The Firing Line Forums

Go Back   The Firing Line Forums > The Hide > The Art of the Rifle: Semi-automatics

Reply
 
Thread Tools Search this Thread
Old September 29, 2014, 02:17 PM   #1
Dirty_Harry
Senior Member
 
Join Date: January 11, 2006
Location: Kalamazoo, MI
Posts: 1,484
Thinking about an SPR build

First and foremost, what does SPR stand for? I know what it is, but dont know the meaning.

I want a slightly higher end rifle. 18" barrel, 1/7 twist/chrome lined, no quad rail (something slim and lightweight), chrome bolt, 2 stage trigger and magpul furniture.

I guess my basic questions are this, is there a complete upper that fits the criteria? Also how about a quality lower? Any suggestions?
__________________
"The only purpose for a pistol is to fight your way back to the rifle you never should have laid down."

"I won't be wronged, I won't be insulted, and I won't be laid a hand on. I don't do these things to other people and I expect the same from them." -John Wayne
Dirty_Harry is offline  
Old September 29, 2014, 05:10 PM   #2
Bartholomew Roberts
member
 
Join Date: June 12, 2000
Location: Texas and Oklahoma area
Posts: 8,462
SPR stands for "Special Purpose Rifle." The idea was to build an AR15 that had was more accurate and therefore could make effective hits out to longer ranges than the typical M4, while still keeping the qualities that made the M4 handy (auto fire, compact size). The 18" barrel was chosen as a compromise between the 14.5" length of the M4 and the better velocity of the 20" M16.

Quote:
I guess my basic questions are this, is there a complete upper that fits the criteria? Also how about a quality lower? Any suggestions?
Well, the 18" barrel with chrome lining is a bit unusual. Most of the 18" barrel offerings are going to be stainless steel match barrels, since about the only people that order 18" barrels are people building SPRs or race guns and both want a higher level of precision than a chrome-lined bore will deliver. I'm not aware of anyone offering a 1:7 chrome-lined 18" barrel; though you could probably have a 20" cut down if you wanted to go through all that. Most 18" barrels use rifle gas anyway.

The whole 18" is because that is pretty much the sweet spot for compact without losing much velocity to the 20" barrel. If you go shorter, you lose more velocity. If you go longer, you gain a tiny amount of velocity for the extra 2". So I suppose the first questions you have to ask yourself are:

1) Is this a precision type rifle where a high degree of accuracy and a flat trajectory are very important; or
2) Is this a rifle where barrel longevity is more important and 2-3 MOA accuracy with ball ammo is sufficient (maybe 1-2MOA with match ammo)?

If you want number 1, you probably want to go the 18" stainless barrel route rather than chrome-lined. If you want number 2, then you can drop your barrel to 16", and there are literally hundreds of ready-made uppers you can choose from that meet your criteria.

As to lowers, pretty much anything that is in spec and has the holes drilled in the right place, takes the magazines you want to use, etc. will work. It is hard to go wrong here unless you are going for some custom billet lower, or a lower made out of some non-7075T6 Aluminium substance.
Bartholomew Roberts is offline  
Old September 29, 2014, 08:54 PM   #3
pilpens
Senior Member
 
Join Date: April 24, 2008
Location: Ohio
Posts: 1,696
Check out PSA for upper options between the two ends that Bartholomew posted: precision and longevity.

http://palmettostatearmory.com/index...uppers/18.html

I like this one:
http://palmettostatearmory.com/index...ng-handle.html
pilpens is offline  
Old September 30, 2014, 02:59 AM   #4
Rob96
Senior Member
 
Join Date: August 31, 1999
Location: Allentown,PA
Posts: 1,969
The SPR is meant to be a more precise AR with capabilities out to 600m. I run a DPMS MK12 SPR. With my loads using Hornady 75gr BTHP's I am at .327moa at 100yds. If you do a Google search you will see most use stainless barrels.
Rob96 is offline  
Old September 30, 2014, 08:39 AM   #5
Dirty_Harry
Senior Member
 
Join Date: January 11, 2006
Location: Kalamazoo, MI
Posts: 1,484
Thank you all for the info. I just assumed that you could find them with chrome lined barrels. I plan on putting a low 1-4 power optic on it. I just like the thought of a do everything SD rifle.
__________________
"The only purpose for a pistol is to fight your way back to the rifle you never should have laid down."

"I won't be wronged, I won't be insulted, and I won't be laid a hand on. I don't do these things to other people and I expect the same from them." -John Wayne
Dirty_Harry is offline  
Old September 30, 2014, 08:46 AM   #6
Rob96
Senior Member
 
Join Date: August 31, 1999
Location: Allentown,PA
Posts: 1,969
That is exactly what I did.
Rob96 is offline  
Old September 30, 2014, 09:15 AM   #7
Bartholomew Roberts
member
 
Join Date: June 12, 2000
Location: Texas and Oklahoma area
Posts: 8,462
Quote:
I just assumed that you could find them with chrome lined barrels.
You assumed correctly apparently. The Palmetto State link that pilpens posted had a ton of 18" chrome-lined barrels available as pre-assembled uppers in a variety of configurations.

