Probably because things are not always as they seem. A 3" bbl for a 9mm semi-auto is different than a 3" bbl for a revolver.
### Ah Ha Confusion of terms. Man we've about gotten rid of the CUP/PSI thing, but how about all this other conflicting stuff.
Semi-auto:
When they say a semi-auto has a 3" bbl what you are getting is a 3" bbl that has the chamber cut into it to house the 9mm cartridge. A typical 9mm chamber is over .9" long so at the end of the day a 3" bbl'd semi-auto chambered in 9mm actually has just over 2"'s of actual bbl. The rest is chamber/throat/leade.
Revolver:
When a revolver says it has a 2" bbl it means just that. It has a 2" bbl. Add to that the amount of travel the bullet has in the revolvers cylinders. Then subtract 10fps for every 1/1000th's of cylinder gap.
### Am I making this up or do some people (for whatever reason) measure revolver barrels from the recoil plate to the tip of the barrel?????
As with any revolver/semi-auto, short bbl's show a calibers weakness real quickly. The 9mm simply runs out of gas with the heavier bullets. Add to that a short bbl and the end result is what you're getting. Raw pressure only gets you so far so 35,000psi doesn't mean much if it isn't used efficiently.
### Well said.
A link to buffalo bores website.
Pistol and Handgun Ammunition
They make some of the hottest ammo out there. If you take their 147gr 9mm +p+ ammo it's getting 1160+fps out of 4" bbl's. If you take their 158gr 38spl p+ ammo it's getting 1000fps from 2" bbl's and 1160+fps from 4" bbl's. Hot loads and the 38spl out preforms the 9mm with heavy bullets. If you were to drop down to 124gr/125gr bullets the 9mm would run circles around the 38spl.
### i should have known to follow their lead.
The 38spuer actually suffers the same fate as the 9mm. Start running heavier bullets and they become less efficient.
Buffalo bore didn't bother testing/posting the velocities of their 147gr +p+ 9mm ammo in bbl's under 4"'s for a reason. Namely because the heavy bullet in short bbl's in the 9mm become anemic at best.
### That's good info. The short barrels used in SD complicate this a LOT more than I thought it would.
Contender & contender bbl's bring a lot to the table. The firearms themselves have excellent fp hits. Consistent ignition ='s accuracy. The design is very accurate and their bbl's a very useful for testing loads. I use my 9mm/38spl/357/44mag/45acp contender bbl's all the time for load development/accuracy of a bullet. Then transfer those findings over to tuned/accurized semi-auto's and revolvers.
Not trying to rain on your parade just stating what I found/learned back in the late 80's, early 90's. We used to take or 1911 race guns chambered in 38super and fit 6" bbl'd 9mm bbl's in them. It took a 6" bbl/9mm combo to get any real horsepower out of the 9mm using heavy bullets. Namely th
lyman 158gr rn 358311.
### Not at all. I guess it was worth this exercise for you to bring that knowledge out into the open.
We had to step up to a 6" bbl from a 5" bbl to get any real results from a 9mm with a 158gr bullet. You're trying to use a 3" bbl.