hollombj

Just recently got back into reloading after being away 30 or so years.You folks have been very helpful so first I say thanks. Now the next question. My cases are at or close to the max. length for .38 special( 1.155) but I can't find any specs. on what to trim them back to. I measured 2 different factory loads as best I could with calibers and they were 1.135 and 1.145. Both were heavy crimped +P rounds.Any recommendations

Sr40ken

both Hornady and Speer manuals have lenght I'm not near them tho. You can go into SAAMI

http://www.saami.org/specifications_...wnload/205.pdf

Seneca

Trim to length for the .38 sp.

Lyman manual #49, 1.149

Hodgdon manual 1.150

CCI manual 1.150

So the trim lenght for the .38sp. looks to be .005/.006 under max case lenght of 1.155. Myself I try to keep my cases under the max length and trim slightly above or near the trim to length. The key is to keep them uniform in length and under the max case length. Also size first and then trim...

FlyerTom

When I started reloading back in 1970, I did .30-06, .22-250, .222, .30-30 and .44 Magnum cartridges, and trimmed them all using one of those Forster trimmers. I sold off my equipment some years later, but started up again when I recently retired. A few things surprised me upon re-entering the hobby. One, a Forster trimmer is outrageously expensive this time around! Two, many posters on this and other forums claim to never trim their pistol cases!
Hey, they all grow due to the resizing process, even the straight-walled handgun brass. There was several occasions where, if I failed to check my .44 brass, the crimp would fill the cannelure of the bullet because the case was too long. Everyone here knows that rimless semi-auto pistol cases headspace on the case mouth, so the length is really important with those calibers. Is there any justification in not trimming the brass? Or is it like those that don't clean the primer pockets? (but that's another issue)

Dale53

SAAMI minimum case length is.010" under Maximum length. You can safely trim to minimum and that will delay the time when you have to trim again.

FWIW
Dale53

humboldt

Straight cased pistol brass probably will never need trimming. Just be sure that there are no cases split. I have .44 special brass with over 100 reloads, and never trimmed. However saying that, if you see a huge fireball coming out of the barrel of your revolver, it might be prudent to check the cases very carefully.

Seneca

Revolver and pistol cases both should be trimmed, for one thing it keeps the crimp uniform and a uniform crimp has a desirable effect on peformance...

Two, as mentioned a pistol case headspaces on the mouth of the cartridge, when a pistol case gets too long you loose the correct head space and the cartridge fails to chamber or if they do chamber they are wedged in too tightly...

It's really simple...What you are looking for here is consistency and uniformity...within the established demensions for a specific cartridge...

TMan51

The other end of the "Never Trim" opinion spectrum.

Of the tasks in handloading, trimming is my least favorite, especially handgun brass. I dislike trimming 9mm/.45 ACP brass to the extent that if it doesn't clear my no-go guage, I toss it.

On the other hand, over the decades, I've shot in club leagues for slow fire spot shooting, and silhouette fun shoots. Not super serious, but I do like to shoot as good as my talent limitations allow. Over time I have found that uniform cases do make a difference, and it's especially visible with slower powders. My 77/357 and 77/44 can find differences in consistency I'd never see with a wheel gun shooting offhand.

So I trim cases for my .38/.357/.44M loads, to maintain a uniform crimp, once. I use a bit of lube with my carbide dies, and resistance is so low they never really stretch, even after several cycles.

Seneca

Agree, trimming pistol/revolver cases can be a pain...

I batch my cases and will trim a batch of brass when it reachs or nears the max lenght...

I have some batches of brass that are freshly trimmed, some that are near needing to be trimmed and the rest in between...since the cases are a uniform length within a batch, I can focus on trimming only those that actually need trimming...

pgeobc

Not many reasons to worry about trimming .38 Spec. cases, as they do not grow much, if at all with firing.

