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Discussion Starter · #1 ·
....Well maybe a little more than a low budget... lol.

I know these are not the most ideal systems for long range, that the training and experience is the most important part of the whole equation but I am writing this to help a friend that wants an AR to shoot far away and this way we all can learn
maybe one thing or two.

So here we will document a series of points and discussions regarding a long range build in the AR15 portfolio.
The expectation is a simple solid build with good accuracy but w/o braking the bank 'too much' so we will wait on the
less baers for after the economic recession.
What is needed for an AR everyone knows so with all lego discussions aside we are going to talk first about
a few casing options with the ones that are easy on the pocket first but w/o discarding some other offerings.
While we do that we will find a nice billet and some of the other needed goodies.

What caliber?
.223 Rem Bolt / parent
.223 rem itself
.223 rem AI
6x45
6mm-223 *30
6mmTCU
Don't really have the case capacity for the .25 or .264 wilcats to push LR bullets. So we will stop here at the .243 bore.

Russian 7.62x39 Bolt face
6.5mm LBC (I liked this chamber better than the Grendel)
6mm LBC (very similar to Bob Whitley's 6mmAR)
6mm PPC
- no need for fire-forming option on this section to keep it simple -

6.8SPC bolt face
6.8 SPC itself (a bit too much but we can do something with the latest reviewed chambers)
6mm-6.8
6mm DTI

308w. Bolt face
6mmBR norma (lapua)
6.5mmBR norma (lapua)

There are other calibers but I feel these are the ones where we can find bolts, barrels and extensions faster
(not all fast) and probably good options for folks to get started in AR long range whether is paper, steel, coyotes
or woodchucks ;-)

So before we discuss casings and options it is better to find out what bullet is needed and for that we need
to talk about what purposes.

So for the sake of the discussion we will start with some simple proposal:

-A long range AR capable of popping a coyote at 500-600 yards (if you can hit it ... that is a different story)
-Capable of punching paper out to 800 yards with a nice somewhat flat trajectory. or if given the opportunity
taking a chance at a woodchuck.
I do not think that a lot more could be asked for a first build but if someone feels like they need to get out there
to 900 or 1000 yards w/o too much drop and/or drift there are options (if you can hit the targets too, otherwise we will get you huge ones! lol!)

First do not think the .223rem cannot do much. it is actually my first logical option for a starter. The question
is what are the voids and how they can be filled? I try to think what is the easier way to fill that void first so lets
see if we can find any reasons and follow always the KISS process: Keep it simple and stupid.
 

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YES!!! This is what I'm talking about. Really looking forward to all the advise & opinions for my build. I love the AR platform, yet I want more range. I know I could switch to a different rifle, but I know this platform could be pushed even more with the right ammo & components.

I don't know much about the specs for ammo or the components and just finished my first AR w/5.56. I just recently got another lower receiver from Allstar Tactical, so does that limit me to certain calibers? Cause I've been thinking about 7.62x35 or making my own from 7.62x39. Are their advantages using the 7.62x35 over the 6.8?
 

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Discussion Starter · #3 ·
YES!!! This is what I'm talking about. Really looking forward to all the advise & opinions for my build. I love the AR platform, yet I want more range. I know I could switch to a different rifle, but I know this platform could be pushed even more with the right ammo & components.

I don't know much about the specs for ammo or the components and just finished my first AR w/5.56. I just recently got another lower receiver from Allstar Tactical, so does that limit me to certain calibers? Cause I've been thinking about 7.62x35 or making my own from 7.62x39. Are their advantages using the 7.62x35 over the 6.8?
The advantages of the 7.62x35 (Blackout) are:
- It can use .308 bullets with many options including surplus ones for practice.
- brass parent is .223 that is inexpensive or virtually free at the range pickup if one decides to form and prep. all the brass from scratch.
- a 220gr OTM subsonic makes a nice load making this the primary reason for choosing this caliber but in NY supressors are not allowed. :-(

The advantages of the 7.62x39 are:
- Compatible with the AK (if you have it). Can find inexpensive bulk, value packs from pliking and general purpose, including soft point hunting.
- The brass is more expensive but it also can be pushed further than the blackout providing a little better ballistics in supersonic mode.
- Barrels with the proper twist are hard to find but it can do a good job in subsonic mode using 303 british including some surplus.

