Case Trimming Help

[Joshua M. Smith]

I don't know what that was!

Wow. I'd like to know the rest of the story, as well!

Anyway...

It's time to trim some cases. I don't have a case trimmer... so I'll need one. Nothing expensive. What do you recommend?

The 7.62x54R has a max length of 2.115" and should therefore be trimmed to 2.105"... right"

Now, what's the point in trimming a case that headspaces on the rim? I'm not getting this, and would actually like the case neck to be a bit longer. The rifle has a long lead.

Thanks,

Josh

 

[ColtPythonElite]

I'd love to hear the rest of the story...

 

[gamestalker]

????

 

[LiveLife]

+1 on Huh????

I am going, "What does this have to do with case trimming ..."

 

[Seedtick]

Kinda like flippin on the TV in the middle of a show and getting all interested in it and then the power goes out.

Crap.

Might have been a good one.

Seedtick

 

[GP100man]

LEE case trimmer ,the kind ya chuck in a C/D & hold the cutter in ya hand works & as consistent/square as many others .

Some are better & some faster ,but ya won`t beat setup time for a small batch of brass!!

 

[joneb]

I don't know what that was!

Me neither.

Wow. I'd like to know the rest of the story, as well!

Me too.

Here's a good trimmer for bottle neck and taper walled cases.

http://www.lewilson.com/casetrimmer.html

 

[gamestalker]

Maybe he had a discussion going on another forum and then posted to the wrong forum and din't relaize it?
????????

 

[Joshua M. Smith]

Nope, that was not my stuff.

Only thing I can figure is that GlockTalk was just hacked. Some porn movie started playing. I am running some massive security here, and it all locked down, but maybe something stored in the buffer beforehand.

I was sitting here watching it get hacked, so it's plausible that I picked up a rogue convo. Only thing that I can figure -- if it was even from me.

Josh

 

[magnum338]

There was a question concerning the reasons for trimming rimmed cases. I'd like to add a few things that may be able to contribute.

Has anyone measured the difference between the stretch of the case in firing and that during neck expanding? I have. Even with the neck lubed the stretch during expanding is 2 to 3 times more than during firing. I say this because the case should be measured after sizing, not before, to account for this. If not, the cases may be too long.

When loading a rimmed case for use in a rifle with a tubular magazine the bullet must be crimped. Otherwise, the cartridge will actually shrink during firing from cartridges thrust backwards during recoil.

If a bullet is crimped in a too long case it forms a circular bulge at the mouth which does not allow the cartridge to chamber. Usually, only some case in a batch are that long, some are OK and you don't know which until bullet seating which is which. The bulge will occur whether the ammo is meant for a tubular or box magazine, and the chambering effect is the same.

Another thing, and this one can be dangerous. If the cases are allowed to grow too long without trimming they can interfere with chambering the round. The case mouth can extend into the rifling start (leade) in the barrel. Our response is normally to cram the bolt handle down forcing chambering. The bullet is held much more tightly forcing the powder gasses to work much harder to move it. This means excessive chamber pressure; a potentially very dangerous condition.

I believe what I've said to be true. I've experienced all these conditions in the many years I've been handloading (since 1954), and also found similar things in the literature. Luckily, I've always been careful so that when one of these occurs I've stopped, evaluated the situation and corrected it before getting into trouble.

I hope I've not sounded too preachy but I think ideas ought to be open to dissension and wanted to explain myself in preparation.

 

[Smokey Joe]

Case trimming...

Joshua M. Smith--For personal use, for case trimming, IMHO nothing beats a Lee Zip Trim, along with the Lee Case Trimmer. It does the job, doesn't cost an arm and a leg.

My review of the Lee Zip Trim is at http://www.thehighroad.org/showthread.php?t=417337&highlight=Lee+Zip+Trim Lee catalogue listing can be found at www.leeprecision.com/xcart/Case-Trimming-Tools/

 

[popper]

Try possum hollow trimmer. He can probably make one for you. Works fine by hand or drill.

 

[rcmodel]

would actually like the case neck to be a bit longer. The rifle has a long lead.

The leade has nothing at all to do with the location of the end of the chamber.

There is usually a sharp step there, before it transations into the leade, which then transations into the rifling.

The risk of a too long case is that it will extend past the end of the chamber step, into the leade.

That in turn will not leave room for it to expand enough to release it's death grip on the bullet, and higher pressure will result.

rc

 

[Joshua M. Smith]

Thanks folks.

Guess I'm still thinking in handgun mode.

Lee trimmer has been ordered; I left the "Zip" out of it as I prefer a drill press for most things that require turning.

I am beginning to understand.

Sometimes I really dislike living in a state which forbids high powered rifles for deer hunting (they just started allowing pistol-caliber rifles!)

Thanks!

Josh