My ar-15 reloads are extremely accurate right after I load them but after they sit for awhile they arent near as accurate. They arent compressed loads they arent crimped. I dont know whats up. does anybody know why or what I can do to help this. Thanks Ryan

I've never heard of that. I typically have a go-to hunting load for a particular rifle and I will load 100 or so up and use them over a couple of years without issue. My brother has a 25.06 that he loaded his hunting ammunition for in the 70's and still uses a couple of them every year.

The only thing that I can think of that might effect that is if you have some sort of contamination (lube?) that is breaking down the powder over time.

Yeah the older I get the worse I shoot and the better I was Sorry couldn't resist. I have never heard of this either but have typically never shot the same loads for groups over time except hunting loads to recheck zero on my rifle and have not noticed this phenomena. When I used to shoot competition, I would typically load every week and shoot a match so none of those rounds ever sat for more than a week. I can't imagine anything doing this unless you have some marginal components? Try a different lot of primers or powder.

I've heard of some of the benchrest guys noticing this. Some of their guns like fresh ammo some like the ammo to be a couple weeks old or more. I always thought it was BS, but maybe there is something to it. Can't say I've ever noticed the phenomenon in my own rifles. Is the difference in accuracy significant or .1 moa?

I'd be looking to some sort of contamination, or substandard components as well. Are the rounds handled a lot so that the bullet tips may be getting messed up?

One thing that happens over time but probably is'nt the case here is slight corrotion will bond the bullet to the neck of the case. This will cause all kinds of problems accuracy being the least.

How old is your ammo? It normally takes a couple of years for the problem I'm discribing to occure.

The cure for this is to put the ammo in your seating dye and bump the bullet down just enough to make it move and break the bond.

Again I doubt that this is your problem but it would be worth a try. Otherwise I have no idea what might be going on.

Sometimes-accually most of the time-I'm not very accuarate if I sit around too long. It always takes me a few groups before I come around. Try a couple of practice groups or dry fireing before you get serious. Powder,primers and bullets should not deteriorate if kept in fairly good conditions. I haven't noticed what you are experiencing anyhow. Dave

The only time I have ever seen this was some ammo that had the insides of the case necks lubed. Many years later the lube had glued the bullets in place. The ammo would not hit a 4x4 back stop at 100 yards.


My guess is either your gun has changed, it was more windy that day, or your shooting is not as good as last time.

How long do you let them sit before accuracy drops off?

Cold-welding (bonding of bullet and case neck) takes quite a while to take place.

Long ago, when the 300 Winnie was popular for 1,000 prone matches, we noticed that bullet pull (the tension with which the case neck holds the bullet) sometimes relaxed over time, bringing awful vertical stinging on the target. The cure was to shoot the ammo soon after it was loaded. I don't know what your accuracy standards are or under what conditions you shoot, but you may look at using different brass.

My two cents, worth every penny

Mark

I've had HORRIBLE issues with accuracy from aging reloads of 5 to 15 years old. I can't believe it isn't discussed more.

Ideally I always thought it would be great to work up a pet load for each gun and have 50 or 100 of them sitting around ready to go. As opposed to reloading for each hunt. Life just doesn't seem that easy.

For example - I had a load for a .300 Wby. hunting rifle I'd worked up that would shoot 1/2" at 100 yards and I even once shot a 1.5" group at 300 yards. These were all quality components. After a few years of storage (dry place, stable temperature, underground garage in plastic storage boxes, etc.) I couldn't get those EXACT loads to shoot well enough to even tell if the gun was sighted in. They literally shot 4 or 5+" at 100 yards after several years.

Another example - I had a load worked up for a Sako rifle in .340 Wby. with an S&B scope and using premium components in new brass. That load would shoot around 3/4" or a bit under when I took them to Namibia and made lots of 1 shot kills. Loads from the SAME EXACT batch of reloads (some traveled, some didn't) shoot about 3 to 4" at 100 yards now.

The neck tension theory is the only one that makes much sense to me. When I get some time I'm going to do some testing with some of these older loads. Shoot groups as they are and compared to those which have had the bullets moved a bit. Rather than seating them deeper I thougth of pulling them partially with a collet puller and reseating them to the same depth. I've also thought it might be worth messing with the Lee Factory Crimp dies to see if the bullet pull would be more consistent over time.

