Load Data Question

[Tigerfish]

Loading 9 mm (115 gr JHP) with Bullseye powder.

Hodgdon Data Manual #26 says starting load is 4.0 grains of powder with a max of 4.4 grains.

Hornady 4th edition says 4.5 grains starting load and 5.1 grains is max.

Again both for Bullseye powder.

Which to use?

Anyone has a similar issue with suck a wide disparity where the max loaded as stating by one manual is less than the starting load of another manual?

These manuals were given to me when I started reloading. I've never really compared data across them. I'm about to start loading for some WWII warhorses that I've added to my collection. Can't risk damaging them. Anyone have a recommendation for a better manual?

 

[HitNmiss]

Using Hornady bullets I would assume,but I would start with the lower barge weight and just work it up over the chrono

Also just checked a 8th edition Hornady book of if they r Hornady bullets.for xtp and fmj Hornady bullets with bullseye it says 3.9-4.6

 

[Blue Diamond]

They are for reference only. Start low and work your way up till u find what u are looking for. Check for signs of overpressure always.

 

[noylj]

Just consider: you don't have the same gun, the same lot of powder, the same cases, the same primers, and, probably, not the same bullets or COL. So, which is safer? I start with the lowest starting load I can find.

 

[beauxdog]

When these folks prepare information for their loading manuals that set down criteria they go by and all have different versions. Some, like Lyman use test fixtures and others use real, everyday firearms. After all the information is written down the lawyers get to put in their two cents worth and you can be assured they leave room for folks that mess-up or just plain don't know how to read. All the reloading manuals are a little different. If you follow what they say, you should be safe and make good useabl ammo.

Beauxdog

 

[Tigerfish]

Thanks for the replies everyone.

 

[Redd508]

Thanks for the replies everyone.

Yup. All good advise. I hardly ever use max data in my loads. I do however, get pretty close in hunting loads. If your pistol cycles well at or below the lower max, i would call it good and save the extra powder. JMHO

 

[noylj]

I would expect they all have to use a Universal Receiver (or, at the least, a T/C Contender-like gun) for the pressure testing. You simply can't use a standard handgun. For the velocity/accuracy tests, they may or may not use a standard handgun. If it was easy to use a standard handgun for pressure tests to meet SAAMI requirements, there would be fairly affordable units for the reloader and our guns would have strain gage rosettes on them, probably with Bluetooth capability.

 

[gwpercle]

The discrepency is , in part , due to the bullets. Not all 115 grain bullets are identical, ergo differences in data.

My solution is to use data worked up specifically for the bullet you are using. Not always possible so I go to plan B.
Average the data you have. (#1) 4.0 +4.4 = avg. 4.2 . (#2) 4.5 +5.1 = avg 4.8 .
(#1) 4.2 + (#2) 4.8 = avg 4.5....I would start at 4.5 grains. With the 9mm , usually the starting loads are not the best for functioning ( I've tried and always had to go above starting ). Start at 4.5 and see how those do. If they function , start fine tuning for accuracy.
It's not a very scientific method , but it works surprisingly well.
I usually find Hornady data reliable and tend to lean towards thier data.
Gary

 

[Tigerfish]

Thanks Gary!