Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login
Site Notices
9/22/2017 12:11:25 AM
Posted: 3/1/2006 9:16:16 PM EDT
I have an opportunity to get a new Douglas barrel, 20", .223 wylde chamber, 1/9 twist, in a medium/heavy contour, at a very reasonable price.

I also have a Leupold Vari-X II 6x18 sitting around that I've been looking to do something with.

Questions -

1. Using 69 gr bullets, is it reasonable to think I'll be capable of going out to 600 yards? 800 yards?

2. Using the new DOuglas barrel, a quality upper/lower combo, fulton armory bolt/carrier, a free floated carbon fiber handguard, etc etc - are there any "secrets" that are going to prevent me from putting together a 1/2-3/4 MOA gun? I'm mechanically inclined, have built 2 nice 1911s and my other AR, and I have the basic tools, so I'm not a complete hack.. but if you have to know "tricks" to get them down there, no point in wasting my time as I'm new to this game.

I will (eventually) be hand loading, for what that is worth.


Link Posted: 3/1/2006 9:24:42 PM EDT
A 1/8" or faster twist would be a lot better for what you are trying to do, because it would enable you to use heavier bullets with a much better b/c. You can buy a RR 1/8" twist stainless barrel for a pretty good price, or a woa for not much more. Either of these would be a better choice.

TC
Link Posted: 3/1/2006 9:48:26 PM EDT
Why not go out to 1000 yards?
Link Posted: 3/1/2006 10:18:15 PM EDT
[Last Edit: 3/1/2006 10:19:42 PM EDT by pangris]
the barrel I can get cheap is a 1/9, only reason I'm considering it. Including the glass I'd be in the gun for less than $1000.

why not go to 1000? 600 is the range many PR1 classes go to, and I have access to a 500 yard range.


Paul
Link Posted: 3/1/2006 10:31:16 PM EDT

Originally Posted By pangris:

Questions -

1. Using 69 gr bullets, is it reasonable to think I'll be capable of going out to 600 yards? 800 yards?




I think you may need a 1:8 or faster twist & 75gr, 77gr & maybe even 80gr bullets for 600+yrds

Link Posted: 3/2/2006 5:51:58 AM EDT
I can testify that 69's will shoot alright at 600. They just won't hold the wind like 77's, 80's or 90's.
Link Posted: 3/2/2006 7:08:40 AM EDT
I have built a 600 yard gun and I would say pass on the douglass barrel. With a 1x9 you will only be able to shoot the Hornady 75 BTHP. Not the A-Max though. 69's will get blown around too much at 6. 75's will be ok, but not past 600. Once you start going for accuracy you will wish you got a Krieger.

A krieger 1-7.7 will handle the SMK 80gr's. If you get a pacnor 1-6.5 you can use the 90 grainers.

If you truely will only go out to 600, you could get by with the douglas, but will be thinking how much better could I have gotten with the Krieger.

The next important item for 600 yard shooting will be a really good 2 stage trigger. A Jewell, a Geisel, or better.

Frank
Link Posted: 3/2/2006 8:30:50 AM EDT
With a 1:9 twist the best bullet that would be stable is the Hornady 75 gr Match BTHP. I'd recommend Winchester or Lake City brass, WSR primers and Reloder-15 powder - that's what I use for my 200-300 yard loads for NRA Highpower. I use the 75 gr A-Max for 500-1000 yards, but it won't be reliably stable from a 1:9 barrel. You'll be accurate with the BTHP, but you'll have ~10% more wind drift than with the A-Max. When you replace the barrel, you'll want a 1:7 twist for the A-Max or a 1:6 for the JLK/Sierra 90 gr. I've tested the JLK vs. the A-Max and find that it has no advantage - JLK inflates the BC and velocities are 250 fps slower, making them ballistically identical.
Link Posted: 3/2/2006 10:23:26 AM EDT
Guys, I sincerely appreciate the input. I think I may end up passing on the build period and will wait for a deal on a 1/8 or 1/7 barrel.

As a final curiousity regarding these long range builds, at what point are the loads so heavy/long they don't fit in magazines?

Link Posted: 3/2/2006 11:01:06 AM EDT
[Last Edit: 3/2/2006 11:01:49 AM EDT by Dano523]
Link Posted: 3/2/2006 12:26:00 PM EDT
I see.. I'd heard that some were getting so long that had to be loaded one by one. I suppose that is at a different level of play...

