First AR build...buncha questions

[huaco]

Sorry for the length of this post and all the questions. Please answer any or all if you are so inclined.

I have in my possession an RRA lower and LPK with an RRA two stage trigger. The mag release is installed but I'm waiting for a set of punches and brass hammer to arrive from CDNN before going on. Trying very hard to do this right the first time and not go the instant gratification route I sometimes take. I've spent many hours reading all the info and opinions available on ar15.com and other places I've found but still have a few unanswered questions and would like to see what folks here have to say.

Just to put this in perspective I have fired a few ARs but I've never seen one broken down. Many years ago as an engineer I designed, drew up, and put together parts made on mills, lathes, injection molds, etc so I have reasonable mechanical aptitude and experience. My eyes and hands aren't what they used to be.

This build is intended to be mostly KISS with the intention to put a scope on it eventually. I live quite close to a club range where I can shoot rimfire rifles and most any handgun but don't make the 35 mile drive to the other club range where CF rifles are ok very often so I may not shoot it that often once I get it like I want it as has been the case with my AK. I'm doing this just to build and own an AR so I know about them and have one should I need it.

I'm leaning toward a 16 inch barrel and midlength gas system. The midlength seems to make sense but I've seen nothing about the drawbacks or limitations it carries as opposed to the CAR configuration. Are there any?

I think I came across tubes, buffers, and springs designated CAR and otherwise. What is correct for midlength.

Milspec buffer tube or commercial, does it really matter? It looks easier to buy a rifle kit with commercial parts but I can just buy an upper and milspec tube, buffer, stock separately if it makes a difference. I've seen both described as superior. The complete kit will leave me with a spare LPK with standard trigger but that might be nice to have around.

I think the A2 upper looks better but the A4 seems more flexible and I'm leaning towards the A4. What am I missing here? A picture thread of KISS builds on ar15.com included very few A4s.

What's the deal with T marks? I see them mentioned often but don't know what it means.

The options for rear sights on an A4 are overwhelming. I'd like to build something with decent iron sights that I can put a scope on later. Cowitness would be nice but not required if initially very expensive. I am right handed and shoot that way but left eye dominant. Suggestions?

This is mostly a build a decent, reasonably priced rifle project. I'm leaning toward an assembled RRA upper because I think I know where to get it like I want it at a decent price but I've seen many suggestions that LMT, CMMG and a few others are better for one reason or another. Would RRA really be a mistake?

Thanks for your patience and any info/opinions your can provide.

 

[sierrabravo45]

This should answer about 90% of your questions.

Here is the main link.

http://www.ar15.com/forums/topic.html?b=3&f=4&t=226782

Here is the general link.

http://www.ar15.com/forums/forum.html?b=3&f=4

An a4 is a good way to go and so is the 16 inch barrel. The mil spec or commercial tube doesn't really matter. Except if you want to change to a nicer stock in the future then its better to go milspec.

A RRA upper is fine. I am probably picking up one this week, and sticking it on a Armalite lower....


I got a couple of AR's 16 inch through 24 inch barrel. The 24 is nice for varmints such as pdogs, but the 16 is nice for yotes and 3 gun matches. Actually IMO I like a 18".

Just start messing around and having fun. There really isn't a right or wrong answer with Ar's.

I am probably picking up a RRA upper, and sticking it on a Armalite lower.....

 

[dakotasin]

huaco- i can't answer most of your technical questions, but can tell you to have confidence in the lower build.

i fired my cousin's bushmaster a couple times, which is how i got the bug. i had never seen one even broken down - i had no idea the upper and lower hinged/detached like that until i put the lower together. just print out the instructions from ar-15.com and dedicate 45 uninterrupted minutes, and you'll be done w/ time to spare.

good luck to ya!

 

[blackhawk2000]

I'm leaning toward a 16 inch barrel and midlength gas system. The midlength seems to make sense but I've seen nothing about the drawbacks or limitations it carries as opposed to the CAR configuration. Are there any?

16" midlength is a great barrel to go with. The AR was designed around the 20" gas system. Everything about the 20" gas system is easier on the whole extraction process. A midlength system is closer to what the gun was designed to work with.

I think I came across tubes, buffers, and springs designated CAR and otherwise. What is correct for midlength.

Milspec buffer tube or commercial, does it really matter? It looks easier to buy a rifle kit with commercial parts but I can just buy an upper and milspec tube, buffer, stock separately if it makes a difference. I've seen both described as superior. The complete kit will leave me with a spare LPK with standard trigger but that might be nice to have around.

For starters you need to determine if you want a fixed stock, or a collapsible stock. I reccomend collapsible. I'm not positive what buffer is best for midlength, but I would start with a CAR buffer. Milspec for me. It's got better thread engagement, and is the proper spec for the reciever. Also there is a reason why the mil specs it, and not the commercial tube. A standard USGI single stage trigger is going to hold up better than a 2 stage. 2 stages are for target guns, not SHTF guns. Figure out what you are building and pick the trigger accordingly.

I think the A2 upper looks better but the A4 seems more flexible and I'm leaning towards the A4. What am I missing here? A picture thread of KISS builds on ar15.com included very few A4s.

I too like the looks of the A2 better, but if you ever want to go with an optic, get the flat top. You should also have quality back up irons even with an optic.

What's the deal with T marks? I see them mentioned often but don't know what it means.

Just the numbers on the flat top, for putting whatever you took off back on the same slot.

The options for rear sights on an A4 are overwhelming. I'd like to build something with decent iron sights that I can put a scope on later. Cowitness would be nice but not required if initially very expensive. I am right handed and shoot that way but left eye dominant. Suggestions?

Tough call here. There are lots of options out there. Don't skimp on the price though. You usually get what you pay for, and you don't want your irons taking a dump at the wrong time. Try to get something with a same plane aperature. Also go with the standard front sight post. I too am left eye dominant. I shoot long guns left handed now. It's much easier to get my hits this way. The AR is very easy to use left handed. Don't listen to those who tell you otherwise.

This is mostly a build a decent, reasonably priced rifle project. I'm leaning toward an assembled RRA upper because I think I know where to get it like I want it at a decent price but I've seen many suggestions that LMT, CMMG and a few others are better for one reason or another. Would RRA really be a mistake?

I would go with CMMG, first but only because they make a 16" midlength lightweight profile barrel, and that's what I'm building right now.

Thanks for your patience and any info/opinions your can provide.

No problem. Just ask away if you have more questions. Someone should be able to answer.

 

[Mot45acp]

My mess up on my first build was switching the disconnecter spring that seats into the trigger, with the bolt release spring.

The springs are the same size just one is bigger on one end. The big end seats itself into the trigger for the disconnecter.

The front pivot detent can be a pain. What I found to make it easier, was to use your drivers license ( or similar slim card not a credit card)to retain detent pin and spring, then insert pivot pin.