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9/22/2017 12:11:25 AM
Posted: 3/15/2006 7:05:25 AM EDT
Hey guys,

I want to build a precision AR. At first, I really wanted to build a “SAM-R” clone but after pricing it out, I quickly realized that to do it right, it was going to cost more then I could justify spending considering my intended use for it and my current skill level. So now the plan is to build a “SAM-R”’ish clone on a budget.

The range this weapon will be used at will be mostly 200 and 300yrds but there may be some 600yrd shooting in my future. I have decided I want at least 1/8 but preferable 1/7 twist rate and M4 ramps because it will be fed a consistent diet of 75gr+ loads. I have also decided I would prefer a mid-weight profile, something like a .840 dia from the camber to the gas block then .750 the rest of the way out.

Krieger, PAC-Nor, Noveske all make very nice barrels but considering my budget and skill level, those all seem like over-kill. I think White Oak makes a good compromise between quality, accuracy and price and should be perfect for my build.

So here’s the catch. White Oak makes exactly what I’m looking for in their “SPR” barrel. SS barrel with a Wylde chamber, 1/7 twist, M4 ramps, mid weight profile but it’s an 18” barrel. I have started communications with John Holliger from White Oak to see if they will make the same thing in 20”? I haven’t worked out all the details yet but it seems like they will. The question is, do I spend the extra money and wait longer to get the barrel I want in the length that I want or just deal with the 18” barrel?

The reason why I want a 20” is because I figure I’m not going to be humping this thing around or trying to quickly enter\exit cars or buildings so losing 2” isn’t helping me any but it will cause me to loose some velocity. The flip side is, the only thing I will be killing is paper so the velocity shouldn’t matter too much and the 18” version is ready and available now (and probably a little cheaper).

So which way would you guys go and why? Thanks
Link Posted: 3/15/2006 7:23:10 AM EDT
18" the shorter the stiffer. Also get that sucker fluted! A fluted barrel might get hot faster but it cools down faster once it gets hot. And if you're feeding it 75gr bullets then go 1:8 twist not 1:7 because 1:8 will reach out farther more accurately than a 1:7. Example: the military SPR barrel is a 1:8 twist as opposed to the M4 which is a designated 1:7. This is because at a distance the 1:7 twist begins to keyhole and throw bullets in somewhat random directions. I've seen it happen and its ugly, very ugly.
Link Posted: 3/15/2006 10:36:42 AM EDT
I have an 18" and am VERY happy with it. Very handy.
Link Posted: 3/15/2006 6:20:04 PM EDT

Originally Posted By ironsight-boy:
18" the shorter the stiffer. Also get that sucker fluted! A fluted barrel might get hot faster but it cools down faster once it gets hot. And if you're feeding it 75gr bullets then go 1:8 twist not 1:7 because 1:8 will reach out farther more accurately than a 1:7. Example: the military SPR barrel is a 1:8 twist as opposed to the M4 which is a designated 1:7. This is because at a distance the 1:7 twist begins to keyhole and throw bullets in somewhat random directions. I've seen it happen and its ugly, very ugly.



I have one 18" MRP and a 16" Recon barrel from Denny that both have 1:7 twist. I shoot these rifles out to 600 yards frequently and have never had a problem with keyholes. I mostly shoot M262 with some 75 gr. Hornady in the mix.

From everything I have ever read you want to go with the faster twist for the heavier bullets so they stay stabilized in flight. If I am wrong please correct me.
Link Posted: 3/15/2006 6:33:12 PM EDT

Originally Posted By peasant:
I have an 18" and am VERY happy with it. Very handy.




Originally Posted By michealj:
I have one 18" MRP and a 16" Recon barrel from Denny...



Dammit Jim! We need Pictures!
Link Posted: 3/15/2006 6:42:10 PM EDT
[Last Edit: 3/15/2006 6:44:19 PM EDT by chromeluv]
18 or 20 inches, you will be fine either way. What is going to make or break you is yourself first, how well you can execute each shot, and then the glass you put on your rifle..


eta: Also depending on ammo of course, your loss in the avg. velocity between the 16inch and 18inch shouldn't make as much difference to affect your precision , as long as you have good glass on a base with enough MOA to account for the drop, you should be GTG.
Link Posted: 3/15/2006 7:53:45 PM EDT
I'm currently building one too, and I since I figured that I'm only buidling this thing one time, I went with this 20" Pac-nor SS 1/7 fluted fore and aft. I installed the block Sunday, still waiting on many parts though.

