Masterbeta success! .357 loading question

[*chris*]

I determined to get more serious about reloading I needed a chronograph so I bought a Master Beta. What a great unit, I was able to set it up and get it running by only glancing at the user manual. Here is my loading data and performance:

S&W 686 with 6" barrel
Powder - 3 grains of 231
.357 mag case
standard primer
158gr DEWC
COL is really long, to meet the 38 special recipe I am using, I probably need to press the bullet in another 1/8" or so.

Based on the reloading book, I should have around 800 FPS out of this combo. Will pressing the bullet in farther increase the FPS? How do my stats look, are they considered consistent?

My load is the one on the right compared to a factory 38 special load.

A final closing thought was a weighed every round and they probably varied 4 grains from low to high, I shot all the heavy ones as a group and saw no difference in performance. I did weigh a couple of bullets and they do vary a few grains each.

Chris

 

[Slowdive]

Your thread title caught my eye...especially when you read it with a Worcester accent. Just be careful, you could go blind.

How many shots in each string, the SD #'s are OK, not great for a slow moving bullet? They generally aren't statistically meaningful unless your strings are at least 7 or 8 shots (sample size) and preferably 10 or more. A statistician would tell you need 30 observations or more, but the Chrony limits you to 10 shot strings which is fine.

My initial impression is that your pushing them too slow and that may account for the reasonably large ES #'s. String #1 the ES/AveMV is 13%, the rest are between 6% and 8%.

I think you could do better w/ a stronger charge...3gns of WW231 seems light and 580 fps seems very slow. You should get more consistent numbers w/ a MV of ~800fps or more.

 

[*chris*]

Thanks, I follow all your points. String length was 10 shots each.

One thing I am trying to figure out is I should be at 800 fps with this combination, is it lower due to the COL being too long? The MV is a full 30% slower. Should I increase the powder AND change the COL or just start with COL?

Chris

 

[Slowdive]

Thanks, I follow all your points. String length was 10 shots each.

One thing I am trying to figure out is I should be at 800 fps with this combination, is it lower due to the COL being too long? The MV is a full 30% slower. Should I increase the powder AND change the COL or just start with COL?

Chris

I wouldn't worry about COL now, I'd boost the charge. Until you get north of 6.5gns of WW231, your not near max pressure. You have a small charge in a reasonably large case...lots of empty space, shortening the COL won't do much to change the pressure characteristics. Once you get close to max pressure, then COL starts playing a larger role.

ETA: Your bullets have a crimp groove, I assume that's how you set COL....which is correct.

 

[swampy]

Your thread title caught my eye...especially when you read it with a Worcester accent. Just be careful, you could go blind.

Sadly its too true.

 

[TBalls]

That company needs to seriously rethink their name.

 

[WanMan99]

That company needs to seriously rethink their name.

Maybe not..... Bet you won't forget it.

 

[EddieCoyle]

Will pressing the bullet in farther increase the FPS? How do my stats look, are they considered consistent?

Maybe, but don't do it.

With revolver bullets, the bullet is going to determine your seating depth. Seat hollow-base wadcutters flush, seat all other cast bullets (including double-ended wadcutters) to the crimp groove, and seat jacketed bullets to the cannelure.

There are a bunch of reasons why you won't match the velocity in the reloading book. You're probably not using the exact bullet, case, primer, and lot of powder that they used in their testing. Even temperature and altitude can have an effect on velocity.

Also, look in the book and see what they were using for a test firearm. Lots of times they use a universal receiver with a 10" test barrel. You're not going to get close to those velocities with a revolver.

ETA: The crimps on your rounds look a little light.

Also, how did they shoot? If they're accurate, I wouldn't worry about boosting the charge to increase velocity. They're wadcutters. All they need to do is make a hole in paper.

 

[*chris*]

Maybe, but don't do it.

With revolver bullets, the bullet is going to determine your seating depth. Seat hollow-base wadcutters flush, seat all other cast bullets (including double-ended wadcutters) to the crimp groove, and seat jacketed bullets to the cannelure.

There are a bunch of reasons why you won't match the velocity in the reloading book. You're probably not using the exact bullet, case, primer, and lot of powder that they used in their testing. Even temperature and altitude can have an effect on velocity.

Also, look in the book and see what they were using for a test firearm. Lots of times they use a universal receiver with a 10" test barrel. You're not going to get close to those velocities with a revolver.

ETA: The crimps on your rounds look a little light.

Also, how did they shoot? If they're accurate, I wouldn't worry about boosting the charge to increase velocity. They're wadcutters. All they need to do is make a hole in paper.

I am using the Hornady book and they use a 4" barrel S&W 15 so it is a pretty close comparison to my 4" barrel 686.

At 22' handheld, I could put 6 bullets in the hole the size of a nickel with a few flyers due to bad technique.

Looking at my photo, I could see how much more crimped the factory bullet was compared to mine. These rounds are very sooty as well, is this due to too light of a crimp? Will increasing the crimp also increase the MV? How many thousandths of an inch should my crimp be?

Chris

 

[*chris*]

That company needs to seriously rethink their name.

The name of the company is Shooting Chrony. They already reworded the name, mine is now a Beta Master chrony. Throughout the manual, the refer to the Master Beta though which tells me the name was unintentional!

Chris

 

[Jasper]

if they're accurate, run with em.

I've been using a CED Millennium 2 (IR screens, most of my chrono'ing is done indoors, and the beta/master I was using was WAY to flitzy with light levels. I actually had my own .357 success last week. 125gr JHP going 1480-1490FPS out of a 4" S&W L frame. just about no kick, accurate as can be, and throws one hell of a fireball

 

[EddieCoyle]

These rounds are very sooty as well, is this due to too light of a crimp? Will increasing the crimp also increase the MV? How many thousandths of an inch should my crimp be?

A bit more crimp might make them a little cleaner and faster, but I wouldn't expect a miracle. Lead is always going to be dirtier than jacketed because of the lube.

Just try to duplicate a factory roll crimp.