PF vs POPPER FALLING QUESTION

[1SOW]

Class: Production

PF of chrono'd match Cartridges: 127.5PF

Pistol: Full size CZ 75

If a Full Size Popper is hit at 7:00 one inch inside the circle at 90 degrees to the face and then doesn't fall (twice in this case) the rules say a challenge can be initiated.

A Cartridge is carefully fired by the RO and the popper is hit dead center and just barely falls and the miss is upheld.

How does THIS jibe with the rules saying 125 PF is the minimum acceptable PF?

I appreciate your responses.

[JAFO]

You didn't say whether the chrono reading was your own, or from a chrono stage on match day, but some possible reasons I could think of:

- Chrono error on your loads due to lighting conditions, etc

- Chrono sample was too small (eg, Flex recommends 20 rounds per chrono batch)

- Temperature difference between when your rounds were chrono'd and match day causing velocity changes

- Poppers being calibrated with ammo above 125PF (either before the match or during the challenge)

- The first two hits moved the popper enough that it fell on the third shot

- Was there any wind? Was it different from the stage run to the challenge?

Since PF is truncated and not rounded, your official PF would be 127. That's not much of a cushion.

[Bunchies95]

Class: Production

PF of chrono'd match Cartridges: 127.5PF

Pistol: Full size CZ 75

If a Full Size Popper is hit at 7:00 one inch inside the circle at 90 degrees to the face and then doesn't fall (twice in this case) the rules say a challenge can be initiated.

A Cartridge is carefully fired by the RO and the popper is hit dead center and just barely falls and the miss is upheld.

How does THIS jibe with the rules saying 125 PF is the minimum acceptable PF?

I appreciate your responses.

Plain and simple, unlucky.

Slightly higher hit will give it more leverage. The first two hits may have moved it enough that it reached its tipping point. Was it at an odd angle and did the RM shoot it from the same position?

Calibration ammo is supposed to be around 115-125 PF for exactly this reason, if it falls for that, it SHOULD fall for minor. But S4$t happens. Was this a local match? If so chances are the ammo used for calibration was RO's match ammo, which would be greater than 125PF. Next time, if real calibration ammo is not available, have them shoot it with your gun.

It could have been a low powder drop on those cartridges. You should load you ammo hotter though, 127 is cutting it mightly close to shooting for no score.

[Bunchies95]

Oh yea....what JAFO said too.

[Sarge]

127 and change is nowhere near enough for Production. Seems most like about 132-134. I have seen poppers not fall for really good hits with legit ammo and the RM's 120 pf load knock it down like a MAJOR PF load. Like has been said, sometimes S#!t just happens. Turn your loads up and you probably won't have to worry any more about it.

[1SOW]

I appreciate the responses, but they don't answer the main question.

IF production loads actually DO exceed minimum requirements, should steel be set to FALL anywhere in the legal hit zone, 90 degs to the steel AT those minimum PF requirements?

If that's true, how should challenges be tested.

Bunchies95, If steel is NOT set to fall at 125 PF (at 90 degs to the plate), then shouldn't a new minimum PF should be established?? Is steel guaranteed to fall at 130 PF, 135PF, 140? Should the steel have a line drawn midway across the round hit zone and make ONLYthe top half legal--who's to SAY?

I'm not being a whiner--I wasn't even upset over this. My ammo is actually loaded to 129PF by a CED Dig. Pro Chrono on more than one occassion. I've been shooting this same bullet and load for a long time..The paint showed the solid hit, so I'm satisfied with my shots.

It does seem the rules are at least loosely interpreted in this situation. Just curious.

Edited July 10, 2013 by 1SOW

[Sarge]

In that case I think the current rules are more than adequate. There is no guarantee that steel will ever fall. Sounds like you want a sure fire black and white no questions asked "If I shoot a 130 load the steel should fall without question.

Wind can play a major part in steel falling or not falling. There is no way to plan for that.

Even if the RM shoots from the EXACT came spot he may or may not be shorter or taller, crouch more or less, etc. If the steel has a little bend to it then one load or the other will put much more or less energy on the steel.

There is just no way to factor in all the variables.

By the way 129 is not enough either.

[MarkCO]

Not enough info to be sure, but...

The calibration challenge ammo is rulebook specified. It is supposed to be under 125, but rarely is. The poppers should be set to fall with THAT ammo, and checked each morning. With properly set poppers, on wood, they do not move. I have tested poppers with a force guage and ammo from 120 to 130 PF. The difference from the top if the circle to the bottom is under 2 PF differential. 127 is enough if the poppers are well set, the calibration ammo is right, no wind, and you don't have a light load. Not worth the risk if you ask me. When I shot limited, the last two match chronos had me at 165.2 and 165.4 PF. I load my production load to 135 to 138.

