Foto Joe
07-07-2013, 09:51 AM
So yesterday morning I decided to load up my chronograph and head out to test some loads for 45 Colt using some cast 160gr LRNFP's that I cast from COWW's. I took 24 each of 7.0gr TrailBoss and 7.7gr TrailBoss. Having shot Black Powder revolvers for years I'm quite aware that more powder very often doesn't equate to the boolits putting a better hole in a piece of paper and very often also doesn't mean they'll be closer to what you thought you were aiming at. What DID surprise me was that apparently TrailBoss can have diminishing returns velocity wise at a certain point. Incidentally the gun used was a Uberti Cattleman SAA with a 7"bbl at 15 yards.
The loads that held 7.0gr of TrailBoss averaged out at 973fps with an extreme spread of 107fps. The 7.7gr loads averaged 935fps with an extreme spread of 181fps. The Hodgdon/IMR load data does not reflect these types of results by the way. They claim that the 7.0gr load would have a velocity of 903fps with an increase of approximately 100fps with a max charge of 8.5gr. I personally can't remember EVER running a load that exceeded the velocity of what the load data suggested, it's always been the other way around. I really don't care how fast the boolit is traveling, my whole point to running the chronograph is to see how my data compares to the manufacturer. If I should for instance exceed their fps with a max load that might indicate to me that I'm over doing it, which by the way isn't a circumstance I've ever encountered.
Although I would never claim to be a "good shot", I was quite impressed with the 7.0 loads.
The loads that held 7.0gr of TrailBoss averaged out at 973fps with an extreme spread of 107fps. The 7.7gr loads averaged 935fps with an extreme spread of 181fps. The Hodgdon/IMR load data does not reflect these types of results by the way. They claim that the 7.0gr load would have a velocity of 903fps with an increase of approximately 100fps with a max charge of 8.5gr. I personally can't remember EVER running a load that exceeded the velocity of what the load data suggested, it's always been the other way around. I really don't care how fast the boolit is traveling, my whole point to running the chronograph is to see how my data compares to the manufacturer. If I should for instance exceed their fps with a max load that might indicate to me that I'm over doing it, which by the way isn't a circumstance I've ever encountered.
Although I would never claim to be a "good shot", I was quite impressed with the 7.0 loads.