For as long as I can remember S.O.P. for trim-to pistol case lengths is SAAMI maximum -0.005". Note that this is a trim-to length and not a minimum case length as defined by SAAMI.

Case lengths are only important when figured into uniform crimping and that affects load precision.

In some ways, it is probably more important that the case mouths be absolutely uniform/level/even all the way around to avoid more crimp on one side than another.

Please do not inside and outside chamfer your cases, just knock off the burr from trimming. The sizing die will usually knock off any outside burr to the extent needed and the inside belling of the case mouth will knock off the inside burr. Thick case mouths last longer and give stronger, more uniform crimps.

hollombj

Can you break down your statement about the Sammi trim to length.Not sure about the .005 Is that .005 less than max.length? I understand where your coming from about chamfering the case mouth and making it thin,but I don't care for the idea of knocking or smearing off burrs with the sizing die or flaring tool.It is possible to deburr with a hand chamfering tool without creating much of a chamfer.It just takes a light touch.By the way,I have approx. 300 cases that are at or within .002 of max length after only 2 reloadings.This is from factory loads without any previous trimming. Thanks for the info.

bhefley59

Years ago I bought Lee case trimmers for 9mm , 40cal, 38, .357 and 45acp. I mic'ed a few of the cases and even bought a case gauge . Even after countless reloads they still don't need trimmed . I never load near max but still I would think I would see a long case sometimes . I do have a case crack sometimes .
I always use a taper crimp instead of a roll crimp on 38 / .357 when I can.

Seneca

Minimum/maximum case lengths for a particular cartridge are established by SAMMI the 38sp is 1.155 -.020. If a case length falls within the specified minimum or maximum it is considered to be within the specification for that cartridge.

Since the manufacturer takes care to ensure the cases are well above the minimum length that is something we as reloaders don't have to contend with. It is repeated firings and reloadings which stretch that we have to contend with.

Most manuals specify a trim length for the 38sp. that is .005 under the maximum length of 1.155 or a trim to length of 1.150. If you happen to trim to 1.149 or 1.151 it's really not a problem as long as all the cases are the same length. You'd still have to trim off well over .010 of case length before you reached the minimum...so no worries...

For example...I want to trim a batch of 38sp. brass. I size all the brass first, then measure them with a set of dial calipers. Out of 100 cases I find that they range in length from 1.146 to 1.160. If I want to include the shorter 1.146 length brass in the batch then I'd set up to trim to 1.146.

With the next batch I find that the shortest case is 1.153, and the longest one is 1.159. In this situation rather than trim them all to 1.153, I would trim them to specified trim length of 1.150.

I also give myself about a thousandth of an inch leeway, since I have yet to trim a batch of brass and have them all come out to the exact trim length...

I do use a chamfering tool, not to chamfer but to remove any burrs left behing by the trimming process.

TMan51

I think you are 99.9% correct, as nothing is 100%, except for taxes.

I trim to get a length that will put even crimps in the case over different brands of brass. But once trimmed, they go for ages, maybe even decades.

I had a friend that was a detective in a local police force, and he brought me a 5 gallon bucket of .38 Remington brass that was headed for the dumpster, circa 1980 or so. I spent weeks, literally, trimming it up. I have about 1500 cases left that have never been fired. I use it for my .38's, and some of it has seen several seasons of on/off league competition and is still going strong. It is still in spec.

I think it is partly due to using a carbide die with a dab of lube. They resize with little more than the weight of the arm of my RCBS Jr press.

Really hot .357 loads will split before they stretch, 20-25 cycles, but they go a long way also.

pgeobc

See Seneca's reply, as that sums it up nicely. Although I do occasionally see some case growth when sizing pistol cases, it is rare. Rather, I see cases that are too short as a problem and that, mostly, is in calibers that headspace on the cartridge mouth. Rimmed cases are a no-brainer, as anything between real SAAMI maximum and real SAAMI minimum will work fine. It is just that cases that are very uniform from case-to-case give better, mor uniform, crimps.