[Chills1994]

1SOW, you can do an advanced search of my screenname and say like the keyword "popper". This topic gets hashed and re-hashed, and re-re-hashed like every 3 months. All I can tell you is "them'thar is da'rules". the rule book pretends that a popper is a ballistic pendulum. it is not. in real life, it is a crude tool with which to measure PF. it also in some respects measures bullet construction and materials, however minutely. IMO, if I was King for a Day, a popper with a legit hit in the calibration zone (you gotta paint those poppers between shooters, FOLKS!), I'd make a balky popper a range equipment malfunction (RMF) and an automatic reshoot.

Supposedly there is some new rules discussion going on right now at the forum at USPSA.org . Log in and give 'em your input.

[Nik Habicht]

I appreciate the responses, but they don't answer the main question.

IF production loads actually DO exceed minimum requirements, should steel be set to FALL anywhere in the legal hit zone, 90 degs to the steel AT those minimum PF requirements?

How do you know that a 127 or 129 pf round hit the steel? Did it fly over the chrono? Or are you assuming it was equivalent to the three or more rounds fired over the chrono that averaged 127.5?

At a major, my calibration ammo comes in around 120, and we make sure that poppers fall to that.....

[1SOW]

I appreciate the responses, but they don't answer the main question.

IF production loads actually DO exceed minimum requirements, should steel be set to FALL anywhere in the legal hit zone, 90 degs to the steel AT those minimum PF requirements?

How do you know that a 127 or 129 pf round hit the steel? Did it fly over the chrono? Or are you assuming it was equivalent to the three or more rounds fired over the chrono that averaged 127.5?

At a major, my calibration ammo comes in around 120, and we make sure that poppers fall to that.....

[1SOW]

KNowing is EASY. They are repainted white for every shooter. Almost no wind, Solid hits and another shooter had the same problem.

[1SOW]

In that case I think the current rules are more than adequate. There is no guarantee that steel will ever fall. Sounds like you want a sure fire black and white no questions asked "If I shoot a 130 load the steel should fall without question.

Wind can play a major part in steel falling or not falling. There is no way to plan for that.

Even if the RM shoots from the EXACT came spot he may or may not be shorter or taller, crouch more or less, etc. If the steel has a little bend to it then one load or the other will put much more or less energy on the steel.

There is just no way to factor in all the variables.

By the way 129 is not enough either.

It's been enough for 9 years using a pistol with 60K rds on it. Maybe my new pistol isn't up to the job yet.

[1SOW]

I appreciate the responses, but they don't answer the main question.

IF production loads actually DO exceed minimum requirements, should steel be set to FALL anywhere in the legal hit zone, 90 degs to the steel AT those minimum PF requirements?

How do you know that a 127 or 129 pf round hit the steel? Did it fly over the chrono? Or are you assuming it was equivalent to the three or more rounds fired over the chrono that averaged 127.5?

At a major, my calibration ammo comes in around 120, and we make sure that poppers fall to that.....

Thanks NIK, this wasn't a Major match, and not a big deal. I was just curious.

I know 129PF isn't a big margin, but I've had good results from it until now; so I asked the question.

The responses make good sense. Local matches just can't be set up that technically to test by PF, and this particular club sets up very good matches IAW the rules.

No problem. 120PF testing is a more than satisfactory test at major matches.

Thank you for responding

Edited July 11, 2013 by 1SOW

[pjb45]

Listen to Mark. He is on the money. If the popper is not securely anchored, then there are all kinds of variables that come into play.

I was on RO on a stage at the HDC in ABQ. There was a cargo container as a barrier with a popper nearby. Sometimes the popper fell and sometime it did not. Turns out the venturi effect of the wind coming around the corner of the container had an effect on the ability of the popper to fall. More often than not, the challenge was defeated.

I truly believe I was at Nationals one year when they (RM) said they were using WW 9mm as the calibration ammo. The RM said they were using 130 PF to calibrate the poppers. A lot has changed since then.

[Chills1994]

Class: Production

PF of chrono'd match Cartridges: 127.5PF

Pistol: Full size CZ 75

If a Full Size Popper is hit at 7:00 one inch inside the circle at 90 degrees to the face and then doesn't fall (twice in this case) the rules say a challenge can be initiated.

A Cartridge is carefully fired by the RO and the popper is hit dead center and just barely falls and the miss is upheld.

How does THIS jibe with the rules saying 125 PF is the minimum acceptable PF?

I appreciate your responses.

If that was a local match and the MD/RM actually shot a calibration round at it, well, I am impressed. Every local match I have been to where I had a popper not fall, the MD came over and gave it the highly scientific knuckle test and says, "Oh, yeah, that even feels heavy." Or they will say, "Don't worry about it. Go ahead and re-shoot the stage."

