OT - Do reloads degrade...?

[deerwhacker444]

I recently went out and shot some loads in my 444 Marlin that I had on the shelf from 3-4 years ago. I noticed that there was a consistent 150-200 fps difference between now and the first time I shot them. I was wondering if anyone has experienced loads degrading over time.

[Pisgah]

While it is possible that your loads could have degraded, if they were properly assembled and stored the odds are very small that's what has happened.

A much more likely explanation -- that was then, and this is now. Think of all of the possible variables: Same ambient temperature and relative humidity?; Which chrono is being used? Same, or different?; Is it set up EXACTLY as it was before? Or, has it begun to show some changes in its reliability?; Has anything changed with the bore of the rifle?

An indication of a 100-200 fps variance could simply mean it was gray and cloudy the last time you shot them, and bright and shiny when you shot them again.

[AJMD429]

I've shot 35-year-old 6mm Remington reloads I made, and although I didn't chronograph them (didn't have a chrony 35 yrs ago anyway, so nothing to compare them to), they DID still shoot about 1/2 MOA in the same gun, so if they 'degraded', at least they did so 'uniformly'...

[Old Savage]

I have not experienced any differences in the ones I have used that may be 10 years or more old but I would not expect that kind of difference over normal variance in conditions if the same rifle is used.

[shooter]

If you shot those loads 3-4 years ago in the summer in hot temps, and then just shot them in much cooler weather, that could very well explain the difference. I have always heard to develop loads in the summer, especially when dealing close to max, because if you develop in the winter and shoot in the summer the heat raises the pressure. So it's possible that if you loaded and shot those in the summer previously, the powder was hot and thus produced a higher velocity.

[AJMD429]

Given the MAJOR velocity variations sometimes seen with simply 'muzzle-up' or 'muzzle-down' positioning just before firing, I'm not that surprised that temperature would be a factor, as well.

It seems all the elements conspire against uniformity...

[deerwhacker444]

If you shot those loads 3-4 years ago in the summer in hot temps, and then just shot them in much cooler weather, that could very well explain the difference.

**** Ding Ding Ding **** Winner Winner Chicken Dinner...!

I bet that's probably it. I developed these loads at the beginning of summer. I remember it being hot because I had to get to the range about sunup to shoot, because it was getting hot quick during the day.

I've only been reloading for about 6 years now and had heard that some powders are temperature sensitive, I bet that's the reason.

Anybody have a list or idea of what powders are/are not temp. sensitive..?

Thanks for the replies.

[Sixgun]

Not in my experience--Proper storage is everything. The ammo that took my son's elk last week was loaded by me in 2004.

Back in 1972 when I first started loading, I loaded a box of 38 Spls. for the sole purpose of testing them out each year. Every year I shoot one for the fun of it and the last time I checked (last year) well, she went off fine. --------Sixgun

[Old Savage]

I like to load in summer so the pressures will not rise with the pronounced heat here if you load in winter.

[COSteve]

I called Hodgdon's tech support line 2 weeks ago to ask about their new Leverevolution powders. During our discussion, I also asked about the lifespan of powder when it's stored correctly (original container, 65°-70°, low humidity, out of the sunlight) and the tech told me that their spherical ball powders are developed with a 60+ yrs lifespan, their flake powders have a 50+ yrs lifespan, and their extruded has somewhere in between. I also asked about the lifespan of ammunition loaded with their powders, and he said that if the ammunition is stored correctly (same way as the powder) it should have a lifespan slightly longer than the bulk powder.

[Cast Bullet Hunter]

If you shot those loads 3-4 years ago in the summer in hot temps, and then just shot them in much cooler weather, that could very well explain the difference.

**** Ding Ding Ding **** Winner Winner Chicken Dinner...!

I bet that's probably it. I developed these loads at the beginning of summer. I remember it being hot because I had to get to the range about sunup to shoot, because it was getting hot quick during the day.

I've only been reloading for about 6 years now and had heard that some powders are temperature sensitive, I bet that's the reason.

Anybody have a list or idea of what powders are/are not temp. sensitive..?

Thanks for the replies.

DW,

All small arms propellants are temperature sensitive, it is a matter of some showing more variation than others. Likewise all are position sensitive so the higher the loading density the less variation they will show, right up to compressed loads that, theoretically, should show no position sensitivity.

Single-base flake or extruded propellants should show the least variation to temperature.

Four years is nothing. I have .45 ACP and .38 Special that I loaded thousands of when I was still shooting competition bach in the mid-1970s that still perform flawlessly. I just can't get around to shooting them all up, especially the .45s, I hate chasing brass!!!!

[BAGTIC]

I recently came across some old .222 Remington that I loaded in 1962. During their life they have been moved from California to Florida to Oregon to California and finally to Missouri. When I shot some of them they still put three shots inside of an inch from an old 6 pound SAKO L-46 Vixen with its original two position peep sight.