First 308 build

B0fuh · January 7, 2017

26 minutes ago, jtallen83 said:

Have you looked at the LUTH-AR adjustable? Pretty light for all the adjustment. I see it use a lot in the 3-Gun crowd now;

http://www.luth-ar.com/

Look at you guys giving me good ideas on stocks. I'll check it out. The most important thing is that it can mount on the existing receiver extension so I can swap out easily. I was also considering jl billet's modular stock

jtallen83 · January 7, 2017

22 minutes ago, B0fuh said:

Look at you guys giving me good ideas on stocks. I'll check it out. The most important thing is that it can mount on the existing receiver extension so I can swap out easily. I was also considering jl billet's modular stock

They make versions for both rifle and carbine extensions so swapping them out would not be an issue.

B0fuh · January 7, 2017

3 hours ago, jtallen83 said:

They make versions for both rifle and carbine extensions so swapping them out would not be an issue.

Just did a little digging on it, definitely my favorite stock so far. Thanks for the recommendation.

MikedaddyH · January 7, 2017

Did a review on a Luth-ar stock. Do a search. I have install a couple on customers guns. They are light weight and adjustable but spartan.

MikedaddyH · January 7, 2017

8 hours ago, B0fuh said:

Mikedaddy, I like that idea. I've only found one barrel nut that will work to fit a tube large enough to clear the obnoxiously sized gas block.

Get a low profile gas block ! You do not need a Big Azz gas block with a mini rail on it . Please save your self the trouble and get a steel gas block, aluminum gas block are just not that durable.

jtallen83 · January 7, 2017

I've only found one barrel nut that will work to fit a tube large enough to clear the obnoxiously sized gas block.

The SLR adjustable titanium gas block is pretty small, expensive, but small. Not sure why the barrel nut would have to go over it?

B0fuh · January 7, 2017

1 hour ago, jtallen83 said:

The SLR adjustable titanium gas block is pretty small, expensive, but small. Not sure why the barrel nut would have to go over it?

The inside diameter is .875", the outside is 1.52" vertically, and 1" across. With the clamp on style, it will only leave around 1/8" or less at the bottom on most lighter handguards I've looked at. I'm not convinced that will be enough. I'm going to have a bipod and with my giant melon resting on top of it, I'm concerned it will contact the gas block. For reference, the jl billet handguard has 1.52" inside diameter and will have just north of 1/4" on either side and close to 1/8" below the screws on the bottom.

Here is where my inexperience shows, feel free to point out any flaws in my logic because in a perfect world, I would love to use the jl billet handguard.

jtallen83 · January 7, 2017

I've got a couple SLR gas blocks, a set screw and a clamp on, in use with AR-15 platform rifles/pistols using slim handguards. I've got a 1/16 inch clearence to the bolt that holds the flat spring on a 300 BO build and seen no issue with it.

" I've only found one barrel nut that will work to fit a tube large enough to clear the obnoxiously sized gas block. "

Still not sure I follow, is the fitment issue getting the barrel nut over the gas block or the handguard not clearing the gas block?

shepp · January 7, 2017

1 hour ago, B0fuh said:

The inside diameter is .875", the outside is 1.52" vertically, and 1" across. With the clamp on style, it will only leave around 1/8" or less at the bottom on most lighter handguards I've looked at. I'm not convinced that will be enough. I'm going to have a bipod and with my giant melon resting on top of it, I'm concerned it will contact the gas block. For reference, the jl billet handguard has 1.52" inside diameter and will have just north of 1/4" on either side and close to 1/8" below the screws on the bottom.

Here is where my inexperience shows, feel free to point out any flaws in my logic because in a perfect world, I would love to use the jl billet handguard.

I'm not sure if you think your barrel nut should slip over your gas block? I'm taking a guessing here. Your barrel nut goes on before your gas block then your hand guard ID needs to be greater than your gas block, OR your hand guard must be shorter than the distance from your barrel nut to your gas block.

im totally assuming here if that's what your thinking I hope it helps, if not what your thinking did reguard

B0fuh · January 7, 2017

Jt, the issue being the outside diameter large enough to accommodate a tube that would clear the gas block. I just had a conversation with my smith about it and it sounds like I'm fabricating a problem that doesn't really exist

B0fuh · January 7, 2017

Thanks shepp, I wasn't clear enough. The barrel nut issue was with regard to making my own handguard with a tube that would have to slide over the outside of the barrel nut. I had the brigand arms barrel nut in mind. I'm going to do some math but it sounds like I'll be able to use the jl billet handguard.

98Z5V · January 7, 2017

2 hours ago, B0fuh said:

I'm going to have a bipod and with my giant melon resting on top of it, I'm concerned it will contact the gas block.

I'm not sure what that statement is about - you're talking about a gasblock, right? And a free-float handguard. A bipod won't matter, and you shouldn't flex a quality handguard enough to contact that gasblock, no matter how much you load the bipod. Also, the weight of your head, with it on the stock, won't affect anything at the handguard/gasblock area, no matter how large or heavy your head is...

