SPR Build Parts

[CommsNBombs]

Hey yall, just finished out an 80% lower build on a PDW AR15 build. Waiting on my Form 1 to SBR the bad boy.

Kind of reconvinced myself to go back to 5.56 and the AR15 platform.

Looking at making a SPR clone. It'll be Mk12-ish but not making a literal copy, the SEALs can keep their Gucci gear, I want a 500 yard weapon to punch holes in...stuff with.

Building just the upper on a budget, this will be the first upper I've made from scratch so Im not sure of all the parts I need.

The barrel is the one I had more of a question on, I can't justify spending a car payment on it, I was looking at this one from customar15
https://www.customar15.net/shop/barrels-ar-15-upper-receivers/18in-stainless-straight-fluted-heavy-barrel-wylde-chamber-18-twist/

Is 416 Stainless a bad thing? All I know is I "should" get a SS barrel.

The free float tube I was looking at is the AM15 made by Anderson Mfg
http://www.andersonrifles.com/product/am-15-rifle-free-float-tube-assy/

Matching it with their light weight stripped upper
http://www.andersonrifles.com/product/lightweight-sport-upper-these-upper-receivers-do-not-have-forward-assist-or-ejection-port-cover-capabilities/

Will that gas block mate with a rifle length gas tube and this rifle? Or should I not mismatch when it comes to companies?

The gas system is the only thing I cant wrap my head around.

Thanks in advance, and Im open to suggestions regarding SPR'ing

[jcluff]

Am I reading this right? Did you say you are going to SBR an 80% lower? That seems counter to why 80% lowers are built...

As for your mk12 build and 416 or other barrels. It is a myth that 416ss barrels are more accurate. The barrel manufacturing process is more important than whether or not it is 416, 410, 4140 or 4150. 410 and 4150 are your stronger steels, and will typically last longer than 416 or 4140.

Decide how much you are willing to gamble/spend for a highly accurate barrel and then shop for a manufacture that will provide you the barrel profile you want that fits your budget. Douglas, Krieger, Pac-Nor, etc... will be some of your higher end barrel manufactures that have a better chance of providing you an extremely accurate barrel. However, if all you are looking for is sub-moa, your options really open up.

Good barrels for 1moa or less: Wilson Combat, Stoner, Brownells, Rainer Select, Prairie Tactical, Saturn (know to make Brownells), and much, much, more.

Remember, the lighter the barrel profile, the easier it is to carry, but the more likely it is to start walking (or becoming less accurate) after it starts to heat up. I have seen many a gun that fires a great 3 round group in under a .5 inches, but if not allowed to cool off some, round 4 and five really open it up to about in inch or greater.

Decide what your goal is for the rifle and what your budget is, and get the barrel that is right for you. There are a lot of really good articles online that go into some very detailed depth about barrels.

Also, don't overlook the trigger. For my money, the SSA-E is the way to go for precision, but the RRA 2 stage, is a very good second in my opinion, and costs about 1/2 the price.


Sent from my iPad using Tapatalk HD

[Guest tangojuliet]

LOL im just now finishing my spr build dont  worry about stainless steel unless you shoot about 1500 rounds a month the  barrel i went with wilson combats spr barrel with a 1:8 twist  so i cant say anything on the company you posted, forend i cant tell you anything about andersons forend cause i went with a samson evo rail wish i would have gotten the 15 instead of the 12 inch , and upper its all personal preference  ,and gas block if its .750 yes if not no   and yes you can mismatch parts 

 

 

some suggestions though

save your money up for a barrel  thats the heart of your rifle 

 

upper i would suggest one with a dust cover  and i forward assist but i mind you its personal preference 

 

and imo the forend your looking at is a lil short   for what you're making 

[CommsNBombs]

Jcluff, I am orig from NYC so I wanted my first AR to be something I "built" id have to Form 1 it either way even if I did a stripped lower.

I had a feeling the type of steel wouldnt matter too much. I was just looking for SS but without breaking the bank, and trying to stay lightweight.

However sub-moa is what im looking for, I dont need it to be a tack driver at 500 yds, im not going into any competions.

Tango,

I appreciate the incite. I wont be shooting too much, all I usually ever do is take the weapons out to verify zero then only shoot if I get bored.

I always thought the super long FF forends looked wierd, but would a longer one actually help stabilize the barrel even if its FF?

[Jct1911]

I've never heard of that customAR place. I'd spend a few bucks more and go with a manufacturer of known quality. Fluting is nice for looks and mild weight reduction but not needed. Length of the free float has no effect on the barrel, the longer the better, provides a physical rest and protects the barrel and your hands. SPR rifles in actual use would have to be shot from non-traditional positions and from walls/ barriers, etc..., the long free float is a necessity, also had a bi-pod and the further out the bi-pod is the easier it is to adjust shooting position. As said, chasing an exact copy will cost money. Throw money at a barrel, trigger and good BCG, the rest can be filled in with less expensive stuff. Here's a link to a quality barrel from a company that produces quality barrels at a good price and are well known. They have others to choose from also.

http://www.gmriflebarrel.com/gm-m24-5-56mm-nato-18/

Pick whatever 15" free-float handguard you can afford. For good quality and a solid mount I really like ALG. For the price it comes with barrel nut and wrench and can be installed with simple tools from home.
http://algdefense.com/15-ergonomic-modular-rail-black.html

Triggers are personal, inexpensive would be the RockRiver 2 stage. Geisslle on the higher end. I like the CMC trigger in the middle of the price range, mine breaks at 3.5# with a very short reset and no take up. Edited March 3, 2015 by Jct1911

[Guest tangojuliet]

I've never heard of that customAR place. I'd spend a few bucks more and go with a manufacturer of known quality. Fluting is nice for looks and mild weight reduction but not needed. Length of the free float has no effect on the barrel, the longer the better, provides a physical rest and protects the barrel and your hands. SPR rifles in actual use would have to be shot from non-traditional positions and from walls/ barriers, etc..., the long free float is a necessity, also had a bi-pod and the further out the bi-pod is the easier it is to adjust shooting position. As said, chasing an exact copy will cost money. Throw money at a barrel, trigger and good BCG, the rest can be filled in with less expensive stuff. Here's a link to a quality barrel from a company that produces quality barrels at a good price and are well known. They have others to choose from also.

http://www.gmriflebarrel.com/gm-m24-5-56mm-nato-18/

Pick whatever 15" free-float handguard you can afford. For good quality and a solid mount I really like ALG. For the price it comes with barrel nut and wrench and can be installed with simple tools from home.
http://algdefense.com/15-ergonomic-modular-rail-black.html

Triggers are personal, inexpensive would be the RockRiver 2 stage. Geisslle on the higher end. I like the CMC trigger in the middle of the price range, mine breaks at 3.5# with a very short reset and no take up.

 

 

 

^^^^^^^^^^^^^^^ ALL OF THIS ! 

[CommsNBombs]

Good copy on all of that Jct.

I probably will go with a more expensive barrel, I was checking more to see if any of the midpriced SS barrels were good. Think I might go with a Noveske in the end.

Im also trying to keep the weight down, as much as is possible...granted Ive humped Scar 17s, ACRs, SAWs and all sorts of other funky shit along with demo and radios, but Im not going to the Box, itll just be fighting paper.

Does the BCG really matter that much? Ive never used more then cheap no named Bolts and Carriers on all my Work and Personal weapons, never gave me an issue.

I was looking towards a 3.5 lb Timney single stage. But I might just take a stone and file to a SS anderson mfg FCG to lessen the pull.