Patrolmen Posted January 8, 2015 Share Posted January 8, 2015 New to the forum but I have been reloading for about 2 years. I see a lot of discussion about major or minor loads. What exactly does that mean? Thanks! Link to comment Share on other sites More sharing options...
parashooter38 Posted January 8, 2015 Share Posted January 8, 2015 major or minor is for power factor in uspsa shooting. minor is 125 power factor and major is 165. they multiply your bullet weight by how fast it goes through the chrno Link to comment Share on other sites More sharing options...
ss+P Posted January 8, 2015 Share Posted January 8, 2015 to add to parashooter38, it also depends on what sport you are shooting and what division you are competing in. Factory WWB and similar products generally chrono at about 1100 FPS or less for 124 gr 9mm. Bullet weight (124) X Bullet speed (1100 fbs) = 136 power factor (minor) For USPSA we look for the best combination of bullet weight and powder burn rate to get the softest feeling recoil we can get. all of that equates to faster shooting (in theory for most of us). A lot of this depends on the gun and barrel combo as well. I have shot custom loads thru some factory barrels and not made the specific power factory, then shot the same load from the same gun but with a custom fit aftermarket barrel and got the specific PF I was attempting to achieve. Link to comment Share on other sites More sharing options...
Patrolmen Posted January 8, 2015 Author Share Posted January 8, 2015 OK. now I get it. So for general shooting, plinking, etc this does not come into play at all. Just follow a credible recipe and shoot. Just was not sure what this pertained too. Thanks for the info guys. Link to comment Share on other sites More sharing options...
Majja Posted January 15, 2015 Share Posted January 15, 2015 That is correct. Link to comment Share on other sites More sharing options...
jmbaccolyte Posted January 16, 2015 Share Posted January 16, 2015 I switch between Minor power factor loads and Major pf loads for general practice. But Minor pf is also perfect for teaching others to shoot handguns. Major pf loads are part way between the Minor loads and full power .40 S&W loads (like Winchester white box or duty ammo). Our power rating system isn't perfect because it multiplies the bullet weight by the velocity. A better way to do it would be multiplying (velocity times velocity) times bullet weight because that's how they measure how much energy a load has. So our way of figuring power is biased toward heavier bullets and doesn't count velocity as much as it should, but this system was started by .45 ACP guys who used heavy bullets and its simpler than squaring the velocity before multiplying by the bullet weight. Link to comment Share on other sites More sharing options...
kneelingatlas Posted January 16, 2015 Share Posted January 16, 2015 this system was started by .45 ACP guys who used heavy bullets and its simpler than squaring the velocity before multiplying by the bullet weight. I'm not sure how accurate that is. I certainly wasn't around when the PF rule was made, but from what I gather it was designed to handicap the emerging double stack 9mms which would be an advantage over the 1911s in competition. If PF were a function of energy, factory 115gr 9mm would score roughly the same as factory 230gr .45 (~330ftlbs of muzzle energy) and I don't think anyone could argue that would level the field. Link to comment Share on other sites More sharing options...
jmbaccolyte Posted January 23, 2015 Share Posted January 23, 2015 Did the 1911s in .45 ACP dominate action pistol competitions when some guys started using high capacity 9mms? And is it simpler to calculate a power factor by multiplying velocity times bullet weight or velocity times velocity times bullet weight (especially without a calculator)? We used slide rules back in the day- talk about primitive. Anyway, do heavier bullets at lower velocity tend to feel like less recoil to most of us than lighter bullets at higher velocity at the same energy level? As for rule changes to level the playing field, that's a pet peeve of mine. It makes sense to separate the $600 pistols from the $2,000 pistols, but limiting my Tanfoglio to ten rounds in the magazine when I can fit 14 or 19 (aftermarket parts added) like IDPA does to level the playing field, stifles progress. A few years ago Formula One (car racing) limited the number of tires each team could use in practice, qualifying and the race, ostensibly to level the playing field between the well financed teams and the poorer ones. At the time, Toyota's race team had 1,000 employees and the top team- Ferrari had 600. How many employees did the poor teams have? Just guessing maybe 100? Sorry for the rant. I know you're more knowledgeable than I am about pistols and competition with them, but some of these bogus rules chap my .... As for caliber, I like the 9, .40 and .45 all really well, but have more experience with the .40 because I picked up truly once-fired brass every quarter for twelve years or so when 250 guys would qualify. Finally, I love the 1911 design as you can probably tell from my user name and am really intrigued by the 2011 versions, but I've got two kids in college for the rest of this semester (one's working on her master's degree which will be in a different field than her undergraduate degree and the only local school that would work with her on that is quite expensive), so no 2011s for a while. But I'm loving the Tanfoglio Match at $600. Link to comment Share on other sites More sharing options...
GrumpyOne Posted January 23, 2015 Share Posted January 23, 2015 There was no math in the beginning. There was a pendulum. If your bullet made the pendulum swing a certain distance, it made power factor. It didn't matter if it was a 9mm bullet or a 45 caliber bullet. The math came later when chronographs became affordable to the common man. There was only one division at that time I believe. Link to comment Share on other sites More sharing options...
kneelingatlas Posted January 23, 2015 Share Posted January 23, 2015 (edited) Did the 1911s in .45 ACP dominate action pistol competitions when some guys started using high capacity 9mms?I don't know, I was in diapers is it simpler to calculate a power factor by multiplying velocity times bullet weight or velocity times velocity times bullet weight (especially without a calculator)?It's not about simple, if you square the velocity a 115gr bullet at 1,100fps is the same energy as a 230gr bullet at 778fps, but if you use the formula as is the first is 9mm is 127PF and the .45 is 179PF, which do you think kicks more?do heavier bullets at lower velocity tend to feel like less recoil to most of us than lighter bullets at higher velocity at the same energy level?See above, at the same energy level, heavier bullets produce more recoil, at the same PF they produce less, hence the preferred method picked by guys shooting .45s... Edited January 23, 2015 by kneelingatlas Link to comment Share on other sites More sharing options...
jmbaccolyte Posted January 23, 2015 Share Posted January 23, 2015 Grumpy- Thanks. So that's why they went with a momentum based power factor, instead of energy. Sounds like you used slide rules too back in the day. How about computer "punch cards"? Atlas- When I wrote that I like all three calibers I should have mentioned that I meant I believe each would work effectively for self defense if the shots were placed well. That said, I haven't shot a .45 in a few years and the last time I shot a 9mm was back in the early 1980s, but since you pointed out that the energy is the same, I would have expected the 9mm to recoil faster and be back on target quicker than the .45, but for the .45 to feel softer. Obviously that's not the way it is though. I appreciate the churching up guys, I learn a lot here. Link to comment Share on other sites More sharing options...
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