In a supersonic role none of the above can even begin to compare to the 6.8spc in terms of ballistics and terminal performance. The 6.8 is a superior round in every way. Practically the only way one would stay above the 6.8 is for shorter ranges I would say 150 yards? that at the other
hand is more than plenty for most people but in case one feels the need to take a longer shoot should consider this.

So back to the long range purpose... For the long range one what are the objectives/purpose you have in mind?
 

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The goal I was thinking, was being able the hit a target at least 500yds without the bullet dropping out of supersonic. I want it to maintain full velocity as much as possible.

If longer range is possible with minimum drop, then that's the route I'd like to take. Punching paper is fine, but I would rather be to take out a melon. I shot a blackout before with a suppressor and was pretty impressive, but was only at a 100yd range. With my AK, found taking out target at est. 300yds wasn't too bad, would have rather used a SVD. I never use 6.8. Never even gave it thought. Some of the things your talking about, to be honest, I have to google. Lol I'm learning as I go.
 

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Discussion Starter · #5 · (Edited)
The goal I was thinking, was being able the hit a target at least 500yds without the bullet dropping out of supersonic. I want it to maintain full velocity as much as possible.

If longer range is possible with minimum drop, then that's the route I'd like to take. Punching paper is fine, but I would rather be to take out a melon. I shot a blackout before with a suppressor and was pretty impressive, but was only at a 100yd range. With my AK, found taking out target at est. 300yds wasn't too bad, would have rather used a SVD. I never use 6.8. Never even gave it thought. Some of the things your talking about, to be honest, I have to google. Lol I'm learning as I go.
No worries. We can explain in simple terms. The .223 rem still is a great alternative. Also, you see, the 6.8 and .308's are great to keep the barrel reasonably short and still deliver a good punch. Since the .308 is a larger bore and the bullets have to be shorter so they are not too heavy they have more drag in the air and therefore decelerate faster than smaller calibers with more slender bullet. For example a 115gr bullet in .25 caliber is going to be a lot more slender and aerodynamic than a 115gr bullet in .308 and even a 125gr in .308 of course assuming both have similar characteristics and do not have a flat nose or anything like that. The force of gravity and acceleration toward the ground is always the same but as the bullet slows down it is exposed for longer time to gravity and that is what makes less 'aerodynamic' bullets fall faster. So this is a big thing when I refer to ballistics efficiency and I say good bullets I mean in my own words 'efficient bullets' that cut well through the air. A .224 bullet in 75 to 80 grains can be a very efficient bullet. I will explain more tomorrow.

Think of it this way: you can start very fast and end very slow with a short bullet but in contrast with a long slender bullet you can start slower but end up way faster. Any trajectory of any bullet can be represented quite accurately on paper.
 

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Discussion Starter · #6 · (Edited)
Just to give you an idea of how some of the popular calibers behave I created a comparative chart from my own data and math using a .223 national match barrel, a long range match barrel and then just regular barrels from the larger AR15 calibers. I set brake speed at 1,300fps at which point I disregard any data for supersonic purposes. That is why you see those spikes and drops as I force excel to drop the values. I should take the ugly lines from the charts but I am still learning the new MSoffice 2010. They changed everything including all the buttons these Microsoft goons!

Velocity Data


Velocity Chart


Drop Data


Drop Chart


Energy Data


Energy Chart

 

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Very impressive! Being able to see the different calibers in graphs makes a big difference for me, seeing the pro/cons. It's like having one of my cars on a dyno. This made me narrow my choices real easy, between the .223 & 6.8. Now I can set my goal closer to the 800yd range. When I get out of work I'll be able to study this more, read it on my pc and not me phone. I should have my pick later tonight.
 

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Discussion Starter · #8 · (Edited)
Very impressive! Being able to see the different calibers in graphs makes a big difference for me, seeing the pro/cons. It's like having one of my cars on a dyno. This made me narrow my choices real easy, between the .223 & 6.8. Now I can set my goal closer to the 800yd range. When I get out of work I'll be able to study this more, read it on my pc and not me phone. I should have my pick later tonight.
I think the learning from this is... do you need energy early (short to moderate range) which is great for hunting, defense and most purposes from more manageable size barrels or you don't mind a long barrel that can shoot a .223 with plenty of energy for lots of things and can sustain long range pretty decently at least to get started learning about this.
I would also seriously consider professional long range training. You will learn more in one weekend one on one with a good instructor that all the DVDs, books and youtubes you can see in a lifetime.
I know some folks that have classes down south in NM and AZ that are very good at this.
I still think the .223 rem with a nice match barrel is a no brainier for your purpose but if you want I can pull out the data for the 6x45.
 

