The Firearms Forum banner
1 - 13 of 13 Posts

·
Registered
Joined
·
68 Posts
Discussion Starter · #1 ·
I have heard once or twice that since 9 mm bullets and .357 bullets (38 cal) are very close in size, they can be used interchangeably to a degree. I have a few questions that I would like help with from those who have valuable input. First, I have some 38 special/357 magnum cases and also some 9 mm. Now at this time I only have .357 bullets (Berry's platted 135 g), I set one of said bullets on top of a 357 mag, and as I expected, the bullet was slightly larger than the case mouth, I also found a 9 mm case, and did the same, but the bullet would more or less slide right into the case. Now, mind, this is just range brass, and has not been sized or anything yet, so I guess that leads me to my first question which is, does the 357 bullet fit better in the 9 mm once you have sized it? For instance, does in narrow the mouth of the case when you run it through the die? Also, I would have no fear loading a 357 bullet in a 9mm, as it is slightly smaller, but would it be troublesome if someone loaded a 9mm bullet in the smaller 357 mag or 38 special? And lastly, even though it means very little, would their be an accuracy difference in the 9mm if it where loaded with the slightly smaller 357 bullets, is the dimension a big enough difference to notice?
Thanks for any thoughts.
 

·
Registered
Joined
·
68 Posts
Discussion Starter · #5 ·
@howlnmad
I stand corrected! I will be honest and say I had not looked in a book for dimensions untill just now, i just started setting bullets on cases! Sierra lists the 9mm as .355”, and 357/38 as, surprise, .357”.
So I guess that means that my first post is almost completely backwards. Now, following that logic, would it be safe to load a bigger, .357” bullet in a 9mm? And also, would the accuracy of a 357 be hurt by loading it with a smaller 9mm bullet? I assume so.
 

·
Registered
Joined
·
2,333 Posts
It's interesting to note that all of Berry's 9mm bullets are .356 dia and Hornady offers 9mm bullets in both .355 and .356 dia.
For just plinking and speed shooting I have ran .356 in my .38 / .357 pistols without issue. My 38 Super runs .355 - .357 without a problem. I was surprised to see that range of diameter(s) for my 38 Super in the Hornady manual.
I don't think that I would try to squeeze a .357 down the throat of a 9mm.
 

·
Registered
Joined
·
2,366 Posts
355/356 lead or jacketed bullets run fine in 38/357 carbines. Not so much in revolvers with lead as leading will be more pronounced because the cyl throats are larger and gas passing by superheats the lead and blows it up the barrel.

The groove diameter is typically 356 in both 38 and 9 barrels but the chamber is not the same at the throat plus the 9 headspaces off the brass mouth and 38/357 off the rim. Thus 9mm bullets have no canalure to roll crimp in. The nose design of the 2 bullets is not the same - 357 bullets are not shaped properly to work in the 9mm chamber and even if you resize them to the correct OD they dont fit properly and can stick and also not give the correct pressure or OAL. In addition to all this a 9mm case is tapered on the outside and inside with thicker brass on the rim end and the 38/357 bullets are designed to be seated deeper so if you cram them in too deep the case is out of shape and the volume reduced.

suggest just to buy the correct bullets for what your loading - some 9s can be difficult to load for and trying to use the wrong type bullets wont help any. Hornady action pistol bullets (HAP 125grn) are accurate and not to expensive - you might try those if cost is an issue.
 

·
Registered
Joined
·
614 Posts
I cast most of my 9mm bullets from wheel-weights and size the cast bullets to .357" ... 5 different 9mm Luger pistols use this size cast bullet ,

The 38/357 bullets I cast are sized .358" for use in handguns .
This is normal for cast and swaged lead bullets to be ,00!" or .002" larger than jacketed bullets .

Just wanted to throw this in so you wont be any more confused than you already are ... Don't let anyone tell you reloading is simple ...lots of stuff to get confused about !
Read the informational chapters in the beginning of every reloading manual ...
Lot's of good info with photo's and it will help you get all your facts straightened out .
Gary
 

·
Registered
Joined
·
23 Posts
I have a 9mm that never patterned any better than a shotgun. When I slugged the barrel it measured .356 across the lands. .357 jacketed bullets made it a shooter. The wasp waist is a little more pronounced, over 1k of .357 and no problems.
YMMV
 
1 - 13 of 13 Posts
Top