What advantage does .32 ACP have over .32 S&W Long for B

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John C
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What advantage does .32 ACP have over .32 S&W Long for B

Post by John C »

I've seen all the threads on the .32 ACP Pardini. I'm wondering what the advantages are for this cartridge over the same pistol in .32 S&W Long wadcutter. Can someone please explain?

Also, I saw a while back where FC60 (Dave Wilson) mentioned that he tried to rebarrel a Walther GSP in .32 ACP, with little success. Why is that?

Thanks,

-John
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GOVTMODEL
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.32 ACP vs .32 S&W Long

Post by GOVTMODEL »

The slow twist of the .32 S&W Long makes for marginal 50 yard performance. Lots of folks have seen significant improvement with a 10 or 12 in twist barrel.

The .faster muzzle velocity of the .32 ACP in conjunction with the faster twist barrel yields a more stable bullet that shoots better at 50 yards than the .32 S&W Long.
cgroppi
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Post by cgroppi »

My pardini 32 acp shoots 1" at 50 yards with the Hornady 60gr XTP bullet. That was on my first try with handloads. No special barrels, no endless load development, it just worked.

The bad part is the rings move on the gun, but that's an easier problem to solve than bringing a 3" group down to 1".
pistol champ
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32 acp load info

Post by pistol champ »

cgroppi wrote:My pardini 32 acp shoots 1" at 50 yards with the Hornady 60gr XTP bullet. That was on my first try with handloads. No special barrels, no endless load development, it just worked.

The bad part is the rings move on the gun, but that's an easier problem to solve than bringing a 3" group down to 1".
What is your hand load information? 1" is great.
powder type and amount
OAL
crimp size
velocity
primer manufacturer
cgroppi
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Location: Tempe, AZ

Post by cgroppi »

60gr Hornady XTP JHP
2.3gr +/- 0.05gr Hodgdon Titegroup
New Remington pre-primed brass
0.925" OAL +/- 0.003"
0.332" crimp +/- 0.001"

I use a Dillon 650 with a UniqueTek CNC bolt-down toolhead, a Lee sizing die, a UniqueTek micrometer powder bar, a Hornady seating die with micrometer and a Redding taper crimp die.

I have not measured the velocity, but I estimate about 950fps from the reloading manual info.

Groups were fired from a ransom rest, 5 shots.
John C
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Post by John C »

So is the issue solely the faster twist? Or is there another advantage to the conventional cartridge versus the wadcutter?
cgroppi
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Location: Tempe, AZ

Post by cgroppi »

I would expect the bullet shape has a lot to do with it.
GVJOHN
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Post by GVJOHN »

I'm beginning to think 60 gr jacketed bullets at 950 or so is the only reason 32 acp works at 50 yds. I asked Pardini USA what differences there were between the 32 S&W L and 32 acp and twist was NOT one. That was surprising to me and don't know it is still true. It would be interesting to try this Hornady bullet in a 32 S&W (not 32 S&W L) case in anyone's factory twist barrel. A heavier recoil spring and/or heavier slide would most likely be needed for continuous use of this load.
fc60
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Good Ammunition Is the Key

Post by fc60 »

Greetings,

Converting an existing 32 S&W Long pistol to 32 ACP has one major downside. You can chamber a 32 S&W Long in the 32 ACP chamber but it will not close fully. Some pistols will fire and set off the cartridge sending pieces of metal all about.

Pardini machines a special bolt with a smaller rim cutout just for the 32 ACP. You would have to work hard to get a 32 S&W Long cartridge to fire in one.

I have obtained ten-x groups with factory barrels using the German H&N bullets. The downside is they are only available from Canada and hence very expensive.

I have also fired excellent groups in factory 32 S&W Long barrels using cast bullets. The problem I have encountered is barrel leading. Once the barrel fouls with Lead, accuracy is gone. Also, trying to cast quality bullets is a challenge with these little bullets. This is why I test and recommend my barrels with swaged HBWC bullets.

I have found through sending many bullets downrange that barrels with a smaller bore, 0.308"-0.311" and a faster twist, 10-14, stabilize the Speer HBWC bullet better than the factory barrels.

The Speer bullet is not pure Lead, it is an alloy and does not slug up as well as the H&N bullet which is much softer.

The 32 ACP shoots exceptionally well with jacketed bullets ($$$$$) They are about $15.00 per hundred. Also, you get to buy new loading dies and shell plates.

There are others on this forum diligently working up a cast bullet load for the 32 ACP. It looks promising. Again, careful hand loading is key.

Cheers,

Dave
Spaceball
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Post by Spaceball »

Lots of great information in there.

I think the question was.
Could you load a 32S&W (not long) or a cut down 32S&W long case with the 60grn bullets that they are using in the 32 acp and drive them at similar velocities to the 32 acp out of a standard 32 S&W pistol?
Using a cut down 32S&W case because of head spacing off the rim.

Would you get better accuracy at 50 with the lighter shorter bullet traveling faster (and faster spin rate) then with the standard 90-100grn WC out of the same gun?

Would there be issues with the throat?

Just some crazy thoughts.

