoot bullets of the same weight differently.

You won't know what you're going to get from a barrel until you get the barrel.

If you're plinking with cheap 55gr ammo, I think a 1:9 is the best starting point.

Go with 1-7 or 1-8 twist. 1-9 imparts too little spin to longer and/or heavier bullets. MIL uses 1-7 for 62gr and heavier. That's a clue. For 55gr-65gr, 1-8 should perform well.

For your use, 1-8 would fit best. Covers more bullet weights. 1-7 is best for the heaviest ones. Minimum 18". Think of any dmr or spr rifle sold. Also mid length gas tube. I'm sure YMMV. I've had good groups with 55gr out of 18" 1-7 twist at 50&100 yards. M855 was crap.

dist1646 said:

White Oak Arms. A 1-8 twist barrel will do what you want. The quality of White Oak is hard to beat or even equal, especially for the money, unless you go to a premium barreled custom upper. For one of those, White Oak Precision is top notch.

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This!

Great company, great barrels and mine shoot 55-77 with no issues. Little more money but well worth it.

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Boom Boom said:

Go with 1-7 or 1-8 twist. 1-9 imparts too little spin to longer and/or heavier bullets. MIL uses 1-7 for 62gr and heavier. That's a clue. For 55gr-65gr, 1-8 should perform well.

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All true - but the military also has tracer rounds that are longer and 1:7 is a must-have for those. Some people feel that 1:9 is optimal for 55 grain. Many match AR's I have seen have a 1:8 stainless barrel.

Stainless steel is suppose to be more accurate. 223 (or 223 Wylde) is suppose to be (according to all the "experts") tighter/accurate than 5.56. Chrome-lined less. Yet - I have a 5.56 BCM upper that is chrome lined and a 1:7 twist that shoots better groups than my non-chrome-lined Remington 1:9 in 223 Rem.

I don't know know how much difference all this makes unless you are doing some serious long range competition shooting. Just get a 1:8 barrel that suits your style of rifle and shooting.

I could be wrong but I would put that more on the BCM vs Remmy than the barrel material.

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dreadpirate said:

All true - but the military also has tracer rounds that are longer and 1:7 is a must-have for those. Some people feel that 1:9 is optimal for 55 grain. Many match AR's I have seen have a 1:8 stainless barrel.

Stainless steel is suppose to be more accurate. 223 (or 223 Wylde) is suppose to be (according to all the "experts") tighter/accurate than 5.56. Chrome-lined less. Yet - I have a 5.56 BCM upper that is chrome lined and a 1:7 twist that shoots better groups than my non-chrome-lined Remington 1:9 in 223 Rem.

I don't know know how much difference all this makes unless you are doing some serious long range competition shooting. Just get a 1:8 barrel that suits your style of rifle and shooting.

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Stainless steel also wears out quite a bit faster. All about tradeoffs.

Twist rate can make a big difference for hunting, especially varmints, depending on the load. Tightening up a group 1-2 inches can mean a dead varmint versus an injured varmint that gets away.

If the OP wants to shoot 55gr-65gr, 1-8 is the way to go. If he wants to shoot 62gr-77gr, 1-7 is the way to go.

Answering your other questions to the best of my knowledge; may get other opinions from other members:

Can 1:9 stabilize 70gr and under? 1:9 works for 55 and 62 grain - my Hornady reloading reference says 1:8 (or 1:7) for 70 grain [EDIT - For 5.56 NATO, Hornady states 1 in 8" or faster for 70, 75, and 80 grain bullets they sell. Hornady has no twist caveats for 55, 60, and 68 grain. Take that for what ever it's worth ]

Del-tron and Stag arms. Any thoughts on either? Stag has a reputation for making nice uppers; DEL-TON is suppose to be a good value. Members on this forum seem to have good results from both.

Chrome lined barrel? Chrome lined barrel I think is not needed for the average shooter unless you are shooting a lot; e.g. full auto like the military

Bolt carrier group? Better coatings? Regular parkerized coating is good; nickel boron is not needed. The bolt steel is more important than the finish. Carpenter 158 steel bolts are good.

