357 Reloaded ammo question

[EICRtech]

Hello everyone.
Been visiting this site a lot recently and decided to join since everyone seems to really be helpful to each other here. I have really been enjoying lurking at this site for a while and hope to become a productive member here.

I am fairly new to reloading and have been making 223 ammo for my AR.
However, I just recently obtained a new firearm that requires reloading if I wish to shoot it.
I have a concern that may not be anything to worry about but thought I would ask here before assuming anything. Being new to the reloading game, I have a bit of discomfort making changes from the manuals.
I have made 40 rounds with 2 different powders while keeping all other components are the same.

OH- I guess it would be helpful to know that the ammo in question is for 357 Maximum.

Anyway, utilizing the latest Sierra manual, I chose to start with .4 grains over minimum charge for the 180gr FPJ. I have gone astray with 2 variables in the manual. My COL is 1.900" -my trim length was .005" over recommended TTL (while still being .005" under max length), and I am seating/crimping in the middle of the cannalure (sp?). I am comfortable with the COL variation but I am not comfortable with the other variable. The manual called for Fed205M primers. I don't have those so I used Rem7.5 primers instead.
After doing this, I read that the 7.5's are very close to magnum specs- of course I have also read that these are OK since they are BR primers and not magnum primers. Sometimes too much info is a bad thing.
Since I am fairly new to reloading, I wanted to get opinions of this change and whether it should be an issue at close to minumum charge loads.
I would think it should be OK but wanted to ask you pros to give me your opinions.
I would not even consider shooting these if I were at max load specs with a different primer than called for. May not even be an issue, but as long as I keep an eye out for signs of problems, should I have a problem sending these downstream?

Just a bit more info on these loads to insure we are on the same page:
20rds- Sierra 8370 180gr FPJ, Rem 7.5 primer, Rem case at 1.600", 18.8gr 4227 powder, COL 1.900"
20rds- same as above with 20gr H110 powder

Opinions?
Thank you.

[Unclenick]

Welcome to the forum.

You've done three things wrong here that all accumulate toward higher pressure. One is not starting with the minimum load. There is a reason it is called a starting load. I have personally got overpressure signs in one revolver from the lowest load in one manual. On another forum this last week a fellow got sticking cases and primer leaks from a .22 Hornet start load from another manual. When you've looked around enough you'll find more than one example of the maximum load from one manual being less than the starting load in another for the same powder and bullet. They don't develop their loads in identical guns, and the difference in chamber and case dimensions are enough to cause trouble using the same loads in different guns. This is why a good rule of thumb is to find load recommendations from at least three sources and use the lowest starting load you find from among the three.

Sierra, Lyman, Hornady, Alliant (data available on line), and Hodgdon (data available on line), and Accurate (data available on line) all develop their load data independently, so they can be consulted for different opinions. The Lee book, Modern Reloading, has data culled from other sources and is often a good source of overall minimum loads. The temptation is to start in the middle of the load range as a load development short cut. You get away with it most of the time, which may lull you into a false sense of security. But it isn't worth saving the extra time and trouble if it costs you a bulged chamber or worse. And there are manual listings out there just waiting to surprise you like that.

The second mistake is using shorter COL. Peak pressure depends on the space in the case the powder has to burn in behind the bullet. The smaller it is, the higher the pressure for a given charge weight. In a large bottleneck rifle case it isn't usually as big a deal because the bullet base intrusion changes the percentage of the total volume very little. In a straight wall case, seating the bullet deeper reduces the % volume rapidly, so if you seat deeper you need to reduce charge, sometimes below minimum, and work back up again. The exception is your H110, which can produce loads that squib out and leave a bullet stuck in the barrel if you load them down too much. A good rule of thumb with that powder is to figure out how deep your bullet base will seat into the case and fill the powder up level (uncompressed) with that bullet base, then weigh it and reduce that weight by 3%. I think, for you, that will be about 17.9 grains instead of 20, but I don't have your bullet's length in my database, nor do I know the water capacity of your particular cases, so you would have to figure this out for yourself.

Third is moving to a hotter primer. That also increases pressure. You need to reduce a load recommended for a standard primer by 10% and work back up in small increments (0.3 grains is small enough) watching for pressure signs. The exception is H110 and Winchester 296 (the same powder in a different package) whose pressure characteristics are unique and which should not be done as I described above and which requires a magnum primer for reliable ignition.

