.......just tell me NO and let's move on.....

[Palladan44]

I have a huge, huge huge amount of 147 grain .355 JHP bullets, with cannelure. They are de-milled Speer Gold Dot G2s.

I'm pondering the idea of loading them in 38 Specials. As you can see, I've discovered that there is insufficient neck tension due to being a .355 bullet going into a .357 resized case. The bullet was able to be set back using hand pressure on the side of my wood bench....

What if I ran just the top of my fully resized 38 batch of brass (after being full length resized in the .38 die), then run the whole batch of .38 brass through a 9mm die, but only say about .375" down from the mouth? This would get the neck tension right. I also would likely switch the powder funnel/expander over to the 9mm one probably.....I'd play that part by ear....

These would remain light to medium .38 special velocities.

Any thoughts, or is this a bad, bad idea?

My main reason for wanting to do this is....im not loving these bullets in 9mm whatsoever. No matter what OAL, they have FTF issues and im just tired of tinkering with them in 9mm.

 

[alfsauve]

I use 147gr plated 9mm bullet almost exclusively for my lighter 38spl loads. Just screw your crimping die down and put a substantial crimp in them.

 

[beeenbag]

This seems like a lot of extra work to produce a sub par accurate round. Its not just the case diameter that is larger, your bore is also larger. So, NO, move on

Edit: I stand corrected, the bore is the same, I'm sticking to my initial opinion of moving on, solely due to the extra steps you seem to need and me being too onery to add extra work.

 

[Jim Watson]

Good luck. I tried 9mm bullets in .38 Special and could not arrive at a combination that would give adequate bullet pull.

When Ed Harris wrote it up for American Rifleman, he had RCBS make a sizing die that put a slight bottleneck on the Special case.

 

[alfsauve]

This seems like a lot of extra work to produce a sub par accurate round. Its not just the case diameter that is larger, your bore is also larger. So, NO, move on

I seem to recall the grove diameter is the same for 9mm and .38spl. They stabilize well and give good accuracy in my revolvers. Then I’m only running them at ~760fps

 

[hoardingthemanual]

Why put so much energy into doing it wrong when you can just as easily do it right with added peace of mind? No.

 

[Palladan44]

I use 147gr plated 9mm bullet almost exclusively for my lighter 38spl loads. Just screw your crimping die down and put a substantial crimp in them.

I've already tried this, and it doesn't work good enough. All it does is swage the bullet down, then the brass springs back a little bit where the swaged down bullet does not spring back. This equals- still no neck tension. And with the forward taper of the longer ogive makes it even harder.

There is an actual cannelure, but it is way too far near the base of the bullet. What I'm going for is one of the stamped in rings around the bullet to crimp into.....these are shallow grooves probably engineered into the bullet to help slow/expedite expansion...something like that.....

 

[ballman6711]

Is it possible to get a 9mm conversion cylinder for your .38?

chris

 

[Palladan44]

Why put so much energy into doing it wrong when you can just as easily do it right with added peace of mind? No.

Tinkering around is just part of the fun I guess....provided It's safe to do so

 

[Palladan44]

Is it possible to get a 9mm conversion cylinder for your .38?

chris

Not in the cards

 

[Charlie98]

I've already tried this, and it doesn't work good enough. All it does is swage the bullet down, then the brass springs back a little bit where the swaged down bullet does not spring back.

Have you tried a taper crimp die? ...or perhaps the 9mm crimp die (which is likely a taper crimp.) Trying to mash a heavy roller into that sounds like a bad idea. FWIW, if you can't get those bullets to stay still, you are kind of at a dead stop.

 

[fxvr5]

The answer is - yes.

As you discovered, neck tension is an issue. 38 brass and dies are deigned around 38 brass and 38 caliber bullets, and using smaller bullets can cause less neck tension.

Your remedy might work. I use a Lee undersize sizing die for the brass, and a 9mm expander die and that provides good neck tension.

And you can, as you know, crimp them over the shoulder.