Should I just consider a 16" upper and worry about getting a 20" later? 16" is more handy. 20" for more velocity and loner sight radius for iron sights (if using a front sight gas block as opposed to a flat top). Both can be very accurate. You need to decide.

I assume all fore grip furniture is replaceable? Yes. Keep in mind you can get a free-floated barrel (metal tubular hand guard) versus the old school style of removable polymer hand guards that come off in two halves. The free floated tubes generally allow you more options. Some of the free floated tubes are more difficult to remove than others. But yeah - you can change those out.

Is there a big difference between mid length and rifle gas block? The shorter gas carbine length gives you a shorter sight radius if using a front sight gas block as opposed to a flat top / free floated barrel. The shorter carbine gas tube has a little more kick than a longer gas tube - but 223/5.56 has very little recoil so probably not an issue. I would say mid length is preferred but carbine length is not a show stopper if the upper has everything else you like and priced well.

Ideally I'd like to spend less than $500 You should be able to get a solid upper for that price.

The correct rate of twist for a particular bullet relates to its length not its weight. Use the Green hill rule "The length of the bullet in calibers multiplied by the twist rate in calibers per turn is 150" Gyroscopic stability less than 1.0 means a serious loss in accuracy while1.3 is marginal. the sweet spot is right in the 1.5 to 2.0 area. The useful range goes from 1.3 all the way up to 4.0 or 5.0 the higher GS figures do not start to affect accuracy until it gets to 5.0 or higher. An ar 15 rifle with a 1-7 twist using a 55gr. fmj has a GS of around 4.1 and can be quite accurate. Rather than calculate every example look at Doug Shilens chart. Ever had any short varmint bullets over stabilize and start to deteriorate in flight. However select bullets carefully because some may be short for their weight and can be stabilized with a slower twist. Of course barrel condition and type and manufacturing tolerances all contribute to performance as should be expected. You never know what your going to get without some experimentation, my Bushmaster DCM shoots well enough for me with a 1/8 twist and Winchester 55gr. FMJ with relatively careful hand loads. Have fun!

I've had good luck with RRA uppers...

https://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_ID=200

There are some threads around here that recommend various HBAR (heavy barrel to be Maryland "compliant") uppers in the $500 price range.

https://www.mdshooters.com/showthread.php?t=196108&highlight=HBAR
https://www.mdshooters.com/showthread.php?t=192716&highlight=HBAR
https://www.mdshooters.com/showthread.php?t=188386&highlight=HBAR

1:7 shoot 55gr with no problem. 55gr being the most common ammo there is it will probably the lightest you shoot. Over all a 1:8 covers the most type of rounds. I wouldn't even bother with a 1:9 IMO

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I'd go 1:8. My 1:9s handle 69gn rounds just fine, but any longer bullets don't group so good.

I have shot 40gr. Winchester varmint xpress with very good results at 50&100 yards too.

I have shot everything from 52gr. to 80gr. out of a 1-8 twist barrel with excellent results. By excellent results, I mean less than MOA and most often sub 1/2 MOA. The difference in barrel life between stainless and chrome molybdenum steel barrels is insignificant in the long run. Most recommend the Wylde chamber because it will handle just about any ammo. It is throated for 80gr. bullets but gives excellent accuracy with lighter bullet loads. I know from experience that a 1-8 twist barrel will get it done out to 600yds.

Like everyone else said, its ALL ABOUT THE BARREL. Fancy BCG's, fancy coatings, etc are meaningless. An excellent barrel, a proper gas block (ideally pinned), and a carpenter bolt, MPI, is the ticket. I found that palmetto's premium BCG and Stag BCG are superb for the money. As I recall, Stag is the commercial for Continental Machine (a military contractor). And we all know that Palmetto uses a lot of FN stuff. Please consider the Criterion barrel. They are advertised as HBAR.