getting an AR which caliber?

[roberts1]

I have decided to purchase an ar but I need a little input from some experienced owners/reloaders. My intentions for the gun are plinking/range use and possibly some hunting. I would like to cast & reload for it as well. I don't have any rifle reloading experience but have loaded/cast for my handguns for a couple years now. I have two calibers in mind 5.56 and 300blackout. I was just wondering if one was easier to cast/load for over the other as far as getting decently accurate leading free results and if there is a barrel twist or length that is preferred so that I start out with something that will give me the least grief as I get it set up. Thanks in advance for your input and suggestions.

[dh2]

I do not know any one that has had much luck running cast bullets in an AR-15 in 5.56 but components are readily available.
the .300 AAC Blackout is very common to run cast bullets in from 200 gr. and up.
you could always start with one and buy the upper receiver for the other down the road. every thing else is the same except for the barrel

[dilly]

300 blackout is heavy bullet at low velocity. 556 is a light bullet at high velocity. The former is by most accounts easier to do with cast bullets than the latter.

[xacex]

Cast: 300 Blackout...most fun with a cast boolit. I use 125 cast boolits, all the way up to 245 grain with them. Fun times!

Jacketed: 6.5 Grendel...If guns were lasers this is close as you will get in the AR platform. Boringly accurate and a capable round for distance.

[7br]

I have a 6.8 spc. I ordered my mold from Mountain Molds and it shoots them very well. brass is very hard to come by right now.

[roberts1]

thanks for the replies. I thought maybe the 300 would be a bit easier to cast for but its nice to hear from those who have done so. I thought about a second upper too but wanted to keep the cost below my wifes freak out range lol. Whats really driving this adventure is the low availability of handgun powders in my area. My solution is to get a rifle to work with until it comes back. I was in Grafs this weekend and they had no handgun or even suitable shotgun powders at all.

[xacex]

Staying under the "wife radar" can be harder than casting zinc .22's. I got the eyebrow this month when a big truck dropped off a crate in front of the house with a mill in it. "Oh thats right, I ordered that for half off like last year or something...just forgot about it". Doesn't quite pass the wife test when she asks "what's half off." I am a true believer of omission is not a lie, but when the question is direct you can be in some hot water.
How I have swung the AR's with her is buying them in pieces, and putting it together. I spread it out so she doesn't notice. Oh, and building her one to take to the range helps too.

[roberts1]

lol yeah I tried "don't count my guns and I wont count your shoes"... not recommended

[roberts1]

If you want to shoot your own cast, 300BO is the answer. I'm running 160-175gr cast at full throttle from my 16" barrel. IMO, the 1-8" twist will be easier to work with (cast supersonic) than the 1-7". If I were going to order a barrel specifically for cast, it would be in the 1-10" to 1-12" twist range. The quick twists are for stabilizing loooong, heavy projectiles both sub and supersonic.

Barrel length? 16" is gonna be the most common length unless you're gonna pay the $200 tax for a SBR, or go without a buttstock on a "pistol". IMO, for shooting supersonic, 16" barrel with carbine length gas system will be the simplest. If you're gonna want to shoot subsonic and retain full function, you'll probably want pistol length gas, adjustable gas block, and may still have to mess with springs and buffers.

I have seen results on deer with heavy, cast, subsonic, and they will get it done. Realize that subsonic is less than 1100fps, so will limit range. 160-175gr cast can run up to about 1900fps. If you want to go faster(for hunting) 110gr Barnes will get you 2500fps and textbook expansion.

Grumpa (here on this forum) makes 300BO brass to perfection, so that isn't a problem. You'll want thick cup small rifle primers like RP 7-1/2, CC450, F205, or the military equivalents. Powders for supersonic will be from 2400 of the fast side to 4198 or Reloader 7 on the slow side. Most seem to be shooting Lil Gun, H110, WW296, and 1680. AA2200 and AA5744 will work just fine.
Thanks for the info. I ran across one but the barrel is 1-7. is anyone having good results with this twist rate or will I just be making things more difficult than they need to be?

[Smoke4320]

300 Blackout all the way.. So much easier to cast for and shoot accurately from slow to fast subsonic to super .. targets to deer ..
one word of advice.. if you have any thinking of shooting subsonic get a pistol length gas system and a 1:7 Twist .. It will just make life simpler when developing subs at cycle 100% of the time

[pull the trigger]

I would suspect you will need to powder coat the boolits so thegas system does not get gummed up with lube and lead.

[ph4570]

I have good success with .225+ cast boolits in my ARs. Good accuracy, no leading and no lube fouling of the gas system. Mold is 62 gr Mihec NATO. Powder is H4895. Group is 1-1.5" at 100 yds out of AR carbine.

[seagiant]

I have good success with .225+ cast boolits in my ARs. Good accuracy, no leading and no lube fouling of the gas system. Mold is 62 gr Mihec NATO. Powder is H4895. Group is 1-1.5" at 100 yds out of AR carbine.

Hi,
+1 out of my DD "middy" barrel!

[roberts1]

anyone shooting one with the 1-7 twist rate? my presumption is you couldn't push them as fast a with a slower twist rate.

[OBIII]

1-7 twist is a "fast rate". They require (for optimal performance) a heavier bullet for accuracy. Also, if you have anything that uses .308 go with the .300 BO. Or, if you have rifles in a different caliber, try to go with one of those. I find it easier to maintain similar types of calibers, rather than adding something new. (for .308 you would have to move up to an AR-10 platform).

OB

[2wheelDuke]

I've been quite happy with cast in the .300blk. I haven't had any issues with leading with water dropped lead and Tac 1 lube from Randy Rat. I haven't messed with any of the newfangled coatings just yet for the .300.

[Green Monster]

556 has better accuracy than the 300 but not much. The 300 is easier to cast for but harder to find components for. The 556 is everywhere so its easy to find tacticool or super accurate thingymabobs to strap on to it. The 300 is going to be better for hunting as it is a larger 308 round then the 22 cal. Id say start with the 556 and save up for the 300aac upper. Then when you want to just two pins and a mag full of the rounds and your off. Or you could jus build your own in each and sell the one you dont like to pay for the one you do. But youll end up keeping both.

[Moonie]

556 has better accuracy than the 300 but not much. The 300 is easier to cast for but harder to find components for. The 556 is everywhere so its easy to find tacticool or super accurate thingymabobs to strap on to it. The 300 is going to be better for hunting as it is a larger 308 round then the 22 cal. Id say start with the 556 and save up for the 300aac upper. Then when you want to just two pins and a mag full of the rounds and your off. Or you could jus build your own in each and sell the one you dont like to pay for the one you do. But youll end up keeping both.

The accuracy thing is debatable but why do you say the 300 is harder to find components for? Same bolt, same magazines, same basic case (300 is made from .223/5.56) and there are far more 308 caliber molds than .225 molds.

[Green Monster]

Some people dont want to form their own brass and either buy it off the shelf or pick it up. In my area its hard finding 300aac loaded or 1xfired but 223 is everywhere. Thats what i was trying to get at. I do agree with the larger ammount of casting options in the 300aac.

[roberts1]

so is the 1 in 7 barrel a worthwhile option or should I keep looking?

[roberts1]

Thanks sgt.mike looks like if I go with the 1-7 300bo ill be using longer heavier boolits but it seems doable from what I have read. Again im wanting a range/possible deer hunting gun that I can get reasonable accuracy from. We get arctic temps here in Mo. but I tend to stay indoors and the same when triple digits hit. Im leaning towards the 300 so I can cast for it. Now to follow the thread in the mould section to see what people are having luck with...