View Full Version : 5.45-5.56-6.8
Bib3773
10-13-2009, 07:08 PM
When I bought my AR I bought the 5.45. I wanted the 5.56, and could have bought one for the same money, and one I didn't like that much for a little less money, however my thought process was that I wanted to be able to shoot the hell out of it and AMMO, decent Ammo was almost half the cost.
Anyway my goal was and still is to get a 223 upper, actually thinking about getting two, one slick and long, and another shorter for play. Anyway to drag this down closer to the point, all I have to do to shoot a 5.56 through my AR according to the guy at the gun store I purchased it at was change the upper and everything else will work. So question one would be---IS that TRUE?
No for the actual reason I made this thread, I would like to eventually have a 6.8. I have been told that all I need is another upper, and to change out the bolt. With the 5.45 and the 5.56 there isn't that much difference, and if I was downsizing I could see the lower still working as well, but I looked at a clip for the 6.8 and it could be my imagination but it looked larger than what a regular 223 clip is. So question number 2 is
Do I have to basically get well basically a new gun to shoot the 6.8 I do know a guy who bought th e 6.8 and he can size down to whatever but sizing up seems very questionable.
Third question- Chris was telling me about this and I wanted to ask, can I knock the front site off My AR without it affecting the gun. I will try to take a picture if I can get to the store tonite or tomorrow and get some new batteries for my camera.
I guess 3 is enough for now, I have about 20,000 more but I guess I can spread them out over time.
JaxChris
10-13-2009, 07:48 PM
The only parts that need to be changed between those three calibers is:
1 - Bolt
2 - Barrel
3 - Magazine
The remaining parts are universal for those calibers (gotta love the AR platform). But swapping barrels on the same upper receiver takes a lot of work and would require to zero the weapon again after each change.
The best thing to do is get a complete upper for each caliber. When I say complete I also mean sights, because moving sights from one caliber to another would require zero'ing again also (different calibers behave uniquely at all different ranges).
For the FSB (front sight base/tower) on your barrel, yes you can remove it - but if you don't have all the proper tools I would let a gunsmith do it for you. It is likely pinned, possibly welded, and either way could be on so tight you'll scare yourself into thinking you're breaking your barrel.
They have vise blocks for any and all gunsmithing you would want to do - but building uppers is more challenging if you want it to be factory accurate and still be in-spec when you're finished. Lowers are much easier and almost anyone can do with it some improvised tools laying around the house.
You cannot shoot a vastly different caliber out of your existing barrel. In fact, the 5.45x39's chamber won't allow any other caliber through it.
Of the three you mentioned:
5.45x39 is the thinnest and shortest; it would rattle around inside a 5.56x45 or 6.8x43 chamber.
5.56x45 is the longest of the group; too long to fit inside a 6.8 chamber, and too wide to fit inside a 5.45 chamber.
6.8x43 is the widest of the group; too wide for either caliber, and too long for the 5.45 chamber.
These differences are what would hopefully prevent someone from accidentally using the wrong ammo in a particular weapon.
If you want help finding or building some decent 5.56 and 6.8 uppers, let us know. =)
Satan_3pc
10-13-2009, 09:41 PM
:ss1: :The grammar police will be here shortly. Until then, please remain calm and enjoy this prepaid programing....
:secpro:
:nub:
Bib3773
10-13-2009, 10:14 PM
Thanx Jax, any useful input is appreciated
JaxChris
10-13-2009, 10:23 PM
It's no problem. =)
he said clip :bolt:
You see, teach a man to fish and it appears my work is done. Slowly but surely every gun enthusiast on this board will know the difference between a clip and a magazine. :raspberry:
I've personally found the theory of multiple caliber uppers for one lower to be flawed due to the irresistable urge to "grow" your lower collection to match your upper collection.
Chris
10-14-2009, 07:45 AM
to offer some insight on query 3
if your rifle is not gas piston driven when we remove the front sight we will have to get a gas block.
