I remember when Olympic Arms was cranking out the lowers and even full rifles. There was a gunsmith here locally that built some that took Grease gun mags, if I recall correctly. Worked like a charm. Not sure these are so common these days, though.

 

I have one from Oly Arms that use 45 acp Old Stick Mags. I am told that you can hear the pop of collision with the pig. I was surprised that it was such a shooter. These old stick mags are heavy but work excellently. Have an old red dot 512 mounted on it and still glowing. I believe I could take out a lot of hogs with night vision.

 

Plenty of pcc’s out there. I have built Oly and cmmg .45s. Olympics are heavier, dirty but run anything, cmmg’s are lighter, cleaner but are bullet shape sensitive. This is my cmmg rifle.

I use CNC lowers which are dedicated gg mag lowers. But you don’t have a lrbho. There are .45 pcc’s that use glock mags too. Bought my cmmg bcgs/ barrels from optics planet. Good luck on your build.

 

The problem with that is that the .45 acp round does not really derive much of a benefit velocity wise from a carbine length barrel over a pistol length barrel. Whereas a carbine length barrel running a nine millimeter round will get a significant boost in velocity.

 

But we can't ignore the fun factor - which is sometimes more important of a concern than any actual, practical gains! Case in point: the semi-auto Thompson. Sheer joy as a Steel Challenge PCC! Practical? No, not really. Far from it, really. But the enjoyment factor - Off the charts. Once all of the tactical, defense, SHTF stuff is set aside, shooting is primarily about having fun, so, if it has to be an AR, why not in .45?

 

I've got 3 ar-9's built on 9mm lowers. Need a large frame glock lower or 223 lower with adapter for .45. Midway has .45 uppers for cheap. Also you are gonna have a choice between maybe 3 barrels and 2 bolts. If you want thousands of options instead of half a dozen, go 9mm instead.
16 inches and 45acp is asking for problems. Ammo is designed to work in a 4-5" barrel. Go 10.5" at most or 4"+can Even then the recoil should be bad and you should need an 11 OZ buffer. Anything longer doesn't make sense to me. Would be cheaper and more powerful and less recoil and more reliability to stick with .223 past 10.5"
My longest 9mm barrel is 7" and that's enough extra barrel to see an obvious power increase down range, specifically a larger entrance wound. With a standard 5.4oz buffer it's downright abusive on the shoulder. The 4"+can on the other hand is a pussycat.
Seen too many pcc barrels packed full of bullets. I wouldn't have any peace of mind with a 16".
No matter what you do be prepared to clean the nastiest gun you've ever seen. Blowback runs filthy. When I clean one the whole house reeks of gun.

 

Not true about the lack of velocity pick-up in a 16" barrel. It is just as proportionate to 4" barrel velocity as the 9mm. For example, 880fps/5" to 1016fps/16" (from 'Ballistics By The Inch'). This was a 230gr at standard pressure. The more special loads are also proportionally faster, like 1196fps/5" to 1438fps/16" for 185gr +P. To me this is nothing to sneeze at and no reason at all to not consider a .45 ACP carbine.
BTW, Olympic used to make a .30 Carbine AR. At the time, it made no sense to me but now I would love to find one.

 

Not true about the lack of velocity pick-up in a 16" barrel. It is just as proportionate to 4" barrel velocity as the 9mm. For example, 880fps/5" to 1016fps/16" (from 'Ballistics By The Inch'). This was a 230gr at standard pressure. The more special loads are also proportionally faster, like 1196fps/5" to 1438fps/16" for 185gr +P. To me this is nothing to sneeze at and no reason at all to not consider a .45 ACP carbine.
BTW, Olympic used to make a .30 Carbine AR. At the time, it made no sense to me but now I would love to find one.

We went down this road years ago Sax with a table that you supplied. You were wrong then and you are now unless you have newer information.

