How do they measure PF at an event?

[igolfat8]

I have never been to an organized event or competition and wondered how they measure PF to determine Major and Minor. I have a basic understanding of the terms Major and Minor now. But how do they measure your ammo and gun? Do you have to submit a cartridge for every time you shoot? Do you hold the gun and fire through a chrono or does someone else shoot your gun or do they shoot it through a test gun? Are you measured just once for the day or each time you come to the firing line? How does it all work?

[NicVerAZ]

I have never been to an organized event or competition and wondered how they measure PF to determine Major and Minor. I have a basic understanding of the terms Major and Minor now. But how do they measure your ammo and gun? Do you have to submit a cartridge for every time you shoot? Do you hold the gun and fire through a chrono or does someone else shoot your gun or do they shoot it through a test gun? Are you measured just once for the day or each time you come to the firing line? How does it all work?

You are sometimes clocked prior to the event, especially if it is a local event, sometimes at the event itself and you have to declare the mass of the bullets you shoot. It is based on trust that you are actually shooting 147gr 9mm bullets when you say so and not 125gr.

If you clock at 900+, then you pass minor factor but if your rounds are 125gr, then you are cheating. That said, good luck pushing down pepper poppers.

Random rounds of ammunition can also be inspected and taken apart, the bullets weighed.

You are usually only clocked at main events (regionals and nationals). Club matches very rarely clock you, unless there is a doubt that you are cheating.

Edited December 19, 2012 by NicVerAZ

[Sarge]

There will be a chrono stage that your squad will rotate through just like every other stage. At the beginning of the match, usually on your first stage of the day match officials will collect 7 rounds of ammo from each shooter. That ammo goes to the Chrono stage operator. They will pull a bullet from your ammo and weigh it. When you get to chrono the chrono guy will tell you to pull your gun out, clear it and lay it on the table. He will then ask for an empty mag. He then will weigh your gun and mag if your division calls for a weight restriction. He will then put the gun in a USPSA box to see if your gun fits. Again, that is if your division requires it. Then he will load up the mag and fire three rounds over the chrono. He will calculate PF by multiplying the EXACT weight of the bullet pulled and the average velocity of the three rounds. When he is finished he will clear the gun and hand it back to you and tell you to holster it.

[RePete]

IDPA matches that I run the chono at, when you go to your first stage the SO will ask you for 7 rds (honour system, my preference) or say which rds he wants to take. The rds are bagged and your equipment tag stuck on the bag.

The bags are sent to me where I chrono them in match guns. If you make PF then there is no further action, however, if you don't make PF, I will request your presence at chrono with your gun, and proceed shooting your gun. If you make chrono with your gun, then all is good and if not then a DQ is issued.

I have charts that and friend and I have made (Excel) indicating velocity and PF.

[BostonBullit]

The only time I've seen a chrono stage was at the Area match and it was the most exciting stage of the day! I was in danger of not making major and got down to that last bullet where you need to decide if you want it pulled and weighed or fired over the chrono....it's like a game show or something. Had them shoot it and ended up making major by .3

[RePete]

The only time I've seen a chrono stage was at the Area match and it was the most exciting stage of the day! I was in danger of not making major and got down to that last bullet where you need to decide if you want it pulled and weighed or fired over the chrono....it's like a game show or something. Had them shoot it and ended up making major by .3

As I would tell shooters who end up like you, use a bigger shovel because you're too close to the line.

[Poppa Bear]

The only time I've seen a chrono stage was at the Area match and it was the most exciting stage of the day! I was in danger of not making major and got down to that last bullet where you need to decide if you want it pulled and weighed or fired over the chrono....it's like a game show or something. Had them shoot it and ended up making major by .3

I ran into the same situation a couple of years ago. My home range chrono had me at 170 PF but I was at 165.0 +/- .1 as the rounds went across at the match. Shot the 8th round and made it at 165.0. I place the blame on their chrono set up because we had an open shooter with rounds that ran around 1,480 at our range who got clocked at between 500 and 600 fps for several of his shots. Chrono was out in the blazing sun without any shade so we did not put to much credence into its accuracy.

[BostonBullit]

The only time I've seen a chrono stage was at the Area match and it was the most exciting stage of the day! I was in danger of not making major and got down to that last bullet where you need to decide if you want it pulled and weighed or fired over the chrono....it's like a game show or something. Had them shoot it and ended up making major by .3

As I would tell shooters who end up like you, use a bigger shovel because you're too close to the line.

I had tested the load the week before and was around 173pf so I chalked it up to a discrepancy between my chrono and their setup. In the future I'll find a co-witness chrono at the club before big matches. The ones at the area match read in the expected range for a few people I talked to but some had real issues; including a guy from my club who failed to make minor using PMC factory box ammo!

[Poppa Bear]

Most major matches have the chrono set up correctly in that it is enclosed in a box so that it cannot be effected by sunlight or shadows. It uses either incandescent lighting or Infra Red lighting. It should be a pair of chronos so that they can be compared against each other.