As for chrome-lined barrels, it all depends on what level of accuracy you need. When the Marines and Army were exploring the Designated Marksman/Squad Advanced Marksman concept, they both experimented with stainless match barrels and reached the conclusion that very few of the people in their study had the level of skill necessary to make use of the stainless barrels. Basically, the shooters didn't see any accuracy difference between a good chrome-lined barrel and a stainless barrel. However, they were also using M855 ammo, which was probably the limiting factor on accuracy and explains why the barrel made no difference.

When SOCOM looked at the same concept (an accurized AR), they did go with the stainless barrel, even though they have a much higher training rate and the stainless barrel isn't going to last as long. Of course, they also were using the 77gr Mk262 match ammo and had high standards of training and more regular refresher training.

So some questions to ask are:
1) What are my accuracy requirements - how big a target do I need to hit and at what distance do I need to hit that target?
2) If you give me a rifle that can meet those requirements, do I have the necessary skill to actually make it hit at those ranges?
3) What kind of ammo can I afford to feed it? If you buy a $600 AR15 and feed it cheap 55gr FMJ, you are going to get 3-4 MOA accuracy. If you buy a $3,000 top of the line precision AR15 from Knights or Noveske and feed it cheap 55gr FMJ, you are going to get 3-4 MOA accuracy. If you aren't going to handload or go with premium ammo, there isn't much point in spending money for an accuracy capability you'll never use.

Quote:
I plan on putting a low 1-4 power optic on it. I just like the thought of a do everything SD rifle.
Every rifle is a compromise. For years, I tried to create a "do-everything" rifle that could do anything you could think of. In the end, I had a rifle that I liked a lot; but it weighed around 12-13lbs loaded and while it could do almost anything you asked of it, it couldn't do any one job as well as a more specialized rifle could have. The "jack of all trades, master of none" result.

That approach also overlooks one of the great benefits of the AR15 - they are extremely modular. Instead of trying to cram it all into one rifle and make that one rifle do everything OK, it is much easier to take advantage of that modularity. Have a red dot and a scope in quick detach, return-to-zero mounts and swap them out as necessary. Don't need the <insert piece of gear here> for today's shooting event? Take it off. Want a precision AR15 and an AR you can use for blasting without burning out the barrel? Get an extra upper and swap them out.

Having said all that, an 18" chrome lined barrel with a 1-4x optic is going to be extremely versatile and be able to do a lot of tasks well. I'll just tell you right now to save weight where ever you can because it is real easy to add it back on with various accessories.
Bartholomew Roberts is offline  
Old September 30, 2014, 09:42 AM   #8
HiBC
Senior Member
 
Join Date: November 13, 2006
Posts: 8,274
Along with weight,budget may be a factor,also.

Given a 1x to 4x scope,IMO,a barrel that may fit into a balanced package for you is the Daniel Defense "S2W".Its made to some Navy spec.

Its hammer forged,18 in,and chrome lined.The contour is interesting.S2W stands for strength to weight.

Instead of the typical stepped cylindrical profile,its a contoured taper like a typical sporting rifle barrel.

Its lighter than an H-bar,without being the skinny M-4

Price about $270 or so,last time I looked.

Mine is + or - 1 MOA with 77 gr handloads.Not a bragger,but it will whack prairie dogs as far as you can use a 1x to 4x scope on them.

For ball park the same price,or a little more,look at what White Oak offers,at least to compare.They are not chrome lined.

If you want to blaze rapid fire,the chrome makes sense.

Squeezing one round at a time for accuracy,chrome is not so necessary.

Look at Yankee Hill for a forend.There are others,of course.YHM has a strong attachment and moderate price.They make one that only has a little bit of rail on it.Its customizable .
The Rock River NM 2 stage trigger is not a bad choice.

Look at the Rock River ring mounts.I like them,reasonable price.
HiBC is offline  
Old October 2, 2014, 06:57 AM   #9
Dirty_Harry
Senior Member
 
Join Date: January 11, 2006
Location: Kalamazoo, MI
Posts: 1,484
What do you guys recommend for a lightweight slim hand guard? I don't really want a quad rail as my dd has one already. Also would want it free floating.
__________________
"The only purpose for a pistol is to fight your way back to the rifle you never should have laid down."

