Chronographing

[Phil Dunlop]

Erik,

I too ran 320 at the D.C. and it was exactly the same as at home, 170p/f

P.D.

[ErikW]

Well I just chronographed my A2-DC ammo through both guns. I haven't even cleaned the gun I shot at Rio Salado.

The damned thing matched the A2-DC chrono almost shot for shot, around 900 fps. I figured something was seriously wrong with that gun, but shooting the ammo through the other, faster gun produced only a few more fps. (That same gun was shooting that same ammo 50 fps faster at the LimNats.) Also, my records show that same ammo going no slower than 939 fps on September 1 when I was chronographing my nationals ammo.

I also chronographed the same load in other brass loaded in the same session and the same load in other brass loaded in different sessions. It seems the slowest velocities came from the once-fired Federal nickel cases.

I can't put up with this voodoo nonsense. I'm gonna crank up the load a bit, to 175 or 180 PF and see how it works. I may have to switch powders.

I also chronographed Winchester 165gr white box, WUSA40SW, through my slower gun. Lowest was 994, highest 1065, most around 1025, 169 PF. Anybody else shot this factory ammo through a 5" bbl for comparison?

[Singlestack]

Eric,

I chrono'ed My friend's SV about 3 months ago with white box Winchester 180's. I have not shot the 165's though. Hope this helps some. His SV has less than 5k through it.

CED chrono.

Hi- 1024

lo- 986

ES- 27

SD- 11

APF- 180.7

(Edited by Singlestack at 4:44 pm on Nov. 19, 2001)

[johnny]

i don`t know about that, i was chrono`ed at the nationals

and the desert classic and the fps average was only off by 1 fps. i was impressed

(Edited by johnny at 2:18 pm on Nov. 21, 2001)

[Lumpy]

Maybe your powder dump got out of whack? Your all looking to the chrono as the problem, when it could be simple as a slight nudge of the knob on a powder dump or even a dirty seating die...

Just trying to think simple, I'm told quite often I'm a simple minded idiot. That's good right? ;-)

(Edited by Lumpy at 4:33 pm on Nov. 21, 2001)

[ErikW]

No, I check it every time I load. I wonder if the scale calibration changed by .2 gr or something.

[Even]

Erik,

I just talked to a friend of mine from Colorado who also shot the Classic (he placed right behind you). He told me that he dropped from 173 pf down to 167 pf. At the Nationals he was right on.

Even

[Flexmoney]

Erik,

Here is something to ponder...

I have been watching the Burner's videos.  In his reloading section he talks about when he once left his powder in the powder measure for about 12 hours.  In that period on time there was a storm.  The humidity level went up.  His powder had retained some of that moisture.  He didn't make power factor at his next match.

I know that you said:

I loaded up a bunch of "big match" ammo with the same brass, same jug of powder, same lot of primers, same case of bullets.

I don't know if you loaded all that ammo in one sitting ?

I just thought I would mention it.  While watching the video your post imediately popped into my head.  I thought this would be a good place to post the info

[TDean]

WOW!

Never thought about that Flex.  Sounds like we need to load cases based on weight instead of volume.

[Julien Boit]

Sometimes the chronoman, not Greg Lent, our in france, is not the most qualified RO to play with the CEDs.

I remember the 2000 French standard Nationals.

On the first day he shot my ammos through the chrono and it gave 173, ok I planned 174 but, no big deal.

On the second day, It was 168 , what ,minor ?!

After dealing with the CRO , a bunch of shooters asked to go back to the chrono, me too.

Third time: 159 ! ! !

Then I noticed a little "thing" on the chrono, what is it ?

Nothing, just a bullet hole in the Cells !

They were brand new when the importer of the CED products set them up . . .

One week later, it was the Open national, and guess what : The Chrono is now a fine piece of modern Art : 38 super sculpting !

DVC

Julien  

[ErikW]

I just happened to shoot several rounds of my 180 gr Clays match load over the chrono last weekend. Dead-on 170 PF, nothing slower than 935 fps. This is with a new jug of powder I thought was slower than the old one.

Voodoo, I say!

