Thoughts on 9mm revolvers? and barrel size for 38's rather than .355 for 9mm?

sgc said:
I have been thinking of picking up a 9 mm revolver since ammunition seems a lot cheaper than 38's. I read though that some barrel sizes, like in a 986, are the same size as 38 specials and not 9 mm which I believe was said to be .355. Just curious if this is true and any other thoughts on a 9 mm revolver.
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op: maybe i am misinterpreting your post, but if you have a .38/.357, and you are mechanically inclined and detailed you could put together a basic reloading setup for those rounds at around the cost of a decent new 9mm handgun.

I still load for 9 (it’s now a wash vs buying the cheapest new) but also load for .38, .357 and .45 where it’s still less expensive to handload vice factory ammo.

Just my 2 cents. But full disclosure: I’m retired so my hourly wage costs are called ‘having a hobby’. If you’re employed and should be paying more attention to the wife and kids - disregard this message.
Best
Tim
 
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I've owned Ruger .357/9mm convertibles, a 686 with extra cylinder converted to 9mm, and other 9mm revolvers. I've not been able to determine that .357, .38 Spcl. or 9MM is consistently more accurate, though .38 Spcl. is more pleasant to shoot. Likely a better shooter, or Ransom Rest, could determine that. Then a different revolver, or different ammunition, might change results again.

FWIW, SAAMI bore and groove diameter specs for .38 Spcl. and .357, 9X19mm , .38 Super, 9X23 Win., .357 SIG, etc. are the same. Seems most shooters assume .38 Spcl. and .357 groove diameters are exactly .357" and 9mm is exactly .355". Well, OK, maybe...
 

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I just bought a 9mm cylinder for my Uberti .357.
I haven't tried it yet but have no worries that it won't do well.
When I had a Ruger Blackhawk Convertible, it did great but preferred 147 gr. ammo over 115 or 124 grain.
 
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929 throats are .357. i don't know about the barrel. When shooting lead bullets it's best to match bullet to throat diameter or be a smidge on the large side i.e. use .358 bullets. Jacketed bullets aren't as effected by these small differences. When relaoding lead I use .357 bullets in my 929. When shooting jacketed I just use normal 9 mm bullets. The gun is very accurate out to 50 yards with the correct loads.

I like my 929 but they have gotten to be pretty expensive($1,500 range) and are kind of a niche gun. Factory 9mm ammo is quite a bit less expensive than factory .38 Special so it'd wouldn't be too hard to make up the price difference if you are shooting on a regular basis.
 
I own only one revolver that accepts 9mm - an old model Ruger Blackhawk convertible .38/.357/9mm. For just plinking, the 9mm is adequate, and way less expensive. As far as loading and unloading the cylinder goes, the same procedure works for everything. Accuracy is acceptable, well within a minute of bad guy... Nice thing is that you can purchase ammo for this gun pretty much worldwide.

John


(Click for larger image)
 
I'm not much of a 9 mm or bottom feeders fan but will definitely be checking into that .357 mag. Coonan. Thanks for posting.

Sure looks sweet.

Al
 
Posted this prior, had forum vendor Protocall Design sell me a Lothar Walther .355 barrel (9.8-1 twist) 6". Installed it on my 986 and it is now a 9mm nail driver at 50 yards.

Like the 986 so much that I bought a 686 PLUS cylinder and shortened it to fit the 986. Shoot 9mm with full moon clips, swap in the 686 PLUS cylinder - shoot 38 spl (38 Colt short/long) with speedloaders.
 

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I really wanted to like my 940 w/3” barrel.
I like moon clips and I’m happy with 10 mm & 45ACP caliber revolvers using them.

Regarding the 940:
Accuracy is okay but not great.
Big complaint is the very difficult extraction. Honing and polishing the cylinders wasn’t much help.
 
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9mm bullets work fine with any nominal .38 caliber. .38 Spl, .357, .38 S&W, .38 Super, etc. SAAMI specs for minimum bullet diameter for all those is around .355” or even less. Except for .38-40. Look it up.
 
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I have a lcr in 9mm it's a great gun. I carry it in a pocket holster in a belly carry,
 
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sjmjax said:
I really wanted to like my 940 w/3” barrel.
…
Big complaint is the very difficult extraction. Honing and polishing the cylinders wasn’t much help.
Click to expand...

I’ve heard and read that from others about the 940. I was expecting that when I got my LCR 9 but it hasn’t been the case. Same with a friend’s LCR.
I know that’s only two examples, but I still wonder what the difference could be.
 
