Case trimming technique

[londonhunter]

Hi need a bit of advice here about case trimming

I purchased a Wilson case trimmer system

If I take one particular caliber I look after 6.5 x 55 sweede

the SAMMI published length is 2.165 inches

I tried to use a Sinclair chamber length gauge (gage - as printed)

used a fired case, partially neck size it and insert the gauge into this case

however I have a break open hunting blaser K95 rifle so that's where my first difficulty comes I cannot push the adapted cartridge into this chamber slowly with a bolt

Anyway I turn to another rifle 6 x 47 lapua

I shoot only lapua brass

and on first fired cases they vary at most 0.004 in extreme spread ES

At this point in time they are all below the measured chamber dimension less shall we say 0.04 as my datum point

However I can see with my naked eye that quite a few cases are NOT squared ?

Question one what do I do about that with the Wilson case trimmer at this stage
I would love to square them but the Wilson is not really the best tool since I have to adjust each screw for length individually - any suggestion for a faster way to square things off without trimming it much ? I DON'T really want to lose neck length for accuracy sake - am I correct ?

So my decision now is to monitor the length after each firing until cases surpass my chosen datum - question 02 - is this correct ?

Thanks for any input

Please criticize so I can learn from you folks

 

[jonbearman]

The wilson trimmer is the most accurate trimmer there is in my opinion.I would trim all the cases to square them.First measure and find the lowest measured cases you have and square them up,now if you have say 10 cases that are way shorter than the rest,set them aside and use the shortest case to determine your minimum trim length to square the rest of them up to a uniform length.If they are shorter than sammi dont worry about it.You need to get the case mouths squared up. Now ,did you order a fired case holder or a full lengthed sized holder.If you try to put a non sized case in a full length holder,they wont fit right and you could get a case crooked and trim it that way.I trim all my .223 remington brass under sammi spec.I also measure the new ammo and it is consistently way over sammi length to begin with.It is an industry standard to set minimum length so you have a starting point when reloading. It is almost imposible to have cases to sammi spec to begin with because most new brass is not sammi spec(longestlength permitted in the reloading manuals)it is usually shorter till you full length resize it and then check length and you again have to measure all the cases to establish your max length you can trim tnce you fireform you will get growth and after 3-4 firings the brass settles down and it will grow.I hope this helps you get an idea of what to expect.Someone will chime in if I am wrong about anything. Read your reloading manuals over and over till you understand what they want you to do.If you dont have a manual,get the hornady and sierra as they are excellent books and worth every penny you pay for them.

 

[K22]

I believe the Wilson Case trimming system is one of the best if not the best and is quite easy to use. Unless the trimmer is defective, it produces highly squared ends.

I'm sorry, but I kind of got lost in your discussion but if you want advice on case trimming using the Wilson tool, here it is:

1. First, the case must be new or full size to fit the case holder properly.

2. Measure the case with a Veriner Caliper and compare to specs for the case. This will give you some idea of how much needs to be trimmed. For most calibers, the spec is to trim .01 inches below max length. Example, 243 max case length is 2.045, trim to 2.035.

3. Insert case into the proper case holder, tap base of case slightly against bench to insure it is seated solidly, place in trimmer, then turn screw on trimmer so the case just touches the cutter. Turn the screw (clockwise) very slightly, trim, measure, repeat until you have the case trimmed to the trim length specs. Use this case as your standard to set trimmer in the future. Tighter set screw on trimmer and start trimming. Measure first case to make sure you're at "trim length specs", (normally .01 under max. case length.) See your reloading manual. I periodically check lengths while trimming to make sure nothing has changed.

4. Make sure you chamber inside and outside the necks after trimming.

You should be able to get several firing before reaching max case length and having to trim again. I check with Vernier caliper before every reload after three firings from the last trim to verify that I'm still below max. length.