Link Posted: 3/15/2006 8:32:59 PM EDT

Originally Posted By Onslaught:


Originally Posted By michealj:
I have one 18" MRP and a 16" Recon barrel from Denny...



Dammit Jim! We need Pictures!



Here's a few from the last couple weeks:







Link Posted: 3/15/2006 9:06:36 PM EDT
your going to have to UN-instal your gas block to get your barrel nut on.

Invisiblesoul
Link Posted: 3/16/2006 1:00:51 AM EDT
Right, it is definitely not attached with the set screw yet, just snug in place. I had to take off some of the kg coating under where it sits so that it would fit over, so this was after I finally got it where I liked it fit wise.
Link Posted: 3/16/2006 3:37:56 AM EDT

Originally Posted By chromeluv:
18 or 20 inches, you will be fine either way. What is going to make or break you is yourself first, how well you can execute each shot, and then the glass you put on your rifle...



That's kind of what I was thinking but that's why its not an easy decision. I can see minor reasons to go either way but nothing major enough to make it a clear and easy decision.

I guess what it boils down to for me is this. I was leaning 20" because I really wanted to make a SAM-R clone. The problem is, when I look at some of the extra parts I'll need to buy to make it even close to a clone, and how much the cost of those parts will drive up the total cost of this build, I'm having a hard time justifying it. So I may just skip the "clone" part which if I do, then there is little reason not to just get the 18"?

Now adding to my indecision, after playing e-mail tag with John yesterday, it appears it won't really cost me any more to go ahead and order the 20", in the specs that I want. The only downside to that route is time (4-6 turn-around) which is no big deal in my case. I'm in no hurry and I still have other parts to buy and decisions to make. (The Optics choice is going to kill me!)

Anyway, thanks for the input guys and letting me ramble
Link Posted: 3/16/2006 5:39:51 AM EDT
Link Posted: 3/16/2006 6:11:29 AM EDT

Originally Posted By JTAC_Supply:
I've got an 18" fluted SPR barrel in stock.



Great, my crack dealer is stalking me! Sent ya an e-mail Jason
Link Posted: 3/16/2006 6:24:44 AM EDT
If this helps you make your decision...

According to some velocity tests that MSTN ran a while back, there's roughly 50fps difference between 18" and 20" using the 77gr stuff, 15fps with 62gr, and 9fps difference with 55gr.

After seeing that, I doubt I'd ever both with that extra 2" of barrel... But then, I don't build "clones", so authenticity isn't important to me. If it is to you, then there's a good reason.
Link Posted: 3/16/2006 8:17:45 AM EDT

Originally Posted By Onslaught:
If this helps you make your decision...

According to some velocity tests that MSTN ran a while back, there's roughly 50fps difference between 18" and 20" using the 77gr stuff, 15fps with 62gr, and 9fps difference with 55gr.

After seeing that, I doubt I'd ever both with that extra 2" of barrel... But then, I don't build "clones", so authenticity isn't important to me. If it is to you, then there's a good reason.



Yes, that does help. I would have thought the difference would have been a little more then that. The 18" is sounded better all the time.

I don't typically build clones either (matter of fact, this would be my first if I built it) but I felt in this case that SAM-R is a pretty sweet setup and worthy of emulation. Thing is, the more I think about it and consider my needs, skills and budget, its getting much harder to justify.
Link Posted: 3/16/2006 9:10:01 AM EDT

Originally Posted By cgv69:
Hey guys,

I want to build a precision AR.


The range this weapon will be used at will be mostly 200 and 300yrds but there may be some 600yrd shooting in my future.




Longer barrel = more velocity. More velocity = less wind drift and bullet drop. For precision, go with the 20.
Link Posted: 3/16/2006 9:38:21 AM EDT
[Last Edit: 3/16/2006 9:54:47 AM EDT by Lawman734]

Originally Posted By ironsight-boy:
18" the shorter the stiffer. Also get that sucker fluted! A fluted barrel might get hot faster but it cools down faster once it gets hot. And if you're feeding it 75gr bullets then go 1:8 twist not 1:7 because 1:8 will reach out farther more accurately than a 1:7. Example: the military SPR barrel is a 1:8 twist as opposed to the M4 which is a designated 1:7. This is because at a distance the 1:7 twist begins to keyhole and throw bullets in somewhat random directions. I've seen it happen and its ugly, very ugly.



