small ar15 questions

[Soybomb]

As I'm drawing near the end of my ar 15 build I have a few questions still on the small parts that I'd like some advice on.

Its a 16" barrel with a mid length gas system, rifle length rails, auto carrier, and will have magpul's UBR stock on it.

What buffer and spring would you put in it? Should I put in something like superior shooting system's stronger spring and a heavy buffer or is that a problem with the heavier carrier and longer gas system?

I think I want a rail mounted fixed front site. Is it just pick any of the handful of sights like this http://www.armalite.com/ItemForm.aspx?item=E20151 and go with it?

Are any of the low profile gas blocks actually functionally different from the others? I'm sure larue's is great but will my $15 get me anything over midwest industries?

Thanks!

 

[aloharover]

I would use a carbine H buffer.

Unless it's an adjustable gas block, not much difference.
You can get the YHM lo-pro for $30 shipped.

There is a difference between sights if you look at spring loaded versus manual. GG&G are some very nice spring loadeds.
The MI and YHM manuals are almost identicle.

 

[DnPRK]

Heavy buffers and springs are a way to tune unlocking of the bolt/bolt carrier based on the gas delivered by the gas tube. I'd start with a standard weight carbine buffer and spring and see how it cycles. If you get signs of over gas (extractor skips over the case rim or extractor bends the case rim) then go to a heavy buffer and maybe heavy spring.

There are other methods of curing over gas:

• Use an LMT enhanced bolt carrier that delays bolt unlocking
• Install a gas tube with regulator screw that lets you turn down the gas flow
• Install a regulated gas block that lets you turn down the gas flow
• Install a bushing in the gas block to reduce gas flow

 

[Soybomb]

There is a difference between sights if you look at spring loaded versus manual.

I'm planning to put a fixed front sight on the rail.

 

[Bartholomew Roberts]

I think a standard carbine buffer and spring will work just fine. At the heaviest, I would go with an H-buffer. The H-buffer is nice if you are running a suppressor, full-auto or running the rifle really hot. Otherwise, standard carbine is probably the way to go.

Now if you are building a race gun and know what type of ammo you will be shooting consistent, you can play with all the different buffer weights and "tune" the rifle; but you are talking nanoseconds of difference and the heavier weights and springs can cause short strokes if you change to a weaker ammo.

 

[Soybomb]

Good to know, the first batch of ammo I'll be running through it is some radway green I bought a year or two ago. As I recall it was rumored to be a little weak then.

 

[RockyMtnTactical]

I would use a carbine H buffer.

Me too.

 

[aloharover]

I'm planning to put a fixed front sight on the rail.

Doah..should have followed your link

Yes that or the MI or the LHM are all pretty mucht he same thing.

Pete