"I won't be wronged, I won't be insulted, and I won't be laid a hand on. I don't do these things to other people and I expect the same from them." -John Wayne
Dirty_Harry is offline  
Old October 2, 2014, 10:17 AM   #10
WeedWacker
Senior Member
 
Join Date: December 13, 2006
Location: Body: Clarkston, Washington. Soul: LaCrosse, Wisconsin
Posts: 1,591
Look at Troy, Midwest Industries, Knights Armament, or any other big names. Alternatievely, the VLTOR CASSV is a unique option that utilizes the flat-top picatinny rail to attach to the rifle.

I have a Midwest Industries SS rail on my 18" build. The modular design lends to lighter weight and variety in accessory placement than a standard 12/3/6/9 o'clock quad rail allows. The newer keymod and Magpul M-LOK type systems are easier to attach accessories.

MI M-LOK rail example:
http://vtsupply.com/mi-midwest-indus...handguard.html

TFL member Plouffedaddy has some info on the M-LOK and some handguards on Youtube (Mr. Guns N Gear).
https://www.youtube.com/user/Mrgunsn...ch?query=M-LOK
__________________
- Jon
Disequilibrium facilitates accommodation.
9mm vs .45 ACP? The answer is .429
WeedWacker is offline  
Old October 2, 2014, 02:28 PM   #11
Fishbed77
Senior Member
 
Join Date: November 23, 2010
Posts: 4,862
Quote:
What do you guys recommend for a lightweight slim hand guard? I don't really want a quad rail as my dd has one already. Also would want it free floating.
I used a Rainier 18" stainless SPR barrel with a Rainier 15" Evolution rail (similar to the Sampson Evolution rail, but lighter and better-looking) on my SPR build. It is a superb combination in my experience. The Rainier Evolution rail is very light, very slim, mounts easily to a stock AR barrel nut (no proprietary nut to fool with), and is rock-solid when mounted.
Fishbed77 is offline  
Old October 2, 2014, 02:45 PM   #12
Dirty_Harry
Senior Member
 
Join Date: January 11, 2006
Location: Kalamazoo, MI
Posts: 1,484
I really like that Midwest, especially in OD green. For an SPR I would want a 12 inch correct?

Also, what else would I need to be able to put that on a rifle?
__________________
"The only purpose for a pistol is to fight your way back to the rifle you never should have laid down."

"I won't be wronged, I won't be insulted, and I won't be laid a hand on. I don't do these things to other people and I expect the same from them." -John Wayne
Dirty_Harry is offline  
Old October 2, 2014, 03:38 PM   #13
Fishbed77
Senior Member
 
Join Date: November 23, 2010
Posts: 4,862
Quote:
I really like that Midwest, especially in OD green. For an SPR I would want a 12 inch correct?
Typically, SPR barrels have rifle-length gas systems, so you would need a longer free-float forearm than that if you wanted to cover the gas block. If you were using a gas-block-mounted folding sight, then a 12" forearm should work.
Fishbed77 is offline  
Old October 3, 2014, 08:25 AM   #14
Dirty_Harry
Senior Member
 
Join Date: January 11, 2006
Location: Kalamazoo, MI
Posts: 1,484
Cool, thanks for the info. I am learning a lot. What optics are you guys running on yours?
__________________
"The only purpose for a pistol is to fight your way back to the rifle you never should have laid down."

"I won't be wronged, I won't be insulted, and I won't be laid a hand on. I don't do these things to other people and I expect the same from them." -John Wayne
Dirty_Harry is offline  
Old October 4, 2014, 11:25 AM   #15
WeedWacker
Senior Member
 
Join Date: December 13, 2006
Location: Body: Clarkston, Washington. Soul: LaCrosse, Wisconsin
Posts: 1,591
I've used a Nikon M-223 1-4x20 and a Burris Fullfield II 3-9x40. I would like to get a Weaver 1-5x24 Tactical. Depends on what I want to do with the rifle. If I'm varmint hunting I like the added power and field of view of the Burris. For "tactical" shooting in local league matches the Nikon works well, but imprecision of the point blank reticule makes me twitch for longer range shooting (3.5 MOA dot covers part of the target).
__________________
- Jon
Disequilibrium facilitates accommodation.
9mm vs .45 ACP? The answer is .429
WeedWacker is offline  
Old October 4, 2014, 12:38 PM   #16
Dirty_Harry
Senior Member
 
Join Date: January 11, 2006
Location: Kalamazoo, MI
Posts: 1,484
This is what I am leaning towards right now.

http://www.midwayusa.com/product/119...vc=subv1119257
__________________
"The only purpose for a pistol is to fight your way back to the rifle you never should have laid down."