 

JRC sells a AR[-like] carbine. The 45acp parts worked great, then I switched to 9mm to test and THAT worked great, then switching BACK to 45acp was a nightmare.

I think it was the stupid ejector-plate that was NOT indexed/irreversible, but I sent the 45acp parts back for a refund when the emails started to get heated.

I like the design, but sorry: there is ZERO excuse for an ejector plate (unique to each caliber, plus reversible left & right) having DIFFERENT SCREWS, and not being indexed so there is NO CHANCE of inverting them 180 degree. They were not even etched/cast/stamped with caliber PLUS directional info.

That said, the JRC 9mm carbine is quite fun.

 

I currently have a 16in Ruger PCC in 9mm which I find to be quite fun, I generally shoot it out to 100yds and it is very accurate at that range. I have a Vortex 3x sight on it.

I did a one point inquire with Ruger about a .45 version several years ago, they said they were looking at it but apparently bought Marlin instead. I would buy one !

I truly enjoy my 9mm PCC and was thinking a .45acp version would be a hoot as well. It does have more recoil than I thought it would but it’s not terrible.

 

Went looking for a 45acp carbine and settled on this one .

 

I

I always thought that those H&Ks had a pretty cool distinctive look to them. I thought about getting one back when they were selling them with 30 round magazines. Then they stopped selling them. Subsequently the have started selling them again but you can only get ten round magazines for them. So for that Kind of money I will pass.

 

I use an Oly .45 ACP upper mounted on any of my Evil Black Scary lowers. To do that requires me to use dedicated Oly mags that hold 18 rounds each. A trio of those mags are quite heavy to carry. I need a mag loader assist to fully load them. It's fun, different, and a downright dirty mess inside the gun to shoot. I don't believe Olympia makes them any longer.

 

I just want to say 2 words to you, just 2 words, are you listening?

Thompson 1927A1 (although only in semi-automatic)...

Thompson 1927A-1 Long Guns - Auto-Ordnance | Original manufacturer of the world famous "Tommy Gun"

OVERVIEW: THOMPSON 1927A-1 OVERVIEW: THOMPSON 1927A-1 For more than 100 years, the “Chicago Typewriter®”, the time-honored submachine gun, has been a favorite among collectors and shooting enthusiasts. The .45 ACP caliber Thompson 1927A-1 has a pinned Cutts compensator, which lengthens the...

www.auto-ordnance.com

 

I just want to say 2 words to you, just 2 words, are you listening?

Thompson 1927A1 (although only in semi-automatic)...

Two more words.

Full Auto.

One of my friends shooting my TommyGun for the first time.

Charlene TommyGun

M1

youtube.com

 

I built a 45 ACP AR many years ago using the Oly 16 inch upper and a dedicated purpose built Khalan Weaponry lower that uses Grease Gun mags. The carbine is fun and scary accurate with a simple red dot mounted. But the thing is heavy and fully loaded Grease Gun mags are really heavy. Luckily I found and bought a dozen or more of the Grease Gun mags as they are now pricey and not easy to find.

 

I think as soon as you pull out a Thompson the game is over. Intimidating as hell. And also, heavy as it too.

 

But if I had an AR-15 or several AR-15's, and was considering a .45ACP AR.... ....I think a Thompson 1927A1 would be a more novel choice and fun to have...

At the same time, folks are bring up you could buy/build a .45 upper to use on existing AR-15 lowers, which would win out simply on costs....

 

45 acp, 11.5 New Frontier Armory upper 80% lower in Colt/Glock pattern. Working on one in M3A1 Grease Gun format.
Fun is an understatement.

 

IMO CMMG Banshee 10mm but if need to have a 45 they make em 2. Hard to top those models.

 

Intimidation?
Nah, gimmie a 12 ga. with slugs and buckshot

 

I'm a huge 12 fan and in fact I have an 870 Police one 1 floor and a 1187 Police on another. This one I have to say you just might not be in the right. These small SMG's, even the civi versions are so, so simple to operate and accurate as heck. A 10mm or 45 is really hard to beat. But I get the love for the 12.

