APPENDIX D5 — Single-Stack Division

[Gary Stevens]

The scale is a simple fix with a suitable check weight. I would hope that MD's and RM's who want to present a professional match would already be doing that. Does USPSA need to mandate it, perhaps since we do have a procedure of sorts for the chronograph.

IDPA has a 43 ounce limit, and that upper weight in USPSA has been explained before to a great extent. IDPA shooters apparently don't have a great problem meeting weight. I also note that the 99+ percent of SS shooters don't have a problem making weight. Both of my STI USPSA 40 cal 1911's weigh 40.2 ounces with a Tripp 9 round 40 mag inserted.

Edited July 27, 2012 by Gary Stevens

[sperman]

If I recall, at the previous match where Matt was bumped to open, they used the 80 gram check weight from the bullet weight scale. 80 grams is approximately 1/15 of 43 oz.

[Gary Stevens]

If I recall, at the previous match where Matt was bumped to open, they used the 80 gram check weight from the bullet weight scale. 80 grams is approximately 1/15 of 43 oz.

There, I fixed my previous post:)

[sperman]

[Poppa Bear]

How repeatable is a roll of quarters? If the weight is repeatable then a roll or two of quarters is easily attainable anywhere in the country.

[Racer377]

Nope, because we already built plenty of cushion into the rules. You have to actually try to push your luck if the rule was 45 ounces. Not so with 43. There are factory guns out there that with a magwell and grip change would exceed the weight limit. I think you'd be hard pressed to find a factory gun that was >45 with the common add-ons and nothing else done to it.

I do think it'd be possible for people to push their luck with a higher weight limit, and hopefully they'd get stung. But that doesn't change the fact that giving competitors a little bit more cushion would eliminate problems (e.g., needing an aluminum MSH or a GI guide rod to make weight, which costs money for no material benefit in competitive equity).

At 45 ounces, nobody would have any excuses. At 43, I don't think that's the case, although 43 is admittedly more lenient than IDPA if I recall correctly.

True.

My bone stock TRP, right on the edge.

Reading around here, other have had to do the same.

It mildly sucks that I have to modify an off the shelf gun to make it legal, kinda seems backwards. But rules are rules. Some lighter grips and maybe a lighter guide rod and it should have a nice margin of error.

[ktm300]

And the check weight was 10 grams not 80. 1000 grams would be a very good number and they are easy to get for about $20 if you don't need it to be traceable.

[Round_Gun_Shooter]

...it came in at 42.9 with the heaviest mag, (1 out of 10) I have in it at the local post office.

Wow! Just WOW! Your local Postmaster allowed you to weigh A GUN on their scale. You, my friend, live in an enlightened area! Appreciate it.

I have been using the scales at the post office for some time and I live in Massachusetts I use the federal way of looking at things. "Don't ask, Don't tell" Padded envelope, gun in envelope, "can you weigh this for me?" Sure no problem. Second envelope empty "Can you tell me what the envelope weighs?"

Thanks,

That is all there has been to it.

Edit to add: Local deli is another good place.

Edited July 27, 2012 by Round_Gun_Shooter

[Braxton1]

And the check weight was 10 grams not 80. 1000 grams would be a very good number and they are easy to get for about $20 if you don't need it to be traceable.

I like this idea.

1000 grams is 35.273 ounces. This is a lot better than scale checking using 80 grams (2.821 oz.). If we used a 1000g check weight, we'd be right in the middle of the zone that we're really trying to weigh (between 24 oz Glocks and 43 oz. Single-Stackers).

I'd like to call on the BoD to commission EGW to build the Official USPSA Scale Checker weight. You could buy one at the same time as your mag gauge and Official USPSA Box.

(Attention George Smith: Since it's my idea, I want a free one.)

[ktm300]

[sperman]

McMaster Carr has them for about $70. A little more if you want NIST certification.

[Skydiver]

How repeatable is a roll of quarters? If the weight is repeatable then a roll or two of quarters is easily attainable anywhere in the country.

Unfortunately, it varies on the minting of the set of coins that make it into the roll. There is a predictable range, but I don't think that it is to the precision that is needed. That's part of the reason when I first posted my "3 or 4 quarters idea", it had to be that same set that weighed on the bullet scale, and then on the gun scale.

The standardized check weight is a much better idea long term, I think. Even if the match is held in the mountains of Colorado or other places where the force of gravity is slightly different than other places, at least the scale will record a consistent value for that location. (I hope the match staff doesn't start fiddling with the scale to make the scale display match with the number it says on the check weight.)

[sperman]

(I hope the match staff doesn't start fiddling with the scale to make the scale display match with the number it says on the check weight.)

Isn't that the whole point of the check weight, to make sure the scale reads 1kg when you place a 1kg weight on it?