[Nik Habicht]

KNowing is EASY. They are repainted white for every shooter. Almost no wind, Solid hits and another shooter had the same problem.

Really? That doesn't address power factor. Those bullets could have chronoed at 100, 105, 110 -- unless they flew over the chrono on their way to the steel, we don't know....

You can't tell bullet weight or velocity by the mark on the steel....

[Nik Habicht]

I appreciate the responses, but they don't answer the main question.

IF production loads actually DO exceed minimum requirements, should steel be set to FALL anywhere in the legal hit zone, 90 degs to the steel AT those minimum PF requirements?

How do you know that a 127 or 129 pf round hit the steel? Did it fly over the chrono? Or are you assuming it was equivalent to the three or more rounds fired over the chrono that averaged 127.5?

At a major, my calibration ammo comes in around 120, and we make sure that poppers fall to that.....

Thanks NIK, this wasn't a Major match, and not a big deal. I was just curious.

I know 129PF isn't a big margin, but I've had good results from it until now; so I asked the question.

The responses make good sense. Local matches just can't be set up that technically to test by PF, and this particular club sets up very good matches IAW the rules.

No problem. 120PF testing is a more than satisfactory test at major matches.

Thank you for responding

I absolutely feel bad for the shooter, when I see a hit on the popper, and it falls to my calibration shot. I take no pleasure in that....

I'm assuming that you've chronoed the load out of the new gun and that you're still getting 129? My production load is making 133 out of the slowest gun, and a bit more out of the fastest, 134-5. I'm not noticing any difference in how the load shoots, compared to the much softer chrono ammo....

[Chuck Anderson]

I think some of what Nik was getting at was there is no way to know the PF of that specific round. When I chrono I never have exactly the same MV round to round. They average three or more and that's my PF. Maybe you hit it with a slow one.

The other element it doesn't address is bullet weight for your round versus the Calibration gun. Someone shooting a 95 grain bullet at 125 is going to have a different effect on steel than someone with a 147.

Steel is not perfect but I'd rather shoot the game with it there than not. And I haven't seen/heard of a better and/or more efficient way to use it yet.

[sperman]

Steel is not perfect but I'd rather shoot the game with it there than not. And I haven't seen/heard of a better and/or more efficient way to use it yet.

If you shoot this game long enough, you will eventually get burned by a flakey popper. Chuck pretty much sums it up.

[GuildSF4]

Additional information almost no wind is not the same as no wind. A 5 mile per hour wind has a PSI rating of .12, taking that to the popper that would add approximately 24 pounds of force holding the popper up at that rate a 1 MPH wind adds about 5 pounds of force. The point is even a small amount of wind can add a fair amount of force to to the amount needed to knock the popper down.

(Rounded down the size of the popper to 200 square inches for illustration, the actual area is larger.)

Edited July 11, 2013 by GuildSF4

[bbbean]

I appreciate the responses, but they don't answer the main question.

IF production loads actually DO exceed minimum requirements, should steel be set to FALL anywhere in the legal hit zone, 90 degs to the steel AT those minimum PF requirements?

How do you know the round in question met minimum requirements? If you're loading to 127, it doesn't take much variance at all or very many rounds to make it a near certainty that there will be the occaional round that falls below minimum PF.

Thre's also the simple fact that between design and mechanical variance in poppers, poppers being set by different people after each run, varying wind, etc, there is a strong possibility that a popper may occasionally be more difficult to knock down.

That's why so many prod shooters load to PF=130-140. It's still nice and soft, but you dramatically reduce the chances that your one light round happens to meet the one stiff popper just as the wind shifts from the wrong direction.

[Chills1994]

Why even have a pre-match calibration procedure?

set the poppers just heavy enough that the wind doesn't blow them over.

There is at least one other shooting sport that the last time I looked at their rulebook they didn't feel the need to include a calibration procedure.

Do the 3 gunners have a calibration procedure for shotgun birdshot on poppers?

[juan]

Why even have a pre-match calibration procedure?

set the poppers just heavy enough that the wind doesn't blow them over.

There is at least one other shooting sport that the last time I looked at their rulebook they didn't feel the need to include a calibration procedure.

Do the 3 gunners have a calibration procedure for shotgun birdshot on poppers?

I agree

to set poppers up to diferentiate between major and miner is problematic at best, to many varibles at hand,

loose ,mounting, wind

to many times Ive seen the caibration ammo used just to see if it falls over and not to see if it is set heavy enough,

Edited July 14, 2013 by juan

[L3324temp]

When I 1st started shooting production I was using 115g bullets at 128pf and constantly had issues with steel. I tried running the 115's hotter and still had issues. Changing to 135g bullets and bringing the PF up to 132-133 fixed it.