What Caliber for the AR-15 ?

[wv109323]

I have a lower receiver for an AR-15 that I would like to build. I have two other ar-15s. One is in the heavy barrel A2 configuration and the other is a scoped flat top receiver with a 24 barrel. Both are in .223 Rem or 5.56 Nato. If you were going to build another rifle what caliber would you build ?
I would like to get as much energy as possible out of the ar-15 platform. I was looking at one of the WSSM and the 6.5 Grendel. I reload and for this application I would probably stay with j-bullets. your opinions

[RU shooter]

Dont know about the energy levels but ,I would go with the 300 blackout or whatever they call it,same as the 300 whisper but looser chamber in the neck If I understand it right. lots of bullet selection uses regular mags and brass to make it is laying around on the ground everywhere and I'm a 30 cal guy!

[johnly]

My 7.62x39mm AR-15 is a spectacular cast boolet shooter and the brass and ammo is cheap and easy to find.

John

[Otony]

6x45, nothing to mess with except for the barrel. Everything else interchanges insofar as parts are concerned, no modified or special magazines. Heck, you can even use .223 brass.

I read a Shot Show report that detailed info about a new (well, recycled) roundthat the sharps company is starting to use in their ARs. Before anyone jumps up about the Sharps name, it is apparently used by a company that makes AR uppers and lowers, no connection with Shiloh or C. Sharps.

Anyway, they have a .25x45, which appears to be an improved .223 necked up to .25 caliber. If I recall correctly, Kimber had somethig like that called the .257 Kimber back in the Clackamas days. Just a thought.....

[82nd airborne]

.257 Kimber is great, one of my favorites. If you want cheap firepower that minimizes non standard parts, just go with .300 BLK, or neck .223 up to any caliber you want.

Stay away from Olympic arms WSSM uppers with factory ammo.

There is also the 6.8spc II, that is good, the many varieties that can be done with the 7.62x29 as the parent case.
.338 spectre off of the 10mm mag, 30rem. or 6.8.

Then there are the plethora of big bores.

[johnly]

6x45, nothing to mess with except for the barrel. Everything else interchanges insofar as parts are concerned, no modified or special magazines. Heck, you can even use .223 brass.

I read a Shot Show report that detailed info about a new (well, recycled) roundthat the sharps company is starting to use in their ARs. Before anyone jumps up about the Sharps name, it is apparently used by a company that makes AR uppers and lowers, no connection with Shiloh or C. Sharps.

Anyway, they have a .25x45, which appears to be an improved .223 necked up to .25 caliber. If I recall correctly, Kimber had somethig like that called the .257 Kimber back in the Clackamas days. Just a thought.....

I'd be in for a 6x45 if the barrels became easily available again. Loosing 6 PPC brass out of my Olympic Arms upper gets spendy pretty quickly.

John

[82nd airborne]

I can make them in fairly good time. I shoot 6x45 and 7x45 alot. I think they should both be more popular than they are.

[huntinmo]

Since you mentioned that you are looking for energy, I can say that I really like shooting my 458 Socom. Not the cheapest ammo, but it does handle boolits just fine as long as they have a GC. :castmine:

[Ickisrulz]

I have a lower receiver for an AR-15 that I would like to build. I have two other ar-15s. One is in the heavy barrel A2 configuration and the other is a scoped flat top receiver with a 24 barrel. Both are in .223 Rem or 5.56 Nato. If you were going to build another rifle what caliber would you build ?
I would like to get as much energy as possible out of the ar-15 platform. I was looking at one of the WSSM and the 6.5 Grendel. I reload and for this application I would probably stay with j-bullets. your opinions

"...as much energy as possible out of the ar-15 platform" would come from the big bores. .50 Beowulf and .458 SOCOM.

[BD]

I went with the .450 Bushmaster for practical reasons. Much cheaper to keep fed. It uses standard mags. It has better boolit selection, better brass availability and life, and it's a production round now with factory ammo and brass from both Hornady and Remington. BDC retical scopes that match the factory ballistics are available from both Nikon and Leupold. You can buy a 16" upper for under $550.

