9mm to .38 super

First topic message reminder :

I have a Springfield loaded 9mm I was wondering what it would take to convert to .38 super. Would I just need to have .38 super mags and have a barrel fit?

Rechambering a 9mm to 38 Super, from SAAMI chamber dimensions. Reference of .150 from the breech face as a conservative point at which the walls are thinned out, .0035 larger in diameter. I doubt there'd be an issue with over working of the brass.





Of course this is just theory from the spec's. Dimensions are minimum chamber. Tolerance for both is +.004. So if you had a fat 9mm and ran a min 38 into it, there'd be more 9mm left.




I was surprised to see the 38S doesn't have a shoulder for the case mouth, just a leade from case diameter like quite a few of the old rifle cartridges.

tovaert wrote:Curious...what is the advantage of 38 Super comp over 9 mm? Is it softer shooting? More accurate at 50 yds? 147 gr XTPs through a 1:10 twist barrel are generally quite accurate even down to 850 (+/-) fps subsonic.

While I do not like to do it on purpose all 9MM cases are +p. Can you reload to +P on once fired brass, probably, can you reload a case 20+ times like 45acp to +P 9mm , no way. 

147gn out of a 38 super at 800 FPS is accurate 9mm till have excessive yawl at 50 yards under 950 +/- FPS. I loaded up some 9mm using vv310 and 147gn over 3.8gn and the bullets hit sideways at 25 yards. Getting that bullet to shoot soft with 9mm is easy getting it to shoot accurate is nearly impossible unless you load mid to high range. 


For example, 147 Jfp RMR over 4.2 CFE is accurate but the it recoils more than 45acp target loads.

james r chapman wrote:If you just want to play with .38 super, Ebay was selling Sig .38 super bbl's for $40 awhile ago. basically drop in.
also, if you pull the spacer in the back of 9mm mags that aren't crimped in the front, the recommended supercomp brass will work.

Are those Clark Para Barrels? And did they come with a bushing?

Wilson/Nowlin and no bushing...

james r chapman wrote:also, if you pull the spacer in the back of 9mm mags that aren't crimped in the front, the recommended supercomp brass will work.

I tried that with my Wilson 9nn magazines.  You need to use the follower and spring kit bit it's hit or miss.  When he built my gun, Jon found the 9mm feed lips were too long and they would release to round too late.  On his recommendation I went to Ed Brown magazines and haven't looked back.  My pistol even feeds 148gr button nose wadcutters without issue.