Case Trimming?

[rmansu2]

Some buddies and I have recently gotten into reloading(less than a year). Only one of us has ever done reloading before this and I have some questions. We have been reloading 9mm and 40Cal and have never trimmed or lubed any cases.

Is this something we need to look into?

How many guys don't trim their cases?

 

[96/44]

Never had an issue with straight walled cases, rifles on the other hand usually need trimming after a few firings. Lube isn't neccesary if you are using carbide dies, but a little bit sure makes it easier to resize.

 

[Bucks Owin]

Those who don't ever trim straight walled cases aren't getting consistent crimps.... Think about it :wink:

 

[Driftwood Johnson]

Those who don't ever trim straight walled cases aren't getting consistent crimps.... Think about it

OK, let's think about it a little bit further. If you want absolute consistency in your crimps you are going to have to trim your brass after each loading. Right? Otherwise you will have small differences in case lengths depending on how many times the cases have been fired between trimmings.

From a purely practical standpoint, when I first started reloading I bought a case trimmer because everybody said you had to have one. But measuring a bunch of 45 Colt cases both before and after firing I could detect absolutely no stretching of the brass. None-nada. The simple fact is, most straight walled pistol loads do not develop enough pressure to stretch brass at all. So I simply never bothered to trim any of my brass. Today after many reloadings my 45 Colt brass has still not stretched any measurable amount. Neither has my 45 Schofield brass, 45 Auto Rim, 44 Special, or 44-40. So I still have not bothered to trim any of it.

My crimps may not be absolutely, microscopically consistent, but they are good enough for my shooting. If I was shooting long range benchrest rifle I might start trimming my brass, but my eyesight is not good enough for that kind of shooting anyway.

 

[rmansu2]

Thanks for the responses. I am glad to hear from someone with years of experience. I'll mic some brass when we get together again to see if there is a need to trim.

 

[Bucks Owin]

I see no need to trim after each use, but cases certainly do stretch a little after repeated sizing. Especially in oversize chambers that allow a significant bulge forward of the rim with stiff loadings..(eg .45 BH)
Also, new brass generally can stand a squaring off of the case mouth.....JMO

(And yes, it's just a "little thing" crimp wise, makes little difference, but if you're after perfection in your handloads.... :wink: )

 

[Rclark]

I admit I never have for revolver straight walled brass. Rifle brass yes.

 

[gerryb158]

The OP was asking about 9mm and .40 S&W which are taper crimped. I don't believe trimming brass that will be taper crimped would show any improvement from case trimming. Roll crimped straight wall brass "may" be slightly improved by careful trimming as to the consistency of the crimp but I've never bothered with trimming pistol brass of any caliber and never had a problem. If you have the time and patience it certainly won't hurt though. Gerry

 

[edfardos]

I don't trim 40S&W, in fact, i was surprised Lee actually makes a trimmer for that, so it's not inconceivable. The lengths do vary, but I don't think they change much. I spot long brass when they slightly shave my plated (Berry's) bullets since the crimp becomes a bit excessive. If the copper looks wrinkled or crunched, I mark the back of brass with an X, and discard it after it's been fired.

--edfardos

 

[Ruber]

I like consistency, but I also approach this issue from a 'methods' standpoint. If I trim all my new brass and keep them together and they all stretch accordingly, well I can then more easily seat and crimp in the same step. So.... Trim once and repeatedly load while seating and crimping together or... don't trim and either sort the brass by length or seperate seating and crimping. For me, that initial trimming saves a bunch of time down the road.

 

[BearStopper]

For the 40 and 9 it is a matter of headspace if the cases are incorrect. Overtrimming is as bad as not trimming when necessary. While it may not be needed at every reloading it is definitely something to look for during the process.

 

[I_Like_Pie]

I trim 9mm and 40s&w one time....when I first get them. That is it. Trim, deburr, and shoot'em till they split.


The only reason I do it is for the mentioned worry above. Don't want one to be short, cause unintended setback, and spike pressure in a bad way.

 

[MidLife]

I trim ALL my new brass. You would be surprised at the differences in length. About 1 in 5 actually trim a little. Trim after sizing, though.

 

[Ale-8(1)]

I have never -- ever -- trimmed a straight-wall handgun case, rimmed or rimless. I do chamfer them, lightly.

Never have experienced any problems that could even remotely be attributed to case length.