JimCunn said:
Check the SAAMI specs for land and groove diameter of .38sp and 9mm barrels. Accuracy is not affected by conversions from one to the other.
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Well, file this under "Never too old to learn", this is correct. Shooting Times did an article on it and the SAMMI website comfrms it. They are the exact same barrel.

9mm and .38/.357 Barrel Bore Diameters Explained - Shooting Times

Now, reloaders, just choose your bullet based on throat size since the barrel issue is mooted.

Anyone else remember 9mm Federal? Maybe not such a dumb idea, after all.

EDIT: I poked around for twist rates and apparently S&W currently uses the same 1:18.75 twist for both 38/357 and 9mm. 1:10 is also a common TR for 9mm.

Twists

Also, before anyone objects that manufacturers don't necessarily adhere to SAMMI specs, I am aware of that. But the article above slugged a bunch of barrels - the differences are negligible and well within the arguing on the internet range.
 
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OK - I will be the contrarian in this thread. To me the 9mm cartridge is one of the best ever invented and for it's size, weight and effectiveness almost impossible to beat! That said, my personal feeling is that they really belong in semi auto pistols and not revolvers. Yes, I am aware they have somewhat successfully "made" them fit revolvers but to me I'd just feel comfortable with a rimmed cartridge in wheel guns.
 
sgc said:
I have been thinking of picking up a 9 mm revolver since ammunition seems a lot cheaper than 38's. I read though that some barrel sizes, like in a 986, are the same size as 38 specials and not 9 mm which I believe was said to be .355. Just curious if this is true and any other thoughts on a 9 mm revolver.
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I own many revolvers capable of safely chambering and firing 9MM Parabellum ammunition. Some are Factory offerings while others are conversions

940.jpg


940%20TRIO-1S.jpg


547.jpg


627%209x23-1.jpg


627%20V-Comp%20%20Rs.jpg


My standard 940s have had their chambers lengthened for shooting 38SUPER. The PC 940 Specials are all Factory chambered in 356TSW.The Model 547 is a 9MM chambered K-frame from the Factory that does not need moon clips. The two Model 627s have 2nd cylinders which are chambered for 9x23 Winchester.

Remember that rimless autoloader ammunition headspaces on the moon clips in most Smith & Wesson revolvers (except the 547). This allows revolvers like my 9x23 Winchester Model 627s to safely chamber and shoot all of the shorter cartridges including 38SUPER, 38 ACP, 356TSW, 9x21, 9MM Parabellum, 380 ACP and others

Accuracy is mostly a function of proper bullet spin.

Bullet spin is caused by the rifling engaging the projectile

JimCunn has it right, but most people forget that there is both a land and a groove diameter involved when they talk about bore diameter. What is actually measured when folks slug a barrel is the groove diameter.

The difference between the land and the groove is the depth of the rifling (the part that actually engages the projectile) which causes the spin.

This difference is somewhere around .008" - .013" depending on the type of rifling and who did it

bore-types-handgun.jpg

Image courtesy of Hand Gun Safety Course​

9MM jacketed, plated and coated 9MM projectiles typically measure anywhere from .355" - "3565" depending on the manufacturer. There is still plenty of projectile for the lands to grab onto a 9MM projectile and get spin even in a .357" barrel.

I have been shooting jacketed 9MM projectiles through many different .357" barrels for several decades now.

The accuracy exception/complaints from shooting 9MM ammunition in a .357 bore comes when we are discussing lead projectiles. Cast lead projectiles should be matched to the diameter of the barrel they are being shot in. This is of course true in all firearms
 
From Post #34
"EDIT: I poked around for twist rates and apparently S&W currently uses the same 1:18.75 twist for both 38/357 and 9mm."

That is correct, and as you stated, also the same land and groove diameter. I knew the barrels were identical before I did my first conversion.

I like exposed hammers and light weight, so each of my three Airweight 637-2 revolvers has three cylinders
The original unmodified stainless steel .38Sp cylinder
An unmodified titanium .357Mag cylinder
A modified titanium .357Mag cylinder reamed for 9x19 and moon clips
(One is reamed for 9x23)
It takes about a minute and a half to convert between the three cylinders.
I confess that I am somewhat overrun with cylinders.

9x19 recoil is painful enough to suit me, so I don't shoot 9x23 or .357Mag in these pistols - but I've shot enough .38Sp and 9x19 to know the barrels don't care which round is passing through. Due to my age/vision (82 and 20/25 now), I no longer shoot as well as I used to - but my preferred J-frame distance is still 50-75 feet. They do just fine at that distance.

As an aside, I have worn out the rachet lugs on one of my stars cut for moonclips. Gonna have to cut a new one for the clips for that gun..
 
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