Maybe if someone is nice they will throw up a visual aid for me, im off to bed shortly
to give some insight to everyone, Bib wants to free float his AR, though I havent seen the gun Im betting were gonna need to get a lo-pro gas block unless he's got a piston
Yankee Hill Low Profile gas block....
http://yankeehillmachine.com/store/media/9383-9384.jpg
rob_s
10-14-2009, 08:23 AM
I also find that uppers tend to grow lowers, but it's nice that you can start out with a new upper on an existing lower and be ready to rock.
Also, if you're going to shoot the corrosive surplus 5.45 you're probably going to want a dedicated lower in case you're not as thorough with the cleaning as you thought you were and you get failures in your primary.
anthony20031
10-14-2009, 09:37 AM
well he doesn't necessarily need a low profile gas block would he? He could get like a 7" Troy free float which is what I have on mine. I happen to have the Yankee Hill front flip up sight that works as a gas block as well, but you could keep the stock front sight on there if you went with a 7" rail. Right?
JaxChris
10-14-2009, 10:00 AM
Yankee Hill Low Profile gas block....
http://yankeehillmachine.com/store/media/9383-9384.jpg
These are the only gas blocks you should ever use. They are the same part everyone else puts their logo on and if you look around you can get them for about 20$.
The one of the right is the standard one to get, unless you are pinning your flash hider (i.e. 14.5" barrel + pinned phantom = legal 16") then you want the one on the left so you can still remove it without having to unpin your flash hider.
There's a few options with the FSB. As Chris said, you can change it out for a low profile gas block that allows a longer than gas tube length free floating rail forend to be installed or you can install a proper sized rail forend and keep the FSB or swap it out with a flip up FSB like the Yankee Hill as Anthony mentioned above. I believe rob_s mentioned this in the past and I completely agree, your 3rd option is to cut down your FSB leaving just the gas port/gas tube resulting in a low profile block that is stronger due to the tapered pins than any aftermarket low profile gas block that is not pinned in place (most are not). A cut off wheel on a dremel with some grinding stones and some cold bluing will get it looking really nice. You can also slice off the bayo lug as well.
rob_s
10-14-2009, 11:12 AM
These are the only gas blocks you should ever use. They are the same part everyone else puts their logo on and if you look around you can get them for about 20$.
It depends on what you mean by "everyone". For example, the Vltor (http://vltor.com/lpgb.htm) is not simply a re-stamped YHM. The YHM is open on both ends, meaning the longitudinal hole is drilled all the way through. This isn't a big deal since the gas tube is plugged on that end, but not drilling it all the way through does add cost and seeing the hole go all the way can confuse some people.
I am NOT saying that the Vltor is necessarily worth 3x the price in terms of function, but I do think they probably have 3x the manufacturing costs.
http://vltor.com/images/lpgb/all_blockssmall.jpg
The one of the right is the standard one to get, unless you are pinning your flash hider (i.e. 14.5" barrel + pinned phantom = legal 16") then you want the one on the left so you can still remove it without having to unpin your flash hider.
I'm not tracking here. The one on the left is simply split down one side meaning it is held on in a clamping design instead of the set-screws pressing against the barrel in the example on the right. How does that make the one on the left capable of being removed with a flash hider still in place?
I think maybe you're thinking of their two-piece gas blocks as seen here (http://yhm.net/store/gas_blocks.html) like the YHM-9836A, YHM-9377A, YHM-9378, and YHM-9390A?
rob_s
10-14-2009, 11:13 AM
I believe rob_s mentioned this in the past and I completely agree, your 3rd option is to cut down your FSB leaving just the gas port/gas tube resulting in a low profile block that is stronger due to the tapered pins than any aftermarket low profile gas block that is not pinned in place (most are not). A cut off wheel on a dremel with some grinding stones and some cold bluing will get it looking really nice. You can also slice off the bayo lug as well.
If you're going to cover it up with a rail anyway, high temperature grill paint works great to refinish it when you're done, and you can get it at Home Depot or Walmart.
