45 ACP...for a carbine

[Mr_Flintstone]

I’ve not loaded much 45 acp. Just a few for my 1911 Govt. model. I’ve never considered making some loads specifically for a carbine, but I have loaded a lot of 38 special and .357 for lever action. From that activity I have learned to use slow powder to extend the pressure curve further down the barrel. (I may not be using that terminology correctly, but you get the point.) The problem I see with 45 acp in a carbine is the smaller available case volume and lower pressure than something like .357 magnum; so something like H110, 2400, or IMR 4227 is out.

Would using a powder like Longshot have the same effect in 45 acp that slow powders do in .357 magnum? It’s about the slowest powder I can find data for, but I’ve never used it for anything. I’m not looking for magnum level loads, but trying to find loads that make use of the longer barrel most efficiently. Apparently the optimal barrel length is somewhere between 12-16 inches depending on powder, and I’d like to find one that continues to accelerate all the way down the barrel instead of peaking and then slowing down.

 

[joneb]

Powder choice will depend on the action of the carbine. I have a Marlin Camp 45, Unique and Accurate #5 work very well for this blow back action from 185-230gr bullet weights.

 

[Charlie98]

There are some differences... a .357 is usually in a locked breech (read: lever action) where a .45ACP carbine is usually semi-auto. Joneb is correct... a medium-rate powder like Unique would work very well in such circumstances.

 

[Mr_Flintstone]

You guys bring up some things I hadn’t thought about. The carbine I plan to load for is a Hi Point 4595-TS. It’s a straight blowback; not even locked breech. I guess I’ll just have to experiment some.

 

[joneb]

I should add this to post #2 regarding the Marlin Camp 45, Unique is sooty and the Marlin is not easy to clean. #5 and VV N340 are two of my favorites for this carbine.
Velocity gains with a 16" blow back are not that impressive compared to a 5" lock breech, maybe a 50 fps gain with a 230gr and a 200 fps gain with a 185gr bullet.

 

[Waterboy3313]

I don't load 45 acp for a carbine but I do load it for a 1911 with a 5 inch barrel. I have had great results with titegroup. My go to load with a 230gr rn plated bullet is probably more accurate than I am and feels like a factory load. I do find for my 1911 with the bullets I use that my accuracy tends to be best .050 longer than the published load data calls for oal.

I think with a little bit of working up you should be able to get where you want to be in no time.

 

[DocRock]

I have a High Point carbine in 45acp. I shoot the same ammo I load for 1911. In my case, 230 grs played RN and 7.9 grs HS-6. Get like 950 fps from the carbine.

 

[Charlie98]

Velocity gains with a 16" blow back are not that impressive compared to a 5" lock breech, maybe a 50 fps gain with a 230gr and a 200 fps gain with a 185gr bullet.

Jeepers... I thought it would be more. That's almost a 'why bother?'

 

[Walkalong]

You guys bring up some things I hadn’t thought about. The carbine I plan to load for is a Hi Point 4595-TS. It’s a straight blowback; not even locked breech. I guess I’ll just have to experiment some.

Heavier charges of a slower pistol powder will get you more FPS in a carbine than a fast one, but will be harder on a blow back.

 

[Walkalong]

I should add this to post #2 regarding the Marlin Camp 45, Unique is sooty and the Marlin is not easy to clean. #5 and VV N340 are two of my favorites for this carbine.
Velocity gains with a 16" blow back are not that impressive compared to a 5" lock breech, maybe a 50 fps gain with a 230gr and a 200 fps gain with a 185gr bullet.

Yep, won't be a lot in .45ACP. Not worth the extra stress on the blow back carbine IMHO.

 

[joneb]

Yep, won't be a lot in .45ACP. Not worth the extra stress on the blow back carbine IMHO.

Yep, I tried Blue Dot with some 230gr gold dots this load may have caused the recoil buffer in my Marlin camp to fail which then caused the hammer strut bridge to fail.
I tried Accurate #7 with a 230 JHP which left a lot of unburnt powder in the action. I may try Be-86 next, I think it will work well in the Marlin camp with 185-230gr bullets.

 

[Toprudder]

I recently acquired a semi-auto 16” Thompson. Since I was in a hurry to try it out, I took my normal loads that are reduced recoil loads - 200gn plated, Clays powder, normally about 750fps. (Just in case they would not cycle, I also took some factory Winchester ammo). Even though the Thompson has a very heavy bolt, I was pleasantly surprised that they all cycled and shot very well. I have not shot across my chrono yet, so I don’t have any idea of the velocity. I did not bother trying the factory ammo, no reason to beat the gun up.

 

[cfullgraf]

I also have a Thompson semi-auto rifle. I just shoot my standard 45 ACP loads in it. I get a bit of a bump in velocity as a result of the longer barrel.

I suppose you could develop rilfe only loads for the rifle using slower powders than would be suitable for handgun cartridges.

The Thompson with standard 45 ACP ammunition is quite pleasant to shoot.

 

[Charlie98]

Even though the Thompson has a very heavy bolt,

Top, is the modern Thompson a blowback?

 

[mdi]

I have a HP carbine in 45 ACP. I believe the gun was designed to use a pistol round so I have used pistol handloads in my carbine quite successfully (my "Just In Case" ammo uses mid-upper charges of Universal with a 230 FMJ). I haven't run any loads over a chrony with my HP, but it isn't a gun/cartridge that would benefit from an extra 100-150 fps and prolly harder on the gun than necessary. My carbine is really accurate at 25 yards, is good at 50 yards but beyond that, it gets a bit "iffy". So my pistol handloads that gained a few fps from a longer barrel are working just fine.