 

My AR, configured in 42MM....

Its a Golf Ball Launcher.... ....you use blanks for the propellant, and drop a golf ball into the tube on the end of the barrell....

Yea, its stupid, but it is hella fun....

 

I've been very happy with my CNC lower and Oly upper. I'd really like to SBR it though.

not me shooting.

 

I have a CMMG "AR" carbine in .45acp with a Leupold DeltaPoint Pro on it. It’s not blowback, it locks up similar to an AR but with CMMG's hybrid design. So it has no heavy bolt slamming back and forth. The bolt carrier group looks very similar to a standard AR. It looks like a beast with the big barrel, but shoots very easy. It’s fun to shoot on the pistol steel plate range, and whacks the thick steel with noticeably more authority than the 1911 in the same caliber. I wanted something different since everyone seems to have 9mm PCCs. I would never purchase another CMMG however, as their customer service is horrible.

 

So I tried the the Bazooka boys and CMMG, couldn't get a response... Justin at CNC called me back and we spent a lot of time on the phone. It appears the lead length on the NF upper is to short, I'm milling back the rear mag wall around a quarter inch to see if that alleviates the feed issue. we will see. The 11.5 inch NF upper changes the overall round speed about 200 FPS. A standard 230 ball round is still sub sonic, my 200gr SD rounds are to hot in the AR. They make a funky pop sound where the 230 FMJ just goes "THUD". I'm dying to to can it, just to see what happens. Of course I'm not buying one. Been studying the issue.

 

.45 ACP does just fine in a 16” barrel. Picks up a nice bit of extra momentum. Plus, .45 out of a barrel that long is comparatively quiet. Very fun to shoot!

 

Whats fun about the AR 45 is figuring out the functional balance. In the Blow Back setup you have to figure out the recoil force on the BCG in the short stroke and how to compensate for the return to battery in an efficient manner without stop bounce. Turns out a 10 oz. buffer and an AR 10 -.308 buffer spring work well together. In the Grease gun format I need a lighter buffer, but the geometry is to straight so I need to figure out the breech rise to bolt lockup without floating the round. I am currently using the CNC lower which appears to be to shallow for the release angle of the M3 magazine. But I'm working on it... Might need to move the Mag position back and soften the extractor spring.

 

Mark60, you’re the first shooter that I’ve come across in all the forums that I’m on that has ever mentioned the CNC lower I do believe. For years I thought that I was the only guy Justin was building them for, I have 3. How long have you had yours? I’ve shot mine in several zombie and ipsc matches. If primers were available I’d shoot them much more. A very fun gun. This was my first sbr’ed .45 build, it has a forward charger on the left side. Never liked the AR charging handle. Bad elbows.

 

I bought mine used several years ago. I freaking love the thing suppressed. I'd like to cut a couple of my mags down to 10-15 rounds though.

I'd also like to get a DI upper for it someday.

 

AR45

 

Pretty nice...No "GIGGLE" switch ?

 

The CNC lower works with Olympic and cmmg uppers. Greasegun mags are not hard to cut down. A piece of thick aluminum shaped with a 1 inch bench belt sander and a couple screws. You could use a piece of hardwood too. I stamped the rd count on the bottom, of course cut down the way too long mag spring.

 

I vote for a Mech-Tech upper. I have one with a dedicated 1911 lower.
I've been immensely happy with mine.
Under 60 yards, wherever I put the green dot, there will be a .45
hole. My unit has never failed to feed, fire, or extract.
The ONLY drawback is I can't find a reliable mag that holds more
than 10 rounds.

 

Like others have already said, too heavy of a round to really get any speed going, so why?
If you want a lead slinger in the same caliber as a handgun go for the Tommy Gun, SBR'd of course.

 

Because 230 grains of suppressed subsonic ass whoppin' is awesome.