I don't have the Sierra bullet in my QuickLOAD database, but it show using the Speer 180 grain FP that moving from 1.990" to 1.900" COL takes the 20 grain load from uncompressed to compressed and increases pressure by about 130%, to well over listed maximums. So, my suggestion is you get an inertial bullet puller (not expensive) and disassemble you ammo and start over with the new loading information. If you call Sierra, they will give you recommended load data over the phone for that bullet seated to its cannelure length.

[EICRtech]

Unclenick-
Thanks for your response. I am always up for constructive critisism.

A couple things to note.
One of the reasons I started slightly above minimum was due to the H110 powder. From what I have read, this is one powder you definitely don't want to go under minimum with. I loaded a little high due to concern for a potential error in my scale. I've been told with a magnetically damped scale, it can take up to .2 grains before any movement of the beam is noted. Of course I realize that any changes in the recipe change the equation. (primer)
The load is still in the bottom 25% of the data available.
Like I stated earlier, sometimes too much info can be a bad thing.

As far as my COL, I am actually .025 OVER recommened, not under- I know this would be a major mistake with pressures. In Sierra's manual, it shows COL to be 1.875". Is there an error in this manual?

And yes, I've read that the 7.5 is a hotter primer, thus my concern.
I absolutely have no objections to pulling the bullets and starting over, especially if safety is an issue.
So would you recommend starting over with 10% under minimum, especially where H110 is concerned? ***I just read your response again- I think there was an edit about the H110 and 3% reduction***
BTW, the firearm Sierra used for testing is exactly what I own.

Thanks again for your response.

[EICRtech]

A little more info from the Sierra manual as far as these loads are concerned.
I'm not being defensive, just trying to provide as much info that I am using in case anyone sees a problem.

Directly form the Sierra V manual-
Firearm used: Dan Wesson 40V8S - this is what I own
Case: Remington - this is what I use
TTL: 1.595" (I am at 1.600" and Max case length spec is 1.605")
Primer: Federal205M
COL: 1.875" (I am at 1.900" and crimped in the cannelure)

#8370 180gr FPJ Match
Powder: H110- start load 19.7gr/ max load 21.5gr = load in question 20gr
Powder: 4227- start load 18.4gr/ max load 21.5gr = load in question 18.8gr

I am in no way disputing that I have started over minimum, which is a mistake. I have also strayed from the COL specs and used the wrong primer.
I will pull these down and try to use a less hot primer- I have some CCI 400 handy. I sure wish I could find the 205M somewhere- this would take every potential question out of the equation.
I suppose that I should go ahead and trim my case lengths down to recommended spec and utilize the called for COL while I am on a roll- Better safe than sorry.

Thanks.

[Unclenick]

Yup. I have the bad habit of not reading through until the post is up, then editing where I left something out or needed a change. Sorry about that.

The warning with H110/296 has shifted over the years. Originally Winchester listed just one fixed load for each bullet weight with it and said not to use anything else. Period. Then the 3% rule showed up. Then the nominal published loads began to vary which moved that 3% number around some. Now the general take on the warning is not to load below the low end of the recommended charge range by more than 3%. The lower reduction limit, AFAIK, only actually applies to revolvers (though they don't say so) and is a problem caused by pressure bleeding off through the barrel/cylinder gap. Reducing loads same as you would any other powder should be fine when you are loading for a rifle or a single-shot pistol. Indeed, I know a number of people who've done exactly that.

The Federal 205M primer is a small rifle match primer. It will be about half way between a standard small pistol primer (Federal 100) and a magnum small pistol primer (Federal 200) in strength. It's main advantage in a high pressure pistol round is the harder primer cup used for rifle primers will withstand high pressure better than pistol primers. That tells you right off that Sierra is messing with high pressure loads in the data. Small rifle primers are usually recommended for pistols running pressures about 45,000 psi and up, which is already above SAAMI maximum for the .357 Maximum (40.000 psi). But this is a case where the gun involved is beefier than average. It will probably work alright in the DW, where it might be problematic in a lighter frame. I would still work up to it, though.