IMHO it's the .45acp of the black rifle world.

BD

[45r]

Since you already have stuff for the 6.5 grendel I'd get one of those,it would be quite accurate way out there.It's not so much how hard you hit sometimes but how well you place your shot.My next AR is going to be a 300whisper or 300BLK.It will do anything the 7.62x39 will do with easy to get brass and feed well with easy to get mags.My son likes hunting with my old mini-30 and it works real well on deer with speer 125's over AA1680.I figure the 300whisper would work just as well using 125 ballistic tips.

[crawfobj]

I have an upper in 300 whisper and I've been impressed so far. Still tweaking loads a bit.

My next one will be a big bore - either 450 bushmaster or 458 socom. Have GC molds for either diameter, so primary considerations will be bolt face, magazine compatibility and brass cost and availability. Don't anticipate using factory ammo at all.

I have a couple of projects ahead of this one, but it's on the list...

[82nd airborne]

I like .450 BM as well. I agree with BD's assesment, and he is one of the more knowledgable sources on said caliber.

[Landric]

I'd likely go with the .300 Blackout. As it happens, there is a 250 grain +/- GB going on right now for a boolit intended for the Blackout. If I can find some money I'm considering getting in on the buy, just in case I later decide I "need" a .300 Blackout rifle.

[Otony]

You can pick up 6x45 barrels nowadays. There are a few fellows making them. I bought mine about 6 or so months ago. Let me check for the outfit in Texas that is making them.

BTW, the owner of the company is the fellow who started up Springfield Armory as a commercial venture back in the late '70s.

[Ole]

450 Bushmaster!

[Artful]

Hmm so many AR choices besides 223, you asked "If you were going to build another rifle what caliber would you build ?"
When I did that it was 300 fireball aka 300 whisper ala 300 blackout - now with factory ammo availability and you can always convert 223. - advantages - 30 cal bullets from 70-250 grain cast or jacketed - only need to change barrel and it's back to 223 - works subsonic and supersonic and miserly on powder and easy on the rifle. You can set up with dual port barrel and with turn of a screw go from pistol to carbine gas tube length. (I'm still working on having dual gas ports) but of course this requires you like suppressed guns to really enjoy.

but you said "I would like to get as much energy as possible out of the ar-15 platform. I was looking at one of the WSSM and the 6.5 Grendel."
So it sounds like your looking for the long range not up close energy transfer so I can leave out the various .50, .45, .40, .35, .338 rounds -
I'd have to say I'd choose the 6.5 Grendel then, with right bullet you can match 308 at 1000 yrds in energy. And it betters the 6.8 SPC and other possible choices.

[82nd airborne]

Black hills is making 6x45 factory ammo now too, which will help resale value, if you ever decide to sell it. It is a great deer round.

[Moonie]

Hmm so many AR choices besides 223, you asked "If you were going to build another rifle what caliber would you build ?"
When I did that it was 300 fireball aka 300 whisper ala 300 blackout - now with factory ammo availability and you can always convert 223. - advantages - 30 cal bullets from 70-250 grain cast or jacketed - only need to change barrel and it's back to 223 - works subsonic and supersonic and miserly on powder and easy on the rifle. You can set up with dual port barrel and with turn of a screw go from pistol to carbine gas tube length. (I'm still working on having dual gas ports) but of course this requires you like suppressed guns to really enjoy.

but you said "I would like to get as much energy as possible out of the ar-15 platform. I was looking at one of the WSSM and the 6.5 Grendel."
So it sounds like your looking for the long range not up close energy transfer so I can leave out the various .50, .45, .40, .35, .338 rounds -
I'd have to say I'd choose the 6.5 Grendel then, with right bullet you can match 308 at 1000 yrds in energy. And it betters the 6.8 SPC and other possible choices.

