Bullet grain don't mtach up to load data?

[Josh45]

Sorry for the question that is probably easy to find the answer to! I have to ask this because it is really bothering me and I don't want to make am mistake down the road!

I will be reloading .38 special rounds and before I do that I need some bullets.

I have the Lyman manual for loading. Im looking at SWC/DEWC data. I noticed that when I had gone to MBC or Berrys, Sometimes the grains of the bullets were off. Not by much. I have data for a 150 GR but the bullet is a 148 grains.
I just wanna make sure that I can use that data for that bullet?

Also, My father will be reloading for the 30-30 and bought some 150 GR FN bullets to reload. After looking in the manual, All I can find is 150 GR RN and 125 GR. Im assuming I can use the 150 gr RN data for that?

Thanks guys for taking the time to read and explaining this to me! Appreciate it a lot.

 

[ranger335v]

"I have data for a 150 GR but the bullet is a 148 grains. I just wanna make sure that I can use that data for that bullet?"

Yes. Ref. using heavier info to load lighter bullets for any cartridge, it's not going to be ideal of course but it's plenty safe to do so. But the reverse is not safe.

 

[Jim Watson]

Two grains difference in bullet weight will make no difference.
Use data for the correct TYPE of bullet. A wadcutter seats deep and leaves less powder space than a semiwadcutter or roundnose. That affects chamber pressure; less space, higher pressure.

The nose shape makes no difference, roundnose or flatpoint; as long as the bullets are the same TYPE; jacketed or cast, don't interchange data promiscuously.

 

[Josh45]

Phew! That's good to know! This was really bothering me guys, You have no idea...Or probably do anyways.

So, Im guessing he is good to go with the FN even tho it is RN data. Both are 150GR. And yes, There both the same TYPE as in jacketed.

Appreciate that fellas!

As far as lead or jacket data goes, I have read that I should follow the MFGR recommendations on it such as Rainer says lead data and Berrys says Jacketed data. Thats correct?

Since two grains dont make a difference, How much would a 25 grain bullet differ? I can only imagine it would not be very wise to do so

 

[Cherokee]

A few grains difference +/- 5 gr at less than maximum loadings is nothing to worry about. 25 gr difference puts you in a new weight class for which you should find approprate load data. Always start low and work up the load in your gun(s).

 

[Josh45]

Thanks for verifying that. Now, I can place my order in and get to loading up!

 

[Josh45]

Use data for the correct TYPE of bullet\


Okay, I was going to place my order because I had thought that I had the right bullet here.

#358665 out of the Lyman Manual is a 158 GR FP I think, The only thing I can find in that weight is a SWC from MBC.

That will work fine? Im asking because since you said that a WC would sit that much deeper than a SWC or a RN, I figure for safteys sake I would ask.

You probably already answered this but for some reason, The clock isn't ticking right hence asking the questions ( newbie reloader )