New user- Installing new uppers

[Augee]

Hello,

I'm a new user here at M4carbine.net, brand new to the big wide world of being a gun owner, as a matter of fact. Just some background, so that you understand my situation:

I'm a member of the South Carolina National Guard as an SMP cadet, basically, I'm an ROTC cadet from The Citadel, Army contract, and I should be commissioning with the SCARNG with 1/263rd Armor as a platoon leader in December. So basically, I'm very familiar with the M-16, having used the A-1 and A-2 while training. That being said, all I'm familiar with is the issue equipment, and its interesting to me to see the world of the private rifle owner, where there are so many choices out there, rather than making due with what's been issued.

I recently bought a Doublestar "M-4" that I'm trying to make relatively close to an issue style weapon, but right now it has a 16" barrel with a 1/9 twist. I'd like to replace the upper, however, with a 14.5" barrel with a permanently attached "A-2" style flash supressor to make it the legal 16". I'm not as concerned about the twist, though 1/7 is preferable.

I've been looking throughout the internet for parts to replace the barrel, and potentially the entire upper assembly, while trading out/selling what I already have, particulary right now a Rock River Arms upper assembly with a 1/9 twist, but I was wondering whether or not there were any problems with swapping in and out parts from different manufacturers. For example, if I were to buy a stripped upper receiver with just the barrel attached, could I go ahead and take the bolt carrier assembly and charging handle that I already have and stick it into the new upper receiver? A month ago I wouldn't have thought twice about it, but reading up, I'm noticing a lot of references to differences in gas ports, headspacing, and other details that I wouldn't have originally considered. Can I safely swap parts without problems, and/or having a deleterious effect on the weapon's functioning?

Thanks,
~Augee

[K.L. Davis]

Augee,

Sounds like you got a pretty good lock on things so far... For the most part, parts should be interchangable across the board -- there are some concerns with receiver extensions (buffer tubes) and the correct buffer, and yes your question about headspacing is valid.

Real MilSpec parts are designed to interchange, as you know (or will) this "feature" is something that is most welcome on the battlefield. The rub here is that some manufacturers/suppliers do not make MilSpec parts, either because they don't have the proper reference material, or they have intentionally changed some stuff, hoping to make an "improvement".

First, I would say shoot what you got till it needs a new barrel... then I would strongly suggest that you apply looks as the last concern in your new choice. Most here know that I would steer you towards a 16" mid-length system over about anything else out there.

But, otherwise, here is what I would suggest... your bolt assembly and charging handle should work in any upper receiver you pick up -- I would hit up one of the dealers on the board and talk to them, maybe you can get a deal on the upper you want and I am sure you will find that anyone that deals on M4C will almost surely have no problem with you sending the bolt to them to check headspace, just so you are all warm and fuzzy about that part of it. Also, unless the upper receiver you have now is just now what you want, a simple barrel swap is not that big of a deal... again, there are a half dozen folks on here that can hook you up.

Oh, and I hope you have heard this many times by now... but when you report for that first Plt Leader job, trust your NCOs ;)

[UVvis]

Something else to ponder, are there any unit armorers around that you are on good terms with? Some are very good resources and have good tool sets on hand.

[Augee]

Thanks!

The whole reason I want to switch barrel lengths is to try as best I can to replicate the firing properties of the M-4, so that I can be familiar with it if it ever comes to use of an issue weapon in a combat situation. That's why I purposely decided not to go with what seems like the more reliable mid-length gas system when I bought my own rifle, as it's not what I'd be working with in the field.

From what I've read, however, it seems like the barrel length changes the firing properties of the rifle, and how it "feels" when firing, I've definitely noticed a pretty big difference when going from the 20" M-16's that I've trained with to the 16" M-4 profile rifle I'm using now, more bite when firing the round, as well as being louder, and while that 1.5 inch difference may not make that big of a difference, I'd still like to get as close to what I'll be using, and just a little bit more kick when you shoot that second round in a control pair might mean the difference between hitting the target with that second shot when firing reflexively.

I'm not as much worried about the types of ammo, and have pretty much been buying whatever's cheapest in .223 at local shops and WalMarts, I might see if there's any green tip if I want to do more marksmanship, but right now I'm mostly working on uber-familiarity with the weapons system, one less thing to worry about in the field if I'm 100% confident in my ability to make the weapon work, which is why I wanted to buy an M-4 in the first place.

Also, how much difference is there in the firing properties when using different bolt carrier groups? Mine seems to be specifically built for the civilian market, as it is fully open at the back, making the rear profile look kind of like a "C," rather than the "O" I'm used to in issue weapons. How much of a difference does that make? I know it can't be used for selective fire, but then again, I've never much like the auto or burst fire, I much prefer the semi-auto and a good control pair where necessary. That being said, laying down suppressive fire with an A-1 on full auto is no bore either!

~Augee

[svtar15]

Augee,
If you bought the upper from DSC, then just call me and we can work out something. I have 14.5" 1/7 chrome lined barrels in stock that I can attach a phantom to for you. If you are worried about different manufacturer's barrels fitting, it should not be a problem. Any "mil spec" barrel should slide right into the receiver.
As far as the carrier goes, we have both semi and full auto carriers available. If it is going in a duty weapon, I suggest a full auto carrier. If it is your personal weapon, we have the improved semi carriers that have a little more meat in the back then what we used to sell. If you want to stick with Doublestar, give me a call or send me a PM.