Build Thread Bump SAW Reborn! My new long-range AR15

[Joe Link]

Some of you might remember the Bump SAW @bolus helped me build back in 2016. It was a lot of fun for a couple years, but thanks to the new bump stock rule that gun had to be re-purposed. I've been wanting a precision AR15 for a few years now, and this gun already had an 18" heavy barrel, a drop in trigger, and an integrated upper/rail system. Maybe not the best, but it seemed like a great place to start. Some of the other parts I had, some I stole from other builds, and some I had to order.

I was finally able to get it mostly together, mount a Vortex Crossfire 2 4-12x50 AO, and take it out a couple weeks ago. Considering I'm still learning about the AR platform, scopes, and long range shooting, I was very happy to find it had no problem ringing a 12" gong at ~250 yards. I bought some proper targets and a stand this week, so next time I'll see what it can actually do on paper. I also stole a Vortex PST 5-25x50 FFP from another project and mounted that

CURRENT PARTS

LOWER RECEIVER: Northwest Firearms Stripped Lower
LOWER BUILD KIT: Palmetto State Armory MOE LPK
UPPER RECEIVER: Aero Precision Gen 2 M4E1
HANDGUARD: Aero Precision 15" Gen 2 MLOK Enhanced Handguard
BARREL: Tactical Ordnance 18" Stainless Heavy 1/8 Twist
GAS BLOCK: Tactical Ordnance Low Profile
MUZZLE DEVICE: VG6 Epsilon
BOLT CARRIER GROUP: Palmetto State Armory Freedom
CHARGING HANDLE: Palmetto State Armory Freedom
TRIGGER: KE Arms DMR
STOCK: Magpul CTR
GRIP: Hogue Rubber
BIPOD: Magpul M-LOK
SCOPE: Vortex Crossfire 2 4-12x50 AO
SCOPE MOUNT: LaRue LT204 C.A.N. QD SPR

FUTURE PARTS

Stock - The CTR doesn't work well for this application, but it was the best I had laying around.
Scope - Once I shoot this with the Vortex PST I'll get an idea of what I need to look for based on the capabilities of the rifle.
Charging Handle - I need something easier to manipulate with a scope.

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[American123]

I have a rifle practically identical to what you have done. The intention was a semi auto in .223 that would lend itself toward more easy accurate fire on target at range. Furthest I have done so far is 275-300 according to the rangefinder in Eastern Washington. Barely any wind, but based on things you mentioned you may want to change. Here are my recommendations from my own build.

AR-15 Dual Ambidextrous Charging Handle

Several outlets sell this style. It's sold under several different brands. This is just one outlet I found, but I have found it to be great for scoped AR's since it does not require coming over the top, it can be solely pulled from either side pretty much with an individual finger/knuckle. This makes the scope clearance irrelevant because you can charge from pulling on the side rather than over the top. I believe it's basically a knock off of the more expensive radian, etc.

Stock - of course lots of options, but I love the Magpul STR stock and even more so if you put a limsaver str recoil pad on it. They used to be on amazon for about $20, but recently have shot up to around $35 for some reason, popularity? Naysayers will poo poo the idea of a recoil pad for a .223, but the fact remains that when you are trying to be as accurate as possible at range, you want to eliminate as many factors as easily done. Also, the rubber texture of the recoil pad lends itself nicely to maintaining a consistent shoulder placement.

Scope - who knows what route you will go, but I found myself content with the 4x16 primary arms 30mm model. Their mil dot version is FFP and can be had for $200. They also have a MOA version if that is preferred. They also have a strong warranty.

The larue MBT2s trigger is on sale right now for $87, that's my preferred, but it sounds like you already have your trigger.

I don't have any experience shooting past 300 yards, but found the repeat-ability of shots on target with the previously mentioned set up to be 'boringly reliable' at the 275-300 distance I was shooting. Proned out with a harris bipod in the grass, groups were no more than 6 inches, but we were shooting multiple targets at various ranges in a somewhat fast paced scenario practice for fun with card board cut outs. I definitely would like to do farther in the future when I have time.

Still on my to do list is to make accurate dope cards for everything.

Sounds like you already have a fun shooter ready to go and just may make minor adjustments to make it exactly as you want it.

 

[Mr Smith]

FUTURE PARTS

Stock - The CTR doesn't work well for this application, but it was the best I had laying around.
Scope - Once I shoot this with the Vortex PST I'll get an idea of what I need to look for based on the capabilities of the rifle.
Charging Handle - I need something easier to manipulate with a scope.

suggestions for minimal budget friendly changes that will improve two areas you're looking at changing without breaking the bank.

Stock:
LUTH-AR MBA-4 "Skullaton" Adjustable Carbine AR Stock - Black
Use your same buffer assembly. Just slide that on and use the hex tool attached to the stock to tighten down two set screws on the stock that eliminates 100% of the slop making it into a fixed stock once the set screws are set. Then put the took back in it's holder and you're ready to fire.

For the charging handle side of it:
UTG Pro Extended AR Charging Handle Latch
or strike industries makes a good one too in different colors (red, blue, black, FDE, ODG, etc)

Add that to your charging handle and you can charge your rifle around the scope without needing to replace the entire handle.

 

[Joe Link]

Thanks for the tips guys

For the stock, I think first I'm going to give one of these LaRue RISR's a shot on the CTR. Length of pull isn't an issue so much as not being able to establish a proper cheek weld, so if this fixes it for $25 I'll be happy. If not I'm probably just going to bite the bullet and buy a Magpul PRS. I've done a lot of reading and comparing it and the Luth-AR MBA-1. I love the weight and price of the MBA-1 but I've read quite a few stories about poor durability, which is something important to me.

