Big Bore AR-15s

[pmer]

I've been thinking about Big bore AR-15s and thought I would see if anybody would like to talk about theirs and see what they like and don't like about these rifles. They look like they would be fun for plinking and easy to carry for hunting.

[CastingFool]

Don't have one, but a friend just put one together chambered for the 450 Bushmaster. It's legal for deer hunting in southern Michigan, and he took a doe at 177 yds with his.

[adcoch1]

Once I get my SBR lower together (hopefully next week!) I plan to build a 10"-12" 458 socom. What's not to love about 45-70 performance out of an ar15?

[corbinace]

I have been thinking of the 458 socom as well. Have not convinced myself to loose the purse strings yet. That, and the liberals in my capitol have no less than five anti bills in play at the moment, most aimed at black guns.

[Moleman-]

Been deer hunting with them since MI changed the rules in 2014. First with a 357AR (357Maximum-Rimless at 60Kpsi) then a 44x1.6" (like a long 44amp or 445SM off of 308 or 30-06 brass). I've gathered parts (including the fancy bolt and extension) for a 44x1.8" upper that will launch a 265gr fn bullet to 2300fps out of a 16" barrel which is faster that my 24" 444 Marlin and legal for me to use. I used it in an AR10 the past two years but find the ar15 357AR or 44x1.6" easier to carry and handle in a treestand. You can sight them in with a 130ish yard zero so that they're fairly flat out to 150yds, but after that they drop fast, about 6" at 200 yds and 13"-14" at 250yds or more depending on speed and zero distance.

[adcoch1]

I hear you on the anti gunners here in Washington, looking to move ASAP...

[adcoch1]

Moleman, what bolt do you use for the 44 x1.6? And what extension? I may go that route instead of the socom if the parts are reasonably available. I love 44 stuff...

[pmer]

I didn't know about the 44 caliber stuff either. What sites do you go to for that?

Must be taper crimping some these cartridges, taper crimping must enough to hold bullets in place?

[DougGuy]

I would think getting close as you could get to 308 performance in the ar15 platform would be pretty sufficient for hunting and whatever else out to 200yds so I was looking at the 30ARX or something similar. Not sure I would go with bigger than 40 caliber because of the boolit drop at 200yds or more.

[rockrat]

All the big bores I have, shoot well. the 450b was the easiest to find an accurate load for, but the 458 and the 500 were pretty easy too. I really need a heavier barrel for my 450b as that big hole in the middle makes for a lightish barrel.

[Fastleo]

I would like to build a 50 Beowulf or 12.7x42

[Moleman-]

Moleman, what bolt do you use for the 44 x1.6? And what extension? I may go that route instead of the socom if the parts are reasonably available. I love 44 stuff...

The 44x1.6" uses a 450BM bolt and a standard big bore extension. I'm heavy into 44 stuff and stubborn or else I'd just get a 450BM. Either cartridge uses a max of around 40K psi which still get you around 2050 fps with a 240gr xtp in the 44x1.6 or around 2250 in the 450BM with it's larger capacity for max loads. If you can find a 800 series (the rounded lug bolt and extension that don't interchange with a standard one) you can load up to 65K psi. That's what I'm using on my 44x1.8" that's going into an ar15. I use a 444 marlin die set to reload both the 44x1.6" and the 44x1.8" along with a lyman taper crimp die. Using good neck tension you can set the bullets out further to increase your usable case capacity which in turn increases the velocity for a given pressure. Another one to look at is the 45 velociraptor. It's basically a 45 raptor minus a little pressure and col. You need the rounded lug bolt setup for it also. Here's what they look like next to a standard extension and 450BM bolt. Tromix has the big bore extensions (450BM/458)for around $30 https://tromix.com/shop?olsPage=prod...tension&page=4

Here's a good page for the 45v-rap and my 44x1.6", might even have the 44x1.8" there somewhere. Haven't started making chips on the new ar15 one yet so no posts on it other than in my mauser and ar10.

http://mdws.forumchitchat.com/?forum=557720

ar10-with the right extension/bolt will work if it fits in a mag. http://mdws.forumchitchat.com/?forum=557723

[mtnman31]

I've got a 458 SOCOM. Absolutely love it. Brass is available, not cheap, but, not as expensive as other cartridges. Uses standard, unmodified magazines and there's a wide selection of bullet designs to choose from.

[pmer]

Thanks everybody for the information. There are a lot of cartridge names that I haven't seen before, I could not find the Velociraptor I did find the 30 ARX. Has anyone ever tried to neck down the 458 or the 50 Cal to 44 cal? And are you guys having any trouble shooting cast or powder coated boolits with these?

[Moleman-]

45v-rap http://mdws.forumchitchat.com/?forum=557720 I tried necking down a 450BM to 44, but didn't think it would meet MI DNR "straight wall" rule. If you're not limited to straight walled cartridges you have more options.

[Electric88]

I've got the 50 Beowulf. As previously mentioned, whitetail hunting in lower Michigan you can only have straight walled cartridges. Since this shares the same diameter bullet as the S&W 500, I figured it was the best choice for me. Everyone that shoots grins ear to ear afterwards.

[DCM]

Love my 458 SOCOM. Uses unmodified 5.56 mags, shoots 140g ARX to 500g castboolits. 500s I tried were hi-tek coated and left no fouling.
I found a good deal on a Satern/Liberty stainless barrel that shoots Very well when I decided to build this upper and it came with the appropriate sized and head-spaced bolt.
2 Friends have 50 Beowulf and 1 has a 450 bushmaster, we all are very pleased with our compact MSRs for hunting.
I put a Limbsaver recoil pad on my M4 type stock to make it more pleasant but all of these are manageable without it IMO, just more pleasant for extended range sessions with it. Some have muzzle brakes on theirs I do not, as I don't care for the extra noise.

[Moleman-]

I also shoot lead through mine, mostly gas checked. Most cast I've ever shot at a time was around 500. The gun was dirtier than normal but that was about it.

[Ramjet-SS]

458 SOCOM built mine up and it is hammer and very accurate I shoot everything from 300 grain J-words to 460 grain cast from it and it hits like hammer. Everyone who shoots it just smiles and asks if they can shoot some more......

[pmer]

I've shot some cast out a 223 AR15 but not that much though.

I've noticed the 450BM usually has a 1-24 twist barrel, are there any with 1-16 twist barrels for the heavier .452 projectiles?