.38supercomp interchangeability with .38super

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Hi all,
I all looking to see if anyone has any experience with using .38 super brass in a gun built around .38 supercomp brass.

Currently have tons of .38 super brass and am thinking about buying a gun built around .38supercomp...I *think* that re-tuning the extractor is all I will have to do, however I thought it prudent to see if this is really the case.

Thanks
DC
 
It depends.

I have a .38 supercomp, but I have a slide with a 9mm breechface. That means that a regular 38 super case, with the larger rim, will not chamber in my gun.

I have another .38 supercomp that uses a regular .38 super slide. I don't know how reliably it runs regular .38 super, but it I can chamber .38 super in it; I haven't tried enough rounds to see how reliable it would be, though.
 
The proper answer is ...it depends. As HB said if you have a 9mm breachface you would need to open it up to allow .38 super to feed properly. If you have a .38 breachface you should be able to get Supercomp to work fine. All of my Open guns are .38 breachface and I shoot Supercomp pretty much exclusively, but if it's hard to find, regular .38 will work fine.
 
If it's a regular extractor I put just a bit more tension on it for super comp, with an Aftec, I'll keep a 9mm in and a .38 handy.
 
My STI is a straight Super. it will run Supercomp most days, about 95% or better. however Cathy's SVI will puke on supercomp faster then you can say a bad prom date.
 
Why would anyone use semi rimmed anyhow?
38 Super's been around since the days of prohibition, and generally today - it's easier to get and less expensive than 38 super comp.

Super comp is a solution to a problem that hasn't been completely proved as a problem; poor feeding from the double stack magazines.

Theoretically, rimless is better but 38 super rarely has feed issues related to the bullets in the mags, more likely it's something a gunplumber has done to the gun.
 
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when i shot my 170 mm mags in the states without being crippled i used Super. i had zero failure to feeds. however i have been told that if i used super comp i can get 30 into the mag rather then 29. i never tried so i don't know for sure.
 
As a gun tuner I can tell you this, you can use 38 super only
1/ if you have a 38 super breachface
2/ your extractor is set up for 38Super ( it is a larger rim and may not feed well in a tigh supercomp extractor setting)
Conversely 38 Supercomp may fail to ejact or stovepipe in a gun with the extractor set up for 38 Super.

Supercomp or TJ is better as it feeds slicker, don't believe me!, load up a mag with super and try to slide it out smoothly, then try the same test with supercomp, you will see why all the top shooters use supercomp for matches.
 
As I get more experience in this sport I find myself agreeing with Ipsik more and more. Hmmm
While I have no real shooting experience with the two rounds mentioned, I do have a fair bit of experience with rimmed and rimless cases in rifles and other handguns. Rimmed cases always fed worst. So I really don't get why Super is still being used? Or maybe that helps explain 9mm major and its rise in popularity lately?
 
Availability of brass, plus it has little impact on local matches where you can only use 10 rounds. In big mags that hold lots of rounds, the tension of the mag spring increases the drag caused by the rimmed cases; it's a far more important issue in places where you're not limited to 10 rounds.

The popularity of 9mm major is strictly a cost issue. A lot of 9mm brass is easy to get cheapish. However, it is hard on the case. Talking to guys in the US, 9mm brass is only good for 2 firings maximum before the brass is useless (primers apparently fall out of the primer pockets). Unless you have a ready source of 9mm brass, 9 major is not the way to go, either.
 
Not to mention a more limited powder selection, the longer case the supers offer allow a greater amount of case volume for bulky powders like IMR 4756.
The super will be around for a long time, most guns will run fine with it, I have shot super in Para, Caspian, STI and SVI as well as 1911 frames. It will run reliably. The rimless is just a bit better and if you are planning on winning a match, you always want a bit better.
 
Bottom line; if a gun is going to choke it will probably do it in a match. As one who shot 9X21 for years I speak from experience. For small matches maybe the magazine spring pressure won't be enough to cause the rim-lock/nose diving issue commonly seen with straight super, but why take the risk or put yourself through the frustration of trying to make a less than optimum case work for you if you don't have to? Supercomp is the way to go.

I thought about the "savings" of 9mm major as well when I switched back to Open, but when you think about the number of reloads you can get out of a Supercomp case vs. the one or maybe two you can get out of a 9 major, the costs become more similar but the hassle factor goes way down.
 
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but when you think about the number of reloads you can get out of a Supercomp case vs. the one or maybe two you can get out of a 9 major, the costs become more similar but the hassle factor goes way down.

My guess is that the majority of Major nine shooters do not pick brass anyway. That was one consideration for me when I had my Open gun built.
 
Excellent points, PH. (Although I have loaded 124grs with 4756 in major in 9mm major ;) )

My guess is that the majority of Major nine shooters do not pick brass anyway.
Exactly. If you're shooting major 9 and picking brass, you made a big mistake when you picked your caliber.

Besides, it's much more fun leaving used 9mm major brass for the brass scavengers. :evil:
 
I was planning on going 9mm major when I build my Open gun. I get my 9mm brass for nothing, so it's not like need to be stingy with it ;) (Then again I get .40 for nothing too). Anyhoo, how much of a volume difference is there between the Super and Supercomp?
 
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