GWH
GVJOHN
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Post by GVJOHN »

Spaceball, I experimented with the 32 S&W in a Benelli with a 10" twist barrel chambered for the short round. I tried some 80 to 100 gr rn lead bullets and some swc bullets as well. In the end I decided there was no advantage when compared to a wc in a 32 S&W L chambered 10" twist barrel. I do think this acp load might be an alternative to a quick twist barrel. I still have the original Benelli barrel and I'm going to check this out. When I was done with the 32 S&W experimenting I had leftover rn and swc lead bullets so I went ahead and loaded them in 32 S&W cases and 32 S&W L cases where the bullet was seated flush with the case mouth so it would fit in the magazine. There was no difference in performance, both in accuracy and feeding. Deep seating in the long case does not allow crimping so if that matters the short case will be necessary. As I said before I'm a little concerned about the slide velocity when you push a 60 gr bullet at 1000 fps and this might have to be addressed in some manner.
Mike M.
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Post by Mike M. »

That would make for an interesting test. As a rule, the higher the fineness ratio of a bullet, the faster the twist required to stabilize it. Which is why the .32 S&W Long guns seem to have problems...they are usually fitted with a 1:18 twist suitable for RNL bullets, not wadcutters.
John C
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Post by John C »

I had the same thought about the possible use of a .32 S&W with a RN bullet. Do these pistols headspace off the rim, or the case mouth? My thought is the rim, but I've read that older .38 super guns headspaced off the rim, with poor accuracy, until the 1980s when custom gunsmiths changed them to headspace off the case mouth with much better results.

Also, how does the Pardini deal with the recoil of a 60 gr bullet at 950 fps? Is it a heavier recoil spring over the .32 S&W long guns, or a heavier bolt? The difference in energy is significant. Putting the numbers into an online calculator, I see that a 60 gr bullet at 1000 fps is 133 fpe. A 100 grain bullet at 700 fps is 109 fpe. That's 22% more energy.

It would be interesting to work up some loads for a 60 gr bullet. The energy calculator shows the 60 grain bullet at 900 fps at the same fpe as the 100 gr at 700 fps. I have a .32 revolver, so I could work up load data in a revolver before we put this through one of our expensive Euroguns.

Thanks,

-John
John C
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Post by John C »

Dave/FC60;

Which H&N bullet were you using with such success? The safety issue you mention with a .32 ACP conversion is definitely real. I guess chambering a barrel in .32 S&W would pose the same issue?

Thanks,

-John
pistol champ
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pardini 32 acp bolt

Post by pistol champ »

Pardini uses a heavier bolt for the 32 acp. When I shot mine the cases fall only 3 feet from the gun not like the 32 s&w long which sends the cases out at super high speeds.

If you want to shoot a 32 acp in your 32 s&w long Pardini just buy the conversion kit for it.
John C
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Post by John C »

Pistolchamp;

I'd love to get a .32 ACP conversion kit. Alas, I only have a Walther GSP, for which there is no .32 ACP option. Otherwise, I'd be all over it.

In the meantime, I'm very curious about the technical reasons behind the Pardini's .32 ACP success.

Thanks,

-John
fc60
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Where To Get H&N Bullets

Post by fc60 »

Dave/FC60;

Which H&N bullet were you using with such success? The safety issue you mention with a .32 ACP conversion is definitely real. I guess chambering a barrel in .32 S&W would pose the same issue?

Thanks,

-John

Greetings John,

I buy the H&N 100 grain Match Greased HBWC bullets from Cibles of Canada


Jocelyn Langlois
Cibles Canada Targets
181 St-Henri
Gatineau ( Hull ), QC
J8X 4J6
Tel. 819-778-8857
Fax. 819-778-2647
Web www.targets.ca


They are available in 0.312", 0.313", and 0.314" diameter.

Mr. Langois is a former Canadien National Coach and very pleasant to deal with, as most all shooters are.

Cheers,

Dave
pistol champ
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John C

Post by pistol champ »

I'm very curious about the technical reasons behind the Pardini's .32 ACP success?

The 60 grain Hornady bullet is 0.14 shorter than the typical 32 wadcutter used in the 32 S&W long. A shorter bullet of the same diameter and shape at any given velocity is more stable. I know the shapes are different but in this case the length has a larger impact on stability.
Murph
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Post by Murph »

It is curious how this 60 grain XTP in a full factory load, can hold under an inch at 50 yds out of a Pardini HP......and these bullets are only 0.311".
Vladimir told me they tested a bunch of factory ammo and how this Hornady was clearly the best performer, by far.
JamesH
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Location: Australia

Post by JamesH »

John C wrote:Also, how does the Pardini deal with the recoil of a 60 gr bullet at 950 fps? Is it a heavier recoil spring over the .32 S&W long guns, or a heavier bolt? The difference in energy is significant. Putting the numbers into an online calculator, I see that a 60 gr bullet at 1000 fps is 133 fpe. A 100 grain bullet at 700 fps is 109 fpe. That's 22% more energy.-John
It should be the difference in momentum,
100x700 = 70,000
60x1000 = 60,000

The 32ACP should have less recoil, and shoot flatter thanks to the higher velocity, and spin faster so be more stable.
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