culling the accurate cases?

[lpreddick]

does anybody do this? i'v just started culling cases that shoot one hole, even if bullets and powders are different. there must be something near perfect... this case, the bullet, powder, neck tension,seating depth,etc. after collecting a number of such cases, i'll process them as before they shot one hole and see if the case is as important as the "houston warehouse" shooters said. banana cases just won't shot but these cases must have some magic in them, or am i all wet?

 

[1Merlin]

I have no problem getting cases that shoot into one hole. Just getting two of them to shoot into the same hole is the problem... 8)

 

[Barlow]

I have no problem getting cases that shoot into one hole. Just getting two of them to shoot into the same hole is the problem... 8)

That's the same problem I have. Barlow

 

[LongRanger]

Hmmm.

LP, can you give us a critical piece of info, like what distance you are shooting?

Frank B.

 

[coford]

I am not trying to be offensive so please don't take it that way but I think you have it backwards. You would want to cull, or remove from the bunch, all the cases that don't shoot into one hole in the group. If a case consistently throws a shot out of the group you would want to remove it from the good cases and keep all the cases that shoot into one hole in the group. I have never really noticed this happening but I don't shoot benchrest so I don't track each case and where it's shot lands in the group. It would take some serious thought and maybe even round robin testing to make sure the case was causing the shot out of the group.

 

[Raythemanroe]

Probably like ladder testing, if you mapped where your casing hit farther out (300+) it may be easier and beneficial...

 

[searcher]

Another way to look at this might be to evaluate why some "cases" put them into one hole and a few cases don't perform. Granted - you don't know whether it was truly the bullet or the primer for that matter, after all - it can't be you. (ha)

I recommend that you shoot all of your batch of cases you are going to use in a match (if that is the intended use). After shooting each case over a chrono, write the speed on the side of the case with a sharpie and later group them into batches in seperate boxes. The same close speed tells you that piece of brass likely has no major flaws to prevent flyers from the others. Granted, you may shoot it again in a match and produce a flyer after this excercise - yet primers and bullets have their bad days. Thus - the need to also weigh them and batch also.

If shooting steel targets out to three or four hundred yards - don't do any of this. Total waste of time. Good to consider for any serious target shooting whether shooting "point blank", F-Class 600 or 1,000 yard bench-rest.

 

[VaniB]

It sounds to me like you are still in the beginning stages of reloading and you haven't gotten far enough into it.

If you were using cocentricity gages (like Sinclair's) to first check your sized cases and then check your completed cartridge, the sorting and culling will take place before you even get to the range. My culling takes place at the bench. if a component just will not load uniformly or in a concentric manner, it never makes it to the range. I either toss the case or use it for a plinking or a fouling load.

I can tell at the bench when things are or aren't going well. In particular, I have discovered just how important neck tension or bullet pull translates to a tight grouping on the target.

I use a magic marker to make notations on cartridges that were very uniform. And it is no surprise that they are NOT unifom the next time when I go to reload it and use it. It's no surprise to me that if I don't anneal the cases and make sure that I'm seating the bullet in a uniform manner, the tight grouping on target disappears. Just because that brass case did a sub 1/2" group last time, doesn't mean it's going to do it this time. While it sure helps to start with a good uniform case, the remaining prep work is still part of the formula.

 

[Barlow]

VaniB, That is a good post. Barlow

 

[82boy]

I just grab some case and go, if I find one that bolts down hard, or has a click in it at extraction I throw it out. The idea is to make all of your cases identical. when I neck cut cases I do them by the 100 lot. I then grab 25 or 50 cases and fire form them, and shoot them until they wear out. If I have an unexplainable shot I will turn that case upside down and mark it, but other than that I don't mark any cases. I basically want all of my cases to shoot the same, or I get ride of them. Here is a target I shot in the first club match of the year. It is 5 shoots at 100 yards. I have no idea where these 5 cases are in my box, because all of the 25 are capable of producing this.


Funny part about these cases, I bought a used barrel off of a guy. He was upset because the PPC case was so labor intensive. These 25 cases he neck turned, and was unfired. I re-turned the necks, and straightened everything out, and this is what I got. I had another 0 group going that same day, but I got distracted, and shot a mid .1 group.

 

[williamwaco]

Not sure this is the same thing but on three separate occasions I have experimented with culling cases that caused flyers.

