Trimmng .223 brass questions

[Patriot]

A few questions.

1) Why Trim when you don't have to? If it meets the case gauge criteria so what if it's not
quite the same length as the other cases. I realize that this might produce slightly different
bullet characteristics but is it enough to care about for everyday range fodder?

2) When triming, the Lyman book has a 'trim to' value of 1.750" yet I see a number of different
posters sizing to other values. Why? Is it rifle sensitive? If so, how/what does one measure
to obtain optimal trimming dimensions for his/her rifle?

3) For those that size to a 'trim to' value what is your criteria for precision? .001"? Less? More?

ETA: Updated post to change size to trim.

 

[tele_mark]

I don't size unless I have to. Everything .223 -- my own reloads, range brass, new, goes into a "holding tank" from the tumbler. From there, I size/decap it on a single stage and it goes into another container. Then, I go through it with calipers. My "arbitrary" max length is 1.750 -- because it's close enough to what my trimmer trims to -- .020 under max length, or 1.740, that it doesn't screw up alignment with the cannelure too bad. So, as I measure with the calipers, if it's right at the edge of 1.75 or above, it gets trimmed, anything below just goes right into the finished brass bin.

 

[GTOShootr]

Glen Zidiker's Handloading for Competition has all that info. There's a whole chapter on sizing. It depends on your chamber and measuring where your shoulder of a fired round is blown out to.

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=875590&t=11082005

 

[GTOShootr]

2) When sizing, the Lyman book has a 'size to' value of 1.750" yet I see a number of different
posters sizing to other values. Why? Is it rifle sensitive? If so, how/what does one measure
to obtain optimal sizing dimensions for his/her rifle?

That 1.750" is the case length that you trim to. The sizing dimension is measured at the midpoint of the shoulder with a specific tool for the job.

 

[RKG]

A few questions.

1) Why size when you don't have to? If it meets the case gauge criteria so what if it's not
quite the same length as the other cases. I realize that this might produce slightly different
bullet characteristics but is it enough to care about for everyday range fodder?

2) When sizing, the Lyman book has a 'size to' value of 1.750" yet I see a number of different
posters sizing to other values. Why? Is it rifle sensitive? If so, how/what does one measure
to obtain optimal sizing dimensions for his/her rifle?

3) For those that size to a 'size to' value what is your criteria for precision? .001"? Less? More?

I believe you are confusing "sizing" and "case length trimming."

The former has to do with headspace, which involves the distance between the breech face and whatever aspect of the case stops forward travel of a chambering round. In a .223, this is the shoulder of the bottlenecked case.

The latter has to do with the overall linear length of the case. Cases stretch, some (including bottlenecks) more than others (notably straightwalled pistol cases). Most of the time, the stretch occurs forward of the headspace datum.

So long as .223 cases have OALs less then the max. case length, I guess you could say that the differrence between longer ones and shorter ones is small potatoes. However, all .233 cases should be measured for OAL after sizing, since a case that exceeds max case length can lead to all sorts of problems if fired.

All fired cases have to be sized, either full length or neck only (depending on the type of rifle they have been and will be fired in), or else they will have trouble holding a bullet and won't chamber.

 

[1903Collector]

I have always understood that for an auto loader you full length resize to insure reliable feeding.

 

[Scrivener]

I have always understood that for an auto loader you full length resize to insure reliable feeding.

My understanding also. Neck sizing is for those guns requiring a manual action to eject the case.

 

[Patriot]

I believe you are confusing "sizing" and "case length trimming."

The former has to do with headspace, which involves the distance between the breech face and whatever aspect of the case stops forward travel of a chambering round. In a .223, this is the shoulder of the bottlenecked case.

The latter has to do with the overall linear length of the case. Cases stretch, some (including bottlenecks) more than others (notably straightwalled pistol cases). Most of the time, the stretch occurs forward of the headspace datum.

So long as .223 cases have OALs less then the max. case length, I guess you could say that the differrence between longer ones and shorter ones is small potatoes. However, all .233 cases should be measured for OAL after sizing, since a case that exceeds max case length can lead to all sorts of problems if fired.

All fired cases have to be sized, either full length or neck only (depending on the type of rifle they have been and will be fired in), or else they will have trouble holding a bullet and won't chamber.

