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I originally posted this over on the XDS Forum and was advised to post it here as this was where the ammo experts were to be found. Thanks. Shortgun. We had a lot of rain the last few days and I used the time to load all my empty brass for the XDS. I had 185gr. Nosler JHP's and some old Bullseye. I checked loading manuals and decided 5.0 grains should be a mild load-about 800fps was what I was expecting. I loaded just over 400 rounds. I threw powder with a Hornady powder measure and checked weights periodically and it was throwing 5.0 to 5.1 grains.
Today I had my chrono set up to work up some 6ppc loads. It was accurate with them. Decided to shoot a couple of the .45 loads through it to check them. The 3 shots registered 1231, 1235 and 1233 fps. I stopped because this was not what I was expecting.
I checked the primers and they are not flattened--look normal. I measured the case diameter just above the web (above the extractor groove) and the three measured .4735, .4745 and .4725. I shot 3 other 230 gr. FMJ reloads with a mild charge of SR 4756 and those measured .4745, .4725 and .4730. Then I shot 3 factory Win. 230 gr FMJ loads and those cases measured .4775, .4750 and .4750. Something I did notice is that my chamber must be a little out of round because when I rotate the cases inside the micrometer I get varying measurements, but these figures are all midrange of the measurements.
This powder is probably over 30 years old so I thought it could have lost moisture and be giving me higher than normal pressures. I do not want to blow up my gun or batter the frame, and according to the loading manuals, any load giving that kind of velocity must have excessive pressure, but I do not see signs of high pressure and the velocities of those 3 rounds had an extreme spread of only 4 fps, which is great.


So, what do I do? Do I shoot them or pull the bullets? Thanks.
 

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First off. I don't have a clue, but it is intriguing. I would double check the chrono first.
The other thing I've heard is that when using older powder, you should use loads from that time period. Apparently powder make-up and characteristics are different over a long period of time. Here's a 1967 Lyman's 44th edition http://www.castpics.net/LoadData/OM/Lyman44.pdf and it has 4.9gr of Bullseye as the max load at 873 fps. I don't see how a tenth of a grain or two would create an increase of 400 fps in velocity, but also see my first point. :confused:
The Lyman's 49th has the max load for Bullseye at 6.0gr at 976 fps so there may be a difference. The 44th edition does not list pressure.
Lastly. The powder may be to darn old to safely use.
 

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I'm no expert when it comes to reloading, but here's my $.02, for what it's worth, which with this economy is less and less each day.

I'd pull the bullets, reduce the powder charge by 1/2 grain and keep adjusting as needed until you're chrono is registering 800-900 fps, and call it a day.
 

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So did the 4756 loads chrono as expected? Is your chrono 12' from the muzzle? This is why it's always a good idea to not load many rounds until they've been tested. Being that the Bullseye is 30 years old, it coild be contaminated if everything else is within normal parameters. Thankfully you didn't load them any warmer.

Good luck pulling the bullets! ;)
 

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There is no way 5grns of Bullseye is going to give you over 1200fps with an 185grn bullet. NO WAY! Even if you used an extremely short OAL (less than 1.2 or so) you should not be getting this kind of velocity without something going wrong. Thus, I think your chrono was in the sun when the readings were taken and it was shining into the sensors giving you false readings. Granted, your previous loads were "normal" but I have seen this before when a change of caliber using a different bullet gave completely different (read "unexpected") results. The sun hitting the bullets and the sensors at an angle is giving you bad readings. If they were, on the other hand, taken indoors, then florescent lighting could also be affecting the chrono differently with different bullets.

Take another reading, preferably on a cloudy day or with some paper or cardboard screening the sun from the sensors so they are in the shade. Your load is ok from a volume standpoint, but I think your readings are wrong.

One more thing, since you said the powder was pretty old... how did it smell? If it has a rancid smell compared to other powders you might have, it is probably bad, but even so, I don't think the nitro in the mix could have concentrated into a small part of it to give this result. You would have different cartridge readings and primer signs at the pressure levels required to give you those velocities if they are legitimate. So, we are back to the chrono readings being improbable. Also check your batteries in the chrono.
 

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There is no way 5grns of Bullseye is going to give you over 1200fps with an 185grn bullet. NO WAY! Even if you used an extremely short OAL (less than 1.2 or so) you should not be getting this kind of velocity without something going wrong. Thus, I think your chrono was in the sun when the readings were taken and it was shining into the sensors giving you false readings. Granted, your previous loads were "normal" but I have seen this before when a change of caliber using a different bullet gave completely different (read "unexpected") results. The sun hitting the bullets and the sensors at an angle is giving you bad readings. If they were, on the other hand, taken indoors, then florescent lighting could also be affecting the chrono differently with different bullets.

Take another reading, preferably on a cloudy day or with some paper or cardboard screening the sun from the sensors so they are in the shade. Your load is ok from a volume standpoint, but I think your readings are wrong.

One more thing, since you said the powder was pretty old... how did it smell? If it has a rancid smell compared to other powders you might have, it is probably bad, but even so, I don't think the nitro in the mix could have concentrated into a small part of it to give this result. You would have different cartridge readings and primer signs at the pressure levels required to give you those velocities if they are legitimate. So, we are back to the chrono readings being improbable. Also check your batteries in the chrono.
Follow the advice from those with a clue!
 