Actually if you compare Spec II 6.8 ballistics the two are virtually identical and the 6.8 doesn't suffer from the broken bolt issues that the 6.5 Grendel does.

In hunting terms realistically either one is a good sub 400yard gun for deer size critters.

Yes, I have a Spec II 6.8. If I were to get another upper I'd probably opt for something 35 caliber, just seems right to me for a cast boolit slinger, 450BM would be a good choice as well.

[DCM]

OK maximum energy with j bullets, comercialy available. That would be the 300 OSSM from Olympic Arms. Next choice would be the 25 WSSM from Oly or D-tec. The 6.5 Grendel would be a good choice but doesn't come close to the power of the first 2.

[Artful]

Actually if you compare Spec II 6.8 ballistics the two are virtually identical and the 6.8 doesn't suffer from the broken bolt issues that the 6.5 Grendel does.

In hunting terms realistically either one is a good sub 400yard gun for deer size critters.

Yes, I have a Spec II 6.8. If I were to get another upper I'd probably opt for something 35 caliber, just seems right to me for a cast boolit slinger, 450BM would be a good choice as well.

Well last I checked, 6.8 didn't keep up with 6.5 but if you'll give me a link to the 6.8 load your talking about I'm willing to learn. Problem with .35 is getting it in magazine - I was interested by 9x39 ruskie round but I have yet to find a 35 cal for AR that I am willing to build - 358 wcf on a FAL maybe but AR just doesn't seem ideal 35 cal host.

[Moonie]

It really is a word game isn't it, depends on how you define "didn't keep up". True, at 500-800+ yards the Grendel does have more energy and velocity than the 6.8 due to the higher ballistic coefficients of the 6.5 bullets, but 2 things, realistically neither one has the energy to humanely take deer size game at those ranges and as I said, both are realistic sub 400 yard guns for this task.

All the load info you want is at www.68forums.com

I'm shooting 110 Nosler Accubonds over 2700 which is right in line or even over the speeds from the Grendel.

Either are great improvements over the 5.56 and good choices for hunting deer or wild boar.

[dk17hmr]

I have a 6.8 SPC, 6x45, and a 300 whisper all AR15's, I shoot everything from varmints to big game with them all. I will have a 204 Ruger upper pretty soon. Anything based off the 223 case is a good bet, the 6x45 if probably my most used AR15, pushing a 55gr NBT at 3300fps is easy with my 24" barrel and it destroys coyotes, stepping up to a 70 or 75gr in the 6x45 is "fur friendly" and hits coyotes like a ton of bricks. The 6.8spc has taken 2 deer and several small varmints, 110gr v-max is up to the job for varmint and medium game...I have thought about taking it to elk camp with me, 110gr Accubonds would be my choice for that. 300 whisper puching a 125gr NBT at about 2200fps claimed 2 antelope this fall, loading it with a heavy 200-240gr boolit moving 1000-1200fps makes it a very useable rabbit killing rifle without ruining meat.

[82nd airborne]

Dont forget the .257x45! I love about anything in .257...

[GabbyM]

Dont forget the .257x45! I love about anything in .257...

Sort of the way I was thinking for cast.

Has anyone tried necking down the 6.8 SPC to .257 or 6mm bores?

5.56mm bases wildcat is hard to beat. As many people do I've at least a five gallon bucket of 5.56mm brass setting here waiting for something.

[dk17hmr]

6mmx6.8 is a 6 WOA or a 6mm DTI...depending on where the shoulder is.

[Dannix]

I guess 82nd airborne is being humble, but I'm surprised noone has mentioned the .50 HushPuppy. It seems like a perfect "complimentary" AR calibre, unless you first want to get an intermediate 6.8SPCspec2, .300Blk, or 7.62x40.

[82nd airborne]

Your too kind Dan!
I like .50 HP, but I will let other people promote my stuff so it doesnt come off wrong. I dont necessarily like my stuff better than the calibers that are available, and most of our wildcats were designed largely by this board as a whole.

