Strange findings.

[Brick]

Sorry Delkal. I goofed when I originally posted the numbers. The trim length 1.285" is the same in both my old Lyman book and my Sierra 5th edition. Max case length is shown as 1.290".

My issue of concern is not headspace. I'm concerned about getting into over-pressure problems with powder being compressed too much. So I want the cases as long as practical.

[Delkal]

The trim length of the case has nothing to do with the bullet seating length. You set the bullet OAL when you seat the bullet with your dies. It doesn't matter what the case is trimmed too. If you have bullets with a crimp groove you should ignore it. Sometimes the "crimp groove" is to secure the jacketing, not where you crimp the bullet. Set the OAL to the length found in the reloading manuals for now. If you want to get more advanced later for more accuracy there are ways to determine the optimal OAL. But you need to work the loads up and the load is usually for just one firearm. Don't put a max loaded round worked up for one firearm in another with a shorter throat.

I don't know where you found your trim length but it is just plain out wrong. Every manual I have from the last 40 years says trim all cartridges to 0.010 shorter than max. I had my Hornady 6th edition upstairs. It says Max. 1.290. Trim 1.280. I don't want to go into the basement to look at all of the other books. I know what they would say. And trim length makes zero difference in a straight walled .357.

My suggestion was to trim 0.005 shorter than the real recommended trim length to avoid wasting perfectly good brass. Do you think the Starline and Agula ammo that measured shorter was defective and unsafe?

If you are concerned about blowing up.......When working up a load to max pressures trim length doesn't matter. BUT different headstamps can have huge pressure differences since different manufacturers can use different case capacities. For moderate target loads you can use any floor swept / mixed headstamp / untrimmed straight walled pistol case till the neck splits. Then throw that one case away and keep loading the rest. But for max loads you need to sort everything and use just one headstamp, slowly work your max load up, then never substitute different cases. If you do you will have to start 10% under and work up to max again.

[Brick]

Delkal says

"I don't know where you found your trim length but it is just plain out wrong. Every manual I have from the last 40 years says trim all cartridges to 0.010 shorter than max. I had my Hornady 6th edition upstairs. It says Max. 1.290. Trim 1.280. I don't want to go into the basement to look at all of the other books. I know what they would say. And trim length makes zero difference in a straight walled .357."

I decided to save you trouble because my reloading and reference bench is right acroos from my computer desk. So a short search found these results: Reloading Data sources that cite 1.285" as .357 Mag. "trim-to-length" Hodgdon (online) includes Winchester and IMR, Sierra Ed. 5, Lyman. Reloading Data sources that cite 1.280" as .357 Mag. "trim-to-length", Western Powders (Accurate), Hornady (very odd, there were 3 Hornady cases in the batch I got from Brassman each of the 3 measured 1.250"), Speer and Vihta Vouri. Pretty safe to say that neither is "Wrong" only different. I guess it all depends on which book you grab first.

[Delkal]

Cases at 1.250 are short by any definition. Is this the length after you fully resized the brass? Sometimes if a case is fired in an oversized chamber the brass will expand out to fill the chamber and the OAL will get shorter. There is a chance when you size the case it might return to its correct length.

[Brick]

Yep I only check case lengths after resizing and pistol cases are always full-length resized.

[Gunsnwater]

Sorry Delkal. I goofed when I originally posted the numbers. The trim length 1.285" is the same in both my old Lyman book and my Sierra 5th edition. Max case length is shown as 1.290".

My issue of concern is not headspace. I'm concerned about getting into over-pressure problems with powder being compressed too much. So I want the cases as long as practical.

I was never pedal to the metal with my reloading. I preferred to go medium and cost effective. I don’t think I ever reloaded a compressed charge.

[Brick]

I was never pedal to the metal with my reloading. I preferred to go medium and cost effective. I don’t think I ever reloaded a compressed charge.