That statement you made just has me scratching my head... Maybe I'm misreading something...

shepp · January 7, 2017

53 minutes ago, 98Z5V said:

I'm not sure what that statement is about - you're talking about a gasblock, right? And a free-float handguard. A bipod won't matter, and you shouldn't flex a quality handguard enough to contact that gasblock, no matter how much you load the bipod. Also, the weight of your head, with it on the stock, won't affect anything at the handguard/gasblock area, no matter how large or heavy your head is...

That statement you made just has me scratching my head... Maybe I'm misreading something...

Did you know the human head weighs 8 pounds

survivalshop · January 7, 2017

9 minutes ago, shepp said:

Did you know the human head weighs 8 pounds

Some weigh more then other's . :laffs:

planeflyer21 · January 7, 2017

MikedaddyH · January 7, 2017

jtallen83 · January 7, 2017

:laffs:

Edited January 7, 2017 by jtallen83

B0fuh · January 7, 2017

4 minutes ago, 98Z5V said:

I'm not sure what that statement is about - you're talking about a gasblock, right? And a free-float handguard. A bipod won't matter, and you shouldn't flex a quality handguard enough to contact that gasblock, no matter how much you load the bipod. Also, the weight of your head, with it on the stock, won't affect anything at the handguard/gasblock area, no matter how large or heavy your head is...

That statement you made just has me scratching my head... Maybe I'm misreading something...

We used to do a lot of harmonics effect testing with our rifles in the military that were aimed specifically at how things such as slinging into the rifle or laying down in tall grass will change the point of impact. This was very obvious on our dm rifles with a government profile barrel at 500yds. It all kinda makes me paranoid about things contacting the barrel.

98Z5V · January 7, 2017

15 minutes ago, B0fuh said:

We used to do a lot of harmonics effect testing with our rifles in the military...

Tell me more about this - as I spent over 2 decades in the US Army. Never saw any barrel harmonics testing going down.

B0fuh · January 7, 2017

So I'm going to be stubborn, my math shows that there will be just north of 1/8" clearance between the gas block and the jl billet handguard. With any flex in the handguard combined with the harmonics of the barrel, I'm not sure I'm convinced it will be enough. I've seen high speed video of the stresses these things endure with every shot and it is impressive what they go through. I can't imagine I'll get nearly that kind of flex out of the proof research barrel but I don't know that it's worth the risk. Any first hand experience with this would be monumental in helping me make my decision.

B0fuh · January 7, 2017

4 minutes ago, 98Z5V said:

Tell me more about this - as I spent over 2 decades in the US Army. Never saw any barrel harmonics testing going down.

Dont mistake your different experiences with the only way things were done. We used to spend days and sometimes a week at a time on the known distance ranges charting poa/poi in various weather conditions, bore temperatures, floated/unfloated with sling or supported, resting pens and sticks against barrels, contact with bushes....etc. The results were incredibly eye opening.

MikedaddyH · January 7, 2017

6 minutes ago, B0fuh said:

So I'm going to be stubborn, my math shows that there will be just north of 1/8" clearance between the gas block and the jl billet handguard. With any flex in the handguard combined with the harmonics of the barrel, I'm not sure I'm convinced it will be enough. I've seen high speed video of the stresses these things endure with every shot and it is impressive what they go through. I can't imagine I'll get nearly that kind of flex out of the proof research barrel but I don't know that it's worth the risk. Any first hand experience with this would be monumental in helping me make my decision.

The handguard and upper receiver are NOT going to flex ! An 1/8" is plenty of clearance. You are over thinking this big time ! Just get a low profile gas block and assemble your rifle. It will fit !!!

Matt.Cross · January 7, 2017

2 minutes ago, B0fuh said:

So I'm going to be stubborn, my math shows that there will be just north of 1/8" clearance between the gas block and the jl billet handguard. With any flex in the handguard combined with the harmonics of the barrel, I'm not sure I'm convinced it will be enough. I've seen high speed video of the stresses these things endure with every shot and it is impressive what they go through. I can't imagine I'll get nearly that kind of flex out of the proof research barrel but I don't know that it's worth the risk. Any first hand experience with this would be monumental in helping me make my decision.

How are you going to induce enough flex into the handguard to achieve any kind of interference? Bear in mind that a good many of us are career mechanics and machinists, as well as folks familiar with Proof Research and it's outstanding products. If you are concerned because you've seen footage of AR barrel whip during the recoil impulse, it's a moot point once the bullet has departed the muzzle.

Forgive my asking, but what was your MOS when said testing was being done?

B0fuh · January 7, 2017

1 minute ago, MikedaddyH said:

The handguard and upper receiver are NOT going to flex ! An 1/8" is plenty of clearance. You are over thinking this big time ! Just get a low profile gas block and assemble your rifle. It will fit !!!

Haha, calm your tits there fritz! When I buy this handguard, call my besties at super duper high speed video takers world, and they tell me I was right....Imma get judge Judy on your tail and we're going to handle this like adolescent schoolgirls.