Load data discrepancy “New Reloader”

[NRGsharp1]

I’m a brand new reloader. Last week I reloaded some 308 following the hornady handbook. I did everything by the book, double/triple checked everything. My 223 reloads shot fantastic the 308 not so much.
I got a Speer manual between now and then and also found the hodgden website that list load data.
In the 308 I started with a light load and it’s not even considered a minimum load in the Speer or hodgden data. There mid to higher pressure loads are listed as unsafe in the hornady manual. Just thought this was a bit odd and if this is a normal finding? Now I’m considering getting the Lyman manual to compare.
I’m using Varget powder with 150 gr hornady SST bullet.
Thanks

 

[David Milisock]

I’m a brand new reloader. Last week I reloaded some 308 following the hornady handbook. I did everything by the book, double/triple checked everything. My 223 reloads shot fantastic the 308 not so much.
I got a Speer manual between now and then and also found the hodgden website that list load data.
In the 308 I started with a light load and it’s not even considered a minimum load in the Speer or hodgden data. There mid to higher pressure loads are listed as unsafe in the hornady manual. Just thought this was a bit odd and if this is a normal finding? Now I’m considering getting the Lyman manual to compare.
I’m using Varget powder with 150 gr hornady SST bullet.
Thanks

Different test procedures and barrel. Maybe even a typographical error.

 

[Bronsin]

Reloading manuals usually don't agree. I would use the Hornady and Hodgdon data since those are the components you're using. If you're loading for a rifle with a magazine and using the SAAMI spec length, you will be closer to 45grs of Varget than you will to 40grs.

 

[SecondsCount]

On the 308- Do you get better groups with factory ammo? What bullet is the factory load using?

I tried the SST bullets once in my 6.5x47. They weren't terrible, still sub MOA, but the 123 SMK shot groups half that size.

 

[FeMan]

The "max" load will vary to some degree between rifles due to differences in powder lot (differing burn rates), case capacity (different brass manufacturers), bore and groove diameter of the barrel, and other elements of the load. That's why you should start low and work the load up to max, looking for pressure signs.

My wife's 284 and mine are "identical". Hers hits pressures a full grain below mine. In this case, its just barrel differences and they are from the same manufacturer. So start low, work up and STOP if you see pressure in your rifle.

 

[SKWERLZ]

That why reloading data isn’t gospel, only a suggestion keyed to a particular combination.

Different barrel, chamber, brass, bullet, lots of powder and primers change things.
Start safely and work up, you can cheat a bit when you get experience with a particular cartridge.

 

[Texas Solo]

I recently asked Hodgdon why there was no data listed for Varget with 185gr. They sent me all the Varget data for every 308 bullet. If you need data for something heavier than what's in this screenshot, let me know.

 

[JMayo]

I've learned to start in the middle and work up. Why spend time & resources on the minimums.
I don't like to load past the mid range loads either. Fastest/ biggest charge isn't my goal..... Accuracy is.

 

[GuitarmanNick]

Start with a lower charge and work your way up checking for signs of over-pressure along the way. It is rare that my loads get anywhere near the maximum recommended charge before getting dialed in.
Bullet and powder combinations that work in one rifle, do not always perform well in another. Use any recipes developed by others with caution.

 

[K22]

First thing is to know how to read pressure signs.

Second, I would start with the bullet manufacturer's data since results can vary widely depending on which bullet you select. They developed load data for their bullet so usually this is a good place to start.

As others have said, different loading manuals can vary quite a bit in load data. I know this can be frustrating for a new reloader but it's just the way it is. There are so many variables that it is not an absolute and exact process that's why, in developing loads, you must learn how to read pressure signs and work up slowly.

Varget is a good choice for the 308 especially with 150 grain bullets. Work up slowly until you reach the performance results you desire but always checking for high pressure signs.

 

[Bronsin]

I use a blade mic and check my cases for expansion on the solid case web between the .200 line and the extractor groove. On a .308, you will see from .0008 to .001 expansion as a stopping point. These measurements don't correlate to a certain amount of pressure, but it indicates the upper level your brass can handle before the pockets start getting loose. Different brass will expand different according to their hardness.

Another indicator that seems to work is to check the case head after firing for the ejector swipe. At higher pressures, brass will flow into the ejector hole and will leave a shiny spot when you open the bolt. You will also feel a slight amount of extra resistance when opening the bolt.

Comparing the velocity you're getting to the book values is a good place to look also.