Thanks again for all the help!
Link Posted: 3/3/2006 5:49:54 AM EDT

You can load the Hornady 75's and Sierra 77s from the mag, 80's are too long, only single load.

Frank
Link Posted: 3/3/2006 11:17:54 AM EDT

You can load the Hornady 75's and Sierra 77s from the mag, 80's are too long, only single load.


+1, with some manipulation like using a drop tube and letting your charged cases sit on a tumbler to further settle the powder-you might be able to load 80's to mag length. The problem is with all that work, you aren't really gaining anything over the 77's which are made for mag length loads.
The new 1000yd load I've seen a lot of guys playing with in AR's, is loaded with the 90grn SMK's-which are way to long to even be considered for mag length cartridges. To use those you will need a true 1:7, or better yet-a 1:6.5 twist barrel.

I frequently shoot my Mk12 Mod0 out to 700yds using 77grn Nosler's and have no problems at all with dinging the LaRue targets.
Link Posted: 3/3/2006 4:51:33 PM EDT
I shoot 69 grns at 1k range all the time, its slow, but it gets there! 1/9 handles these well also.
Link Posted: 3/3/2006 5:17:27 PM EDT
I'm going with a Pacnor 20" SS 1/7 chambered in wylde, it aint cheap though man.
Link Posted: 3/3/2006 7:10:01 PM EDT
Why are you stuck with the 5.56mm?

Why not just go with the 6.5 grendel or a 6.8mm?
Link Posted: 3/3/2006 7:13:37 PM EDT
[Last Edit: 3/3/2006 7:17:23 PM EDT by pangris]
Standardization. I shoot and inventory 5.56, 308, 9mm, 45, 12ga and .22 LR. My one non standard "luxury" round is the 9x23...
Link Posted: 3/4/2006 5:26:16 AM EDT
[Last Edit: 3/4/2006 5:27:07 AM EDT by metroplex]
I don't really understand 1/8 twist if you can get 1/7 twist to stabilize heavier bullets? Do varmint / long range shooters care about rifle longevity considering most use SS barrels anyhow?

For 5.56, you may want to try a 20" or 24" heavy-barrel, with 1/7 rifling to shoot 75gr-77gr bullets (or heavier using single shot followers), free floated handguard, NM iron sights (or scope), some type of bipod for prone supported shooting, and either no muzzle device w/ 11* target crown, or a flash suppressor (if you really want one) w/ 11* target crown.
Link Posted: 3/4/2006 5:00:37 PM EDT

Originally Posted By fcernese:
I have built a 600 yard gun and I would say pass on the douglass barrel. With a 1x9 you will only be able to shoot the Hornady 75 BTHP. Not the A-Max though. 69's will get blown around too much at 6. 75's will be ok, but not past 600. Once you start going for accuracy you will wish you got a Krieger.

A krieger 1-7.7 will handle the SMK 80gr's. If you get a pacnor 1-6.5 you can use the 90 grainers.

If you truely will only go out to 600, you could get by with the douglas, but will be thinking how much better could I have gotten with the Krieger.

The next important item for 600 yard shooting will be a really good 2 stage trigger. A Jewell, a Geisel, or better.

Frank



my experience with this is similar to most of the other guys as well. the 1/9 is pushing it for anything over 69gr. shooting that far is a little easier with slightly heavier units that require a faster rate of twist.

i have used Jard, RRA, Jewell and Chip McCormick. the Chip McCormick drop in trigger with a flat trigger in two stage configuration is hands down, the finest trigger in an AR i've ever used. a good trigger is a must for precision shooting.

good luck and good shooting.

HTH.

-septic tank
Link Posted: 3/6/2006 10:36:45 AM EDT

Originally Posted By Nbtstatic:
I'm going with a Pacnor 20" SS 1/7 chambered in wylde, it aint cheap though man.



I bought mine from JTAC nice barrel.
Link Posted: 3/6/2006 3:05:48 PM EDT
[Last Edit: 3/6/2006 3:09:37 PM EDT by highdraglowspeed]
some 1X9's will stabilize the 75's and 77's some won't.

If you shoot the 80's and 90's you will want to go with a 1X6.5 twist. PacNor comes to mind. The 1X7 is good for the 80's down to the 69's. However you will have a single shot rifle. If you try to get the 80's to seat at mag length you risk high pressure.

The SPR rifles shoot the 77's because that's the biggest they can fit at mag length.

Wind will be your enemy with the lighter bullets. The 6mm offerings, ie grendal and SPC rounds would be my choice for a long range ctg. out of an AR15 platform.