.223, .243, 38-55

Same result in every case.

Start with 100 cases.

Load them all.

Fire them into 5 shot groups and segregate any case that produced a flyer.


First series culled about 15 to 20 cases.

Then load the remaining 80 cases and repeat.

Since none of these produced a flyer last time, they shouldn't this time ( ? ).

But 15 or 20 would cause flyers.

If you keep this up, you eventually cull them all.


.

 

[37Lincoln1]

Sometimes we need to cull the shooter. ;D

 

[jmatters]

Any time I handle a case and the loading operation hiccups, I magic-marker the head, and use them only for fouling shots. Last match, I wound up with 8 oddballs, and they shot all over the place. Once I got those out of the way, all the rest shot very close. No scope adjustment (1/8 moa) needed over a 50 shot match.

(And by hiccup I mean user brain farting)

 

[Raythemanroe]

I cull when they split!

 

[fguffey]

Culling cases: In the 60s an article was published, since then reloaders and shooters have been discovering and claiming the work as their own, a shooter/reloader/collector purchased 500 rounds from one lot, he sorted and sorted, then shot then sorted again, he indexed cases that were not accurate, and shot them again, then he indexed the cases that did not shoot accurately, THEN!? He discovered the cases that were not accurate but indexed shot accurately when indexed, out of the 500 cases from one lot he settled on close to (wild guess) 47 cases that shot accurately from beginning to end.

F. Guffey

 

[BoydAllen]

I think that is you look around you might find a copy an article by the late Creighton Audette, that showed the relation between runout in the body thickness of cases and accuracy. He did a lot of testing and published his targets and methods in the article. One reason that some may not have found that sorting by shooting was not of much use is that some brass, Lapua and Norma for instance, is very good in this respect, and another reason is that if one is going to sort this way, one needs a rifle that is sufficiently accurate, and a well tuned load. An easier way to sort, that can be done at home, is to make or buy a gauge that will allow you to measure variation in case wall thickness well down the case. A friend who has a lathe and mill made one some time ago, and he can readily see the results of his sorting, on his targets.

 

[fguffey]

I have a set of 10 books, titled ‘Hawkins Electrical Guide’ by Theo Audel, Point? Creighton Audette sounds familiar, I still have the article, problem? I do not believe the effort required to find the book would be worth the effort, he spent a lot of time measuring the powder column, long, short and the diameter, then he went to concentric powder columns. It did not seem he was trying to sell me something except an ideal and or philosophy, if around here a philosophy can be loosely describes as “What one thinks”

F. Guffey

 

[1KBR]

If you were to measure the case thickness runout, at what readings would you start to see an appreciable difference in accuracy when using a modern well tuned rifle?

 

[BoydAllen]

Although the degree of sizing of cases probably exaggerated the effects in his tests, I believe that his information is as important today as it ever was. If you are using high quality brass, you may not see much advantage, particularly if your FL die is well matched to your chamber, but for brass that is of more variable quality, sorting in the manner that he described will show results. A friend has had a home made gauge for a number of years, and sorts his brass for his .223 varmint rifle, that is well built and that has a match grade barrel and a FL die that matches the chamber. His testing showed an advantage in sorting. He is also able to evaluate the quality of various lots and manufacturers. If you are trying to wring everything out of a rifle and you are using brass that has significant wall thickness runout variation, I think that something like the NECO gauge is a very good idea. The accuracy life of barrels is relatively short, and for that reason, I think that sorting brass by a method other than firing is a very good idea. Lots of fellows that claim to be highly interested in accuracy do not want to be bothered with some of the small details that need to be dealt with to obtain it on a consistent basis, they think that by simply doing a few things well that they can achieve their goal, and in a sense they are right, for in most cases shooters that do not compete are happy with an excellent wallet group from time to time. On the other hand, when one competes, consistency becomes a requirement, and for that, no stone can be left unturned.

 

[Bob3700]

Merrill Martin wrote several articles for Precision Shooting years ago that detailed investigations on case wall variations vs accuracy. The distribution of brass in the case exists from the neck down to the head. Measuring this variation was the first step in culling brass. Excessive variation in wall thickness caused the fired case to form a banana shape and loaded round runout increased.
No amount of resizing could eliminate the banana!
So that would be a good place to start. U will find that as your distance increases all of these things impact the size of your groups.
Bob