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Anyone tested cases to see what exactly happens when the case mouths arent square?
I resized a bunch of 45-90 brass to 42 Wesson a couple weeks ago and forgot to anneal them. They all came out pretty square but it took a a couple firings to get them properly resized. today I resized a few more but annealed them first. Some came out with a pretty crooked mouth. Thot maybe this would be a good time to test a few to see the results. before I true them up.
Another cause of this is case thickness concentricity, Walls that vary in thickness dont size the same. Necking down tends to thicken and lengthen cases also. I have had better results with my Bonaza coax press than some other due to the "floating die and shell holder I believe. Theres a certain amount of brass in a case and resizing it it has to go somewhere, thicker thinner walls longer shorter cases depending on if it sized up or down in size. Lightly trim to square and chamfer deburr to remove sharp edges before resizing this helps alot. Checking for wall thickness before resizing may show the problem cases ahead of time also. You didnt state press dies or brand of brass used here, A misalighnment in them may be an issue here also.
My biggest problem is I have no dies to size them down to the proper dimension with. I size them down with a 40-82 die then expand the neck with a 44-40 or 444 marlin neck expander. so they are free to get a little off centered. Didn't realize until now it was better to do them unannealed when doing it this way. I have saved three cases that are over .010 longer on one side than the other to do some tests sometime.
Lay a straight edge to the side of the case starting just above the rim, see if they are also bannanna shaped now.
Maybe fire them before you.trim they may come out right especially if you shoot them greaser sized patched ones :-)
a thing worth trying might be to breech seat some bullets with about a 1/8" airgap in front of a case full of powder in untrimmed cases.
this way, if one side of the case is too long for the chamber, it will not be gripped by the bullet on firing.
they might fireform into a straighter condition, from whence they can be trimmed successfully.
this method also works if you are trying to get cases a little long for a chamber to be a perfect fit for length.
they will just shorten up to perfect length for finger seating in fireformed brass.
this method will often give good accuracy while fireforming, as it will with a crooked or otherwise bad chamber.
keep safe,
bruce.
Seems if I remember from the ones I did a couple years ago that they did finally even out a little after shooting a couple times. I find it interesting that the best method to form them was unannealed.
Making 4050 bottlenecks is the same way if you Aneal them they get too soft and they get mushy
Semtav,
I would like to hear about the 42 Wesson Rifle.
The rifle is just a Browning BPCR that I had the 40-65 barrel bored out to .429 and chamber cut similar to the 42 Wesson but with a 45-90 base.
I'm shooting it with paperpatch bullets because the bore wound up so rough on the rebore it would lead up horribly. Its very accurate with the PP bullets.
My next big test with it will be the Montana 1000 in July. (If I make it this year)
Thanks for the description. Those Wesson rifles and chamberings have interested me for some reason. Good luck at the Montana 1000.
Well I do have a Wesson # 1 in 45-100 that just needs the finishing touches to be ready for the Long Range Matches. Beautiful gun. I've been fascinated by the Wessons too.
Well the wind wasn't horrible when I got done spraying today so I thought i'd test my crooked cases. Plan was to shoot a fouler, two check shots and then the three crooked mouth cases with high side to left, high side to the right and high side to the bottom and then a couple more check shots.
All went according to plan at first. Fouler shot was taken at target at 200 yds to see where I was hitting, then the two check shots were taken and hit side by side almost touching about 2 inches below the fouler. first crooked shell was then loaded with the long part to the left shot and wound up 2" below the check shots. Next shell was loaded with the long part to the right and wound up 3 inches below the first crooked case. since that shell was a little hard to load and really hard to extract I figured it might be a problem so I redid the long part to the right on the third shell and it wound up 3" higher than the check shots. At that point I was convinced the problem with crooked mouths was only vertical since the three shots were almost exactly vertical in line with the center between the two check shots. Thats when my test went off the rails. then next two check shots were high like the last crooked shot and the rest of the shells wound up shooting all over the place . I guess using the other cases that I fireformed at the same time for the check wasn't a good idea. Next time I'll use known cases for the check loads.
Tried the test again today. Only conclusion I came to was that the 10 I resized without annealing are accurate, and the 15 that I annealed before I resized are not. crooked or straight lip.