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Discussion Starter · #9 ·
These are a couple of makers that I use with great results. These are very good long range barrels. I think by ordering from krieger could be just a bit better price but might have to wait...

Krieger Barrel AR-15 223 Remington .920 Muzzle Diameter 1 7.7 Twist 26 SS

Lothar walter

Lothar Walther

.223Wylde (#6200)
.920
24.0
6
.219
.224
7"
426.00


.223Rem. (#6200)
.920
24.0
6
.219
.224
7"
426.00


These are not "cheap" barrels but necessary for the purpose.
 

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Just for the sake of argument, wouldn't it be more benifical to gravitate toward quality optics as opposed to magic bullet and powder combination #3378a?

Its already know that a 14.5" standard M4 bbl is capable of 600m using standard ball, so going a *smidge longer length and perhaps a slightly **different rate of twist would pretty much ***assure you're going to get even further out there and have some semblance of reliable accuracy.

The hard part as I see it is literally that: being able to see it

* say 16"~18"
** only perhaps as its more relevant to stabilizing X weight bullet, not 'range' as even at a tumbling round can go well beyond the desired range of fire. if the ROT is correct for the round to begin with, then no change in ROT is going to make it better yet IOW.
*** due to longer pressure wave shoving bullet. short spitwad straw vs long spitwad straw basically.

Not knocking what you're trying to do as the info you've provided is unquestionably invaluable, just well aware that if it can't seen clearly it can't be accurately engaged.
'Middle upper right of miniscule blob A' isn't really an aiming point dontchaknow
:)
 

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Discussion Starter · #11 ·
Quality glass always, of course but those are two different things. There is not point of building something worth 1/2 MOA without an optic to match that at long range. The longer barrel is needed to burn out every single grain and therefore enjoy the flat trajectory of the .224 best bullets. A short barrel doesn't have the case to bore volume needed to make long range or w/o going straight to the ground.
Good point though.
 

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I was up till 4am looking at those barrels and the one you listed was the one that caught my eye, the Krieger. Pretty proud I was looking in the right direction, lol.
 

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Discussion Starter · #13 ·
I was up till 4am looking at those barrels and the one you listed was the one that caught my eye, the Krieger. Pretty proud I was looking in the right direction, lol.
I would prefer a 24" barrel as we have more versatility with the loads but the 26" inches can maximize the full potential of the platform. I feel the wylde chamber is a good compromise but I would not discard a match chamber.
 

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Discussion Starter · #14 · (Edited)
Some billets I like and I have been using.
The brand (shell) is not important. The key is that they are up to spec and they are solid and tight.
Also check allstar selection. I have no experience with those yet but people seem very happy with the stuff they have and they are local. Also look for good deals. Again, branding is not important.

Whatever barrel these are some nice cutting jobs...

Seekings




Mega - I like the side charging options from Mega, LAR and others...







SI-Defense nicely flared magwell also good but hard to find and now overpriced at Midway since Nemo took over.


Fulton Armory side charging uppers are also very well cut...


POF nice billets too...


This is a good hand-guard (extended rifle) w/o spending too much.



Slotted Customizable Free Float Tube Handguard AR-15 Aluminum Black
 

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The longer barrel is needed to burn out every single grain and therefore enjoy the flat trajectory of the .224 best bullets.
Please to forgive as I've not any practical experience nor even research into the physics of it, but wouldn't max power/thrust be acheived at the *'halfway' point of the burn with everything after that offering naught but diminishing return and perhaps even projectile deceleration due to friction losses in the remaining X of the barrel?

Now I understand that one would in reality want to go a smidge beyond the max point to allow for it to actually have effect due to expansion lag and whatnot, but to go to the last grain before muzzle expulsion seems a little off to me.
But as I said, I'm not actually versed in the methodology, and am going by some minor familiarity with a random smattering of other not neccisarily related or even commonly relevant physics type infobits floating through my head.

