Case head squaring

[goodgrouper]

Is anyone currently doing this and what has been your experience?

I have a friend who makes a good argument for doing it, but I never have done it, and we've both attained good groups from our rifles. I can see the logic behind it but do you think it really does anything?

 

[Guest]

You must be doing this at work? OLD BEAR

 

[Varmint Hunter]

I can't see the logic behind it. You can make a case head perfectly square but it will only stay that way if you don't fire it. The first time that you fire your "squared" case it will conform to the chamber and only be as square as your bolt face and chamber is to begin with. /ubbthreads/images/graemlins/confused.gif

 

[Guest]

Varmint Hunter is right , if you square your case head then fire it in a rifle that has bot been "blueprinted" so that the lugs and bolt face are square with the bore of the barrel then you just going to end up with a fired case that is gonna need squaring again !
How the hell would you square a case head anyway , what do you use as your index ?

 

[goodgrouper]

VH, and J Jones,
Let's suppose the action has been blueprinted. My friend's argument is that squaring a bolt face would especially help when squaring case heads. In other words, a square bolt is squared for straight cartridge alignment but it only works if the case is square. It is a two part system and both parts must be done to gain any benefit.
I kinda think that it is picking fly crap out of the pepper as I have seen many a small group without the cases being squared, but his theory does make good sense.
As far as how to do it, he turns his heads on a wilson trimmer that has been altered to trimming on both ends of the case. I have seen his setup only a few times, and I can't remember exactly how his trimmer has been altered, but I know that he ordered ALL the parts from Sinclair. I believe he is indexing off the Wilson case gages. Of course they only make those things in certain calibers so if you have a wildcat you probably can't do it. I would think that you would only be able to do this technique before your gunsmith threads on and headspaces your barrel or else your headspace would be off several thousandths.
Anyway, I'm curious what you think. /ubbthreads/images/graemlins/wink.gif

 

[bchannell]

I tried it several years ago for a couple of custom rifles I had Shilen build. The guns both shot awesome, and I thought it would make them shoot even better. I couldn't really tell any difference between 1/4" groups at 100 yards. By the way a Wilson case trimmer is used to square them. You simply turn the case holder around, and take as little as possible off the head to clean it up all the way around.

 

[jb1000br]

[ QUOTE ]
I tried it several years ago for a couple of custom rifles I had Shilen build. The guns both shot awesome, and I thought it would make them shoot even better. I couldn't really tell any difference between 1/4" groups at 100 yards. By the way a Wilson case trimmer is used to square them. You simply turn the case holder around, and take as little as possible off the head to clean it up all the way around.

[/ QUOTE ]

THIS IS NOT RECOMMENDED BY THE FOLKS AT WILSON!!!

jb

 

[Paul Wyatt]

These are the same arguments that I always see when someone poses a question about a process to improve consistency - those that don't do it or don't like it poo-poo it. I like to reload. I like to trim, clean, and anneal cases. I like to weigh every charge of powder to the nearest 1/10 grain, and I do all that because I have spent bookoo bucks on the finest action, barrel, and stock combination I can find. It seems to me that if accuracy is the end game then doing everything possible to ensure the best possible ammo only makes sense. I believe that there is such a thing as the whole is greater than the sum of the parts.
By the way - Wilson does NOT recommend this process because it is entirely possible to create head-space problems. I use it with wildcat cartridges where I can create a false neck that ensures a tight fit with the trimmed case when fire forming.

 

[TOM H]

By the way - Wilson does NOT recommend this process because it is entirely possible to create head-space problems. I use it with wildcat cartridges where I can create a false neck that ensures a tight fit with the trimmed case when fire forming.

[/ QUOTE ]
The problem you run into with head -space is with fired cases not new. Wilson was just trying to cover themselves.

 

[Guest]

even if the cases are way out of square after the first firing they are going to be set to the gun so if your chamber is cut perfectly centerd in the bore and the action has been reworked correctly then the case is going to come out strait and doing any case head trimming would be pointless
In order to cut the case head square you have to use something as an index point , what are you going to use for this ? a case that is not perfectly strait , you'll be making a bad problem worse. I could see the point if you had some cases that had a very inconsistant rim thickness , I had this problem with Win 300WSM brass when it firts came out , some of the cases woulden't even fit in my shell holder because the rim was to thick. In this case then yes I could see the point in trimming the case heads but I woulden't expect any accuracy improvement from it

 

[Paul Wyatt]