[Idaho Sharpshooter]

I had talked myself into the 358 AR.

If I may be a bit, shall we say "indelicate"; I want this for mostly two-legged predators. It will be built on a pistol receiver, with an 11.25" barrel. I want to shoot mostly the RCBS 200gr RFN GC out of it. It may get a can down the road.

Now, you guys have me thinking the new 300-something. There will be no separate magazines issue, and 223 brass is still reasonably priced.

For those of you with the Whisper or it's kin, are you able to get decent accuracy with 180gr or heavier cast bullets in it? I just need sub-3" groups at 50 yds.

thanks,

Rich

[82nd airborne]

I think I posted a target in the group by thread. 16" AR 5 shots with a 200g RCBS in 1.1" .300 BLK.

[thehouseproduct]

I can make them in fairly good time. I shoot 6x45 and 7x45 alot. I think they should both be more popular than they are.

Is the 7x45 similar to a 7mmTCU? Do you have a round similar to 6.5MPC?

[82nd airborne]

I load my 7x45 with 7tcu dies, pretty similar!
Im not familiar with the 6.5 mpc, what is that?

[crawfobj]

Rich,

Sub 3" groups at .50 are no problem in my M1S whisper upper. Had I known about 82nd Airborne I would have bought an upper from him.

I have my action ready to build a bolt gun in .300 whisper. Planning to have 82nd Airborne do it when I get the funds together. Gotta fund the can and uncle sam's stamp too.

My next upper will be a big bore. It'll probably be a while, but that will give me time to narrow down which caliber to keep brass costs down and magazines simple. Should be fun.

[bruce drake]

Dang you all!

I'm in the process of having a 300 BLK upper being built by 82nd Airborne as I type this but I am a serious 25 caliber fan as well!

257x45!!! Next!

Just got to go find out who makes the dies.

Bruce

[82nd airborne]

Gotcha Suckers! hahaha!

[thehouseproduct]

I load my 7x45 with 7tcu dies, pretty similar!
Im not familiar with the 6.5 mpc, what is that?
It's a JD Jones round. It's like a 6.5tcu with the shoulder pushes further down so it's 223 mag length for AR15. I always liked it, just can't justify his costs.

[82nd airborne]

gotcha, yea I quit using anything of "his" when he compared himself to John Browning, even though he has never designed a single firearm! what the heck....

[dk17hmr]

..............257x45!!! Next!

Just got to go find out who makes the dies.

Bruce

http://www.ch4d.com has 25x223 dies and that will probably work just fine. Aaron is going to be building a 257x45 barrel for my Savage model 12 (if I ever send the Lilja and other parts out to him), my plan is to use my 6x45 dies with a 25 caliber expander button in to form brass, being a bolt gun I am just going to get a 25 caliber neck sizer from Hornady and see if I can get a seater die from them as well.




By the way I was shooting 675 yards this morning with my 6x45 with both 55gr and 70gr bullets......with a 10-15mph cross wind hits were nearly every shot once I figured how much to hold into the wind.

[82nd airborne]

Yup, I have a new reamer on the way for the .257x45 that should be compatable with the dies from ch4d.

I will probably quit working after it arrives though, as I will be doing nothing but wandering the ozarks looking for stuff to shoot.....

[Dannix]

I need to stop reading. Seems the .25 cal is a virus that causes guys to like it. I'm afraid I may be fighting it -- I need to spend more time with a .30...

I've heard 7mmTCU is an anemic round in a carbine compared to other .223-based wildcats. (I wish I could find the article that said that). Aaron, what are you pushing and how fast in your 7x45 AR? I still like the 7.62x40 idea, particularly if tweaked to have a slightly longer neck, but my impression is split necks could be an non-trivial issue.

[82nd airborne]

I can ger 2400 with a 120gr and I havent chronod the 100g sierra varminter but they give me a tingly feeling, the good kind. They expand like a big game bullet at those velocities instead of blowing up.