Generally I prefer loads to be in the middle of the range given, but often when developing loads I'll test some at Maximum charge. With .357 Mag, it seems that H110 and 296 both require a level of compression for best performance. I tried Blue Dot because it seemed the most efficient offering the highest (well nearly) velocities for the lowest charge weights. I was using the Sierra 5th Ed for data since I was using their bullets. At mid-range the fired cases started sticking in my revolver so I switched to the carbine only to have the high end loads give me a blown primer, cracked case and jammed action. Turns out Sierra has different loads for .357 handgun and rifle with the rifle loads generally lower but with some overlap. In the case of Blue Dot the rifle Maximum is more than 2 grains lower than hand gun.

I found I really disliked H110 and 296 because after a loading session the damn powder would be all over my work station. Blue dot is nice and bulky so it says where it belongs. H110 and 296 don't meter as well either and I couldn't get reliable charges out of my powder measure so i had to weigh each charge. Blue dot weighed out consistently. So now I'm searching for powder that'll give me close to the same performance as H110, meters well and doesn't seep all over the place. Do you have any experience with Accurate #9?

[Delkal]

H110 and 296 (they are the same powder) should only be loaded to max. It needs to reach a certain rather high pressure to burn evenly. The older reloading manuals had a special warning that the starting load should be max-3% for these powders, not the standard max-10%.

Interestingly.......since lawyers started writing the newer reloading manuals you often see current H110 and 296 max loads with charges that were once considered in the no-go zone 20 years ago. For .357 and 45 LC the new loads suck. I tried loading some of the current reduced loads and get a huge spread in velocity and you can tap a fired case and see unburnt grains of the powder on the shooting bench. I went back to the classic old school loads and get a very narrow spread with a very clean burn.

Unfortunately my lawyer just called and told me not to say what my load is. It is above anything you can find in any loading manual printed in the last 15 years. But the velocities are consistent, no cratered primers and I can extract the fired cases from the chamber using my fingernail.

Invest in some of the older reloading manuals. H110 and 296 is the powder for magnum handgun loads with heavy bullets

[Walleye Hunter]

H110 and 296 (they are the same powder) should only be loaded to max. It needs to reach a certain rather high pressure to burn evenly. The older reloading manuals had a special warning that the starting load should be max-3% for these powders, not the standard max-10%.

Interestingly.......since lawyers started writing the newer reloading manuals you often see current H110 and 296 max loads with charges that were once considered in the no-go zone 20 years ago. For .357 and 45 LC the new loads suck. I tried loading some of the current reduced loads and get a huge spread in velocity and you can tap a fired case and see unburnt grains of the powder on the shooting bench. I went back to the classic old school loads and get a very narrow spread with a very clean burn.

Unfortunately my lawyer just called and told me not to say what my load is. It is above anything you can find in any loading manual printed in the last 15 years. But the velocities are consistent, no cratered primers and I can extract the fired cases from the chamber using my fingernail.

Invest in some of the older reloading manuals. H110 and 296 is the powder for magnum handgun loads with heavy bullets

How old?

[Delkal]

I have some from the 70's. Looking at 357 loads Speer #9 (1974) the max loads with H110 for a 158 grain bullet is 2 grains higher then the 1994 edition (don't use this to try and guess the charge). Perhaps the biggest reason for this reduction is Speer (and Hornady) started grouping 3-5 bullets of different design but with the same weight under one load table. These books are worthless. That means for one bullet it might be a max charge but for the rest it is a reduced load.

Another reason is they changed to Sammi spec from measuring pressure in LUP/CUP to PSI sometimes in the 80's?. The new PSI numbers showed higher pressure spikes than the older measurements and people got scared. While the old loads were (and still are) safe the max charges for many cartridges were drastically reduced. Another reason is if a manufacturer starts making a chamber with a short throat or tight chambers the reloading manuals /SAMMI reduce their loads so no one shooting that firearm will get hurt. This ruined the 7mm mag. Look at the newer loading books and you can find .308 loads that are faster than a 7mm mag with the same bullet weight! For decades I have been shooting a load that is so far above the new published loads you would think I am crazy. But no pressure problems and I get the velocity you are supposed to get.

One warning though. When you use the older books make sure you start low and work up. Sometimes I don't make it all the way to max. With the books that came out in the last 20 years I have never had a problem getting to max. And when you do the velocity is usually much lower than they claim.