[Nolan]

Hey Erik,

When I'm loading for a big match I'll load and chrono 20 rounds using all the same lots of components I'll be using at the match.  If everything checks out, I'll start loading for the match.  For every 100 rounds of match ammo I'll actually load 110 rounds and pull 10 rounds at random.  Each 100 round lot will be kept seperate and labled.   I generally will load double the match round count.  Then when I'm finished loading, I'll chrono the 10 rounds from each lot.  If any of them are off, I don't use that particular lot for the big match.

I don't like to load up more than a 1000 rounds at a time because someone may discover a new ulitmate load that is better than what I'm using, or my gun may change it's tastes in ammo, etc...

Also I load 10 pf above the power floor.  The only time I've been close to not making major was the Y2k Area 2 match.  Next time it's that cold I'll remember to warm up the gun and keep my magazine under my arm pit (are you reading this Greg!?!) to make sure it's nice and smelly, er warm.

[Austin Hemphill]

Erik, I was using Clays for a while, and noticed the mysterious loss of power factor too.  I wonder if it is a more hydroscopic powder than others.  I drove me up the wall.  I had a load that was a 168pf from 5000ft to sea level that fell to minor out of the blue.  I finally gave up and went to N320, and load to a 175pf to avoid the problem just to make sure.

[John Thompson]

After getting DQed for making a 101pf.  I will never borrow bullets or not chronograph before a major match again.  Even if it's an emergency like last time I'll just buy factory.  

Eric,

What I've found with my Dillion is that I have to weigh the powder ever few hundred rounds as it tends to go light for some reason.

[Singlestack]

VOODOO!

I agree with Erik.

I hate working up new loads. It took me 4 trips to the range (a 1 hour drive) to get a load for my new blaster!

I have finaly settled on a 176.5 PF load. Anything lower and it is all over the place! I'm talking spreads of over 100 FPS! GRRRRRRR

A friend suggested lowering my sizing die (on a 550) until it hit the shell plate and acted as a stop to increase consistancy. Anybody do this?

[Flexmoney]

A carbide sizing die?  Seems that using the die as a stop would run the chance of cracking/chipping the brittle (but, hard) carbide.

I think plenty of people have them "just touching"...but, using it as a stop is beyong "just touching".  

That is the theory.  I would be interested to hear how it works in real life though.

[Singlestack]

Kyle, yes, he was refering to a carbide sizing die.

I have gone through all of these changes after I thought I already had a load. I went out to double check and.....

Here we go again.

I'm 1/2 a grain heavier now than with the load I thought was good.

[ErikW]

Had a big chrono session the other day. For some reason, everything was unusually fast. One mistake I made was to use a blue barrel as a skyscreen instead of a white barrel. Maybe that speeds things up. I had some benchmark loads, including Win. factory, that were faster than expected. Oh yeah, this was with the slower gun.

Voodoo!

I had this unbelievable string with Clays, 992-1008 fps, every shot within a couple fps of each other, until the last shot blew it with a 1041.

I got in the 990s with N320, too.

Even if the chrono was 3% fast, now I've got a couple shootable loads 10 PF above the minimum. Thank goodness for rifle primers and long firing pins.

BTW, Clays is still noticeably softer, but N320 groups better.

(Edited by Erik Warren at 9:44 am on May 28, 2002)

[gm iprod]

Sorry if this dribbles on, but I stuffed to many matches with crap ammo over the years and I am still learning.

With the exception of an Oehler, I always calibrate chronographs before I use them. The Oehlers when set up properly seem to work the best, bar none.

I use my BSA Target rifle and Eley Tenex, Winchester Expert Premium or Federal Gold Medal Match. I will fire ten rounds over the chrono with the rifle and record all data, comparing this data with previous records. I then shoot my loads and see what's happening. I have tested quite a number of chronographs this way. If you can try and get a heap of chronos at the same time and test them against each other. It is amazing what you will find. I am surprised how few clubs calibrate their chronograph before a big match. A lot is a stake for a lot of big time shooters, they have to have confidence in the gear, if the chrono is unreliable it could really affect the outcome of a match, and in many cases cost some people really big money. I saw a guy come up .5PF short at a match. He was really pissed, he was hoping to get into A grade and would have by a mile except for 169.5PF. One week later his loads chronoed at 173PF on his chrono. We tested his chrono with my rifle/ammo and it was 1% lower than I thought it should be (compared to an Oehler 35P), so he really was at an adjusted 174.8PF so where did the 3.06% go?????????