Admittedly I could be guilty of not cleaning off all the lube in the case necks, or worse yet leaving inconsistent amounts. I just can't get over that more people don't complain about this.

Kyler

I haven't experienced this.. if I did, I would be suspecting the powder as the chief culprit..

but I have used WW 2 loaded powder, that I have disassembled from surpus WW 2 rounds.. and then tried it in a 22.250...

those were more accurate than the current IMR 4895 batch I have..and the rounds those came from were date stamped 1936 to 1942...

The loads have only sit for maybe six months. Its not a huge lose of accuracy some may think I'm just picky but they went from 1 hole 5 shot groups to just over an inch. I thought it was just me so I loaded some fresh loads and was back to 1 hole. I think I will try some new powder or primers.

My guess would also be neck tension...possibly reduced neck tension. I believe that over time most things that are "stretched" to a state of tension by expansion may lose some of the elasticity they had when newer. Of course it is most noticeable with aged rubber bands, things like that, but I think it happens with pretty much everything.

So annealing the necks should help. If your ammo is used as a maraca the powder may break down. I have 8x57, 15 year old ammo that I loaded that is still perfect.

I recently shot some 223 prairie dog loads that have been loaded for at least 26 years.

They shot just fine.

However I have heard of the neck bonding roblem.

I do know some people that shoot High Power Competition and load a LOT of ammo at one time.

They leave all their bullets long seated, and seat them to the proper oal a short time before a match.

After reading some of the above posts, perhaps I have experienced this and didn't recognize the problem? I worked up some 165gr TSX loads for Mrs Blacktailer's Kimber 308 when we went to Tanzania in 07. At the time, they were grouping well under an inch. Recently I took her gun out to check the zero and was getting 3 and 4 inch groups at 100 yards. Gave the gun a thorough cleaning and checked all of the screws but haven't taken it out since to see if this made any difference. Could be the loads.

Blacktailer
Next time you shoot the .308 take a few of the .308 rounds and bump the bullets down a hair then compare a group shot with those against a group shot without moving the bullets. It may not do anything but it might.

I haven't noticed this, but this leads to the question, does this happen to Factory bought ammo also? That wouldn't be very good, buy a box of factory ammo but make you shoot it before the expiration date?

I'd have to say I'd lean towards either contanimation (lube) in the powder or in the case of compressed loads maybe the bullet is getting pushed up or out and throwing off the COL Ogive.

I use a Lee FCD to avoid any bullet movement, just one less thing I don't have to worry about Waidmannsheil, Dom.

Were there significant temperature differences between shooting sessions?

quote:

Originally posted by Dom:
I haven't noticed this, but this leads to the question, does this happen to Factory bought ammo also? That wouldn't be very good, buy a box of factory ammo but make you shoot it before the expiration date?

While I have never experienced w/commercial factory ammo, have had case neck/bullet bonding problem w/GI ammo. One particular lot of 30-06 Match ammo wouldn't shoot 6" group @ 100. When I "bumped" the bullets in a seater die, most, but not all, would make a loud pop when bullet broke loose. Accuracy was what one would expect from GI Match after bumping.

As far as handloads, I use Imperial dry neck lube and do not remove it before seating bullets. Never had any problems w/ammo loaded up to 5-6 years earlier.

OP didn't say how long the ammo had been loaded, but I would suspect loss of case neck tension rather than bullet/neck bonding if less than 5 years. Contamination, of course would cause same issue.

Regards,
hm

quote:

Originally posted by Akshooter:
Blacktailer
Next time you shoot the .308 take a few of the .308 rounds and bump the bullets down a hair then compare a group shot with those against a group shot without moving the bullets. It may not do anything but it might.

I bumped a few rounds back yesterday and shot them. When I bumped them back, I didn't feel any extra resistance, they just slid back nice and smooth so it would not appear that the bullets and brass had bonded. They didn't group any different than the originals but everything grouped better than the previous session so maybe the cleaning/tightening took car of the problem.