"I won't be wronged, I won't be insulted, and I won't be laid a hand on. I don't do these things to other people and I expect the same from them." -John Wayne
Dirty_Harry is offline  
Old October 4, 2014, 12:48 PM   #17
HiBC
Senior Member
 
Join Date: November 13, 2006
Posts: 8,274
Buy what you like,but at least take a good look at that Daniel Defense 18 in chrome lined 1in 7 S2W contour barrel.
HiBC is offline  
Old October 4, 2014, 05:33 PM   #18
Dirty_Harry
Senior Member
 
Join Date: January 11, 2006
Location: Kalamazoo, MI
Posts: 1,484
I will for sure, I love my ddm4v1 after all.
__________________
"The only purpose for a pistol is to fight your way back to the rifle you never should have laid down."

"I won't be wronged, I won't be insulted, and I won't be laid a hand on. I don't do these things to other people and I expect the same from them." -John Wayne
Dirty_Harry is offline  
Old October 6, 2014, 03:22 PM   #19
marine6680
Senior Member
 
Join Date: July 24, 2012
Location: Parker, CO
Posts: 4,594
A good chrome lined barrel won't loose too much accuracy. Mine can shoot MOA with good ammo.

I'm using a PSA CHF barrel. I was actually surprised by the accuracy. I would say that 1.5 MOA with decent ammo is plenty for inside 500yds... Unless you just want the absolute best groups shooting paper.


An illuminated reticle 1-4x scope can be used in a similar manner as a red dot on 1x, with some practice you can do it on 4x too.

If you're looking in the $500 range, I would ditch the secondary red dot in favor of higher quality in the main optic.

I am running a vortex PST 1-4x and I like it. On my next build I am thinking of trying something different though, just for variety.
marine6680 is offline  
Old October 6, 2014, 07:28 PM   #20
agtman
Junior member
 
Join Date: July 26, 2001
Location: midwest
Posts: 2,374
Skip the wannabes. You get what you pay for. White Oak Armament is what you want.

My SPR runs WOA's 5.56mm upper receiver (BCG included) with 18" SS 1/7 twist tube (w/ Wylde chamber & PRI gas block), free-floated inside a PRI 3rd Gen tube.

Using factory 77gn match ammo (e.g., Norma) it will put 5-shots into 3.5" at 400yds consistently. That's the farther I've shot it.



Above set-up includes: Vortex 30mm 2.5x-10x in ADM QD mount, Harris bipod, Geisele DMR trigger, MagPul grip & CTR stock w/ LT RISR cheekpiece, and BFG sling.


Last edited by agtman; October 9, 2014 at 07:15 PM.
agtman is offline  
Old October 6, 2014, 08:08 PM   #21
Fishbed77
Senior Member
 
Join Date: November 23, 2010
Posts: 4,862
Quote:
Skip the wannabes. You get what you pay for. White Oak Armament is what you want.
Wait. Since Douglas made the original SPR barrel, that would make White Oak the wannabe.
Fishbed77 is offline  
Old October 6, 2014, 08:24 PM   #22
HJ857
Senior Member
 
Join Date: January 9, 2007
Posts: 447
This is the Stag 3G (upper only). 18" stainless, fluted. 1/8 twist, Samson Evolution tube, comes with a matched BCG. Not sure what you're expecting, but none of this style upper will be as light as a standard M4 format upper.

$715.00
http://www.ar15sales.com/store/page2.html


HJ857 is offline  
Old October 7, 2014, 03:52 PM   #23
Dirty_Harry
Senior Member
 
Join Date: January 11, 2006
Location: Kalamazoo, MI
Posts: 1,484
That stag upper is sharp. I may have to give it a look.

I received an offer of an upper with a WOA barrel, I am trying to work it out.
__________________
"The only purpose for a pistol is to fight your way back to the rifle you never should have laid down."

"I won't be wronged, I won't be insulted, and I won't be laid a hand on. I don't do these things to other people and I expect the same from them." -John Wayne
Dirty_Harry is offline  
Old October 7, 2014, 06:36 PM   #24
HJ857
Senior Member
 
Join Date: January 9, 2007
Posts: 447
I opted for the Stag because I liked the build and because I could put a WOA barrel on it down the road, however the Stag barrel has proven to be pretty darn good, even though I would prefer a Wylde chamber rather than a standard 5.56 chamber.

If I had the chance to choose between the two, and didn't have to wait half a year to get it - I'd go White Oak.
HJ857 is offline  
Old October 10, 2014, 11:08 AM   #25
Dirty_Harry
Senior Member
 
Join Date: January 11, 2006
Location: Kalamazoo, MI
Posts: 1,484
The deal for the WOA upper fell through. I did take a 20" PSA rifle on trade for something else though. I know without the free floating handguard/and it has a chrome lined barrel the accuracy isnt going to be near what a good SPR build would be.

I am going to mount some optics and test it though.
__________________
"The only purpose for a pistol is to fight your way back to the rifle you never should have laid down."

"I won't be wronged, I won't be insulted, and I won't be laid a hand on. I don't do these things to other people and I expect the same from them." -John Wayne
Dirty_Harry is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 05:05 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.06208 seconds with 8 queries