Question about small magnum primers

[JohnhenrySTL]

I was testing some .357s today. They were 16.4 grains of IMR 4227, I believe 1.590 in length, once fired winchester brass, winchester standard small pistol primers. The bullets were Hornady 125 grain jacketed. The recipe came from a phone call about length.

The chroneograph reported 3 speeds all around 950 fps.

I almost get that speed with my .38 158 grain range load.

This is way too slow for my liking.

I won't be able to chronograph at an outdoor farm again for a while. I want to make atleast 100 actual .357s.

Is my load slow because of the non magnum primers? I had read on here winchester standard primers can handle magnum loads. If they werent fully igniting they would not have been as close in speed. I have thousands of standards and only 100 magnum primers.

Is it a simple primer issue? What should I up the charge to? I want real deal .357 magnum speeds.

If it matters I'm shooting a GP100.

Thanks.

 

[X-Ring]

Lymans 49th shows a min of 15.6 and a max of 19.5. Using IMR 4227 over a Hornady 125g JHP. I think you just have a light load there and the primers are OK.

 

[JohnhenrySTL]

Thank you. I'm thinking 18 grains.

 

[X-Ring]

Play it safe and work up slowly. and I forgot to say that 19.5g load is compressed.

 

[rcmodel]

Your primers are fine.

Your powder charge is even lighter then anything I have seen in print.

Lyman 47 listed 15.6 Start, 19.5 Compressed Max with a 125 Hornady.

In short, you can't get enough IMR-4227 in a .357 case and still seat a 125 grain bullet on it to get in too much trouble.

Your load is way too light!

rc

 

[JohnhenrySTL]

Thank you guys. I actually edited my post. I had 14.7, but it was 16.4 grains. I'm sure still not heavy enough.

Thanks again for the confidence.

 

[GRIZ22]

Keep in mind pressure increases sharply when you add "just a few grains" of powder.

 

[mdemetz]

I had read on here winchester standard primers can handle magnum loads.

Only their LP are rated for both standard and magnum loads. They make both types for SP.

 

[TimSr]

Is my load slow because of the non magnum primers?

The proper primer can make your chrony results more uniform, but its more a matter of fine tuning, and will not result in a dramatic velocity change.

I don't think 4227 loads even specify a magnum primer, though a lot of people report better performance with one.

 

[ArchAngelCD]

Like already said, it's not the primers. Your charge weights are very light.

As for Winchester primers, you got it wrong. Only their Large Pistol primers are rated for both standard and magnum loads. The small pistol primers are sold in both ratings. In general, magnum primers will burn slightly hotter for slightly longer. They Wil generate very little differences in pressure and velocity. They will not create a nuclear explosion lol.

 

[USSR]

4227 is really not a good powder for light for caliber bullet loads. It is better suited for 158 gr and heavier bullets.

Don

 

[PO2Hammer]

Do you have a good crimp on those?

 

[Reloadron]

You choose a primer based on the powder used. Spherical and or Ball type powders usually reflect using a "Magnum" primer as hose powders are a little more difficult to ignite. IMR-4227 does not require the use of a "magnum" primer and is not the problem.

I agree with RC in that:

Lyman 47 listed 15.6 Start, 19.5 Compressed Max with a 125 Hornady.

Given a choioce I prefer powders like Bullseye or Unique for 125 gr. JHP bullets in a .357 Magnum load.

Ron

 

[JohnhenrySTL]

Thanks again guys. In my Lyman 49th, it doesn't specify primers for powders. It list a magnum primer on the introductory to the round. But I'll stick with my standard primers for now and up the charge.

 

[Reloadron]

Thanks again guys. In my Lyman 49th, it doesn't specify primers for powders. It list a magnum primer on the introductory to the round. But I'll stick with my standard primers for now and up the charge.

Interesting, Lyman 49th Edition Page 352 .38 Special they call out Primers CCI 500 which is a standard small pistol primer. Then on page 356 .357 Magnum they call out Primers CCI 550 which is a small pistol magnum primer. Yet, many of the same powders are used for both the .38 Special and .357 Magnum?

My older Speer manual #12 gives a good breakdown of which powders get which primers in both .38 Special and .357 Magnum.

Ron

 

[JohnhenrySTL]

This is my first time "going out on my own." I mean doing something not published. I figured worse case scenario was my test batch would not ignite.

But for the sake of conversation and sticking with standard published loads, I was told the primer and the barrel length are just what they used, not necessarily what we should.

Neither of my manuals publish primers for each powder.

This week Im searching for powders that work better through my powder throwers. Im sick of scaling each rifle charge. I'm trying BL C (2). It seems to meter perfectly through my Lee perfect powder thrower. But a google search of ".308 BL c (2)" came up with people saying a magnum primer was needed for my load.

I'm sticking with my standard primers in my test batch, but I'll be listening and feeling for squibs. The standard CCI larger rifle always worked great with my 4064.

Forgive my rant.

 

[Hondo 60]

Maybe your choice of powder is the issue.
I can't say for sure, as I've never tried IMR 4227.

I have tried Accurate #5 here's my results (7 rounds, 11.6 gr)
HI -1282
Low - 1268
AVG - 1276
ES - 14
SD - 5



Here's the results for Alliant 2400. (30 rounds 16.0 gr)
HI -1297
Low - 1271
AVG - 1281
ES - 26
SD - 7

Both sets used CCI550(sp mag) & Hornady 125 gr XTPs - OAL 1.590"

 

[JohnhenrySTL]

It seems to check out okay in the manuals. I have Lee, Lyman, and a real old inherited Hornady I don't trust. I bought the powder when things were scarce.

Thanks for posting your velocities.