45 ACP vs 45 AR

[StrawHat]

In a discussion on another forum, it was stated that the reason for the reductionin loads from ACP to AR was because the AR was available with “balloon head” cases.

My question is, was the ACP cartridge ever available with “balloon head” cases?

Thank you.

Kevin

[ReloaderFred]

Off the top of my head I'd say no. I've got .45 acp brass all the way back to 1915, and it's all solid head design. I don't have any dating earlier, so if it was manufactured with a balloon head, it would have had to have been prior to 1915, but I doubt it was.

I don't recall ever seeing any balloon head cases made for auto loading handguns. It may exist, but I've never run across it, and I've been reloading since 1963.

Hope this helps.

Fred

PS: I've been wrong before, but in my experience, I've never seen any.

[Tatu]

What does balloon head mean?

I bought my husband a single shot rifle for Christmas, and it shoots 45 auto and 45 auto rim interchangeably.

Is a balloon head a different cartridge?

Thank you,

Tatu

[Winger Ed.]

[QUOTE=Tatu;5079380]What does balloon head mean? Is a balloon head a different cartridge?/QUOTE]

It has to do with the construction of the brass case.

They went away a LONG time ago because they can't hold the higher pressures of a full charge of smokeless powder
compared to a solid based brass base.

These are .45 Colt, but the principal is the same.
The one on the right is a old style balloon head case.

[Outpost75]

Solid-head construction of the .45 ACP was a design requirement from the beginning due to the width and depth of the extraction groove in the case head.

[Walks]

What does balloon head mean?

I bought my husband a single shot rifle for Christmas, and it shoots 45 auto and 45 auto rim interchangeably.

Is a balloon head a different cartridge?

Thank you,

Tatu

What Make & Model Rifle, Please ?

[StrawHat]

Off the top of my head I'd say no. I've got .45 acp brass all the way back to 1915, and it's all solid head design. I don't have any dating earlier, so if it was manufactured with a balloon head, it would have had to have been prior to 1915, but I doubt it was.

I don't recall ever seeing any balloon head cases made for auto loading handguns. It may exist, but I've never run across it, and I've been reloading since 1963.

Hope this helps.

Fred

PS: I've been wrong before, but in my experience, I've never seen any.

Thank you, good to know.

Kevin

[StrawHat]

Solid-head construction of the .45 ACP was a design requirement from the beginning due to the width and depth of the extraction groove in the case head.

Also good to know. Thank you for posting this.

Kevin

[StrawHat]

Funny thing about “balloon head” brass. It was originally known as solid head brass and often the headstamp would include an S and an H on either side of the primer. Slid compared to the folded head cases.

Kevin

[Catshooter]

Yes, .45 Auto Rim was made with balloon heads. I have some, Remington-Peters.


Cat

[Oyeboten]

Solid-head construction of the .45 ACP was a design requirement from the beginning due to the width and depth of the extraction groove in the case head.

This makes sense.

Probably was so for all the Semi-Auto Cartridges also...and for the same reason...the Extractor Groove needed to have some sectional density behind it.

[smkummer]

Older manuals from the 60’s and 70’s used loads that were about the same as 45 acp and that was with solid head cases. It appears modern data loads 45 AR on the lower pressure side. I am using data from Lyman’s 45th manual with unique and 452423 and it’s a wonderful full power load in my 1917 Colt.

[Baltimoreed]

I have a bunch of .450 Webley brass that is balloon head brass. I have reloaded them with minuscule loads and 160 gr lead. Certainly wouldn’t them use for any real or even target loads.

[Dale53]

Using modern Starline cases for Auto Rim, I load both ACP cases and Auto Rim cases for my revolvers at the same level without issue. They have essentially the same capacity and give the same pressures and velocity.

You can just use .45 ACP data for either case without issue.

FWIW
Dale53

[Catshooter]

Generally, you have to seat some boolits deeper with ACP than AR. A Keith, for example. This can change things between the two cartridges. Seating depth matters a great deal.


Cat

[Bigslug]

Solid-head construction of the .45 ACP was a design requirement from the beginning due to the width and depth of the extraction groove in the case head.

Yup. That renders it unfeasible by itself, but the 1911's unsupported 6:00 chamber position would have been a heavy strike against it as well.

[nicholst55]

I am rereading Sixguns by Keith, and he repeatedly lists some loads for the .45 AR that I think are rather optimistic, and least in today's world. They approach or mimic some of his enhanced .45 Colt loads, that I personally wouldn't want to use in my 1917 S&W.

[Larry Gibson]

I am rereading Sixguns by Keith, and he repeatedly lists some loads for the .45 AR that I think are rather optimistic, and least in today's world. They approach or mimic some of his enhanced .45 Colt loads, that I personally wouldn't want to use in my 1917 S&W.

Back in the late '60s and early '70s I was enamored with large bore revolvers. Went through a dozen or so S&W and Colt M1971s in 45 ACP, a couple New Service Colts and S&W in 45 Colt and a couple M25 S&Ws in 45 ACP.

Tried a lot of Keith's loads in them. Never had a problem other than the 2400 powder not burning well, even under the 255 gr Keith SWC. The Keith load of Unique under his 255 gr SWC is a very good load in either the 45 ACP or the 45 AR case. I've pressure tested it and it runs right at the SAAMI MAP for the 45 ACP at 21,000 psi. However, my favorite and most accurate load was with a 245 gr Lyman 453490 which is GC'd over a bit more Unique. It runs right around 1000 fps and is comfortable to shoot and very accurate.

The old Speer manual [plastic spiral binder] had some decent cast bullet loads and John Taffin listed quite a bit of useful data for the 45 AR in the Sept/Oct issue of American Handloader.

After shooting numerous N frames I discovered they just didn't fit my smaller hands no matter what grips I tried. I found a cut down set of S&W Target grips was the most comfortable and let me at least shoot the heavier 45 AR loads single action with comfort. Thus I kept one S&W M1917 that had been bubba'd with a taller front sight added and the top strap dove-tailed for a M1911 rear sight. I put a M25 Target barrel on it and a micro rear Target sight. it shoots as well as either of the factory M25s I had. That is the only N Frame S&W I have kept and, these days, I only shoot my standard 45 ACP loads in it with half or full moon clips. I call it a M1917/25.

Attachment 275110

[Dale53]

Larry;
As usual you give good advice! I have a number of .45 ACP revolvers and have shot them a good bit. My favorite is the 625-8 JM Special (4" barrel). However, that doesn't mean I don't treasure my Ruger SS Bisley .45ACP/.45 Colt Convertible. Frankly, the .45 ACP, .45 Auto Rim, and .45 Cowboy Special all get space in my shooting program. I mostly shoot my target load in all three cases (depending on the platform) - 4.0 grs. of Bullseye or equivalent behind a Mihec correct copy of the H&G #68. It is a great target load and works well on edible small game, too.

I have taken all of my deer with a .44 Magnum revolver, but using a full load behind a 250 gr. Keith in a .45 AR or .45 Cowboy Special (again, depending on the platform) would do just fine on large whitetail deer at reasonable ranges. All in all, these are very versatile handguns and loads.

I will state for the record, that the 1917's are not as strong as the revolvers built since 1950 and I would not be shooting heavy loads in them. I have heard of a number of split cylinders with heavy bullet heavy loads in these early revolvers. Just a thought or two...

FWIW
Dale53

[Tatu]

Thank you guys for the explanation of "balloon head", I appreciate the information.

Tatu