rifle primers in a 357 mag load

[snuffy]

Well finally a day that I felt worth a damn, and had some time off from garden preserves/canning.

It seems like I can never have a range trip where something doesn't go wrong, forgot something, or there was a scheduled shoot I knew nothing about. Today the chronograph failed to fire up, dead as a nit, different battery made no difference. But I shot both load work-ups anyway. What a treat to finally shoot that old girl again after so many years. Can't remember when the last time was, had to be 20 years ago. The model 10 or M&P smitty wesson is just a plain jane 38, nothing fancy.

The loads shot okay, just past a 5 of 1 to 10. No leading, and only barely acceptable group size. I haven't done any measuring yet, but the best was possibly 3.5" @ 25 yards.

The main focus of the test was the standard pistol and rifle primers, both Winchester NO SIGNS OF EXCESSIVE PRESSURE! There was some signs of difference in group size, I'll have to judge what that is when I measure them up to see what influence the rifle primers had.

Shooting the ol' 38 wasn't easy. The sights are as crude as I remembered them to be, really crude. So 3.5 inches may be a really good load. Along with my lousy eyesight--------.

Once I get the chrono fixed, or replaced, I'll repeat this test possibly with my GP-100. This test was only about did they fire and how much pressure signs, which was normal. Extraction was easy for all loads. I shot five per increment leaving one hole open. The star extractor easily pushed all five out with no difficulty.

[Jeffm004]

Well. Cabelas Cincinnati cannot tell the difference either, Seillers & Bellot SP being sold as SR. I asked for the internet price of $19.99/1000 and bought 6 of the 10 bricks. I considered buying them all but I was already in $400 and figure one other sole will have some joy as well if they are paying attention.

[snuffy]

I decided to replace the aging pact chronograph with a CED M2 chronograph. I ordered it last Saturday, it was here on Monday via USPS! (Midway USA). 2 day service over the weekend! I spent the day yesterday reading the destruction booklet, and watching the DVD included with the chrony. Also installed the software via CD so I could download the readings.

Beautiful fall day today, partly cloudy and topped out at 68 degrees. I set up to fire a load work-up using matched headstamped R-P .357 mag using Winchester 158 grain HP. Powder is AA # 9, loads starting @ 13.5 and ending @ 15.0. 50 shells half using WW small pistol primers, the other half using WW small rifle primers. My Ruger GP-100 W/6" BBL.

Small pistol HI =highest velocity LO=lowest vel. ES=extreme spread
AV= average of 5 shots SD= standard deviation
13.5 #9
Hi 1318
Lo 1212
Es 106.0
Av1247
Sd 38.5

13.9 #9
HI 1322
LO 1252
ES 70.0
AV 1286
SD 25.1

14.3 #9
HI 1305
LO 1227
ES 78.0
AV 1265.8
SD 28.5

14.7 #9
HI 1304
LO1282
ES 22
AV 1294.2
SD 8.9

15.0 #9
HI 1338
LO 1271
ES 67.0
AV 1303.6
SD 23.6

Winchester Small Rifle
13.5 AA #9
HI 1294
LO 1221
ES 73
AV 1261
SD 26.9

13.9 #9
HI 1287
LO 1259
ES 28.0
AV 1275
SA 9.3

14.3 #9
HI 1317
LO 1264
ES 53
AV 1302
SD 22.1

14.7 #9
HI 1343
LO 1299
ES 44
AV 1319
SD 16.0
I don’t have readings for the 15.0 gr. Load. Somehow that string did not get saved. The target shows vertical stringing so I’d bet there was quite a swing in extreme spread.

The best group was from the SR primed with 13.5 starting load. But hardly the most consistent velocity reading. Second best was the next in line at 13.9, the group was round and only slightly bigger than the 13.5 group, BUT the velocity was very good at ES at 28, av of 1275 and a sd of 9.3.Looks like I found my load.

Now if I were to ONLY follow the manuals, I would never try the SR primers. The small PISTOL primers seemed to be wilder in the ES department, and the group sizes were all bigger. I have some small pistol magnum primers, I may repeat a few with those to see if maybe the SR primers might be a bit hotter, resulting in a better burn of the slow AA #9 powder.

As for the CED M2 chronograph, I wish the pact had died sooner, I would have this one already, having benefited from what it can do. Since it was partly cloudy, it performed regardless whether the sun was behind a cloud or was in full sunlight. It only missed one bullet, failed to trip the stop sensor.

I also ran some tests on 500 magnum, 38 special, 9mm in two guns. But that’s fodder for another thread!

[Kosh75287]

When they were developing the .357 Magnum cartridge, using charges of 2400 that would be considered "injudicious" today, didn't they use small rifle primers? I suspect it was in an attempt to keep the primers cups from failing if a pressure excursion occurred, but I can't remember.

Judging from the data posted, there doesn't seem to be an advantage in velocity with the Small Rifle primers until loads approach max. Aside from this, the only downside I can envision is some tricked-up and lightened hammer springs failing to strike the rifle hard enough to ignite it? Heard of it happening. My .357 is an old Police Service Six, and there's NOTHING light about its hammer fall.

[briandg]

primers are cheap. Buy the proper primers and don't take the chance that any of those possible problems will arise.