 

[cfullgraf]

Top, is the modern Thompson a blowback?

Yes

 

[Toprudder]

Top, is the modern Thompson a blowback?

Yes, it is. The big difference between the full-auto and semi-auto versions is that the semi-auto fires from a closed bolt, and the full-auto fires from an open bolt.

The Thompson with standard 45 ACP ammunition is quite pleasant to shoot.

Yes, it is. It weighs 11.5 lbs so the recoil from the semi-auto is almost like shooting a 22. I’ve shot a full-Auto Thompson, though, and that makes it a different beast!

 

[jmorris]

Powder choice will depend on the action of the carbine.

Strength as well.

I’d start with what you have or some other average type load and just see if the extra barrel length give ps you what you are looking for.

 

[12Bravo20]

You guys bring up some things I hadn’t thought about. The carbine I plan to load for is a Hi Point 4595-TS. It’s a straight blowback; not even locked breech. I guess I’ll just have to experiment some.

While I have not reloaded any 45 for a carbine, I have loaded plenty of 40S&W for my pistols and Hi Point carbine. I use Hodgdon Universal for all my pistol calibers. For the 40, I use 5.2Gr of Universal with 180Gr bullets. The load shoots fine out of my pistols (compact and full size) and out of my HiPoint carbine. With my experience, you will be fine with your loads for both pistol and Hi Point.

 

[Mr_Flintstone]

So far I’ve tried Bullseye, Titegroup, 231, Unique, and AutoComp. They are all pretty much the same, although I haven’t chronoed them.

 

[Charlie98]

I’ve shot a full-Auto Thompson, though, and that makes it a different beast!

I have too... but it was an open bolt, but I was wondering about the semi-autos.

 

[greg_r]

I think that Longshot might just do what you are wanting to do. As I stated on the other forum, I loaded up some 185’s over a near maximum charge of longshot, Hornady manual, and got an average velocity of 1059 FPS out of my 5" 1911. Accompanying that velocity was a tremendous muzzle flash. Lots of powder burning outside the barrel.

Longshot has long been a favorite for getting maximum velocity out of a 40 S&W. That’s the reason that I bought the powder, to try it in the S&W 40 Shield. I did not like it in the Shield, and I did not like it in the1911. Because of the muzzle flash. I think the muzzle flash would be negated in the 4595’s 17 inch barrel.

Just for giggles I looked up BBTI. They have the 185 grain loading in 45 acp. CorBon +P showing 1149 FPS out of a 5" barrel. Almost 100 FPS faster than my hand loads did. The velocity maxes at 1362 in a 16" barrel then drops to 1316 in a 17" barrel. 170 FPS from a 5" barrel to a 17" barrel is not insignificant. Other cartridges might be better, but that’s not bad!

From my experience with my hand loads, I have no desire to shoot these out of my 1911 or my KAHR, but I would have no problems with them in a 4595TS Hi Point carbine.

 

[Toprudder]

I have too... but it was an open bolt, but I was wondering about the semi-autos.

I think the original design was some type of friction delayed blow-back, and I believe most of the full-auto versions are simple blow-back, but the semi-auto is a pure blow-back design. And, as per the ATF, any open bolt design is considered a machine gun, as they are easily converted to full-auto.

 

[25-20 WCF]

How about some actual data versus conjecture and “about”? I’ve owned my Camp 45 for 20 years and have seen the differences powder makes in performance. I use mostly the Hornady 200XTP but have shot 185s and 230s. Using non-Plus P loads compared to Accurate data from a 5” M1911:

185 RP GS:
10.2 grains AA-5: 1052 in 5”; 1291 in 16.5” for an additional 239 fps/230fpe

200XTP:
9.7 grains AA-5: 1050 in 5”; 1194 in 16.5” for an additional 144 fps/143 fpe
12.0 grains AA-7: 1036 in 5”; 1208 in 16.5” for an additional 172 fps/169 fpe
Hornady factory load: 1135 fps/572 fpe

230 RNJ:
Federal factory hardball: 833 fps/354 fpe in my Camp Carbine, about what you’d get in a 5” barrel and about half the energy of the AA-7 load above. Fast powders don’t give optimum performance in long barrels. Longshot is slower than Unique but not slow enough IMO for optimal velocities in the long barrels.

Remember these are not +P loads so they certainly won’t abuse the carbine. Yet they do give meaningful performance increases in the longer barrel. This means better bullet performance at the longer ranges suited to a rifle. I’ve taken several deer with the AA-7 load out to 50 yards with deep/complete penetration and plenty of tissue destruction.

Factory hardball was no different than what you’ll get out of a 5” barrel - Federal 230 @833 fps in my M45. I have shot +P loads using BlueDot and achieved 1353 fps/813 fpe with the 200XTP bullet but the load was excessive in my opinion. Published +P data goes up to 12.7 grains of AA-7 with the 200 XTP, but I’ve stuck to the standard-pressure, highly accurate AA-7 load for over a decade and the M45 loves it.


.

 

[cfullgraf]

I have too... but it was an open bolt, but I was wondering about the semi-autos.

I think the original design was some type of friction delayed blow-back, and I believe most of the full-auto versions are simple blow-back, but the semi-auto is a pure blow-back design. And, as per the ATF, any open bolt design is considered a machine gun, as they are easily converted to full-auto.

The original Thompsons had a Blish delayed blowback system. In the early 1940's, Savage Arms engineers worked to reduced the cost of manufacturer of the Thompson, they changed it to a straight blowback among other cost reductions.