You are correct. I was referring to trimming, sorry. Thanks for the info. I have sized
all of them and now am going to check for OAL and I didn't want to trim every one if it's
not necessary. I updated the first post and the title to reflect the correct question.

 

[GTOShootr]

A few questions.

1) Why TRIM when you don't have to? If it meets the case gauge criteria so what if it's not quite the same length as the other cases. I realize that this might produce slightly differentbullet characteristics but is it enough to care about for everyday range fodder?

2) When TRIMMING, the Lyman book has a 'size to' value of 1.750" yet I see a number of different posters TRIMMING to other values. Why? Is it rifle sensitive? If so, how/what does one measure
to obtain optimal TRIMMING dimensions for his/her rifle?

3) For those that TRIM to a 'TRIM to' value what is your criteria for precision? .001"? Less? More?

RKG is right. Boston Patriot meant trim.

Yeah, some people don't trim for plinking ammo or they trim on the short side to get away with not having to do it after multiple firings. I bought pre-sized and trimmed brass. It is nice stuff.

 

[Steve_P]

Are you crimping your completed rounds? If so, a consistent trim-length will provide a consistent amount of crimp on each round. If the cases are longer or shorter, you will have more or less crimp...

Steve

 

[bpm990d]

I have sized
all of them and now am going to check for OAL and I didn't want to trim every one if it's not necessary. I

Just take your dial calipers and use the set screw to lock the jaws at the max case length. Then use it as a gauge to select the cases that need to be trimmed. Very quick and efficient.

B

 

[EddieCoyle]

Like tele_mark, use the RCBS X-dies. I also crimp my rounds so I want them all trimmed to the same length because I generally like my shots to go where I point them.

The benefit to using the X-dies is that you only have to trim once throughout the life of the case. The downside is that I have to make sure I only pick up my own brass.

 

[Patriot]

Like tele_mark, use the RCBS X-dies. I also crimp my rounds so I want them all trimmed to the same length because I generally like my shots to go where I point them.

The benefit to using the X-dies is that you only have to trim once throughout the life of the case. The downside is that I have to make sure I only pick up my own brass.

I'm using the Dillon dies. I might try to build one of those case trimmers as they are too
damn expensive to justify buying. This case prep is getting out of hand on the .223. I
need to find a better way. I've just sized around 1200 cases, re-cleaned them, inspected
them, sorted them, and now I have to swage (half) them, trim them, de-burr them, and
load them. I might not make it to the pumpkin shoot as I will be still loading .223 on my press.

I had to make up a traveler sheet with each batch of brass and put it in the bag in order
to keep track of about twelve different bags of .223/5/56mm brass I am intending to load.
After I load it I will label it with the load info but this was needed for in process work.

 

[Patriot]

Are you crimping your completed rounds? If so, a consistent trim-length will provide a consistent amount of crimp on each round. If the cases are longer or shorter, you will have more or less crimp...

Steve

Interesting point. I haven't got there just yet. I'm sure that will be another question I will
ask shortly.

I think my bullets have a cannelure,

 

[EddieCoyle]

The Wilson case trimmer with the correct shell holder will set you back less than $40 from MidwayUSA (with a C&R).

 

[Patriot]

The benefit to using the X-dies is that you only have to trim once throughout the life of the case. The downside is that I have to make sure I only pick up my own brass.

What is so different about X-dies that you only have to trim them once? They can't be any
different mechanically than any other die other than precision machining or material. These
are pretty basic pieces of metal.

 

[Patriot]

The Wilson case trimmer with the correct shell holder will set you back less than $40 from MidwayUSA (with a C&R).

Yeah,

I watched your video (Thanks BTW, that was pretty good) and I am considering it. I just
don't know if I want to spend hours and hours trimming if I can find a better way. If not
I probably will take your suggestion.

Thanks,

TBP

 

[Cledus J. Crabb]

Get the Wilson.
You won't regret it.

 

[EddieCoyle]

What is so different about X-dies that you only have to trim them once? They can't be any
different mechanically than any other die other than precision machining or material. These
are pretty basic pieces of metal.

The mandrel on the X-dies has a little step that engages the top of the case neck during sizing. This keeps the case from stretching, so you don't have to trim again.