Major Minor?

[James S]

Since im new to reloading. can someone please explain what major and minor are?

[eric nielsen]

http://www.findarticles.com/p/articles/mi_..._25/ai_78870840

Short answer:

Minor is at least 125,000 [a 115 grain bullet at 1087 fps]

Major is at least 165,000 [a 180 grain bullet at 917 fps]

[sendf1]

Major is what you hope the guy at the chrono says and minor means your pissed for the rest of the match.

[Gun Geek]

How about a little more complete answer. Also I think that article linked has some out of date info:

Major and minor refer to thresholds of something called power factor (PF). In the US (or anywhere else not using the metric system), power factor is bullet weight in grains x bullet velocity in feet per second. If you were using the metric system you would multiply grams x velocity in meters per second. But, from highschool physics, this is momentum. In the states we don't call it momentum because there is a fundamental difference between weight and mass (but that's a thread drift).

In the USPSA rule book, that number is then divided by 1000 to give numbers such as 165 or 125. In IDPA, you don't divide by 1000, so you see numbers in the rules like 125,000 or 165,000.

For handguns, the rule books define major as a pf of 165 or 165,000. Anything below that is called minor. A pf or 125 or 125,000 is the MINIMUM power factor required for these sports. From here how the rules are applied depends on the game (i.e sport, division, etc) you are playing, so check your rule book. The linked article was written in 2001 and kind goes all over the map on major/minor. Any historians want to add to that?

All of this gets down to setting some standard for the ammunition used in the sports. Otherwise, guys would load the ammunition down as far as they could and still get the gun to function (probably after changing springs). The 125/165 numbers were chosen because factory loads will generally be that level or a little higher out of most guns (there are always exceptions). Therefore reloaders don't get a huge margin of advantage just by handloading.

There is another result of naming a pf. At a given powerfactor, the combination that pushes the bullet the slowest will result in the least recoil energy. Strangely enough, that means that you should use a heavier bullet. Here's why: From physics energy is 1/2 x mass x velocity (squared). This means that the energy is controlled more by changes in velocity than in mass. A 200 gn bullet has to go 825 fps (200x825 = 165,000) to make major. A 180 gn has to go about 917 fps. The 200gn load will produce less recoil energy.

Lowest energy isn't the only decision factor. Some guns need that energy to make the slide go, some people like the feel of a shorter snap, then a more gentle push, etc.

Hope this helps!

Edited March 26, 2006 by Gun Geek