The higher of the two readings is used for each bullet sent across as long as the two readings are consistent with each other. So if you are running 123.8 gr bullets and shooting Open Major and the two displays read 1,360 and 1,370 you are OK. If one reads 1,360 and the other reads 800 they have to figure out what is wrong with the one chrono and either fix it or take it out of service.

A great way to test your loads before a major match is to use co-witnessed chronos of different styles, and then use the lower of the two readings as long as they are close to each other. (+/- 20 fps) If you make PF with the lower of the two numbers you should be OK at the major event. I suggest different chronos because using the same make and model can give you a reading that is +/- 2 fps because the machines are using the same software and hardware.

[RePete]

The higher of the two readings isn't what is used, it's the primary reading that used and the secondary is used for comparison. That way it's consistant for every shooter.

[pskys2]

The only thing to add to Sarge's account is if you don't make PF with the 1st three rounds they will fire three more and take the best 3 of 6 average. If you still don't make it you have the choice of having the 8th round fired or the bullet pulled and weighed. Then they will use the highest 3 velocities and the heaviest bullet weight to figure PF.

Oh and they will pull 8 rounds, 1 should be weighed and 3 to 6 fired with the 8th used at your discretion as above if required.

If you don't make declared Major PF and chrono between 164.9 and 125 PF you will be scored minor for all shots fired. If you declared Minor and actually chrono Major, you will still be scored Minor. If you fall below 125 PF, even 124.9999999 you will be shooting for no score. You can still shoot but no points will be awarded, your score would be 0.

This is the official USPSA Procedure, You can go to the USPSA website, NROI tab and download the Rule Book. They should send you one when you join and at about any match where you will be chrono'd as part of the match will require you to be a member of USPSA.

If it's a local club match you may see a looser procedure and it may or may not affect your match.

There have been many good competitors, and good guys, who have been bit for one reason or another. Always make your loads 5 PF points over the minimum for the minimum round chrono'd and you'll always be good.

There are 4 levels of USPSA competition, Level 1 are local club matches and you will rarely be chrono'd, Level 2 are State, Sectional and other Matches and you may well see a Chrono Stage, Level 3 are Area, Special Matches and you will see a Chrono Stage at them and Nationals are a Level 4 and definitely have a Chrono Stage. There are various differences and reasons for the Levels.

Edited January 27, 2013 by pskys2

[bigdawgbeav]

I've only been through 1 chrono stage so far in IDPA. The stage prior to the chrono stage they had a guy come and gather 6 rounds from us. They went into a baggie with our sticker. When we got to the check stage they had everything laid out. We had to unholster and lay our gun on a table w/ and empty mag. The officer loaded up 3 of the rounds and fired them through our own gun. If 2 shots made PF, then we were done.

The chrono was a CED and the rods & diffusers were enclosed in a tent using the indoor lighting kit.

[Ace38super]

Even at a major match I have seen ammo stored in direct sun at the chrono stage, in violation of Apdx 2 rule 31. One match I am aware of that is never a problem is Area 2 as they have a little shack where everything is free from sun impact. At other matches you might want to walk by and see how competitors ammo is stored. Is it in a cooler out of the sun or in a container in the sun or even piled on a table in the sun. This practice gives shooters who use powder that varies one way or the other an advantage or disadvantage that should not exist. So even with all the other procedures followed this puts a big variable in how your chrono stage will go. Rant mode off...

[Chronodude]

Back in the day, the Chronograph state was treated as a Back-Water/leper colony where the sick and lame RO's ended up and various bad procedures happened. Over the past 19 years that I have been running the Chrono Stage at Nationals and various Area and local matches, I've done my best to promote the Chrono Stage as an intregal part of the match where shooters can expect a fair shake. We've standardized equipment, the use of a chrono coffin, artificial lighting for consistent lighting throughout multi-day events. I've written a Chronograph Compendium that's available for the asking and these standards and practices are printed in the Match Director's handbook.

To my delight, horror stories about the chronograph stage have declined over the years. The price of a good chronograph has come down to the point that it's not unusual for several members of a given club to have one. Even small clubs can afford a chronograph for general use of club members.

Sunlight is the biggest offender with chronograph use. Light intensity and angle. By using a chronograph in a box with artificial lighting, you've got as near to laboratory conditions as you can get without temperature control.

Got a chrono issue? Drop me a note.

btw, any major match worth it's salt will have a chrono set up for courtesy checks before competition starts just in case someone needs to make a quick trip to WalMart for a couple boxes of Blazer.

Chronoman

[fastarget]

Good discussion. First match last week, and I was one of the 164.999 pf club, so scored minor. My match ammo was chronoed over 2 pro chrono digital models pre-match , one was in a box exposing only the screens, the other chrono placed in series. Results were consistent at 167-168. Added a tenth of a grain of powder and switched to magnum primers to raise the PF. 169-170.

So do the pro chrono models read lower typically? It is interesting that in "Front Sight" this week, I read the exact thing happening to Dave Sevigny at the SS nationals, his solution as well as mine is to raise the pf enough to avoid issues, in a match, you wont notice 50fps higher.

In IDPA however the procedure is slightly different in that the gun is tilted upward prior to firing each round.