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Crazy question here. I would assume that over time the manufacturer's formulation for a specific powder would be subject to modification as a result of new developments in the technology and chemistry behind the powder. Since the powder in question is roughly 30 years old, is there even the remote possibility that the formulation of that powder 30 years ago is the same that it is today? I would be interested to see if the load data for that particular powder is the same now as it was when manufactured.

Is there also the possibility that the age of the powder has increased the rate of burn, as that would affect the velocity and pressure of the load?

Again, just my mindless ramblings. I'm very new to reloading myself, so please be patient with me!
 

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Powder does not get more powerful as it deteriorates. Check the chrono .
Yes & no. A powder can "dry out" over time. Some o the nitro can evaporate & you get a more condensed version of the powder by weight. This could increase the density, which is like adding more powder. Still, even that shouldn't be giving you such results. I would be triple checking the scale with some check wts.:confused:
 

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Yes & no. A powder can "dry out" over time. Some o the nitro can evaporate & you get a more condensed version of the powder by weight. This could increase the density, which is like adding more powder. Still, even that shouldn't be giving you such results. I would be triple checking the scale with some check wts.:confused:

Especially with double-based flake powders where Bullseye has a fairly high nitroglycerin content.

Shortgun, you probably already know this, but on cloudy/sunless days you should not use the diffusers on the skyscreens. There are several possible scenarios here, so do you have an update on what you've investigated so far? ;)
 

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Especially with double-based flake powders where Bullseye has a fairly high nitroglycerin content.

Shortgun, you probably already know this, but on cloudy/sunless days you should not use the diffusers on the skyscreens. There are several possible scenarios here, so do you have an update on what you've investigated so far? ;)
"Shortgun, you probably already know this, but on cloudy/sunless days you should not use the diffusers on the skyscreens."


Where are you getting this info? I have never seen any thing like that in the user manual of any of my chronos.

don
 

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Direct sunlight interferes with the infared beams put out by the chronograph, so when there is no sun out why would you need to use diffusers? Maybe a difference by manufacturer, but it's certainly stated plainly in my instruction booklet. ;)
 

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Just a question here from someone that has no clue really about reloading. If the chrono readings were that high wouldn't you have noticed two things? One is wouldn't a noticeable greater recoil be felt? I mean +P over standard is definitely noticeable for me. Second wouldn't the sound level be so much greater that it had to be noticed? The 9mm crack sound from breaking the sound barrier due to velocity speed is definitely noticeable over a 380 round.
Maybe my questions are not really in the ball park but thought I would ask anyway.
 

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Direct sunlight interferes with the infared beams put out by the chronograph, so when there is no sun out why would you need to use diffusers? Maybe a difference by manufacturer, but it's certainly stated plainly in my instruction booklet. ;)
Infrared beams? Where are you getting that?

Chronos read the shadow passing over the sensors,no beams of any kind!

What model chrono has that info anywhere?

don
 

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Just a question here from someone that has no clue really about reloading. If the chrono readings were that high wouldn't you have noticed two things? One is wouldn't a noticeable greater recoil be felt? I mean +P over standard is definitely noticeable for me. Second wouldn't the sound level be so much greater that it had to be noticed? The 9mm crack sound from breaking the sound barrier due to velocity speed is definitely noticeable over a 380 round.
Maybe my questions are not really in the ball park but thought I would ask anyway.

Good question because because a significant increase in velocity would make a noticeable difference in recoil. Most of my 9mm ammo is supersonic, but still, since you're wearing hearing protection a higher sound level would be a bit more difficult to detect. There are exceptions like the .357 Magnum that probably has the highest "crack" measurable in dB than most any other common handgun cartridge. ;)
 

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Infrared beams? Where are you getting that?

Chronos read the shadow passing over the sensors,no beams of any kind!

What model chrono has that info anywhere?

don

From beam type smoke detectors stuck in my brain I guess. You're right in that in my Pro Chrono, it uses electromechanical light gathering devices where changes in the light gathered by the front and rear sensor are measured by the time difference that the light changes occur between the front and rear sensor.

Given that, though, it still states that the chrono is more accurate in overcast conditions without the diffusers. ;)
 

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From beam type smoke detectors stuck in my brain I guess. You're right in that in my Pro Chrono, it uses electromechanical light gathering devices where changes in the light gathered by the front and rear sensor are measured by the time difference that the light changes occur between the front and rear sensor.

Given that, though, it still states that the chrono is more accurate in overcast conditions without the diffusers. ;)
All chrono that are meant for outdoors use work this way. The reason direct sunlight w/o diff s rough on any sky screen, the duration of the shadows are shorter, shadows are harder for the screen to see then. Best results, even for the awesome Oehler, is early am & late afternoon when shadows are longer. In direct noon, summer sun, diffuser are almost mandator for best results.
 

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SG:

Is it possible that the chrono was reading the passage of some powder particles or the gas column instead of the bullet?

Just wondering.

Tell us more about the setup and distances involved.

-steve

ps. Try another shot with a piece of parchment paper in front of the chrono.
 
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