18" SPR Build

hlpressley

hlpressley

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Indian Trail, NC
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I have been collecting parts for a few weeks now to build an 18" SPR rifle. Something with a little better accuracy at medium range distances. Primarily to learn about precision shooting before jumping in head first with a 6.5 Creedmoor bolt gun. I ordered the last parts for the build today. Here is how it will end up.

Lower:
Aero Precision Stripped Lower
Geissele HSNM Trigger
Seekins Precision Lower Build Kit
Odin Works XMR 2 ext. mag release
Aero Precision Buffer, Tube, Spring
Noveske QD end plate
Ergo Grip
Magpul ACS stock

Upper:
Aero Precision Stripped Upper
Aero Precision upper parts kit
Fail Zero Exo Coated BCG
Seekins Precision DNA charging handle
Ballistic Advantage 18" barrel
Ballistic Advantage lo pro gas block
Ballistic Advantage gas tube
Geissele MK8 SMR M-Lok 15" Handguard
Odin Atlas 5 Compensator
Odin Works M-Lok Bipod Mount
Harris 6"-9" Bipod

Optic:
American Defense Recon 20 MOA scope mount
Athlon Argos BTR 6-24x50 Mil

Hope to have it all assembled and to the range this weekend! Will definitely report back with some pics and how it performs.
 
sick build, for sure!

18" BA barrel is surely rifle gas, right? You'll want something heavier than a standard carbine buffer. H2 or even H3 depending on its diet.

pics when you put it together.
 
th0m said:
sick build, for sure!

18" BA barrel is surely rifle gas, right? You'll want something heavier than a standard carbine buffer. H2 or even H3 depending on its diet.

pics when you put it together.
Click to expand...
It is rifle gas. I wasn't sure on the buffer weight as this is my first build. Will be using heavier 75-77gr factory loads at first with intentions of reloading for it soon. Which buffer would you suggest?
 
hlpressley said:
It is rifle gas. I wasn't sure on the buffer weight as this is my first build. Will be using heavier 75-77gr factory loads at first with intentions of reloading for it soon. Which buffer would you suggest?
Click to expand...

Rifle gas and no suppressor? Standard M16 cut bolt carrier? You shouldn't be entertaining buffers until you know what the gas port size is, which will give you an idea of how much return gas to expect. I'd be surprised if you needed more than an H Buffer, unless the gas port is extremely large. I'm trying to find out online right now about BA's gas port sizes. Might have to email or call their CS
 
Zedhound said:
Let me know how you like that barrel. When I get back to upgrading my 223 I'm thinking about that one
Click to expand...

I have the 20" version. The rifle ( barrel) with factory ammo does 1/2" 3 shot groups at 100yds( Hornady steel match 75gr and fiocchi with 77gr smk).
 
hlpressley said:
It is rifle gas. I wasn't sure on the buffer weight as this is my first build. Will be using heavier 75-77gr factory loads at first with intentions of reloading for it soon. Which buffer would you suggest?
Click to expand...

I think an H buffer is a good place to start. a carbine rear end is going to have a sharper impulse no matter what the buffer weight. the spring travel is shorter and stronger than a rifle length spring. H3 will put you at the same weight as a regular rife A2 buffer but imo, i think that is too much in a 18" rifle gassed barrel due to the shorter dwell time.

conventional internet wisdom says heaviest buffer that will reliably cycle all ammo you plan on shooting.

personally, i prefer to keep the reciprocating mass in my guns to a minimum. over springing and buffering makes the muzzle dive on return to battery.

my spr has an A5 system with a JP spring and the A5H2 buffer. This setup mimics the full A2 buffer weight but with a better spring.

If you are going to stick with a milspec spring an H2 "might" feel a little better.
 
Personally, I would do an adjustable gas block on any rifle that was that overgassed (needing an H3) and go lighter buffers instead. I'd rather cut gas than add weight.
The ejection pattern should tell you everything you need to know.
 
I just got a email back from BA. The 20" barrel has a .089" gas port and I was told a standard buffer and spring should function fine. I don't think there would be much difference between the 18" and the 20".
 
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Got it all put together today. Shot 10 rounds rounds through it to get it zeroed. Shot and fed those 10 rounds flawlessly. Didn't really feel much like shooting any more than that with the heat and a toothache that has my entire head hurting...

Anyway, a quick pic of the complete rifle. The Geissele trigger is less than impressive so far. Likely due to lack of proper adjustment. Hopefully I can get it worked out.


IMG_3786.JPG



IMG_3782.JPG
 
Took two shots to get it zeroed. Once I got it close I shot a 3 shot group that you can see top right of bullseye. This was with Hornady Black 75gr BTHP ammo. I'm sure the gun is capable of much better once I get the trigger adjusted properly and I actually feel like shooting again. Looking forward to getting it out to 500 on Saturday.




IMG_3789.JPG
 
i coundnt help my self, i also ordered a BA 18 spr barrel, tube and epsilon brake from granite ridge, while i was at it i order another enhanced upper with handguard

ill post it when i gets in this week,
 
Zedhound said:
i coundnt help my self, i also ordered a BA 18 spr barrel, tube and epsilon brake from granite ridge, while i was at it i order another enhanced upper with handguard

ill post it when i gets in this week,
Click to expand...

Uhhg, they have some prices that are hard not to bite down on.

Was on their site last week and ordered crap to finish a new upper. Couldn't resist. Almost snagged an Epsilon, too, but resisted as I don't really need it.
 
NKD said:
Uhhg, they have some prices that are hard not to bite down on.

Was on their site last week and ordered crap to finish a new upper. Couldn't resist. Almost snagged an Epsilon, too, but resisted as I don't really need it.
Click to expand...

I didn't need it but like you said for 50 bucks I was like why the hell not
 
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New barrel and muzzle device.
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My 300blk pistol also got upgraded all fde now. Going to pic up some of those 300blk magpul mags and maybe a new muzzle device. I like the kak can on my 9mm ar but no real purpose here.

Even my 9mm ar got a new sling
IMG_1202.JPG
 
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