[DCM]

[QUOTE=Dannix;1149270]I need to stop reading. Seems the .25 cal is a virus that causes guys to like it. I'm afraid I may be fighting it -- I need to spend more time with a .30...

Yup it all started years ago when I won a 0.257 Obermeyer barrel. Now I own 3 25cal rifles! Durn quarterbores!

You really wouldn't want one of the most versitile and accurate calibers anyways.

[82nd airborne]

Yep, the .250 savage on a very nicely done 96 mauser (by my father) was my first centerfire, and still one of my most loved. And now I am pretty fond of the .257x45. If I can just get redding to get us affordable dies...
Or maybe I could get Buckshot a chambering reamer and a sizer die reamer and he could make us all dies! weeeeeee, fun.

[Kenny Wasserburger]

since we are voting? more or less,

My choice other then the .223 which I have already, 6.5 Creedmoor. Sorry I am a 264 nut.

KW
The Lunger

[Dannix]

You really wouldn't want one of the most versitile and accurate calibers anyways.
I keep thinking why give up meplat and drop from .30 to 6mm/6.5mm/.25/7mm. Then I think of neck splits in attempting to size 223 brass up to .30, so then I think of .30HRT. Then I consider magazine capacity and particularly brass costs and think of <.30x.223 to mitigate neck splitting. Then I think why give up meplat and drop to <.30. ...

It's a vicious cycle, including a sub loop concerning .300Blk and giving up velocity potential compared to 7.62x40 vs gaining greater subsonic capability. And throw in the consideration of making my own longneck .30x.233 wildcat, which is something I keep coming back to as well.

Yeah, vicious. Fortunately I'm disciplined enough to not open my wallet right now. Perhaps by the time I can do so responsibly, I'll at least have a few options weeded out, and a few top picks to tangibly instantiate.

[82nd airborne]

Come by here and shoot several different variations, thatll help you decide!

[45r]

With J-words it seems the 6.8 and 6.5 are better than the 223.I'd be much happier with one or the other over the 223 if I had to go back in the military.With cast the 30 cal is the predominant winner for accuracy with the 30BR and 308 used the most.The AR-15 can't use them unless you get a REM 30RAR.Most will shoot a AR quite a lot and if you aren't rich you probably want someting that uses inexpensive brass so to me the 300whisper/300BLK would be the way to go.You can get a little more velocity with the 30HRT and 30x39 but it will cost you more to feed the rifle.It seems that people are finally starting to see the many advantages of using a suppressor like not bumming out others with the noise,less recoil,muzzle flash,less hearing loss,easier to teach young shooters how to shoot since the noise and recoil is reduced,etc.I hope that enough people get the 300BLK and any other cal that can be easily suppressed that maybe we can get suppressors legal in all 50 states.

[82nd airborne]

I will put pics up of a gnarly .300 BLK suppressor I am making here shortly. Soooo Funn!
I have an old Ideal mould that casts a beautiful 120gr spire pointe gc .310" boolit that will be my supersonic go to, and the noe group buy will be my subsonic go to round.
There are about 10 other moulds that will be used some too.

[P.K.]

I didn't see it mentioned but for anyone leaning to the 6.8SPC, American Rifleman had a really good article on it with load data for various gr. weights and comparison data to factory stuff.

[82nd airborne]

To those of you who want to get brass ready to load for your BLK, and dont want to mess with cutting down .223, www.bradswarehouse.com has it reasonably priced and he is a great guy and a vetran.

[crawfobj]

Saw a post somewhere back in this chain about .450 bushmaster and others using a case head diameter that is the same as .308. Has anyone tried using just a .308 case with the neck cut off and sized (straight wall) to a .429 caliber bullet? Seems to me that this would solve the crazy brass price issues with the bushmaster and socom, and still have a good bullet/boolit selection while giving performance similar to a .444 marlin. Guess you could also use a .30-06 case if you need more length.

