Inconsistent results from ladder testing

[Dusty Stevens]

Weather on different days affects your loads differently. One day your load is fine the next its over pressure. So if youre a proponent of ladder testing you must do another one on each day if the temp/humidity has changed at all. Now you see why pure accuracy shooters work up loads on the fly and have never heard of round robin except in elementary school. I suspect your load was borderline hot then went over the limit on the next trip

[)Stephan]

I am aware of the weather fact. The overpressure showed today just after cleaning. So weather and humidity should be the same. That's why I asked.

[Dusty Stevens]

You may want to run a patch with a little dab of lock eeze on it after youve dried the bore and chamber completely. Nothing dripping wet just a light film. Evidently your bore was real sticky and held the bullet back after cleaning. Lock eeze is a graphite lock lubricant found at napa. Could be different names at different stores. And be sure you shoot 3-4 shots to foul the bore before you start taking official shots again.

[)Stephan]

Thank you, I will do that! Actually you made me search for "dry firing" a lot and it seems as people do not recommend it. So I will get a tube of Lock-eeze later (local bike stores sell it).

Another thing, I did say that after FL-sizing the cases somehow changed in form after that.
Now today I just entered them in the chamber again to see what happened the last days an I wouldn't believe it, they changed again (this time only a few...).
So some cases on wich the bolt just fell closed are good now. And some good cases have gone bad (too loose or tight).
So this is a problem for me as I can only load on the range while training. I can't do that at matches. Also I need 20 cases for the match and some additional sighters and foulers.. I am going crazy over here - that cases have all just been shot 2 times and they were threated exactly the same.

Can this be because of my sizing procedure? I use a Redding Type-S (not made for mychamber but off the shelf) with a TiN bushing. Also i use imperial sizing die wax.
Maybe I use too much wax? Maybe not enough? I think I do sizing in a repeatable and constant fashion..

Talking about the FL die, it does not feel tight, maybe the body of the case gets a little bit oversized but not much.



Well thinking about the fact that all my cases are sized the same every 10 feel different in the chamber, maybe this gives velocity spread and causes bad results?
Actually it does look like I do know why my ladder tests differ from day to day, even with the same temperature.
Actually I have read a post in this forum where somebody said he loaded some rounds on one day and shot a half of it then and the other half later - this gave him a 60fps spread from the 2 days..

So thinking of that, I am going to chrono every shot the next time.

Does a heat cracked or worn out barrel also show high spreads of velocity?
I am thinking of getting a new one, but I have the same problem on new battrrels so probably this does not help...


P.S. Probably neck tension did also change .. I don't know yet, but I am at a level to believe that right now

[Dusty Stevens]

Id try some new brass and do some annealing. When sizing only get lube on the body not on the neck or shoulder at all. Very light wax! Your cases are alive.

[)Stephan]

No wax on shoulder and neck?
Okay you are right - the shoulder is only pushed pack and for the neck I have TiN bushings..
Also I just added a Wilson neck sizer to my wishlist, I only have a standard RCBS or Redding neck sizer (I did use it a lot years ago).

Thanks again!

[Dusty Stevens]

You dont even have to have a tin bushing- even the regular ones are harder than the brass. If you lube the shoulders you cant get a consistent layer in there plus it builds up on the die and is not compressable so before you know it you get all kinds of fluctuations.

[)Stephan]

Nothing new yet..

I just checked the screws for torque, they are all good (base, rings, action)
So I did just order the Wilson neck sizing die (and base). We will see!

EDIT:
I received my neck die today. I will let you know of any updates (maybe next wednesday)