* or as the case may be, the point of max consumption if you want to use that halfway into the woods vs all they way in method of thought
Anything after 'all the way in' is progressively a larger loss of pressure/thrust due to less and less fuel being consumed along side ever increasing volume of the container/barrel between casing and projectile + mechanical drag on top of that.

If I'm dragging this to far OT, please speak up (anyone) and I'll contain myself until some future point when its more suitable.
 

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Discussion Starter · #16 · (Edited)
Hi,
How fast a load burns goes in function of the burn rate of the rifle powder that is used. This is advertised by the manufacturers. The primer ignition is also part of that process. The effect that you describe it can actually happen so that is why careful selection of the right loads must be taken into account. Service loads that are designed for carbines and national match size systems should not be used in long range long barrels if one is to maximize the potential and performance of that load. The same way a load that might be designed for a long barrel is not the best choice for a short barrel. A propellant that is not totally consumed (burned) when the bullet gets to the muzzle then it is all wasted. Internal ballistics is very complex so w/o getting too technical the energy released is a function of the amount of powder used, the case capacity with the specific bullet seated and other factors that interfere with the starting pressure and how the combustion performs. The shape of the propellant has also to do with the way and speed the combustion takes place. Once the bullet has achieved the point after jumping into the lands where the base has passed the neck base (in long bullets takes a tad longer) the volume is consider an incremental value during the whole combustion process. Using a faster powder the peak combustion occurs faster and in contrast with the slower powder takes place later. When using heavy bullets like those needed for long range that is a good thing because the initial pressure spike created by the mass of the bullet and the extra force needed to swag that bullet and make that bullet spin (angular momentum) could create dangerous pressures very soon in the combustion. Since this is all very complex to calculate and determine one must find reliable load data and try the loads carefully starting with a low load and then increase gradually.
Low grain bullets can also used in long barrels for specific purposes such varmint shooting. these might use a tad faster powders than long range and also slower rates of twist in the barrel. A twist that is too aggressive is not needed and could also disintegrate the thin jackets of some varmint bullets.
Many competition shooters that shoot shorter distances like 200 or 300 yards do not go for the most powerful loads but instead for milder light loads that yield the best accuracy called accuracy loads.
Only .223rem long range will use the longer 75, 77smk and 80gr bullets. Hornady, Sierra and Berger all have great products.
I found this article long ago and I think it provides a lot of good info to those interested in getting started in the .223 rem, bullets, powders, primers and barrel lengths including the improved AI version. The .223 rem is a great caliber sometimes underestimated and subjective to the COAL limits of the AR 15 portfolio but there are solutions to those issues like custom single stack magazines designed for long range loads. (also known VLD mags). I am building a new version that will give me 1.36-1.37 COAL feeding semiauto flawlessly.

223 Rem + 223 AI Cartridge Guide

This is a good site with some great info about BR shooting, palma and several other shooting offerings.

hope this makes sense.
Cheers,
E.
 

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Discussion Starter · #19 ·
Here is an example of the original VLD mag... (223 AI pictured)





Do not seem like much but it makes a huge difference for long range purposes...





Here with the 6x45 to compare... (sorry about the crappy phone pics below)

From left to right...
6x45 for hunting/mid range shooting, standard .223rem round, 6x45 Hornady 87gr Vmax and 6x45 sierra 100gr SGK both for long range.



Here the first version of the VLD mag using a different follower type loaded wiht the vmax at 2.34 COAL.


Please remember that the max COAL is not just determined by the magazine but the bullet shape and the chamber itself and how much freebore is in there.
 

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Discussion Starter · #20 · (Edited)
Here I am giving more charts of the 6x45 behaviour next to the .223rem and also a short range blackout for reference.
Both the 6x45 and 223rem parent are very forgiving to reload. the 6x45 is hard to beat in terms of return on investment but we can see how nicely the .223rem parent peforms.
Keep in mind that the 6mm gives also a nice option for those who want to take white tail, pigs or black bear where .223 is no allowed delivering a serious punch past 300 yards. Also a great round to pop coyote out to 600yards if the opportunity is given and one feels capable of doing it.

Speed data and chart





Drop data and chart





Energy data and chart



 
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