How much is too much

[Jsnake711]

Im trimming some. 223 cases, and find that federal cases are really long. Some measure 1.768". So how much is to much to trim off a case. Because seems like almost .020" is a lot.

[big al hunter]

SAAMI spec is Max length of 1.760, recommended trim length is 1.750. min is 1.730. IIRC. Too much would be taking it to the shoulder. Other than that the limiting factor would be if you crimp to a cannelure.

Are you trimming to a recommended length from a manual?

[Jsnake711]

Ah, good point. Yes, trimming to .750"

[Reloadron]

I just size them and then trim them all to the 1.750 suggested trim length. Big_al_hunter already pointed out the Max and Min specifications. I just aim for uniformity when I am done sizing and trimming.

Ron

[std7mag]

I let Lee take care of the trim length.
Insert in case, twist, or better yet use cordless drill.
Camfer, deburr.
Done.
KISS (Keep It Simple)

[mgulino]

Resize and trim to 1.750. You should be able to get 2-3 reloadings in before having to trim again.
I will sort by length as well. Shorter cases still in spec get loaded together as a separate lot.

[Unclenick]

Originally Posted by Jsnake711

h, good point. Yes, trimming to .750"

There's your problem. That's almost an inch too short. Once you get down there, you'll be loading .357 bullets to get any bullet hold, and that's a lot for a throat to take down to 0.224".

Typo's aside, I think you'll find quite a wide range of lengths can work. The 1992 SAAMI standard had the case 1.740"–1.760", so the 1.750" trim-to length in most load manuals was just the middle of the range. The 2015 standard moved the lower limit down 0.010" to 1.730", so you would think that would change the trim-to length to 1.745", but I haven't noticed any loading manuals making the change. Probably just a case of "if it ain't broke... I also don't know the reason for the change, as no other cartridge I've noticed has a length spec that loose.

I believe the military spec for 5.56 NATO cases are 1.7450"-1.7600", so their manufacturers will probably target the middle of that range at 1.7525". Most of their small arms rifle cases are a max length with minus 0.015" tolerance. So Federal may be running 5.56 spec for both 5.56 and .223 headstamp cases, tending to be slightly longer than commercial average. I've not measured them to see.

Back when the M1A was King at Camp Perry, guys using the hard Lake City brass would FL resize and then toss the brass after four reloadings, as that had proved to be the point where a lot of head separations began to appear for them. A number of competitors would trim their brass down as much as -0.040" below maximum after firing the original LC load in them. The thinking was that trimming was a bother to repeat, so why not trim as much as you needed to for the expected life of the case. About 0.010" growth was as much as they saw in one firing, so that's where the -0.40
number came from. There is less bullet grip, but it didn't seem to be enough to affect accuracy for the standard Highpower match targets. I've never heard of any problems with that practice.

Bottom line, you have a good bit of flexibility available to you. If you are going to crimp, pick a number and trim after every resizing (neck growth occurs during resizing). If you are trimming after every resizing, you can use case maximum if you want. If you are not crimping, you can trim shorter and not have to worry about trimming every load cycle. Only if I were shooting benchrest competition would I fret about finding and maintaining a precise and optimal trim at every load cycle.

[std7mag]

Wait!!!
Did Unclenick just say new 357 Wildcat???

[big al hunter]

Wait!!!
Did Unclenick just say new 357 Wildcat???

Yes he did ..but from what I hear about it ...the barrel life is going to be verrrry short

[Unclenick]

Not to mention the gun life!

[std7mag]

Sounds about like the perfect M1 Carbine upgrade.

[std7mag]

Well, in doing some research, the closest thing i've found to the 357UN (Uncle Nick)is the 338-223 Straight. Designed by Max Atchissen in 1972.
Pushes a 200gr bullet approximately 1,850 fps. Barrel length unknown.
223 case trimmed to 1.412".

[F. Guffey]

Well, in doing some research,

Finding research material by reloaders is not easy, the parson doing the research has to be trained in discerning fact from fiction. I built a rifle with a wildcat chamber, the chamber was similar to a 30 Gibbs. From start to finish the cases shortened .045" from the end of the neck to the case head. In all appearances the neck of the case seemed to be short. The neck of the case was .217" long. I understand most reloaders are going to break into a song and dance routine about tension because to be taken seriously. All a reloader is required to do is mention neck tension, not me. I insist on bullet hold measured in pounds.

Once the cases lost .045" in the forming process I started looking for cases that started life as being longer. Again; I have said companies that sell components do not sell components to reloaders that know what they are doing. With the longer cases I increased bullet holed, I do that because I am the fan of bullet hold, I am not a tensioner because I do not have a gage that measures tensions and no one has a conversion for going from tensions to pounds.

And then there was the 'and then' moment. I fired the formed cases. There is absolutely no way we can discuss fire forming if the reloaders does not understand what happens to the shoulder of the case when sized and or formed. That is a tuff concept; that being accumulative..

Again, I chambered 3 Mausers to 8mm06 chambers. After cutting the chambers I loaded the chambers with 8mm57 ammo and then pulled the trigger.

Well, in doing some research

There was none available, The only information I found was "Do not do it" I did find information posted by a member that claimed the firing pin struck the primer and then drove the case shoulder to the shoulder of the chamber. Meaning: confused: he claimed the shoulder of the case stopped moving forward when the shoulder of the case struck the shoulder of the chamber.

Fact from fiction/truth from nonsense: If there was any truth in his statement my cases would have been ejected from the chamber with long necks, I know; there is not one reloader on this forum that understands how that could happen.

To verify the results I fired more rounds and then I changed rifles, same thing.

F. Guffey

[m&p45acp10+1]

For my bolt action .223 Rem. I have not had to trim one in over 5 years. Now for my AR brass I trim it shorter than listed. I only have to trim one time, and when the brass gets too long I scrap it. Most times the primer pockets start to loosen before the length becomes an issue.