Newbie question on loading 38 special and 357 for my GP100

[opos]

I haven't done any reloading for many many years and till now never any handgun loading, and I have a very basic question (I have a number of manuals but can't seem to find the specific answer so I'll ask here)

I understand that the minimum overall length of the loaded cartridge is important because a cartridge with the bullet seated too deep can cause excess pressure.

Is there a "constant" over all loaded cartridge minimum length or does it vary with the bullet weight and bullet manufacturer or style loaded? I see the "COL" in the various manuals and it varies by bullet type and style but it does not say that the "COL" is that "critical" minimum length at which pressure becomes an issue. So is the "COL" shown in the various manuals (that are not constant from bullet to bullet) a suggested length, a maximum length or a minimum length? and is the variation from bullet to bullet based on the different bullet weights and styles?

I'm sure I'm making way too much of this but at my age I don't want to push the envelope with pressures...I'm guessing the "COL" values shown for each bullet type and make are probably the "minimums" for safe pressures but need confirmation..
:?:
Many thanks

 

[Pal Val]

The COL variation is based on the bullet length and style. The purpose is to keep the inside capacity of the cartridge within safe margins. The tables allow for the different capacities resulting from different bullets. This aside, it's always wise to approach maximum loads carefully. Start under and build up, watching for signs of high pressure.

The GP100 is built strong, but that's to give you a safe margin, not to be abused.

BTW, you can never be too safe, have too much information or ask too many questions. Only fools try to get by without those three.

Good shooting!

 

[Jimbo357mag]

I think you are right, the 'COL' or over all length of a cartridge listed in load data is the min length for that load, with that particular bullet. You can go a little longer if the bullet and gun allows but not shorter without making some consideration. The SAMMI specs will descibe the cartridge with the standard bullet for that caliber.

...Jimbo

 

[Rclark]

I think you are right, the 'COL' or over all length of a cartridge listed in load data is the min length for that load, with that particular bullet

+1.

You know I never worried about this in my many years of reloading .357, .44, and .45 Colt. Always just used the crimping groove on the bullet as the seat depth. I have never owned a calipers until just recently believe it or not. Also never pushed the outer limits on loads either . I helped load some .45 ACP for a relative awhile back and we did check it with a ruler for COL. No crimping groove as a guide here. Shot fine.

 

[Rick Courtright]

Hi,

Agree w/ what's already been said: the interior volume of the loaded case is critical w/ respect to pressures.

Keeping that in mind, a couple of my manuals have drawings of each cartridge, giving all the appropriate measurements. One of them is the maximum overall length.

Since many of the COL measurements given in the recipes are shorter than the "max" in that drawing, I treat them as being "minimum" for that particular bullet. Dunno if that's even close to "perfect" practice, but it's worked well for me. I also don't load much "max" stuff these days... "just in case."

Rick C

 

[GP100man]

opos

generally the crimp groove is accepted as the place to crimp but in a smiff 28 ya have to crimp over the front drive band on some styles (Keith) to keep em from stikin out the front of the cyl.

The GP100 has a generous cyl length as it will chamber even the 358429 with room to spare !!

The extremes that come to mind is the lee 105gr swc (which barely has enuff to stik in the case & the solid wad cutter which all is in the case !!! you would certainly need to adjust powder weight to stay in the same pressure range.

As long as you do your research & start at the startin loads & work up to max IN YOUR REVOLVER , you`ll be fine !!

I shoot alot of loads that run in the 1,000-1,200 fps & am very happy !!!

Be Safe !! Have fun!!!

 

[opos]

Thanks to all...interesting that many use the ring on the bullet as the crimp line...but what about things like a copper plated bullet without any ring on the bullet? I think my deal will be to stick to the COL as absolute minimum .... measure with calipers....and load light to start with...I'm going to be using HP38 (or Win 213..I guess the same animal) to get comfortable with things and then begin a bit of very slow and methodical trial and error (hope not many errors) to find loads that I like...Used to load a lot of smaller bore 06 based stuff...many years ago and got pretty good at "sneaking up" on hotter loads...I'm more interested in a reliable and accurate load than burning the paint off the walls at the range.

Thanks again to all that chimed in.
opos

 

[Bucks Owin]

10X to all above :wink: The big no no is deep seating a heavy for caliber bullet IMO..I've never encountered a problem using the crimp groove, or even the ogive with bullets lacking one, and working up the load from the starting charge... :wink: JMO though...

 

[Pal Val]

Thhis is how I dealt with the copper-plated bullets: I took a lead bullet of the same weight and similar design, and set my dies to it. The copper-plated bullets take a light crimp. That's all to it.

 

[flhr62]

I know we are talking about a handgun here, and the minimum oal is because of pressure, there really is no max. oal for a handgun as long as it will function. In a rifle I think it is more important, you do not want your bullet pressed into the lands.