I guess I've either been lucky or not too picky. Of course, I've only been doing this for about fifty years, so maybe I'm due for massive failures.

I am by no means saying trimming is not necessary, just that I haven't found it to be so.

 

[rmansu2]

Thanks again everybody for the amount of responses. Never expected to get this much info. I'll check into what my case lengths are and see if there is a need to trim.

 

[Tam 212]

I haven't found it necessary to... yet.

After 5 firings, my 9mm brass actually seems to be shrinking slightly, not stretching?

 

[Ale-8(1)]

Tam, that's been my experience, too.

 

[Tam 212]

I understand that for maximum consistency, especially with crimp, trimming is good but I haven't had the need since I primarily load up general range/defensive training ammo. If I took up bullseye or benchrested shooting handguns, I would probably take that extra step but I don't.

To elaborate:
I do caliper check and/or case gage my cases regularly so I'm not over max or under min and they are generally within .005" in every batch. I segregate short and long cases in separate piles to get my batches as close as possible.

I realize different guns can be very different so... Has anyone experienced significant case stretching on cartridges that headspace on the case mouth, i.e. 9mm, 40 S&W, 10mm and .45 Auto?

 

[I_Like_Pie]

I realize different guns can be very different so... Has anyone experienced significant case stretching on cartridges that headspace on the case mouth, i.e. 9mm, 40 S&W, 10mm and .45 Auto?

Nope...they won't stretch at all. The only reason to ever trim straight walled brass is if you get it new or pick up some range brass and there might be some variance. I do it 1 time at the first reload and that is it.

 

[Bucks Owin]

I would suspect that any case that is able to bulge slightly, whether from oversize chamber, extractor cut, or what ever reason, displaces that brass when resized. I was OT in regard to the caliber in question, speaking more to hot loads in fat chambered wheelguns, but I think the "brass displacement theory" holds for any case...Maybe not!

Enough to matter? Likely not, but as I said before, I always shoot for perfection being the anal type handloader that I am and a ctg that headspaces on the mouth would get even more scrutiny from me as to case length...

In reality, the lengthening process is very slow and chances may be that the case will be discarded from a split mouth or loose pocket anyway before "needing" a trim. I just like seeing that fresh brass gleaming on a nice square case mouth after I trim a couple thou' off I guess..:lol:

Too fussy? Most likely but.... :?

(BTW, I freely admit to becoming a "trim junkie" from hotrod varmit bottlenecked rifle cases that stretch, thicken necks and occasionally even separate if one doesn't keep a sharp eye on things.. Different deal, I know....:wink

 

[Tam 212]

No worries. This is an informative thread and good food for thought.

I don't load rifle currently but am thinking of doing up some .357 SIG at some point- partly because of novelty factor and partly because I like oddball autoloader calibers. :|

I'll have the pleasure of trimming and lubing soon enough if I go down this road.

 

[MidLife]

I made it easy for myself from the start.
"Cases need trimming if they need trimming."
Simple as that. 8)

 

[COR]

I never trim straight walled handgun rounds. My guns are accurate because I shoot them. If I hit what I am aiming at, why would I waste my time with details like trimming? I hate sitting at a bench reloading when I could be shooting...that's just me.

It's completely unnecesary and is probably some of those benchrest and sillywet freaks putting poison in your coffee.

 

[Tam 212]

Oookay.

 

[Bucks Owin]

Oookay.

:wink:

 

[I_Like_Pie]

It's completely unnecesary and is probably some of those benchrest and sillywet freaks putting poison in your coffee.

LOL....Wouldn't happen. Benchrest folks are way to superstitious to do something like that. The bad karma would affect their posture while sitting at the reloading bench....the change in cadence would be enough to cause accuracy robbing inconsistency and wreck their Saturday shoot.

 

[WESHOOT2]

It is not normally considered worthwhile to trim 9x19 and 40 S&W cases.

Exceptions, of course, exist.

 

[Bucks Owin]

It's completely unnecesary and is probably some of those benchrest and sillywet freaks putting poison in your coffee.

LOL....Wouldn't happen. Benchrest folks are way to superstitious to do something like that. The bad karma would affect their posture while sitting at the reloading bench....the change in cadence would be enough to cause accuracy robbing inconsistency and wreck their Saturday shoot.

Ahhh...So you're a benchrester/silhouette shooter too huh? :shock: Bet you look after all the little accuracy details too...:wink: