Alliant VS Quickload for 357 170 grain boolits (confused)

[357shooter]

Hi guys,

I've been using Quickload for just over a year and love it. The results have been excellent in several calibers. Today I have to ask if what I'm doing makes sense, any QL users that load 357 using 2400 may have run into this too.

I like to check recipes using both Quickload and manufacturer sites, when they are available. I see that Alliant has a max load of 14.5 grains of 2400 for a 170 Speer GDSP. In my bullet library (customized a bit) I have a 168 RNFP (length of .660) that I figured would give me a ballpark validation, so I expected to see 25k to 30k max pressure. I figured my bullet is either the same length or shorter than the Speer and it might even be lower.

Instead Quickload is telling me 14.5 grains is 47k psi. WOW

What I'm trying to do is check out the pressure for loads for a 357-429, what I see posted seems hot and according to QL is over max pressure. So I thought I'd see what pressure a manufacturers recipe produced to just verify my settings. According to what I'm seeing, 11.5 grains of 2400 is about max for the 348429. That doesn't make sense.

Any suggestons? Are the loads posted all hot and over pressure?

[Tatume]

My Speer manual is #13, and it does not list loads for the 170 gr GDSP. The closest bullet listed is the 180 gr TMJ SIL. For that bullet the max load is 13.5 gr 2400.

[357shooter]

Hi,
I pulled that load from the Alliant website.

I'm thinking I've dorked up something in QL. This basic process has worked well with the Hodgdon powders and comes very close, when they list PSI. Velocity is alway close. I just checked my Lyman Cast Bullet Handbook and using the 358429 at their 1.553 OAL and 13.5 of 2400 I get 60k PSI and 1539 FPS out of a 6 inch barrel. That's way off. Either I messed up some setting or the 2400 data in my QL is off.

This is the first time I've run into this alarming difference.

[dragon813gt]

I'd trust the manufacturer's site over QL. Those loads were actually tested. QL is like any other computer program, garbage in = garbage out.

[357shooter]

Thanks,
I would too, but I'm trying to figure out what is off in QL. With other powders its been much closer to the manufacturers load data. At least for the calibers and powders I've used.

[unique]

Thanks,
I would too, but I'm trying to figure out what is off in QL. With other powders its been much closer to the manufacturers load data. At least for the calibers and powders I've used.

I have QL and experienced similar results with 357M & 2400. QL gets it wrong occasionally so that is why I check a lot of data books, use my chronograph, and do a lot of thinking.

Also, if you look around enough you will find fairly wide range of max listing for 2400 powder in 357Mag in the various data books.

[357shooter]

I have QL and experienced similar results with 357M & 2400. QL gets it wrong occasionally so that is why I check a lot of data books, use my chronograph, and do a lot of thinking.

Also, if you look around enough you will find fairly wide range of max listing for 2400 powder in 357Mag in the various data books.

Thanks, that validates what I was thinking, at least what I was hoping.

[williamwaco]

I know zip about Quick Load but I have been loading the .357 Magnum for 50 years and I do know this:

14.5 grains of 2400 with a 170 grain bullet is TOO MUCH!

Many years ago we used 15 grains with a 150 grain SWC, It seriously flattened and occasionally pierced a primer.
It was too hot then but I was "eat up with the macho" and loaded it anyway.

I completely believe the current version of 2400 is faster than the 1960 version and charges with today's powder must be reduced from those old recommendations.

Lee No. 2 lists do not exceed: 12.1gr 2400 with a 170 grain jacketed bullet. 1365 fps and 33600 PSI ( note that is PSI not CUP )
My personal favorite is 11.6 grains with a 160 grain cast.

[DrCaveman]

My notes show that i went as high as 13.2 gr with the 429

I remember that being a very stout load. Accuracy and shootability were better in the 12 gr range for me.

So ive settled on 12.5 gr. I dont see any pressure signs and get about 1100 fps from a 6" gp100

Fwiw i run this same load in 38 spl cases (headstamp marked with red sharpie) and it gets me about 1200 fps and great accuracy. This is a 'Keith' load. I hope it's not over pressure...but it seems just fine in the gp100.

I dont want to shoot it in my model 19 however

[GP100man]

I`ve also settled on 12.5gr & just as DrCaveman better accuracy & it`s as hard hitting boolit/powder combo as you`ll find for the 357 magnum !

[BAGTIC]

On QL did you check that you were using the proper bullet engraving pressure? If you used the file for another jacketed style bullet and merely changed the bullet length, weight and COL but did not change the bullet engraving setting it would give high pressures.

[rsrocket1]

I got closer to 50kpsi with the above load. I see the same for 158g GDHP's with 2400 on Alliant's site. They say 14.8g, QL says it generates 48.5 kpsi. Certainly looks like it's too much. I've seen a leverguns site claiming to test 170g bullets with 14.2g of 2400, but a few overpressure rounds probably wouldn't destroy the gun, but it certainly shouldn't be used regularly. 11.5-12g looks like it would be a better choice.

I know that Alliant only lists max loads and also tends to show minimum safe COL which often leads to overpressure calculations in QL.

I concur that Quickload can be very accurate in predicting MV's, so I am fairly confident that it is close when predicting pressures. An anomaly I did notice is that QuickLoad fails to estimate correct muzzle velocities when using extremely short barrels such as 1.5" or 2" snub nose revolvers.

I usually try to shoot for 75% SAAMI max pressure when choosing a load.

[TCLouis]

In response to a request from someone, I ran QL loading data for some caliber/powder combination. When I compared my results against Accurate Arms Manual, QL listed higher loading lower pressure for every load in that powder/caliber combination. I do not remember the cailber.

Other loads/velocities have been spot on. Not sure about pressure, but assume velocity is an indicator. The fallacy here is that "peak pressure" and velocity may or may not go hand in hand according to what little I know of such things.

[fecmech]

I have loaded 13.5/2400/358429 for a lot of years in my Ruger GP 100 6". I load a little longer than Lyman at 1.635 and taper crimp on the front drive band. I have no idea what the pressure is but it doesn't appear excessive, cases fall out of the gun and primers aren't flat or cratered. Velocity runs about 1190-1250 fps depending on what primer I use in the Ruger and lever gun runs about 1650 fps. It is an accurate load but not as accurate as 296/H110 for me. Personally I'd go with Lyman before Quickload.

[LynC2]

I don't use Quick Load (at least not yet), however I read on another forum where a person encountered a similar situation with straight wall or close to being straight walled rifle cases where the predicted pressures were much greater than the actual measured pressures. Evidently there is a glitch in the program that predicts higher pressures than what actually occurs in certain situations. Of course this is second hand and "hear say" information so take it for what it is worth and it is best to be conservative and work one's loads up considering all the variables involved.

[uscra112]

I have been using QL a lot, for at least 4 years now. I do find that quite often it predicts higher velocities than my Chrony reports. Sometimes a little, sometimes a lot. I do not have pressure measuring equipment to prove it, but the implication is that QL biases it's powder data in the direction of safety, and therefor calculates higher pressures than direct measurement would report for a given load. I would, too, if I were they.

That said, small differences in seating depth make for large pressure differences in pistol cartridges, so be sure that entry in the table is what you are really using.

[357shooter]

On QL did you check that you were using the proper bullet engraving pressure? If you used the file for another jacketed style bullet and merely changed the bullet length, weight and COL but did not change the bullet engraving setting it would give high pressures.Thanks, that could be part of the issue.

[gundownunder]

I use 13.5 of 2400 behind a 175 rnfp in my Marlin and while I don't get flattened primers I do occasionally get a case that's just a little tight to extract. I certainly wouldn't go any higher with 2400.
If you need more from your 357 maybe you need to look at slower powders like 4227, 296, Lil'Gun, etc

Don't forget that every gun is a law unto itself, so what is acceptable in one could well be over pressure and dangerous in another.

[BAGTIC]

There can be considerable difference between two different guns even of the same model. QL has always been very close for me. Using the basic start 5% under max rule it has never estimated a load that I would have considered unsafe.

One reason the results for short barrel revolvers don't match up is that QL prognostications are based on a fixed barrel without cylinder gap. This would normally result in a higher that actual velocity prediction. Offsetting this is that QL measures barrel length rifle style from the face of the breech whereas advertized revolver lengths do not include the cylinder but only the forcing cone to muzzle which overestimates bullet travel and velocity. To some degree the two factors partially offset each other but exactly how much will vary with the powder.