Need a suggestion on a barrel.
Looking for high quality M4 Lightweight 14.5
Considering the CMMG 1:7
Anything else I should be looking at?
What is a good bullet weight for plinking with this barrel?
I have a Bush 1:9 and this barrel is intended to upgrade an existing build
You're question's pretty vague...
What are you looking for? In a 1/7 CL M4 gov't profile (light under the handguards) CMMG is an option, IIRC, Bushmaster may have them, but don't quote me on that, Colt, LMT, those are your major, "mainstream" options. There are also others that are not quite as well known that are out there, like BCM, and many of them are quality as well. However, just from experience, people looking for 14.5" M4 barrels are more concerned with practical accuracy than pinpoint accuracy, if they wanted anything more, there are plenty more accurate barrel profiles and types out there.
Is that what you're looking for? Or do you mean something else by "M4 Lightweight 14.5?"
Are you looking for a whole upper, or just a barrel?
The CMMG will be a quality barrel, but any of the above will.
For plinking, you're almost going to be entirely limited to 55gr. as that's what's found most often available and cheaply. 55gr. will work just fine in the 1/7 twist, though it's supposed to be for heavier bullets. Furthermore, 62gr. and up are available, but are usually more expensive than 55gr. ball, as 55gr. is the most produced, and most reloaded weight. Under those circumstances, whether you have a 1/9 or 1/7 barrel is almost irrelevant, given the overlap of what they will shoot accurately. Again, if you want to do more than plinking, it may be more important to you, but for plinking, it's really just preference.
I fully agree w/about 99% of Augee's response. Just don't quite understand why you're wanting a 1 in 7 barrel. The only advantage in that twist is in the use of the very heaviest match type bullets.
I really do get the feeling that the vast majority of folks who insist on 1 in 7 twist barrels is simply because "that's what the military uses, so it must be the best". In fact, unless you're using those heavy match type bullets, it's not the best. It's a comprimise.
The only reason the 1 in 7 twist was adopted was to stabilize the extra long tracer bullets that the military uses; which is precisely why the commercial market largely went to the 1 in 9 twist. Sure, more recently you can get commercial 1 in 7 barrels, bacause the producers will respond to demand. Hell, that's what they're in business for.
The one disagreemant I have w/Augee's response is his statement that 55 grainers shoot "just fine" in the 1 in 7 twist. Sure, they'll give you a decent group, but everything else being equal, the 1 in 9 will do just a bit better.
So where would 1 in 8s fit into all this?
Are there lightweight 14.5" barrels with a 1 in 8 twist?
I've never seen the 1 in 8 twist listed for anything but match barrels, because that's really the best twist for the heavy match bullets. Understand, the faster the twist, the faster the wear at the throat. The 1 in 8 twist is intended to be fast enough for the heavy match bullets, but be just a tad slower to give the match shooter an extra 1000 or 2000 rounds of use before he has to replace the barrel.
Since the heaviest bullets I use are 69 grain Sierra Match Kings, the 1 in 9 twist works just fine for me.
Your choices for a 14.5" M4 barrel with the proper profile, chrome lining and 1/7 twist are Colt, LMT, BCM, CMMG and Bushmaster. Colt's are not easy to find and not cheap but are very good barrel and worth it if you can find a new one for under $300. LMT's are fine, they take a few shortcuts (compared to Colt's) but nothing major. Only potential problem (depending on what you want to do) is you usually have to buy them as part of an assembled upper. BCM's were real nice but they are not available now AFAIK. CMMG's vary depending on who you talk to? Some people love them, some don't but for the price, I would hold out for either a Colt or LMT. Bushmaster does make 1/7 twist 14.5" M4 barrels but it is not a standard offering for them (so they are not always available). The up side is, price wise they are the best value and the down side is they are not available with M4 ramps (all the other ones I mention come with M4 ramps).
As far as the 1/9 vs. 1/7 debate. Yes, most plinking\surplus ammo is 55gr and while the 1/7 twist barrel will handle the 55gr ammo just fine, in theory, the 1/9 twist barrel is better suited for 55gr rounds. If this is just going to be a range toy, then it really doesn't matter which way you go. Select a barrel based off of the other differences noted or by price or by availability.
While I would agree that a lot of people only buy 1/7 barrels for the sole reason that it's "Mil-Spec" that is not the only reason or even the best reason to do it. If you plan to use this AR for defensive purposes, then for that purpose you should use the best defensive rounds. The best defensive rounds available today for a 5.56MM AR are in the 75-77gr range. For rounds in that weight class, the 1/7 barrel rules. That is why my M4's all have 1/7 twist barrels.
Thanks for all the replies...I decided to tack and went with a Denny Operator 14.5 1:7...which then led to a total revamp and morph.
And yes...I will be throwing heavy lead out of it. 69's, 75's and 77's....
I guess the 1:9 M4 LW that I do have will end up in another build....
What started out as an upgrade has quickly morphed into a something else entirely.
This used to be my camp carbine...it has tested positive for steroids.
Now what am I going to do with all of the other leftover parts? I think I will cobble a KISS together out of the left overs.
The 'upgrade' parts are listed here. The only original parts left are the trigger, lower, MIAD, PRI and Troy:
Denny Operator 1:7 14.5
LaRue Stealth Billet Upper
Primary Weapon Systems FSC556 Flash Suppressing Compensator
DD 9.5 Lite Carbine Guard
PRI Gas Block/Front Site
Young NM Carrier & Bolt
Chip McCormick SS trigger
Magpul UBR (when available)
Magpul MIAD grip
Endyne Hydro Buffer
Thinking either a Elcan Specter DR or a Trijicon...leaning on the Elcan
I didn't know there was a 14.5" Operator barrel.
Still not an Operator barrel though.