Are you going to compete with it? FYI 600 is no longer going to be considered long range according to the NRA news I got at the last match.
It will be considered mid range.
Link Posted: 3/6/2006 5:09:40 PM EDT

If you shoot the 80's and 90's you will want to go with a 1X6.5 twist. PacNor comes to mind. The 1X7 is good for the 80's down to the 69's. However you will have a single shot rifle. If you try to get the 80's to seat at mag length you risk high pressure


A 1:8 twist will stabilize the 90grn SMK's just fine, not only do I use them but I know a number of other guys who do also. Where a lot of guys have problems is with the 90grn Bergers, which due to its design really needs the 1:6.5 twist.
You can get the 80's to mag length by using a drop tube and setting your charged cases on a tumbler to further settle the powder but it's really not worth the effort because there really isn't much gained over the 77's.
Link Posted: 3/8/2006 8:24:24 AM EDT
There are some build techniques if you are building a long range AR. Torquing the muzzle brake/flash hider properly will be important, far more important than a duty rifle.

What brake are you using? Make sure you index it properly, use a crush washer and shims so that you get the brake to the 11 o'clock position with just finger tight pressure, then use a wrench to 12 o'clock. With longer barrels and especially with stainless steel, any more than 5 foot pounds of torque at the muzzle brake will usually impart forces on the bulet as it passes through. This will help greatly (or show the flaw) at longer ranges.
Link Posted: 3/8/2006 9:00:43 AM EDT

Originally Posted By Homeinvader:
There are some build techniques if you are building a long range AR. Torquing the muzzle brake/flash hider properly will be important, far more important than a duty rifle.

What brake are you using? Make sure you index it properly, use a crush washer and shims so that you get the brake to the 11 o'clock position with just finger tight pressure, then use a wrench to 12 o'clock. With longer barrels and especially with stainless steel, any more than 5 foot pounds of torque at the muzzle brake will usually impart forces on the bulet as it passes through. This will help greatly (or show the flaw) at longer ranges.



Homeinvader is completely correct.

The AMU uses standard, unmodified A2 flash suppressors, and installs them only hand-tight, and does NOT use any type of thread locking compound. AMU uses peel washers.
Link Posted: 3/8/2006 10:48:56 AM EDT

The AMU uses standard, unmodified A2 flash suppressors, and installs them only hand-tight, and does NOT use any type of thread locking compound. AMU uses peel washers.


When I first built my SAM/R, I had torqued the flash suppressor on as I normally would with a duty rifle and always seemed to hover right around 1/2MOA.
After reading what the AMU does, I gave it a try. Don't get me wrong, I wasn't unhappy with the performance I was getting-but I wanted to see if I could do better.
I used peel washers and hand tightened the F/S at TDC and then fired for groups. The first group I fired after doing this measured .254" across (5 shots/100yds) and I am very consistent at keeping groups under 1/2MOA, When the planets align right, even 1/4MOA.
Link Posted: 3/8/2006 10:53:13 AM EDT
[Last Edit: 3/8/2006 11:39:45 AM EDT by Homeinvader]
Peel washers are expedient, but won't allow you the fine tuning that a shim set will. With a peel washer, one layer will be too little, the next too much. Once a muzzle device (flash hider or muzzle brake or suppressor) has followed the muzzle threads all the way down to the the shoulder (or washer, spacer, etc), further torque has the effect of pulling the threaded muzzle shank away from the barrel body, sort of like pushing against the ground with your legs when picking up a heavy box. Torque is pushing the device against the barrel shoulder and pulling the threaded portion away, stretching it in effect. Extremely minute, but if the shoulder isn't cut perfectly square, this effect can cause the muzzle to steer slightly one way or if it is square, to choke it off effecting the concentricity of the bore at the muzzle.

Anyway, proper barrel nut torque is important too. Don't follow the ridiculously huge torque range from the M-16 armorer's manual. Again, that's fine for a duty rifle, but torque has the same effect on the barrel nut threads of the upper receiver. Too little torque and you'll get accuracy-hindering vibration, too much and you'll be twisting the barrel extension and crushing the barrel mount on the upper receiver.

Ideally, the gas tube could be inserted through the barrel nut at 35 pounds. If not, apply 35 pounds and go to the next notch, but don't torque too much. If you have to apply more than 80 to get to the next notch, use another barrel nut. You can also try several different barrel nuts to see which one works best in getting you to 35 pounds. Also, you should lube the threads and tighten-loosen the nut three times before final torque.
Top Top