 

[fxvr5]

This seems like a lot of extra work to produce a sub par accurate round. Its not just the case diameter that is larger, your bore is also larger. So, NO, move on

The groove diameter of 9mm and 38/357 barrels is exactly the same. .355" + .004".

https://saami.org/wp-content/upload...rfire-Pistol-Revolver-Approved-12-13-2022.pdf

 

[Palladan44]

Have you tried a taper crimp die? ...or perhaps the 9mm crimp die (which is likely a taper crimp.) Trying to mash a heavy roller into that sounds like a bad idea. FWIW, if you can't get those bullets to stay still, you are kind of at a dead stop.

How can I get more neck tension through the "right" crimp? I'm of the understanding that in straight-walled pistol cases, that no matter how the bullet is crimped, the neck tension will never get to where it needs to be. Neck tension comes from the resizing of the brass to the correct size, and then the bullet being seated into it creates the neck tension. Crimping is strictly to remove the case belling, and no more. Roll crimping is only used in certain situations (most of know what these all are) but even in those situations the Roll crimp does not substitute, or over-ride proper neck tension created from proper bullet to brass fit. In fact some Roll crimps can be botched, destroying neck tension if excess taper crimp is used prior to the Roll crimp.

Has anyone ever ran already properly sized .38 brass in a 9mm die, say only about .250" to .375" of the top part of the brass? I'm going to try this out.

 

[alfsauve]

Wait. Hold on to your hats.

Not only are the groove and bore diameters of .38 Special and 9mm the same.

Wait for it........

The inside case dimension of a 9mm, at the case mouth, is spec'd LARGER than the .38spl. WHOAAAAAAA. (okay, okay it's barely .002")

From the SAAMI specs https://saami.org/wp-content/upload...rfire-Pistol-Revolver-Approved-12-13-2022.pdf
pages 24 and 39 to save you searching.

Grove Bore Inside Case Mouth
9mm .355 .346 .3811
.38Spl .355 .346 .379

No need for anything special other than putting in enough crimp to hold the bullet as you would with any new bullet you were using. In fact when going from X-treme 125gr plated .38spl, to an X-treme 147gr plated 9mm I don't change anything in my setup. And again, these are moving about 760 to make IDPA power factor. Plus the pointed nose helps me in reloads.

 

[mdi]

Yep, experimenting is a fun part of reloading. I have 5, 9mm handguns and 4, 38/357 revolvers. I slug every gun I get, except 22 rimfire. The smallest 38/357 barrel I have is .357", most closer to .358" and the largest 9mm is .357" with most at .355". So there is a difference in barrel dimensions. I might try a few .355" bullets in my 38 Specials, but I wouldn't expect any decent performance. Poor accuracy, perhaps lower velocity and keyholing...

 

[Blue68f100]

Have you tried it without using the expander? Your sizer may reduce it enough to hold.

 

[Walkalong]

Have you tried it with using the expander? Your sizer may reduce it enough to hold.

Without?

Try that, will likely work.

 

[Blue68f100]

Without?

Try that, will likely work.

Good catch. I edited my post.

 

[Seedy Character]

CRIMP IT and go

 

[243winxb]

The newer RCBS 9mm Luger fl carbide die has a tapered insert. Neck sizing 38 spec in 9mm die should work. Use 9mm expander.

9mm in 38. Think Ruger Blackhawk convertiable.

 

[Scooter22]

Try a Lee Factory crimp die. It has a collet that squeezes the neck into the bullet even without a crimp groove. No huge roll crrimp. Just a thought.

 

[Jim Watson]

A .380 sizing die might neck a .38 Sp case down enough further to get a grip on a .355" bullet.
Or just a little way into a .223 sizing die... or seating die.

 

[cfullgraf]

Crimp is not a substitute for proper neck tension.

Try a 9mm expander in your 38 Spec expander die or chuck the expander plug in a drill and sand a .001” or .002” from the diameter of the expander plug. It will increase neck tension.

 

[AJC1]

Should be just as easy as swapping the expander and nothing else.