Different data from Different books

[Thumb]

I'm getting ready to start loading 40 S&W using RMR 165gr FN bullets and Bullseye powder. So I start looking through my data books and found 2 different loads for the same bullet and powder.

Lyman
4.8 to 5.4 max COAL 1.120

Speer
5.3 to 5.8 max COAL 1.120

Now they don't say what bullet manufacturer but they are 165gr TMJ FN bullets.

How can one book say the max is 5.4gr and the other says starting is 5.3gr?
With that kind of data I can't even take an average load.

Maybe I'm missing something?

 

[CatShooter]

I'm getting ready to start loading 40 S&W using RMR 165gr FN bullets and Bullseye powder. So I start looking through my data books and found 2 different loads for the same bullet and powder.

Lyman
4.8 to 5.4 max COAL 1.120

Speer
5.3 to 5.8 max COAL 1.120

Now they don't say what bullet manufacturer but they are 165gr TMJ FN bullets.

How can one book say the max is 5.4gr and the other says starting is 5.3gr?
With that kind of data I can't even take an average load.

Maybe I'm missing something?

What you are missing is that loading is NOT an exact science - different loaders use different techniques to determine the max load. That is why no sane loader will load the max load from the beginning.

Start at the lower of the two starting load and work up. The more manuals you read, the more variations you will come across.

 

[Thumb]

I would never start at the top, that would be crazy but the top of one is the bottom of the other. I guess I can start at 5.0gr and work up until I find one that works for me. I just plink so I don't need to waste powder for hotter loads.

 

[stool]

you sure the lyman is not a lead bullet ??

 

[jonbearman]

No it is a jacketed bullet in the lyman manual.One thing that is very important in the 40 s&w is to seat at the length they suggest.If you seat deeper ,pressures rise dramatically. So be careful.I think lyman deliberately stays conservative for the very reason that I mentioned.Hot loads dont mean extreme accuracy especially in pistols as far as I am concerned.

 

[Thumb]

Well, it's settled and done. I ran a few loads at 4.9, 5.0, and 5.1gr, went to the range and they all cycled and shot well. Even hit the tin can 7 out of 10 shots!

I'm happy with that and will probably load at 5.0 just to make it easy to remember. Oh, the COAL was 1.118 because at 1.120 the flat nose rubs against the mag. On botht Lyman and Speer they use the 165gr TMJ FN as reference.

 

[amlevin]

Would help to consult the powder manufacturer's website. Data in books is only valid at the time of the testing and printing. Mfr's websites are the most recent data available for their current product.

 

[CatShooter]

Would help to consult the powder manufacturer's website. Data in books is only valid at the time of the testing and printing. Mfr's websites are the most recent data available for their current product.

Most of the time, it is tested once and stays the same forever....

Some manufacturers use data from other loading manuals.

 

[Clark]

Read the chocolate chip cookie recipes on the bag. Some brands say one egg, some brands two eggs.

 

[swd]

Differs lots of powder and barrels make results all over the place that’s why they always say start low.

 

[uncle fester]

Most of the time, it is tested once and stays the same forever....

Some manufacturers use data from other loading manuals.

I think Lee buys most of their load data for their books.

 

[cem]

I don't know and do not say that that my suggestion applies here but it might. Lyman especially but any data book is susceptible to using different criteria especially different pressure levels for different purposes. For instance a midrange target load will show a max well below pressure limits. A .38 S&W Special 148 grain hollow base wadcutter may be shot at 2.7 grains of Bullseye for gallery pistol while a full range or 148 grain Keith/Sharpe style may be loaded to much higher pressures and so more powder for shooting black tailed jackrabbits.

I suggest too the possibility that one bullet is plated and the other is jacketed and so different pressure levels are to be expected.

 

[hoz53]

Read the chocolate chip cookie recipes on the bag. Some brands say one egg, some brands two eggs.

this thread is from 2014- how did you dig it up?

 

[0.1 Aggregate]

this thread is from 2014- how did you dig it up?

He didn’t bother to check the date…..he’s not a newbie either.

 

[Webster]

this thread is from 2014- how did you dig it up?

He probably doesn't own the pistol now.

 

[dttheliman]

He probably doesn't own the pistol now.

Historically time for ancient picture of Glock Kaboom



Its so 2014 this ........

 

[Ranger007]

What you are missing is that loading is NOT an exact science - different loaders use different techniques to determine the max load. That is why no sane loader will load the max load from the beginning.

Start at the lower of the two starting load and work up. The more manuals you read, the more variations you will come across.

+1

 

[jsn]

Lyman 2002 data maxes out at 23k CUP, Speer #13 maxes out closer to 35k PSI.

 

[M Zdilar]

Glock Ka boom is very real and happened to me using the stock barrel. I have since put a after market barrel on the gun and repaired the broken parts. Ejector,Ejector spring comes to mind. The issue is well documented and basically comes down to the chamber size which is on the large size to accommodate a variety type of bullets being used. Brass expands when firing to match chamber. This can create the Glock smile above the case head and failure happens in this area. Tools are available to remove the smile but this doesn't solve the problem of the brass being worked that much. Aftermarket barrels is the better choice in my opinion to correct the issue with a tighter chamber. Factory ammo with one firing have had the same issue from police officers during practice with the factory barrel. 40 SW is a good round in a Glock but the issues from above are real and owners need to be aware of potential problems. Good Luck Mike

 

[Big Mc]

I'm getting ready to start loading 40 S&W using RMR 165gr FN bullets and Bullseye powder. So I start looking through my data books and found 2 different loads for the same bullet and powder.

Lyman
4.8 to 5.4 max COAL 1.120

Speer
5.3 to 5.8 max COAL 1.120

Now they don't say what bullet manufacturer but they are 165gr TMJ FN bullets.

How can one book say the max is 5.4gr and the other says starting is 5.3gr?
With that kind of data I can't even take an average load.

Maybe I'm missing something?

They al have different lawyers. Tommy Mc