A buddy and I mocked up a cartridge like this 10 years ago but didn't think it would headspace in an autochunker. Seems to me that the 450 bushmaster proves this wrong.

The thought of scattering .450 bushmaster or socom brass around the pasture when chasing pigs is a big turnoff to those cartridges, but I could wrap my penny pinching head around losing modified .308 or .30-06 brass.

Wondering if it would feed from an AR mag, etc.

Just wondering if all of you that are smarter than me have ruled this out before.

[thehouseproduct]

Saw a post somewhere back in this chain about .450 bushmaster and others using a case head diameter that is the same as .308. Has anyone tried using just a .308 case with the neck cut off and sized (straight wall) to a .429 caliber bullet? Seems to me that this would solve the crazy brass price issues with the bushmaster and socom, and still have a good bullet/boolit selection while giving performance similar to a .444 marlin. Guess you could also use a .30-06 case if you need more length.

A buddy and I mocked up a cartridge like this 10 years ago but didn't think it would headspace in an autochunker. Seems to me that the 450 bushmaster proves this wrong.

The thought of scattering .450 bushmaster or socom brass around the pasture when chasing pigs is a big turnoff to those cartridges, but I could wrap my penny pinching head around losing modified .308 or .30-06 brass.

Wondering if it would feed from an AR mag, etc.

Just wondering if all of you that are smarter than me have ruled this out before.
I'm liking this idea. Let's get it going.

[82nd airborne]

We have been pondering that exact thing over in the Cast Boolits AR-15 Upper group buy discussion thread.

[DCM]

I have a lower receiver for an AR-15 that I would like to build. I have two other ar-15s. One is in the heavy barrel A2 configuration and the other is a scoped flat top receiver with a 24 barrel. Both are in .223 Rem or 5.56 Nato. If you were going to build another rifle what caliber would you build ?
I would like to get as much energy as possible out of the ar-15 platform. I was looking at one of the WSSM and the 6.5 Grendel. I reload and for this application I would probably stay with j-bullets. your opinions

I think 82nd Airborne has the best suggestion yet try it before you buy it if possible!

Lots of ammo see how she shoots and runs.

[crawfobj]

We have been pondering that exact thing over in the Cast Boolits AR-15 Upper group buy discussion thread.

Thanks Aaron. Will be watching that thread for more. That one jumps around so much it's hard to follow!!!

[DDriller]

My favorite is still the 458 SOCOM. I do have an 8.7" .338 Spectre barrel coming and the new 338 swage die BT Sniper is building is going to be awesome for some sub sonic bullets. Also shoot 6.8, 5.56, and long range is a 6mm BRX.

[Idaho Sharpshooter]

Or...

how about a 41 Super Mag rimless? Just use a 308 shellholder, and run them in a form/trim die.

Rich

[MakeMineA10mm]

Personally, I think the guy is crazy, but he took a grizz with a 6.8:
http://forums.accuratereloading.com/eve/forums/a/tpc/f/7621043/m/4721044231

http://i82.photobucket.com/albums/j247/joelbrown_01/anschutz/giz2.jpg

[Moonie]

You skin griz?

[MakeMineA10mm]

Not me, not mine, and I wasn't there. Only reporting what I read at another forum. Upon reflection, I think I'd retract my "crazy" comment above. The fact of the matter is, a LOT of native hunters and people who have inhabited the far North have hunted many years with what most would consider "weak" weapons, including spears, 30-30s, etc. The fact is, they are very successful at getting their animal with those weak calibers.

I suppose the reason for the bigger calibers is the bad situation of wounding or needing to stop a charge, etc. I'm sure that often, even very large, bear are taken with "average" calibers quite cleanly, and the mega-calibers are only needed some of the time. I guess, I'd only feel comfortable hunting a bear with a weaker weapon if I had back up I trusted with a strong weapon. Here's the bear skinned (by the way, all this info is straight off the thread I linked in my prior post):
http://i82.photobucket.com/albums/j247/joelbrown_01/anschutz/giz.jpg

[45r]

My favorite is still the 458 SOCOM. I do have an 8.7" .338 Spectre barrel coming and the new 338 swage die BT Sniper is building is going to be awesome for some sub sonic bullets. Also shoot 6.8, 5.56, and long range is a 6mm BRX.