You did notice that small rifle primers are generally used to ignite rifle powder, in larger cases, right? That is obviously not the same as a pistol powder loaded in a small case. Would you load a rifle primer in a 38 special with a but of bullseye in it? Obviously not, so what do you feel the difference will be loading a slower powder and a larger case?

[snuffy]

You did notice that small rifle primers are generally used to ignite rifle powder, in larger cases, right?

The loads of AA #9 powder were nearly a 95% load density. Also AA #9 is just north of H-110/WW- 296 in burn rate, IOW just a bit faster. So it's a pretty slow dense powder.

I do think the WW small rifle primers are a bit hotter than the WW small pistol primers. I'll be going over the results more carefully, but right now it looks like the rifle primers made for faster velocities at each increment, AND smaller extreme spreads and more importantly smaller groups. Past experience with the ol' pact showed me a hotter primer led to more consistent velocities and better accuracy. I may repeat some of these tests with magnum small PISTOL primers.

Oh yeah, I was shooting of a rest @ 25 yards. I may scan a few targets to post up, might be a waste of time, but as I always say, I have a lot more time than money!

[Sevens]

Anyone asserting that it is some kind of a genuinely "BAD IDEA" to load small rifle primers in to high pressure, slow powder, large charge weight magnum revolver brass is out in left field.

.327 Federal Magnum is ISSUED using only small rifle primers and all loads built in it are spec'd to follow exactly the same method.

.454 Casull, .460 & .500 Smith & Wesson Magnum all use rifle primers exclusively, with -NO- substitute.

One day, folks are going to have to learn and accept the fact that published load data is NOT a strict, definite, exacting recipe. Not possible. For you to follow it in that manner requires the same components from the same production lot fired at the same ambient temp at the same relative humidity and at the same elevation above sea level. Oh... and with the same barrel length AND TEST CHAMBER.

Rifle primers in handgun loads *may* some times resist detonation if you lack hammer spring energy. But properly advanced loads using tried and true methods are NOT ONLY not "dangerous", they are demonstrably more safe than the same loads with pistol primers.

Snuffy, I very much appreciate the work you've done to gather these results and share them.

[Kosh75287]

Thanks, Snuffy. That was a lot of work, and a lot of good information was obtained from it.

[snuffy]

Thanks Sevens and Kosh. I enjoy a challenge, some have called me the reloading myth buster. Especially for Sevens for backup for what I have been trying to say, while saying so much more eloquently.

Some consider reloading manuals as bibles. If it doesn't say you can do something, then don't try it. It's a good thing for reloading nu-bees to follow a manual religiously, then asking a question like xandi did. That's exactly why this forum and others are popular, questions get answered. Not without some arguments at times though.

At times I've gone beyond maximum in a few very well built rifles while observing chrony data and measuring case head expansion. Has anyone here ever fired a 16 inch full sized .308 Winchester in a re-chambered XP-100?

If I wasn't interested in the results, it wouldn't have gotten done. It just so happened I wanted a good jacketed load for my GP-100. I will test further with WW MAGNUM small pistol primers. Then it's on to some coated 158 lead boolits in the same revolver.

Oh, I never even had a hesitation when firing any of the rounds.

[briandg]

Snuffy, not referring to you at all. I also appreciate your research.

What I was referring to was the OP, who is asking us permission to do what he already wants to do. he has that set of materials, and he wants us to say that it's okay to use them.

My point is that if he looked at the official alliant site and checked the data, it shows cci 500, standard, non magnum pistol primers with blue dot. There is what alliant suggests, and unless he has a really compelling reason to use small rile primers, wouldn't you suggest that he use the components that are recommended by the company that manufactured the powder? Just having them on hand isn't really a good reason to use them.

[Real Gun]

Anyone asserting that it is some kind of a genuinely "BAD IDEA" to load small rifle primers in to high pressure, slow powder, large charge weight magnum revolver brass is out in left field.

Certainly not your "large caliber", but I get some light strikes with rifle primers on 327 Federal Magnum, pretty much the champ for high pressure handgun for mere mortals.

[briandg]

There are so many ridiculously minor considerations for this whole thing. I own .357 rifle and pistol, and shoot .38. I could use rifle or pistol in the rifle, I guess, but shoot pistol. The heavier hammer on the rifle would never cause light strikes. .500 magnum runs almost as hot as some of the heavy rifles, would anyone load .444 marlin with a pistol primer? Should my .221 fireball use rifle or pistol? It's a rifle action, after all, and I use rifle.

It all ends up with ambiguous information, calling for careful consideration and judgement when there are so many conflicting ideas. The important thing is to really look at all the information and lean towards the side of conservative actions, and safety.

Taking that into consideration, just like all reloading, you look at the data, stick with the official data, and alter that data carefully,only according to suggestions from reliable sources. You don't just change things willy nilly according to what you have on hand or what sounds logical. Don't load .380 with small rifle just because it's all you have. Don't load .223 with small pistol just because you will be using it in a contender. Reloading requires good judgement, and there are a lot of people who would be much safer using factory data with no deviations whatsoever.

Jack O Connor once said in an article that the god of reloading passed down the edict that "thou shalt respect the data!" and the reloader said "okay!" with his fingers crossed behind his back. If we had blindly obeyed the god of reloading to respect the data, there never would have been a .243 winchester or even a .357 magnum, but some things just aren't worth fooling around with.