I read bullshit on many levels in that post, starting with fluting and then to bullet/barrel twist recommendations.
Fluting doesn't really do anything for a barrel other than add eye candy (I'll be the first one to admit that I've done it before). It doesn't make it more rigid, instead What it does is make it more rigid than a similar unfluted barrel of equal weight. The weight savings are minimal, a 6 fluted barrel used by a match shooter I know gets a weight savings of nearly a 1/2lb on a 30" barrel. Fluting after lapping will actually change the bores internal dimensions under the flutes, which is why custom makers like Broughton and Mike Rock actually flute thier barrels before lapping. Cooling is not a reason to flute a barrel; it still takes a long time to cool and actually increase your mirage when looking through a scope.
The military SPR barrels are 1:7 twist and will stabilize bullets up to 80grns just fine. Some, such as the Krieger my on my SAM/R stabilize the 90's just fine and I have used it in 1000yd comps. A 1"8 twist barrel generally performs well up to 69grns. I say generally because I've seen others shoot 77's and 80's just fine. I've seen Broughton 5C 1:8 twist barrels shoot 90grn bullets with no problems.

As for a SAM/R'ish clone. It's easy to do, here's a brief list.

-Yankee Hill rifle length FF tube-$128 from brightflashlights.com on the EE
-Rock River NM barrel, 1:8 twist-$225 from Adco
-regular A2 flash suppressor-$5 from just about anywhere
-Yankee Hill flip up front sight/gas block-$75 from Brightflashlights on the EE
-flat top upper receiver complete- $115 from Adco, but can be found cheaper
-gas tube and pin, $8 from anywhere
-bolt and carrier-$110 from Adco.

That will get you something similar and the RRA NM barrels are known to be good shooters. By substituting a few things you can easily make a Mk12 Mod1 SPR clone by going with the White Oak SPR barrel from Adco ($255) and a PRI gas block (Adco $55), Ops Inc type brake and collar (from Adco) and a Yankee Hill Rail Mounted flip sight ($64 from Brightflashlights).

I have a correct Mk12 Mod0 SPR from MSTN that I regularly shoot out to 700yds with 69grn and 77grn loads-I have 0 problems getting there. I also have a correct SAM/R that I use to 1000yds with 90grn loads (69's and 77's for anything closer)-I have 0 problems getting their either.
Link Posted: 3/16/2006 10:18:45 AM EDT
[Last Edit: 3/16/2006 10:19:24 AM EDT by Onslaught]

Originally Posted By ipschoser1:

Originally Posted By cgv69:
Hey guys,

I want to build a precision AR.


The range this weapon will be used at will be mostly 200 and 300yrds but there may be some 600yrd shooting in my future.




Longer barrel = more velocity. More velocity = less wind drift and bullet drop. For precision, go with the 20.


I can't imagine how the additional 10-15fps a 20" offers over an 18" would make a single bit of difference at any range. Even with the heavy stuff getting an additional 50fps in the 20", who among us is a good enough shot that it would change anything?
Link Posted: 3/18/2006 7:00:56 AM EDT

Originally Posted By michealj:

I have one 18" MRP and a 16" Recon barrel from Denny that both have 1:7 twist. I shoot these rifles out to 600 yards frequently and have never had a problem with keyholes. I mostly shoot M262 with some 75 gr. Hornady in the mix.




Can you really tell any differance between the 16" and 18" barrel?
Link Posted: 3/18/2006 3:07:36 PM EDT
Why not go with 14"?

Then, why not 12"?

18 is probably the sweet spot for weight, maneuverability and longer range shooting. I find my Noveske 18 quite manageable, and it shoots to 1 in at 200 yds. If you save a bit of money, glass and ammo will be easier decisions.
Link Posted: 3/18/2006 6:53:57 PM EDT

Originally Posted By AyeGuy:

Can you really tell any differance between the 16" and 18" barrel?



I do notice that I have smaller groups at 600 yards with the 18" MRP, but that probably has more to do with the optic than anything else. At 100 yards, they shot the same size groups. I shot the 16" Recon barreled rifle more often, because I hike to were I shoot and that rifle is lighter.
Link Posted: 3/19/2006 3:29:38 AM EDT
Tag. This is a great reference thread...

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