Question about open division and 38 super

I

island

CGN Regular
EE Expired
Rating - 100%
43   0   0
Location
Saskatoon, SK
Hi all:

I notice many open division guns are in 38 super caliber. I think this has/had something to do with the lightest recoil with enough gas to operate the comp properly. Is this the case? I also remember reading something about the power factors changing to make this not the case any more, but didn't get the specifics.

I guess my underlying question is: is 38 super the "best" caliber for an open gun? It's a bit hard to find brass and bullets for - I personally prefer the more "standard" calibers like 40 and 45, but if 38 super is used for a reason, fair enough.

Any insights?
 
The .38 super family of cartridges (9mm major, 9X21, 9mm supercomp, .38 super, .38 supercomp and whatever else) all do the same thing; utilize a very large gas column exiting the gun to assist in the control of linear and rotational displacement of the firearm through the use of compensators and/or barrel ports. .38 supercomp seems to be the favored variety since it is a straight walled case with no rim, so it stacks well in the magazine and eliminates a lot of the feeding related problems that you get with semi-rimmed or tapered cases. however, many are switching to 9mm major becasue of the cost savings in the brass.

Larger bullets like .40 or .45 caliber require faster burning powders and do not create an adequate gas column. They tend to flip more, kick more, and because of the increased diameter, they tend to torque more against the gun.
 
So the question is.. why is .38 super not a common caliber for Standard (Cost issues aside).

in a gun which does not have a comp, is .38 super a better cartridge?
 
yeah cause if it was just up to power factor you could make major with a very hot 9mm load..
 
Ok, that makes sense - so it's not that someone just hasn't designed a comp that works with 40/45 but that it's not possible (given the gas) to make a comp work as *well* with those calibers - plus the extra weight of the bullet of course gives more twist and recoil anyway.

So I guess making major with 38 super isn't a big problem if you need enough gas to work the comp properly anyway?

I think I follow better now, much appreciated :)
 
Yes - because the minimum caliber for major in Open is 9mm/.38

On the power factor change it was reduced, yes reduced in open because people were using very light bullets at high velocity to get the comps working better and better. As the rotation on a barrel is more than you need to actually stabilise the bullet in flight the RPM of the bullet in flight was getting so high bullets were starting to shed jackets or disintergrate on the way to the target because of the high RPM.

The typical twist rate in the 1911 is 1 in 16. At 1000 fps this gives 45000RPM! ((12* 1000/16) * 60). 38/9mm with the reduced PF are making 1200 fps+ over the chrony which is 54000 RPM, still quite a number even with the reduction in PF.

Hence the Power Factor was reduced to ensure saftey.

FYI - 9mm major in a 5" slide configuration gives a really soft nice feel to the recoil. I have shot a Bedell Custom is this configuration (7 port comp) and you would not believe how nice it it to shoot, and his rounds are making 1200 fps.
 
Bartledan said:
In standard, minimum caliber for major is .40
Click to expand...
And the reason for that requires a history lesson.

Not too long ago there was one division - Open (actually no division) and you could not shoot unless you had a minimum caliber of 9mm. Major PF was 175.
That's it. Most guys shot 45s. The Comp was invented, and it was semi-good.

An enterprising young man named Leatham figured out that if you used a fully supported barrel in a 1911, and hotrodded the bejezus out of 38 supers, you could get a crapload of gass to make a comp run very efficently. 38 Super was chosen because it's OAL was faily close to 45 ACP and the 1911 was tuned for that length of bullet in cycling.

The problem arose that a lot of these hot rodded supers blew up guns (hence the term "super face" when a shooters' ammo blew back through his firing pin into his face.)

USA Liability issues crept up, but at the same time, too many people were using supers to force them all to give them up and go to a safer, larger caliber. (Although they did really think hard about it.)

Once Standard was invented (the second division) they immediately made the minimum for major to be 40, so that no one would worry about liability in this division, and it was publicized that open was "anything goes" and it would be harder for someone who hotrodded ammo to blame the shooting org for blowing his own gun up.

Even now, with a 160 PF in Open, you're not going to get any factory approved (under SAMMI pressure limits) ammo that will make major in a 38 super, let alone cycle a race gun tuned for 38 super major.

On the bright side, we have much stronger guns for shooting hotrodded super these days.
 
Onthebeep said:
FYI - 9mm major in a 5" slide configuration gives a really soft nice feel to the recoil. I have shot a Bedell Custom is this configuration (7 port comp) and you would not believe how nice it it to shoot, and his rounds are making 1200 fps.
Click to expand...

I have a 5 inch Bedell in 9 major...

I load about 8.3 grains of 3N37 with a 125 HAP...makes about 1340 fps (approx 168 PF)

With the slide cuts, the titamium comp and the Grams mounted Docter site...it's a very light gun...and it still shoots nice and soft
 
Last edited:
I heard that the reduction in PF had something to do with limitations of factory ammo only in some regions ( Philippines seems to ring a bell). Is that true, or just another IPSC urban myth...?
 
Yup Quigley it was your gun I was referring to, I just didn't want to name you in a post without your prior knowledge.

Honestly folks that gun is AMAZING, none of the blast and shock that you'd normally associate with an open gun (especially a shorty). More like light target loads through a .38 revolver than a 1340fps major round.

I'm still trying to work out how to afford one myself :+)
 
Onthebeep said:
Yup Quigley it was your gun I was referring to, I just didn't want to name you in a post without your prior knowledge.

Honestly folks that gun is AMAZING, none of the blast and shock that you'd normally associate with an open gun (especially a shorty). More like light target loads through a .38 revolver than a 1340fps major round.

I'm still trying to work out how to afford one myself :+)
Click to expand...

Ah ha ...I was wondering about that :cool:

Now if I could only learn how to shot it :redface:

Cheers
Quigley
 
I was told that the reduction to 160PF in Open was because factory 38 super only makes a 160PF and IPSC was trying to accomodate those people in countries where reloading is illegal.
 
hungrybeagle said:
Do you guys have a reasonably priced (ie, less than $35 per pound) supplier of 3n37 out east?
Click to expand...

It's hit and miss...right now it's pretty hard to find. I keep hearing rumours about a local distributer...I'll keep you posted if anything comes of it

Cheers
 
Quigley said:
Ah ha ...I was wondering about that :cool:

Now if I could only learn how to shot it :redface:

Cheers
Quigley
Click to expand...
It's as easy as 1-2-3

1 put dot on target.
2 squeeze trigger until gun goes off with out moving dot.
3 repeate steps 1-2 as needed.
 
38 Super

If you look on Vitavuori website for 38 Super you will find that the biggest majority of the loads that they list make the 160 power factor.
 
You must log in or register to reply here.
Back
Top Bottom