Bib3773
10-14-2009, 10:55 PM
So your saying to embrace the projects and build at least 3 different guns out of at least 4 uppers. I like that idea, my wife won't...lol but i do... It will take me forever but what the hay.
What are you guys thoughts on the 6.8 Other than cost per round compared to some of the others it gets very solid reveiws from everything I have seen. I knows its not like buying rounds for a 50 but still.
Geez I need to sit down and compose a wishlist and then figure out what order I want to try and do all the things i would like to do in.
My next AR project will be a 6.8 SPC if that means anything.....
Bib3773
10-14-2009, 11:31 PM
The 6.8 will probably be way towards the bottom of my list, but I am hoping I can learn some modyfying the one I have so that I can do more with the next one, and from there be able to do even more. I am hoping that by time I get to the 6.8 I can peice it myself, maybe save a little money, and have a helluva gun in the end.
rob_s
10-15-2009, 06:37 AM
What are you guys thoughts on the 6.8 Other than cost per round compared to some of the others it gets very solid reveiws from everything I have seen. I knows its not like buying rounds for a 50 but still.
I have a 6.8 upper on the way from Noveske. I bought it for:
1) Precision use. Long-range matches, maybe a class, etc. High quality accurate 5.56 actually costs about the same as the same quality in 6.8 ammo, so it made sense to use a caliber that could provide me with the same effective range in a shorter barrel. Yes, it means I can't use my cheap 5.56 blasting ammo "in a pinch", but that's something I'm willing to deal with.
2) Hunting hogs. Hogs are not a game animal here and so I can use a suppressor. Hopefully this will help preserve my own hearing, that of my shooting buddies, and scare away less pigs from the area.
3) Hunting deer. I've never done it, but I want to, and FL doesn't have a prohibition against using an SBR on game animals, you just can't use a suppressor. So I'll be able to have a nice compact package in the field with a legal hunting caliber (we can't use .223 here either).
So for me, the 6.8 will do the three above things. Optic selection that will work well for all three is going to be a challenge but at least I know the upper and caliber are capable.
JaxChris
10-15-2009, 09:16 AM
Wait, we can't hunt with .223 but we can use rimfire, 6.8 and .308? Why am I feeling confused?
rimfire for small game only
anthony20031
10-15-2009, 11:12 AM
Ummm I was pretty sure that we were allowed to use .223 here to hunt with. From what I read from the Florida wildlife they didn't say anything about not being able to use .223. Only states that for deer etc you have to use a centerfire not a rimfire I believe.
rob_s
10-15-2009, 11:58 AM
Ummm I was pretty sure that we were allowed to use .223 here to hunt with. From what I read from the Florida wildlife they didn't say anything about not being able to use .223. Only states that for deer etc you have to use a centerfire not a rimfire I believe.
I don't see it in their online guide either, but I'm almost positive I saw it in the statutes at one point. I'll keep looking.
In either case, I'd prefer the larger caliber of the 6.8 regardless of the law. I've taken hogs with 5.56 and would prefer the 6.8 on them as well.
I just emailed my hunter buddy who is on a hunt right now in the Carolinas.. (lucky bastard)
my question was can we hunt with .223 in FL ?
his answer was ... Yes.
anthony20031
10-15-2009, 02:23 PM
alright let's go hunt some boars lol...I agree that if you have a 6.8 it would be better...unfortunately I don't have one:( Hopefully sometime soon in the future. Next purchase I would like to pick up a Remington 700 VTR
langoley
02-01-2010, 06:47 AM
Another noob here,I guess just have to be different.I am in the process of ordering the makings of my second AR,My first one is a 5,56 and this one will be in 6.5 instead of 6.8.I like the ballsitics better,and the ammo is cheaper.
JaxChris
02-01-2010, 08:06 AM
Sadly, for all intents and purposes, the 6.8 is a dead round since the military didn't pick it up and decided to go with heavier grain 5.56 rounds in order to compensation for the short comings of 55gr and 62gr ammunition.
The 6.5 Grendel is still a pricey round though.