For the charging handle, there's a good chance this rifle will be suppressed at some point in the future. Another build I'm working on has the PRI Gas Buster, and if I end up liking it I'll probably go that route. I have a BCM on another build that I really like, and I also like the Radian's that I've used.

For the scope, I've been buying Vortex products for the past couple of years. They make good products and stand behind them with that fantastic warranty. I'm going to look into Primary Arms though, as I've heard great things about their recent offerings.

 

[Mr Smith]

Thanks for the tips guys

For the stock, I think first I'm going to give one of these LaRue RISR's a shot on the CTR. Length of pull isn't an issue so much as not being able to establish a proper cheek weld, so if this fixes it for $25 I'll be happy. If not I'm probably just going to bite the bullet and buy a Magpul PRS. I've done a lot of reading and comparing it and the Luth-AR MBA-1. I love the weight and price of the MBA-1 but I've read quite a few stories about poor durability, which is something important to me.

For the charging handle, there's a good chance this rifle will be suppressed at some point in the future. Another build I'm working on has the PRI Gas Buster, and if I end up liking it I'll probably go that route. I have a BCM on another build that I really like, and I also like the Radian's that I've used.

For the scope, I've been buying Vortex products for the past couple of years. They make good products and stand behind them with that fantastic warranty. I'm going to look into Primary Arms though, as I've heard great things about their recent offerings.

Interesting little attachment. I have a CTR as well on my 5.56 and that might be a nice little addition to it.

Though I might go the extra mile and build an upper with a side charging handle on it instead of having the charging handle scoot the cheek riser back and forth. You're giving me ideas lol.

Also primary arms makes a decent scope. own 2 of them. If you don't mind the reticle it's a good option. Especially the FFP versions.

?avad=228673_f1413ab81&utm_source=affiliate-referral&utm_medium=social&utm_campaign=179625&utm_content=product-review

Add that bit to the end of the URL in the address bar on your web browser when you find the scope you like, hit enter, and it will give an extra option for a free scope mount
got that off some youtubers review but it works on all of their scopes on their website.

 

[Weebs]

You should stack 3 or 4 of these together.

Sightron 3" Stackable Sunshade 70013

 

[v0lcom13sn0w]

nice joe! do you have a chronograph to see what velocity youre bullets are at? ive found it much easier to shoot longer distance (i practice weekly at 520)to find the ballistic coefficient of my bullet and the velocity then either do the math or use a ballistics calculator app on my phone. it gets me on paper then i fine tune the scope from there.

 

[Kruel J]

Showoff.

 

[v0lcom13sn0w]

sportoptics.com usually has good promos on scopes

 

[Joe Link]

nice joe! do you have a chronograph to see what velocity youre bullets are at? ive found it much easier to shoot longer distance (i practice weekly at 520)to find the ballistic coefficient of my bullet and the velocity then either do the math or use a ballistics calculator app on my phone. it gets me on paper then i fine tune the scope from there.

No chronograph yet. If I stick with this long range stuff I can see it and a reloading setup in my future.

 

[11Charlie]

Joe we need to get you to the range!! PM inbound lets plan a day.

 

[Joe Link]

Joe we need to get you to the range!! PM inbound lets plan a day.

We certainly do!

 

[Geardo]

I didn't see a mention of ammo. Make sure to try some IMI 77 grain razor core, or black hills mk262 if the twist is at least 1:7.

 

[Joe Link]

I didn't see a mention of ammo. Make sure to try some IMI 77 grain razor core, or black hills mk262 if the twist is at least 1:7.

Thanks for the suggestions, I'll check those out.

All I've shot so far is this generic Remington UMC 55gr stuff. I also have some Wolf Gold 55gr, PMC Bronze 55gr FMJ-BT, and some IMI stuff, but zero match-grade ammo.

Edit: Twist rate is 1/8.

 

[Mr Smith]

Twist rate of your barrel will determine what bullet weight range will work best out of the rifle.

 

[Joe Link]

Twist rate of your barrel will determine what bullet weight range will work best out of the rifle.

I need to read up on this

 

[Geardo]

Thanks for the suggestions, I'll check those out.

All I've shot so far is this generic Remington UMC 55gr stuff. I also have some Wolf Gold 55gr, PMC Bronze 55gr FMJ-BT, and some IMI stuff, but zero match-grade ammo.

Edit: Twist rate is 1/8.

IMI isn't "match grade" but it is decent. About 1.5 moa for me. Standard deviation is a little high, but they are smoking hot. The vekocity and heavy weight really helps at range.

 

[Joe Link]

It's too bad ammo retailers don't break down a few boxes of various match ammo and sell a 'mixed bag' with some of each

 

[Mr Smith]

I have a 1:8 twist barrel as well and it really likes 62gr rounds.

62-68gr is about the sweet spot for a 1:8 twist.

it will work for 55-77gr just fine though.

 

[Joe Link]

Got a chance to play around a bit more yesterday. Finished off my box of Remington UMC 55gr which did so-so, then tried a box of Wolf Gold 55gr. I shot two three-round 0.4" groups at 50 yards, letting me know that the rifle is capable of sub-moa accuracy if I do my part. I've got to say, that's better than I expected.

My biggest issue yesterday was getting a good sight picture through the scope with the CTR stock. Due to it's performance yesterday I felt the rifle deserved a proper stock, so I ordered a Magpul PRS this morning

I'm putting this equation here so I can remember it.

MOA = (group size in inches) / {(distance in yards) / 100}