SAAMI maximum COL for the .357 Maximum is 1.990". If Sierra gives 1.875" it is because of where they put the cannelure on their bullet and is specific to the shape of their bullet. Since I don't have the length of that bullet in my data, I can't really say where that puts the base or the pressure? I only can say that subbing the Speer 180 grain FP in made pressures higher than I would want to try to start with. Especially given the .357 Max reputation for premature throat wear. Give me the length of the bullet and the grains of water weight capacity of a fired but not resized case from your gun, and I can modify the calculation to match your gun. Use a case from the smallest chamber. PM me with that information if you want to. You can download my Excel file with water weight determination instructions from my file repository.

[EICRtech]

Thanks for the Excel file link Unclenick.

I measured 10 bullets.
2 @ .754"
1 @ .752"
7 @ .753"

Middle of cannelure is .459" +/- .002" from base of bullet (the eyesight isn't what it used to be).
I have not had the opportunity to fire any ammo from this revolver yet, as I just purchased it, so the water test is unavailable.
Fortunately, when I purchased the revolver, it came with the extra unused barrel. I suspect the previous owner failed to keep an eye on the cylinder gap measurement as I received it with .006" gap. I immediately dismantled the weapon, cleaned it, and then regapped the cylinder to the .002" spec (feeler gauge even came with the revolver).
Needless to say, there was some minor forcing cone erosion and just a hint of strap cutting (though almost unnoticeable).
I suspect that the original owner shot maybe 50-100 rounds through it and then sold it.
Here is a pic of the finished round and the bullet for comparison purposes.
This is not a compressed load.

[EICRtech]

After thinking about the 1.990" COL that Unclenick brought up, I checked in my Speer manual.
The Speer 180gr has a whole lot more bullet above the cannelure.
This would certainly explain the extra .115" to the COL over the Sierra spec.

But now, I have to wonder what the seating depth (inside the case) would be for the Speer 180. I noticed that max charge with H110 is a full grain less than the Sierra spec.
If that wasn't bad enough, the max charge for 4227 is 1.5 grains less.

I will definitely be pulling these loads apart, due to the 7.5 primer I used.
I will start at absolute minimum specs this time with a CCI 400 primer, which is at least used with Speer's info, since I have no 205M's available.

[EICRtech]

OK- after much more research and several phone calls, I decided not to pull down the 40 rds. of ammo I have previously assembled.
After talking to Sierra and looking through the Hornady manual (which uses a 7.5 primer and very similar powder weights for this cartridge), I loaded up 10 rounds at minimum start load (18.4gr IMR4227).
Went out yesterday to send them down range and had no problems or pressure signs- accuracy leaves a bit to be desired though.

Projected velocities for this load from Sierra (with Fed205M primer) are 1300fps with 675 ft.lbs. energy.
I cannot confirm or deny the velocities as I have to find a local range that allows setting up a chrono.


Unclenick- you had given me a link to determine the water weight, and now I have some specs for you , if you wouldn't mind plugging them in to QL.

Bullet length= .753" +/- .001" -Sierra 180gr. FPJ #8370
Trimmed case length= 1.600"
Fired case weight, smallest chamber, not yet resized/decapped= 99.2gr.
Same case filled to rim of mouth with water= 131.7gr.

[Peter M. Eick]

As Max shooter, I have a couple of questions for you.

What gun are you shooting it out of?

I try to keep ball powders out of my Ruger SBH 357 Max because they help lead to the top strap cutting. I only shoot 4227 loads in it and try and stay 180 grns or heavier.

In my DW 357 SuperMag I shoot 4227 and some ball loads. I have found 4227 to be a great performer so far.

In my Max I a running 19.5 grns of 4227 (imr) with 180 grn Lasercast as my standard plinking load. I have gone up higher then that with jacketed.

[EICRtech]

Hey Peter.

I am shooting a Dan Wesson.
I took the 4227 loads I made up- they felt pretty weak and accuracy was questionable at 18.4 and 18.8gr (partly my fault, I'm sure).
I haven't tested the 20 rds. of H110 I made up, but will probably stick with 4227 and work up some new loads.
I only purchased a pound of the H110 and have decided to confine it to the 44mag.

I too have heard that ball powders are more prone to strap cutting but that the bullet weight has a major impact on the amount of damage caused.