 

[Bill Norris]

As mentioned different manuals will vary in load data. Lots of variables between testing procedures, equipment, locations, atmospheric conditions, powder lots, and the list goes on.

 

[divingin]

Biggest issue, IMO, is how much risk the company is willing to accept. Their lawyers are very active in determining what "max" charge published, and how much headroom they want to leave to keep people from having accidents and suing the authoring company. They don't know what the end user is doing or the condition of the equipment they're using, so have gotten very conservative since the public has trended towards a more litigious society.

That said, all the other things are valid: differing powder lot burn rates, inconsistent bullets, varying capacity between brands of brass, different conditions of rifles, and of course, variance in what reloaders actually do (in addition to all kinds of other things, of course.)

One flag from the OP that that drew my attention was starting below the "minimum" or "starting" charge weight. While likely not going to cause a problem with popular powders used for 308, it's risky for a new reloader to assume things without experience doing so. There is some reason the "starting" load is called a starting load.

 

[CJ6]

There are some instances where 1 manual will be WAY off in a particular load vs another manual. It's always good to have more than 1 manual (several is better). Sierra and Hornady were completely different on a 270 Win. load. One starting load was 4 full grains above MAX in the other manual and was 10 grains over max at maximum vs the other manual

 

[TQB]

You might want to give GRT a try.
Gordon Reloading Tools is a free Internal ballistics calculator. Google it.

 

[NRGsharp1]

On the 308- Do you get better groups with factory ammo? What bullet is the factory load using?

I tried the SST bullets once in my 6.5x47. They weren't terrible, still sub MOA, but the 123 SMK shot groups half that size.

Slightly better with factory ammo. I was getting around an 1” with Winchester deer season xp in a Tikka T3x. My reloads were about an 1 1/4”.
The .223 in the same brand/model rifle I was getting around an 1” with factory ammo and reloads were averaging 1/2” moa.

 

[NRGsharp1]

Biggest issue, IMO, is how much risk the company is willing to accept. Their lawyers are very active in determining what "max" charge published, and how much headroom they want to leave to keep people from having accidents and suing the authoring company. They don't know what the end user is doing or the condition of the equipment they're using, so have gotten very conservative since the public has trended towards a more litigious society.

That said, all the other things are valid: differing powder lot burn rates, inconsistent bullets, varying capacity between brands of brass, different conditions of rifles, and of course, variance in what reloaders actually do (in addition to all kinds of other things, of course.)

One flag from the OP that that drew my attention was starting below the "minimum" or "starting" charge weight. While likely not going to cause a problem with popular powders used for 308, it's risky for a new reloader to assume things without experience doing so. There is some reason the "starting" load is called a starting load.

I did the load above the “starting load” in the reloading manual as in the one with the higher charge. Great point, before reading my hornady manual they stated pretty much about what you just stated “that the minimum listed is truly the minimum and the max load the max.”
Before reading the manual the thought did cross my mind to go bare minimum but after reading the handbook thought better of it.

 

[qldreloader]

I run the 150gr SST and Varget in my Rem 700 SPS .308 and the Hodgson data was spot on. Every rifle is different.

 

[NZ_Fclass]

I've learned to start in the middle and work up. Why spend time & resources on the minimums.
I don't like to load past the mid range loads either. Fastest/ biggest charge isn't my goal..... Accuracy is.

Accuracy doesn't always lie in the mid-range loads, which is why we ladder test and look for the nodes. Most FTR shooters will be usually around the max loads - and those nodes MAY be well past the loading manual "max", according to the brass, chamber length and neck tension that we use. You gotta get out there and see what the target tells you. But always be safe, watch for the pressure signs - flattened or cratered primer and separation rings on the brass And no - I would never start load work up at the minimum end of the scale - It's just a waste of components.

 

[Doom]

As for maximum load data, what is listed is considered to be a Maximum Safe Load in most manuals. In particular the maximum listed in Hornady will likely never be maximum pressure because they list by velocity so there is a gap with the velocity being less than the maximum pressure velocity. Also the minimum listed is the lowest that was tested. In most cases there is no magic to the number, but there are cases where it matters with slow powders and low case fill.

Hodgdon and Lyman both list specific data for a specific bullet. Hornady, Sierra, Nobler and some others list data for a range of bullets. Powder guys usually list individual bullets, bullet guys list by weight for multiple.

Also different lots, different seating depths, normal test data deviations.