Have you shot your 458socom with cast boolits,I'm leaning towards getting a big bore before a 300BLK now.I'd like to wait and see what everybody has been using and likes before getting a 300BLK.I've read the 458socom is well liked and the same with the 450BM.The only thing I am wondering about with the 450 is will it feed well with fat metplat boolits,I've read the socom feeds them easy and it's accurate.The 450BM is accurate also and there is a new type crimper that is suppose to work better with it.I like hornady stuff,it's good quality and they will be around forever probably.I can always run my lubed 458 boolits through a lee .452 die to make them work in the 450BM.If I see either one of these at a good price I'll have a hard time passing it up.For some reason the 458socom seems to be calling the most,everybody that has one says they like it a lot.

[82nd airborne]

You may consider a .450 BM with an AR performance locking system. That would let you run it hotter, and you could size big ole .458 boolits or bullets down to fit.

[45r]

You may consider a .450 BM with an AR performance locking system. That would let you run it hotter, and you could size big ole .458 boolits or bullets down to fit.

I've read you need to ream the brass with a .452 reamer to use the long 405 grain boolits.The boolits can slip forward if the crimp isn't very good but there is a modified 45-70 lee crimper and another crimper I can't remember now that helps.The 450BM shoots ragged hole groups at 100 with factory ammo but tends to throw a few fliers with cast,some think the taper crimp with straight wall might be part of the problem with the higher ES compared to the roll crimp of the 458socom.Another reason might be the erosion marks left on PB boolit bases on recovered boolits by passing the gas port,even with GC boolits there seems to be a little gas going around the check and in the grease groove.It seems to me that you could get around that by eliminating the grease groove above the check and have it snug right up to the rear band.There is a lot of shooters using cast in both the 450BM and 458socom and their sites are an interesting read on AR use with cast.The pictures of erosion spots from the gas port are something I haven't seen till reading about their efforts.They are doing some muzzle brake tests also that are interesting and some are using hydraulic buffers also.A lot are using the big bore AR's for hog hunting and say they work real well.I'm a 45 fan and want a 45AR but which one,both are pretty good.The socom doesn't need to be reamed for heavy boolits and the roll crimp holds better but the 450BM can be made to work as well with a little more effort and the straight case doesn't have short neck issues.Cast boolits shoot better usually at moderate pressures so I won't try to push them hard,heavy 45 cal boolits work well at slow speeds anyway and the recoil is easier to handle.I've got to get me a 45AR,they sound like a lot of fun.

[MakeMineA10mm]

Are there any of these 45 coversions made on the AR-10 (long) AR action? Now, THAT would be something to behold!! :bigsmyl2:

[bruce drake]

Are there any of these 45 coversions made on the AR-10 (long) AR action? Now, THAT would be something to behold!! :bigsmyl2:

Jeesus! I would hate to touch off a 458x51mm Wildcat in an AR-10. It would have next to zero shoulder to headspace off as well!

Bruce

[Idaho Sharpshooter]

Bruce,

the 45 acp has NO shoulder, as do most of the autoloader rounds. You just have to be a bit more fussy about tolerances.

Rich

[bruce drake]

I've loaded more than enough 45ACP to understand that. The original post was regarding a 45 caliber cartridge based off a 308 Winchester case. Those cases headspace off the shoulder.

[Three44s]

Are there any of these 45 coversions made on the AR-10 (long) AR action? Now, THAT would be something to behold!! :bigsmyl2:

I have heard of an upper in .450 Marlin for the AR10.

That would clear the 'ole cob webs outta the attic .............. no?


