Does the accuracy potential of a load decrease with increased number of firings of the brass? It seems that when I'm shooting 1 or 2 times fired brass, my group size is excellent. When I shoot brass that has been fired 3 or 4 times the accuracy is not as good. What do you guys think?

A little depends on the size of your chamber. An oversize chamber causes the brass to be worked more during resizing. The necks tend to work harden after several loadings thus neck tension changes and they may need to be re-annealed. However, that shouldn't happen after just a couple of loadings.

Make sure your are cleaning the primer pockets good. Check your cases for length and trim to a uniform length if need be. Tumble your brass after every firing. Clean & lube the inside of the neck before resizing. I usually polish the inside of the necks with some #0000 steel wool wrapped around a worn out bore brush and chucked in drill after every couple of firings. I also try to keep my brass separated by the number of firings.

I have never experienced a decrease in accuracy due to the number of times I have used my casings.

jayloar,

That is an interesting question. I have not seen it posted before.

The answer to the question is both Yes and No.

Here are some of my observations.

It is more of a problem with brass we buy today that that which we bought10 or more years ago. I have still have a few Winchester Super X 270 cases from years ago that are far harder than todays brass.

The problem occurs most often when you full lenght resize and load at the range. But size the same cases every few months rather than every hour and the problem is not so noticeable.

Also, if you start with one case and full size, shoot, full size, shoot etc as quick as you can fire them, you do not see the same case failure rate as when you have several weeks between firings. When doing this accuracy goes right off.

I think what also contributes is that the most accurate load with cases that have been full sized where thee is ome heradspace, usually shoot best with the bullet back off the rifling. This in turn means that neck tension is more critical to accurayc than for aload that has the bullets just on or barely off the rifling.

The same problem does not seem to occur with neck sized brass. However I think that also has something to do with the fact that neck sized only brass often shoots best with the bullet on the rifling, or just into the rifling and so neck tension is not so critial to accuracy.

Mike

i believe accuracy to suffer after 5 reloadings or so. it could be due to the fact that after five or six firings and resizings, brass becomes brittle and neck tension iregular, not releasing the bullet in a constant manner from shot to shot.
my two cents.
montero

If you anneal the brass after every 3-5 firings, you probably won't see th eproblem any more.

As the cases are fired the necks work harden and the bullet retention force changes.

Don

Ditto Don. Same lot of brass, one annealed the other with 5 or 6 neck sizing reloads, not only is the annealed brass more accurate but the velocity will drop slightly and the SD will be lower. I've proven it over and over again with several calibers. A Square recommended in their reloading manual, annealing every other reload for this reason. I anneal at 5 reloads. Bob

Tumbling brass bangs up the neck mouths, causing work hardening and nicks. I soak my "match" brass in dishwashing detergent with some vinegar. DON'T USE AMMONIA!

I anneal necks about every five loads. Keep track of brass lots by brand, number of loads.

Some group their brass by weight too.

------------------
PowderBurns Black Powder / Muzzle Loading Forum:

www.hotboards.com/plus/plus.mirage?who=powderburns