[Nik Habicht]

McMaster Carr has them for about $70. A little more if you want NIST certification.

Scales or weights? Link?

[Skydiver]

<div>

</div><div>

</div><div>(I hope the match staff doesn't start fiddling with the scale to make the scale display match with the number it says on the check weight.)</div><div><br></div><div>

</div><div><br></div><div><br></div><div>Isn't that the whole point of the check weight, to make sure the scale reads 1kg when you place a 1kg weight on it?</div><div>

</div><div><br></div><div>It should be.</div><div><br></div><div>A person was trying to explain to me that the check weight has a known mass in a particular environment. Changing altitude and locations changes that environment. A scale measures weight, not mass. The physics details was over my head, but the concept was sound.</div><div><br></div> Edited July 27, 2012 by Skydiver

[Braxton1]

McMaster Carr has them for about $70. A little more if you want NIST certification.

Scales or weights? Link?

http://www.mcmaster.com/#scale-weights/=ildyhi

[sperman]

McMaster Carr has them for about $70. A little more if you want NIST certification.

Scales or weights? Link?

Weights.

http://www.mcmaster....18/1588/=ile254

Oops. Bruce beat me too it.

Edited July 27, 2012 by sperman

[sperman]

As soon as we start holding matches on the moon, we will have to worry about the difference between weight and mass. Here on earth, the differences due to altitude and lattitude are negligible. According to Wikipedia, a few tenths of a percent.

As a practical matter, gravitational acceleration (symbol: g) varies slightly with latitude, elevation and subsurface density; these variations are typically only a few tenths of a percent. See also Gravimetry.

If you properly calibrate your scale to the location it is going to be used, it then measures mass, and not weight.

As a practical matter, when force-measuring scales are used in commerce or hospitals, they are calibrated on-site and certified on that basis so the measure is mass, expressed in pounds or kilograms, to the desired level of accuracy.^[10]

http://en.wikipedia....s_versus_weight

[ktm300]

A procedure that specified that the scale had to match the check weight -.1 +0 would not be all that hard in ounces. If the scale can't do it don't weigh guns.

Add a piece about how big the platform needs to be and how to set the gun on it. I see very small scales with the gun hanging off the side. You can introduce quite a bit of slop with that.

Add something about repeatability. In ounces it needs to read the same thing every time. +- .1 ounce is a pretty wide swing. If the scale can't be consistant don't weigh guns.

Now you can be pretty sure that you are going to get well withen the .1 ounce that is a resonable weight variance when weighing a gun at a match.

[Skydiver]

Thanks for finding those references Scott! It makes a lot more sense. And yes, I agree, just twiddle with scale until it reads what the check weight says it should read.

Matt makes some very good points that can be a strong starting point for how gun weights should be measured.

[Round_Gun_Shooter]

With all that is being suggested in this thread, I see matches lasting an extra day

[Skydiver]

Most of Matt's suggestions in post #69, affect pre-match time: testing the scales, and teaching the staff how to use it.

The only thing I see that may take extra time is if we insist that the gun be weighed with all the mags that competitor has. My thoughts on this is that the chrono officer picks randomly much like how the test ammo for chrono is supposed to be random. What are your thoughts on this?

And then from there, we as an organization should probably let our leadership know, how to deal with an over weight gun. Do we steal something from the IPSC rulebook like the trigger weight test where the gun need only pass 1 out of 3 trials? (e.g. Test gun 3 times: if any test shows below the weight limit, the gun is good.) Or do we want something more complicated like the chrono test: Get average weight of 3 trials. If over, ask for a different magazine and use the lowest 3 weights and compute average. If still over, the shooter gets a choice to try one more magazine, or shoot with a procedural penalty per stage. )

[sperman]

...it came in at 42.9 with the heaviest mag, (1 out of 10) I have in it at the local post office.

Wow! Just WOW! Your local Postmaster allowed you to weigh A GUN on their scale. You, my friend, live in an enlightened area! Appreciate it.

I have been using the scales at the post office for some time and I live in Massachusetts I use the federal way of looking at things. "Don't ask, Don't tell" Padded envelope, gun in envelope, "can you weigh this for me?" Sure no problem. Second envelope empty "Can you tell me what the envelope weighs?"

Thanks,

That is all there has been to it.

Edit to add: Local deli is another good place.

It's one thing to violate fedral law, but to brag about it on a gun forum is just special.

[Round_Gun_Shooter]

It's one thing to violate fedral law, but to brag about it on a gun forum is just special.

FFLs mail hand guns every day so where is the violation. But that is another discussion I guess

[Jammer1911]

Why don't we all just petition for a rule change to add an additional .5 oz? With all the new guns out there and the difference in the quality of steel today we need to be more in line with modern times. Easy Peasy! JMHO

BTW +1 on not bragging on an open gun forum about violating Federal Law.