Three 44s

[45r]

I wonder if the short mag brass can be cut to around 1.65 and necked to 458 or 452 with a little longer neck than the 458socom.I've read that some 458socom dies are a little hard to size the brass.Maybe thats why one hasn't been out yet.A wildcat off the Win short mags would give several brass options,270,7mm,308 etc.I wonder if that brass would be too thick to work with once cut down.Probably need to be annealed and neck turned but brass would probably last a long time.It would be a lot like the socom but have a longer neck.I don't think anybody has done a .452 necked down short mag wildcat for AR-15 yet.

[82nd airborne]

I wonder if the short mag brass can be cut to around 1.65 and necked to 458 or 452 with a little longer neck than the 458socom.I've read that some 458socom dies are a little hard to size the brass.Maybe thats why one hasn't been out yet.A wildcat off the Win short mags would give several brass options,270,7mm,308 etc.I wonder if that brass would be too thick to work with once cut down.Probably need to be annealed and neck turned but brass would probably last a long time.It would be a lot like the socom but have a longer neck.I don't think anybody has done a .452 necked down short mag wildcat for AR-15 yet.

Yes I have one cut down and fires .510" boolits. Im doing a .458" version too.
Bring the pain!

[45r]

I hear ya about big-bore pain.If its like heavy 45-70 loads it can be hard on the shoulder.I think that can be reduced a lot with the AR using Sims pad,gill brakes,hydraulic buffers,heavy springs,etc.Over on the 450 and 458 forums they say they got their AR's shooting like a ***** cat with all the gadgets installed.I'd like to see the 458 wildcat you're making,I have a bunch of 458 boolits and molds and J-words that shoot well in my 45-70's.I think a 452 would be cool also.Some are using 458 bullets in the 450BM with a reamed out throat to use with 284 brass without reaming.Its opened up just enough to still headspace on factory brass and allow use of 458 bullets also.The barrel swages them down.Have to start low and work up loads.Some ream out the 284 brass with a forster reamer to use long 452 bullets and are are swaging 458 jacketed bullets down with a 454 and then 452 Lee push through using imperial sizing lube or dillon spray lube.The lagrendre crimp they're using is pretty cool also.Do you use any kind of side crimp on your HP.They say it works real well,especially farther out on accuracy.Keeps the bullet from slipping forward when straight wall rounds slam forward during chambering.It seems the taper crimp doesn't work good enough,especially with cast.

[MakeMineA10mm]

I've loaded more than enough 45ACP to understand that. The original post was regarding a 45 caliber cartridge based off a 308 Winchester case. Those cases headspace off the shoulder.

Actually, I never said anything about a 308 case, I just asked if there was a longer version of the big-bores that would require the longer action of the AR-10. I left the door wide open to other headspacing options. Myself, I'm thinking a belted case would be interesting. Maybe a 458 Win Mag shortened, that headspaces off the belt.

[45r]

You may consider a .450 BM with an AR performance locking system. That would let you run it hotter, and you could size big ole .458 boolits or bullets down to fit.

They(ARPerformance) have a post about doing some 450BM's on a group buy at AR-15.com with 16 and 18 inch SS barrels and a diamond upper whatever that is.Prices are good.I looked on their website and it looks like they have lots of good stuff,they seem to like the 6.8 quite a bit.Friend of mine wants a 6.8,looks like they make some good ones.Maybe he will get one from them.I think my H-bar Elite has the bigger receiver pins,wonder if I'd have to get another lower,kinda like the looks of the Spikes lower with a UBR or ACE skeleton stock.The thick pad on the Ace ARFX seems like it would help with the recoil.Also wondering if the Tubbs CWS or hydraulic buffer or both if posible would be good to use on a custom build.The 450BM's uppers are going for 550 at Cabelas but if my Colt lower won't fit might as well go custom,don't really want to mess with the Colt anyways I think.Seems like the 450BM is selling pretty good,sometimes you have to wait to get one.I've seen some ragged hole groups shot with them at 100 yards.