We suspect the clubs chrono. Very few people know how to use them properly. Getting an Oehler is a good start.

If the calibration loads are off by more than 3% of what I am expecting I will adjust the values of my testing. Just to be sure I will keep both sets of records.

Always try to chrono your match ammo as close to the match as you can. Make as much of your match ammo as you can afford. Not meaning monetary costs.

Keep your powder as per manufacturers suggestions. Never leave powder in a measure. I also decant large tins 1lb at a time into a tin that holds a lot less. That way you keep the big tin closed for longer. Only exposing the powder in the smaller tin to air regularly.

The same goes for your primers. The condition you keep your primers in is just as important as your powder. Check your loads with a clean and a dirty gun. See if there is a diference. Use the lower figure as your real PF. Not the higher and hope that it goes.

I always go 5% or sometimes more over the minimum PF.

My 38Super NRA loads for my Open gun are 140PF not the minimum of 120, Iwould like to use a little closer to 126PF or so, but the gun works better and it shoots slightly better at present. The loads for my NRA Stock pistol are 125-128PF. For IPSC Std are about 177-180PF.

If your Extreme Spreads or Standard Deviations are larger than usual, check your chrono and your press. Especially if the groups have not changed in size significantly. Also keep an eye on the point of impact. This will give a good indication of unusual velocity loss or gain.

Testing before you shoot is so important, more so in practice than many people think. If you practice with crap you will shoot crap.

If you powder measure seems to get lighter when you load a long run, keep more powder in it. And refill more regularly, or if you run a Dillon, and you should be, use the Low Powder Sensor. It SEEMS to keep the powder under a constant tension, and I FEEL that the loads are more consistant, because of this.

The more you test that your load is right the better. But don't get carried away once you got it right. Just check it every month or so. Adjust as neccessary. Using the above criterior.

[sfinney]

Just got back from Area 4, shooting Open 38 super. 8.5 grains of 3N37, 124 grain FMJ.

I was MINOR, it chrono'ed at 164.47 PF.

My first three shots were @ 163 PF. The next 3 @ 164. My seventh shot (may bullet weight was 124.1, no need to re-weigh) brought me up to 164.5 - ouch.

Everyone there was shocked, saying my "minor" load was the LOUDEST minor open gun they had ever heard

The weird thing is that every shot got faster as they progressed, going up @ 10 FPS every shot, with the last being fastest. What gives??

The week prior my ammo had made 169 - 171 PF on 2 different chronos.

To make matters worse, I lost my class by 1%. Roughly calculating my score at major, I lost at least 5% of the match score due to shooting minor (I did have alot of A's, especially after I found out I was minor!!)

Still happy to finish 2nd, all things considered, though!

[Steve Anderson]

I assume it's illegal to take a back-up load in case you go minor? (Or in prod, sub minor)

You get the one chance at the chrono and that's it?

I guess if it was allowed to use a different load then we'd have people chrono the one load and shoot the other...'course they could do that now I guess.

Are there precautions taken to ensure a shooter uses the ammo that was chrono'd?

SA

(never been to a major match...yet!)

[sfinney]

You're supposed to shoot the same load that you chrono. If for somoe reason during the match you have to switch ammo or guns, you're supposed to rechrono.

Having a "back up ammo" definitley skirts the intent of having to chrono in the first place. Although, unfortunately, some people do submit one load for testing and shoot another.

I think I witnessed a case of this at Area 4... the ammo he put in his baggie for submission (8 rounds) came from his range bag, not a mag on his belt... and man, his ammo sure sounded weak. Except at chrono. Then it was @ 180 PF.  

No one can accuse me of that!!! (or maybe I forgot to hand in my "special ammo" ?  hmmmmm