This summer me and a friend loaded some 260 shells for his 700 adl. The brass was once fired and everything was good and free when we chambered them, they also shot well.
Now it's deer season, 4 months later, the first day the temp was in the 30's, he uses the gun and same loads to take a buck, everything worked fine.2 weeks later on the last day of the season it was about 15 degrees out, the gun and shells were kept inside the cabin all night, the next morning when he got to his stand he went to load the gun, and the bolt wouldn't even begin to close on the first shell he tried, so he put in another one and the same thing happened. He sat there with the 2 shells in his hand for about ten minutes trying to figure out what he was going to do with a gun that he couldn't chamber a shell in. After standing there he thought he would try again, and low and behold after holding the shells in his hand they chambered fine with no resistance. I've never seen anything like this before and wanted to know what your thoughts are, if it's something we did when sizing I'll do it diffrently, but there was no resistance all summer, or after he held the shells. Please let me know what you guys think, and what I should check for.
Thanks, JT

Guns was left outside over night...steel contracted.
Ammo was brought inside over night...brass expanded.
When the ammo cooled, it fit.

ricciardelli,
I think it had something to do with temp also, but I thought it seemed like alot of shrinking and expanding to be that much different. Hopefully it won't happen again, but I thought I'd check and make sure that was the general conclusion before I got to worried about it.
Thanks, jt

Well if the tolerances were so close that temp made a difference then I would have the gun fixed...If warming them up in his hand made them feed, thats another miracle and he can probably walk on water...

I suspect a combination of things, He did not full length resize and some cases spring back to different dimensions when reloading, so full length all "hunting and defence loads". I see this every year in Africa with handloads depending on the expertise of the handloader...

A out of spec chamber might be a problem also and the case will only go in one way after resizing and I am sure there are several other problems that could cause such an experience, but I was not there, so its hard to analize...Most times it the nut behind the stock thats the problem. I would venture anytime a handload fails to function in any manner it is owner related in the wash.

The math for thermal expansion look something like:
DL = aLDT
a[Brass]= 19 x 10-6 C-1
a [steel] = 11 x 10-6 C-1

What does it mean?
over a 30 degrees C change = 54 degree F change, the steel changes .033% and the brass changes .057%
With a .5" diameter and 3" long case, that would be .0003" diameter change and .0017" length change, while the steel only changes .0002" in dia and .001" in length.

The differnce is expansion between the two metals is:
.00004" in dia
.00024" in length

Given that brass is springy in diameter for .002" before the elastic limit is reached, one can assume that change from thermal expansion in the force needed to compress the brass is about 2% of resizing force.
The force needed to resize brass is on the order of 600 pounds. The change in chambering force would then be on the order of 12 pounds.

Of course as soon as the brass and steel made contact they would begin averaging temperatures.

A more likely explanation is that the cartridges would have had trouble fitting at the same temperature.

Fire a case in a chamber.
Take the case out and rotate it 180 degrees.
Now re chamber the case.
It does not go in easy if the chamber is not round and straight.

See some of the most respected experts in my book already responded. However no one mentioned something that I think also took place. I would say that the handloads were probably full and compressed. If the loads were compressed loads, it probably put enough internal pressure on the brass to expand it enough it would not chamber. When it was heated up in his hand it then chambered.

He also may have lubed the cases and not cleaned off the lube and the lube was sticking not allowing the chambering.
When he held them it heated the lube up enough to allow the rifle to chamber.

In WW2 in the Russo Finnish war of 1939, I was reading about that the Finns use to cut their lube for their rifles by 75% to function in cold weather. Russian rifles would jam up or not work at all, and it was the fault of the lube being too much for the extreme cold. It would function fine in better weather. If a gun jammed up in cold weather combat because of the lube on the bolt etc, the Finns would just urinate on their weapons, as was the field remedy ordered.
The heat from the urine being body temp, would warm the lube up enough allow the action to cycle.
Finnish troops picked up a lot of locked up Russian rifles off of their freshly killed owners and urinated on them and used them against their former owners on the spot.

When I hunt in cold weather I always hand load cartridges using mid range burn powder so it is not going to be a full case. Unlike using 4350, 4831 or slower powder.