[ QUOTE ]
even if the cases are way out of square after the first firing they are going to be set to the gun so if your chamber is cut perfectly centerd in the bore and the action has been reworked correctly then the case is going to come out strait and doing any case head trimming would be pointless
In order to cut the case head square you have to use something as an index point , what are you going to use for this ? a case that is not perfectly strait , you'll be making a bad problem worse. I could see the point if you had some cases that had a very inconsistant rim thickness , I had this problem with Win 300WSM brass when it firts came out , some of the cases woulden't even fit in my shell holder because the rim was to thick. In this case then yes I could see the point in trimming the case heads but I woulden't expect any accuracy improvement from it

[/ QUOTE ]

This statement just is not correct according to some pretty extensive testing (not by me). To start with a case that is not square - and many are not, that is shot in a perfect chamber will be bannana shaped after fireing because the brass will stretch on the short side of the case under pressure, so you now have a mishaped case in a perfect chamber for every subsequent fireing.
The purpose of useing a Wilson trimmer is because these trimmers use a case holder that is reamed to chamber dimensions and holds the centerline of the cartridge square to the cutter head.
I grant that this step is the one step that may be superfolurus in case preparation, but in my case, I am starting with 416 Rigby brass that is costing me close to $2 per case, and then I am necking them down and fire-forming them. At that cost, and with all the work involved in getting the cases ready it would be a shame to not take every step that can be taken to ensure that the finished product is a case that is as close to perfection as I can make it.

 

[goodgrouper]

Brass Bender,
The logic of this process is not lost on me. It might just make .0009% of difference, but I am such a stinking perfectionist that I've just got to try it once. By the way, I checked some Lapua BR brass from two different lots this week and neither one was square. It took about .002" off the high side! Then I did two cases of Norma 6.5-.284 brass and it was actually making contact around the whole case head but only in a small circle around the pocket. In other words, the case head was dome shaped!
After these findings, I am going to do all 200 cases I just ordered for my new 6BR and 6 Dasher just out of curiosity. It might be nothing but extra work for no return, but I will try anything once! /ubbthreads/images/graemlins/grin.gif

 

[goodgrouper]

Not true J Jones.
I have taken brass that has been fired many times in a trued action and a custom action and it is still not square. The cutter still took brass off the high side. THE ONLY THING THAT WILL SQUARE A CASE HEAD IS CUTTING A CASE HEAD! It will not staighten itself by being fired in a "good" gun.
As far as starting with quality brass and not worrying about it; worry about it! I just spent all day at 7mmRHB's house squaring 200 Lapua BR cases and it will shock you what I found out! That brass is probably the best out of the box brass made on this planet and out of the 200, 32 were dome shaped, 11 were dished, 4 had dimples, and the remainder (minus the 14 that were good) had a unbalanced high side!!! I might further add that the drilled flash holes still had burrs looking at them through a magnifying glass. On the plus side, there was only 1 that was .006" short in the neck, and the weight difference of the prepped cases varied only 1.2 grains! That kicks serious butt on ANY of the Winchester or Remington brass I've done.
As for the accuracy improvement, it's hard to give it a guesstimated percentage, but I honestly couldn't give a percentage to any of the benchrest techniques we all commonly do. Do you know how much difference uniforming the primer pockets does? Could you put a percentage on it? I doubt it, but we all still do it. 50 years ago, if you told someone that you were deburring flash holes, they would laugh you off the range, now it's common practice and I doubt anyone could say just exactly how much difference it makes. Maybe all or maybe nothing. On a benchrest gun it could be worth your while to square the heads, and it would do nothing to square the heads on brass to be used in an AK47.
All I'm saying is that it makes sense, and a lot of people could benefit from it if they would keep an open mind, and be willing to try something once before they say it wouldn't work. Many people poo pooed the Wright Brothers for thinking that man could fly, now who has the last laugh! /ubbthreads/images/graemlins/grin.gif

 

[bchannell]

I don't necessarily recommend squaring, as I don't see any big benefit to it, and several downsides to it. BUT, if you go by "NOT RECOMMENDED BY THE FOLKS AT WILSON", then, heck if you have problems with any rifle and you tell the manufacturer you're using handloads, you're about to get a BIG surprise, NONE of them recommend it.
While it may not be the best idea, I wouldn't put too much store in what the manufacturers do or do not recommend.

I guess my recommendation would be, if you don't know what you're doing, as far as headspace is concerned, and you aren't using a rifle capable of benefitting from such extreme accuracy measures, then don't mess with it.