Sinclair International makes a number of after market accessories for the Wilson Trimmer that makes the job easier, especially the Trimmer Stand and Case Holder Clamp. www.sinclairintl.com

 

[bozo699]

londonhunter,
Howdy, either you are confused or I am confused, my understanding from the title is your wanting to trim your cases to length, it is not necessary to n/k size a case to use your wilson trimmer, they make two holders, one is for unfired brass ( new brass) the other is for fired brass and for standard chambers that is the one you will use after your first firing or anytime after your first firing. If all you have is the new brass holder you will have to f/l size or use a body die and then the case will fit far enough into the holder to trim. The datum point hasn't anything to do with it, that's a measurement you will use when bumping the shoulder. I am not sure what the break open and the bolt guns have to do with trimming either. If the necks are not cut even then you either have a defective case holder, your not holding the case holder on the rails correctly or the cutter system is off center ??? I have three wilson trimmers and have never had a problem with any of them. I think Jon is right, buy a couple of reloading manuals and read, read, read no pun intended, another great book that covers just about everything is hand loading for competition
http://www.zediker.com/books/handloading/hlmain.html

Also I think there may have been some confusion on the screw on the Wilson, it doesn't need and shouldn't be touched after you determine the length wanted. Again Jon was correct you find your shortest case set the trimmer adjustment screw to just trim that case mouth even all the way around, then lock the adjusting screw down with lock screw and trim all the brass to that length. I myself don't pay attention to sammi specs I usually fire form all my cases then trim to the shortest case and do not trim again until I reach close to chamber dimensions, I usually always have my reamers built to cut a long neck so trimming isn't a issue. I hope some of this helps, and again if your new to the Wilson read the instructions and we will help if we can, if your new to reloading,..STOP what your doing and read some books please! there are also some great articles in the archives of this forum, also one our members, Germán Salazar writes some great articles on The Rifleman's Journal. http://riflemansjournal.blogspot.com/
Take care and good luck
Wayne.

 

[bozo699]

londonhunter,
K22 must have been writing his the same time I was writing mine otherwise I would have cut mine in half because he is spot on, he explained himself very well. I don't want to correct him but on #4 I think he meant Chamfer not chamber,
Wayne. Chamfer isn't recognized on spell check

 

[Keith Glasscock]

I think I see what you are getting at londonhunter,

Here is my advice (take it for what it's worth):

All of your cases need to be exactly the same length and perfectly square on the case mouth for best precision and accuracy.
If you have to trim them a little shorter than the standard number, I would do it. I can't see any harm in shooting a cases that have been trimmed to match your shortest case - you will be shooting one that is that short anyway even if you don't trim them.

I would set the Wilson up to just touch the mouth of your shortest case. Don't get carried away, just trim enough to
square it up. Without moving the adjustment screw, I would then trim all of the other cases to match.

If you are concerned about the necks being too short, I would definately full-length size the cases. It will increase their length. Some people are surprised to learn that a lot of the top-flight competitors full length size their cases. With reasonable chamber specifications, it doesn't hurt accuracy.

As for the chamber length gage from Sinclair, I've never used one, but since the case you are using for it has to be so short, you could modify it so you can push the case all the way in with your finger. Perhaps spliting the neck (after sizing it) would allow you to do this.

 

[londonhunter]

Thank you all for sharing your experience

OK

Let me just confirm what I am reading here

shall we take 6.5 x 55 sweede

SAMMI length is 2.165 inches

Hence I need to trim to 2.155 ideally

The Lapua cases I have are 3rd or fourth firing and they are 98% (out of 100) below 2.155 after full length sizing.

I have trimmed a few and the neck just looks too short

I am not sure to choose 2.135 (lowest) as the reference point or 2.140'ish where the majority of my cases are measured hence I posted the question.

I will put aside the really "short ones" for other purpose.

