Can a load change its accuracy with time?

[dxlbaile]

Variables in reloading can,and will always change.
Throat and barrel change with time.
I never load more than I will shoot in a 2 month period.
Cold weld can be avoided by using imperial dry lube in the necks of your cases if you need to load ammo that will be sitting awhile.

 

[Old Rooster]

I am glad this was posted as I have 30-06 reloads I know is at least 25 years old and maybe a tad more.
I have better ways to reload now and will pull all bullets and then use a neck bushing die to bring it back to I F and run a mandrel with graphite dipped case.
Seat new bullet and that should set matters straight right?
The left over graphite will prevent bullet weld I hope.
I sure don't need to ruin any of my rifles.
Old Rooster

 

[skipglo]

It is not always caused by bullet weld.
I have made up loads and shot them 20 minutes later after completing load development for a comp shoot, which were perfectly fine in those parameters, but after a 4 hour road trip, those rounds changed and on the very first sighter shot I had a locked bolt. It could not be opened at the range, even with a hammer. Luckily I use PT&G one piece bolts because I had to chuck it in the lathe with the brake on and pound it open with a dead blow lead hammer. The case, what was left, was fused to the bolt face.
I removed the barrel and measured lug recesses and all was good. Only real damage was the extractor and ejector and a burn on the boot face where the primer let go.
Don't be fooled, powder settling in a case can change how it burns.
I tested this afterwards, cases charged without any settling and the powder being compressed slightly showed no excessive pressure, charges that were vibrated, with 1 grain less powder showed excessive pressure. I have a theory about this, but the Pressure Trace has not shown a conclusive result yet.
The above charge that was just poured into the case I call fluffy charging.
Cases that have either vibration or swirl charging, I call hard charged, because no more settling occurs even during transport.
Had this happen with RE25 and Retumbo twice now and in 300WM & 338-416 Rigby Improved.

Cheers.

OUCH!

 

[skipglo]

I'm glad you posted this. I have long suspected exactly what you described but never took the time to prove it to myself. If I'm not using a drop tube funnel, I also swirl my powder into the funnel. I've been doing that for so long that its just a habit now. I read along time ago that it would help lower extreme spread. I believe there is some merit to that idea.

Swirling is a practice I have used for years...but the only reason I started it was to have larger charges not plug the funnel...lol...so I do it on all loads..... definitely not for the scientific reasons here, I'm not that Deep....but saves on using the drop tube often!

 

[bullet man]

Well, I have match ammo from LC that's sealed with asphalt sealant that has shot the same as when it was made 40 years ago?

 

[Calvin45]

Well, I have match ammo from LC that's sealed with asphalt sealant that has shot the same as when it was made 40 years ago?

Yeah I've been wondering about it this too. Old factory ammo...do they use a lubricant that ensures this doesn't happen? Are the rounds crimped so hard that other variables in pressure generation are rendered moot? A few years ago my dad and I shot a box or two of .30-30 ammo he bought in the 1970s...and I've done the same with .270 and .303 British of that era. No hiccups of any kind.

 

[Mike Matteson]

I have always found that when accuracy starts to fade with the same load, is when the throat starts to erode.

Dean

I been reading a lot on this. Barrel Erosion, they are saying that the barrel erode at the rate of 0.004 to 0.007 per hundred rounds. Match shooters are changing there COAL as they shoot during there matches, if noting a change in there groups.
I find it very interesting, and sometime wonder how I get a bullet down range and hit anything with it. Ha,Ha. I realize that grouping are must for me. If I don't get down to .5 moa group or very close to that 100yds
before extending my range out. I am not a happy camper. I work on trying to figuring out what I need to do.
I do have loads that are several years old, and hadn't had a problem with them or wasn't aware there was a problem. I know that every round I fire, I check the case afterwards, before putting another round in the chamber. Most of my loads I use a drop tube to place the powder. I am going to add this to info I have already.

 

[Chrsm]

Yes!

 

[Chrsm]

Yes!

I have come to the conclusion that it's better to load as you go! You have all kinds of internal and external factors that constantly change, throat erosion just to name one. So unless, I don't care if I hit a bug virus a silver dollar I won't care as much. that determines the amount I load for a particular rifle.

 

[D$tring]

Swirling is a practice I have used for years...but the only reason I started it was to have larger charges not plug the funnel...lol...so I do it on all loads..... definitely not for the scientific reasons here, I'm not that Deep....but saves on using the drop tube often!

I am right by there with you! I swirl to avoid funnel clogs; I had no clue I was making my loads more consistent as well...good to know that I am accidentally THAT good! makes now wonder how much I still don't know about reloading. I literally learn something new every time I am on here with you guys! Thank you so much for sharing your experience and knowledge!

 

[Nunu]

I believe it's more likely to happen with new brass. Or brass that has had the inside of the neck squeaky clean.

When there's a layer of firing residue on the inside of the neck it separates the copper from the brass

What about the factory ammo? I still have some 308 hunting ammo which I bought in 2006 and since lead bullet was outlawed in CA for hunting I just use them as fouler once in a while. I never experienced any of those mentioned yet in both gas and bolt rifles but now I'm scared to shoot them after learning this. Thanks.

 

[bullet man]

What about the factory ammo? I still have some 308 hunting ammo which I bought in 2006 and since lead bullet was outlawed in CA for hunting I just use them as fouler once in a while. I never experienced any of those mentioned yet in both gas and bolt rifles but now I'm scared to shoot them after learning this. Thanks.

I've shot military ammo 80 yrs old never a problem

 

[Calvin45]

What about the factory ammo? I still have some 308 hunting ammo which I bought in 2006 and since lead bullet was outlawed in CA for hunting I just use them as fouler once in a while. I never experienced any of those mentioned yet in both gas and bolt rifles but now I'm scared to shoot them after learning this. Thanks.

Don't worry about it. You know how lawyered up everything is now. I don't recall a single instance of a munitions company being sued over this particular problem. If ammo was dangerous after less than two decades you can guarantee they'd be covering their butts and putting expiration dates on the stuff. Go shooting!

 

[emp1953]

I read in a book where the author said he had a load that was accurate if you shoot it within a few days. But it sets for a while, the accuracy is unreliable. I have experienced this, but decided it might be temperature and switched my load. But I have suspected this with other loads. I recently tried to pull a bullet out of a cartridge loaded a few years ago. It would not come out. I had to give up. I could probably shoot it, but the neck tension must be incredible. Any input on this phenomena is much appreciated. I have loaded enough 300 WM to last for years of hunting. I hope I did not make a mistake.

On a PA Black Bear hunt in 2004 a hunter in our party using a Win 1894 lever action shooting Super-X ammo from 1956. He hit a bear, moving, 4 times through the chest which we all had to drag out. Age didn't hurt this ammo.