So I am a noob at this. Long distance isn't really my thing, but I got an itch and with the psa p10 sales and then the ba 25 percent off barrels, I decided to jump.

I have the psa gen 2 upper. It has the standard hand guards, so I am really only reusing the upper receiver and the 308 bcg.

I got the ba 6.5 cm 20 inch barrel.

Looking at the dimensions of stuff like a 700, I see that the stock only extend halfway. So the 24 inch barrel only has a 12 inch of stock covering the bottom of the barrel.

So with a 20 inch barrel, is a 10 inch handguard good enough? or is it just an astetics thing?
Mounting a bipod later, would it have been better to go with a 15 inch?

I notice a lot of talk about barrel cooling. Some of the hand guards I see have small inner diameters. 1.34 or so. Is this an issue? or is the shorter handguard helpful here?

I plan on using one of the adjustible gas blocks that let gas pass out the nose of the block instead of just being restrictive. So I though the 10 inch would be better because it would be exposed.

Aesthetics and function play a role.

Most people these days want their gas block covered.  Some think it looks better, some don't want their gas block to get knocked around.

Most reputable handguard manufacturers supply ID, OD, and weight measurements on their website.  You'll want clearance between the gas block and handguard.  The amount varies, but I try to keep a minimum of 1/16" with a preference towards 1/8".  Your barrel flex during the shot...If it contacts the handguards, it defeats the purpose of free floating the barrel.

IMO, an adjustable gas block is the only way to go on a large frame AR.  Everybody seems to drill their barrel gas ports to different sizes and being able to reduce the gas can help reduce recoil and even make cleanup easier.

Many of the better adjustable gas blocks permit adjustment from the front.  Most come with a Allen wrench several inches in length.  So reaching the adjustment screw won't be a problem.

I've shot/built ar15 rifles for 13-14 years, but I'm new to the ar10 .  I stuck to manufacturers with excellent reputations producing ar15 parts.  Centurion, SLR, JP, Midwest Industries, Lancer, and others make handguards for the Ar10.  You won't go wrong with any of them.


I would highly recommend reading all you can about the varieties of large frame ar rifles.  The PSA is a dpms/Sr25 pattern rifle so you'll need to make sure whatever you buy for your rifle is compatible.

Thanks for the reply.

I don't think I will worry about it being knocked around since a fsb is not only exposed but generally a high point on the gun. If that was ever going to be a problem a standard ar would show it.

So I mainly need to make sure there is enough room for the flex. But they don't seem to give the dimension on where the gas tube goes. just ID in the main body.
I measured the 308 barrel and it sticks out so the total area with the barrel is about 1.56 or so vs the 1.34 ID that was given.

But as you say I will start looking at the name brands you called out instead of the generic ones I got flyers on.

What size is your barrel at the gas block?

.875

OP,
    I have that very same barrel and gas block(Superlative Arms) you are talking about.

I have a Aero Precision upper/lower combo with their 15in Keymod Handguard. It extends over the AGB by maybe an inch.

For me this is perfect, because the adjustment screw is right there, just under the handguard, and can be adjusted with just a short allen wrench.

I use my rifle in NRA matches and the 15in handguard allows me to place the bipod more forward, making me to be a bit more stable while prone, than if I were running it further back.

Heat buildup is an issue, during 20+ shot strings, I do start to notice the heat coming off the barrel thru my 12x scope. Am looking at putting covers to reduce this effect, because I do notice it.

Hope that helps,

SY

So you are trying to reflect the heat back down?
So you don't get the heat shimmers causing distortion?

Would keeping more of the barrel uncovered be better or worse since it stll takes so long to cool down?

AH,
    I don't think it matters whether the barrel is covered or not. Heat is going to be a byproduct of shooting the Creed. Nature of the beast.

My ejected brass is hot enough to melt the material on the moving mat I use.

I am looking at ways to minimize the distortion i am seeing, as long as it is away and minimized from the scope sight path, it should be fine.

SY

Thanks.
And how does it shoot?
I am still gathering parts, so it will be a while, but since you have the same setup I am planning on using, I am curious.

Any issues with blown primers I have been reading about? or does the gas block help since it vents?

AH,
    It is a great shooter, sub moa out to 600yds. I am running 130's at 2740 as my match load.

I had a few blown primers using factory ammunition. The issue with that is most factory ammo is loaded for a bolt action, so it is on the upper end for speed. A side note, i have only blown primers when running 140gr bullets. Never with a 130gr.

With Hornady black ammunition, have yet to have a blown primer. The Black line I heard is specifically for gas guns. I have also had good results with Federal American Eagle 140bthp.

I am running a Toolcraft BCG, not a high pressure bolt like is recommended. That has been my experience so far, just over 400 rounds thru it.

SY

Thanks, that is good to know.
I am hoping to push out to 1000 yards.