My reservation was that I will lose too much neck / surface area for grip and loose accuracy that way

I did not know that Wilson make a case holder for new brass and one for fired brass ( I will contact the Wilson agent next week)

My question is - between my shortest 2.135 and my 2.165 (SAMMI) I choose a point where most of my cases are at the moment and trim / square all to that length

If this is correct the THANKS a million for the advice

I hope I am not asking a stupid question but it seems so obvious as well

OK one more question

6 x 47 Lapua and 20 tactical are not a Sammi cartridges

What length do I trim to and where do I obtain this data ?

 

[bozo699]

londonhunter,
Your questions are not stupid so stop thinking that way right now. I had eye surgery and I am having a hard time focusing right now so I can't search for the oal data you need, but what I do wonder is why the large variance in case lengths? have you owned them since they were new? have some of them been trimmed before? were they shot in other rifles? I just can't figure out why you have over ,030 differences from case to case? On the 6X47 an 20 tactical do you know the chamber case length? and lastly are you into competition or varmint or hunting, plinking or what? What kind of shooting are you doing?
Wayne.

 

[londonhunter]

I have had the batch of lapua 6.5 x 55 cases since new. They have had between 03 - 04 firings and they have never been trimmed before and not shot in any other rifles
I cannot figure this out myself

I am into 600 yards prone shooting on NRA targets and not into competitions at this stage however I do enjoy consistency in everything I get involve in

 

[memilanuk]

[quote author=londonhunter]
I did not know that Wilson make a case holder for new brass and one for fired brass ( I will contact the Wilson agent next week)
[/quote]

Don't bother. When I was first starting out loading for .308 Win I saw the Sinclair Int'l catalog listed two different case holders - one for 'new' and one for 'fired'. Well, if they made 'em, I better get 'em, right?

The 'new' one is so ungodly small its not even funny. New Lapua .308 brass barely even sticks out the end. I've had this thing for years, and never needed it - until recently. I was processing a whole mess of Winchester .308 brass... which is notoriously undersized in almost every possible way as it comes out of the packaging. Guess what? That oddball 'new' case holder fit the undersized Winchester brass perfectly. Doesn't fit a damn thing else, though.

Thats the *only* 'new' case holder I've ever purchased, and I've never, ever had a problem with new Lapua brass in a regular Wilson case holder, across multiple calibers from .223 Rem thru .338 LM.

YMMV,

Monte

 

[bozo699]

DaveBerg,
Excellent post the op should have gotten something out of it, I have never cast my own chamber, as long as I have been into it you would have thought I had, but I haven't. I either use my reamer print or measure it with the proper tools but I would like to try a cast.

Quote, You could also make a Cerrosafe cast of the chamber and measure that. Easy to do and only takes a few minutes (after you've done one - the first one is a bit of a learning experience). Quote.

Could you share with me how to go about doing it please. I know you don't do PM's but maybe you could just explain here or my email address is,
waynebezona@cpcinternet.com

Anyway thanks for your time in advance.
Wayne.

 

[K22]

londonhunter,
K22 must have been writing his the same time I was writing mine otherwise I would have cut mine in half because he is spot on, he explained himself very well. I don't want to correct him but on #4 I think he meant Chamfer not chamber,
Wayne. Chamfer isn't recognized on spell check

I never could spell worth a darn, yes, I meant chamfer. Sorry if I confused you.

 

[bozo699]

K22,
I can't spell worth a darn either, if it wasn't for spell check I would sound like a dummy( spell check can't fix everything )
;D

DaveBerg,
Thank you for the info, I think I will order some cerrosafe from Sinclair and take a gun that's nothing special and give it a try, Thanks again.
Wayne.

 

[londonhunter]

Case trimming technique

What's more important

The ability to spell or to shoot straight ?

I know what I will choofe ........oops

Thanks guys

 

[K22]

What's more important

The ability to spell or to shoot straight ?

I know what I will choofe ........oops

Thanks guys

My wife, an ex-school teacher would say spelling - for me, hands down it's shooting straight although I'm not sure I do either too well anymore. :-[