Confusion on Max powder charge

[AbeS]

I’m hoping someone could shed light.
I got a browning bar mk3 in 30-06 as a gift and put leupold vx5hd on it.

Recently I got a decent amount of h4350
I decided I want reload for this rifle (standard sig ammo performed poorly)

only good brass I could find was nosler and decided to go with Sierra 175 bthp match king

Usually with my other rifles I’d pick a max powder charge and load down in increments of .2 grains to get a node.

This time Hodgdon website gives me a max of 59 using the exact bullet I have but they’re using Winchester cases

nosler website gives a max of 56.5 but not differentiating between 180 and 175 grains

hornady newest handbook gives a max of 55.3 but kinda like nosler they have 178 and 180 in the same data and nothing specific to a 175 grain bullet (max velocities in handbok also lower than what I’d like)

my question is would starting at the max Hodgdon provided and loading down 10 loads in increments of .2 be safe as the max loads on other sites are that much lower.
my min load would be 57.2 grains which is higher than the max load provided by nosler, hornady, federal, and Barnes???

can Hodgdon be that far off with their data?

 

[Ironicaintit]

When too many variables cast a doubt, start at the lowest published data you can find, then work up.

Are you saying that you normally start your tests at max, then work down?

 

[243winxb]

Auto loaders are different then bolts. H4350 may be the wrong powder for an auto loader.

Starting at maximum and working down, bad idea.

my question is would starting at the max Hodgdon provided and loading down 10 loads in increments of .2 be safe

No, not safe.

 

[AJC1]

Your trying to work in reverse. It's like trying to drive in reverse. Will you get there sure, will your car blow up on the trip, maybe. Follow standard procedures.

 

[AbeS]

Yes I would normally go off the max load say it’s 50 and load down in .2

example 1 bullet each of 50, 49.8, 49.6, 49.4, 49.2, etcetera

then I’d I go and shoot from the lowest and keep checking for pressure signs as i go up

this is just to find a node after which I’d id pick three or two loads from the node I like and load 5 rounds each I go shoot for groups and then after find the best standard deviation I’d start trying to find the best seating depth

but on this specific bullet and powder Hodgdon max is so much higher that my starting load would be higher than the min loads provided by the other companies

I understand that the semi autos act differently I’ve loaded for a 6.5 grendel on a ar platform before and got in nice sd of 15 I believe it can be done with this browning but weary of using the loads provided by Hodgdon to try find a node for it

you might be right the h4350 may not work I don’t know yet

but as the saying goes if a 30-06 don’t shoot with 4350 it don’t need work it needs and exorcist right?

 

[twarr1]

Starting at maximum and working down, bad idea.

+1
The fact you're seeing so many data points from different sources should reinforce: Start minimum, work up
Another Rule; If the load data doesn't list your bullet weight, always use data for the next heavier bullet of the same type

From Speer - "Reloading data published by SPEER are for SPEER bullets. Many of our bullets are of unique construction; there is no such thing as "generic loading data" any more. Other bullet makes may produce significantly different pressures and velocities."

 

[GeoDudeFlorida]

then I’d I go and shoot from the lowest and keep checking for pressure signs as i go up

---

if a 30-06 don’t shoot with 4350 it don’t need work it needs and exorcist

Just answered your own question. Use the bullet-maker's data (Sierra). The case and primer are much less factors than the bullet and the powder is a known good performer so, the only variable is the bullet. Use Sierra's data for the BAR Mk.II: 55.0gr. H4350 @3.320" COAL & 2740fps/2917FPE (from the Sierra Reloading app on my iPhone).
BTW &FWIW, I agree with everyone else that starting at max is not a good practice but, you're not SHOOTING max to start so, that's good.

 

[sparkyv]

Whew!

then I’d I go and shoot from the lowest and keep checking for pressure signs as i go up

 

[Archie]

After some reading of different loading manuals, one finds nearly all manuals differ in minimum and maximum loads for the same cartridge, bullet, primer and powder. Why?

The manual "A" researchers and checkers used different stuff than manual "B" used. Different cases, either manufacturer or lot; at least a different lot of bullets; different brand or something primers; different lot of powder. Different firearm. Different pressure testing machines. Different day with different ambient temperatures.

The Lee Manual specifically provides charges suited to using a 'dipper' provided by Lee in their loading equipment. They all seem to be quite conservative. I would venture to guess the loads are safe in nearly anything mechanically sound and enables one to have ammunition to shoot today. Even if it isn't the 'snappiest' load ever. Other manuals seem to be more or less main stream and one seems to be uniformly at the highest end. Not much, but usually at the top.

One notes EVERY manual makes the disclaimer the loads shown have demonstrated safe pressure levels in the test rifles - universal barrels - used. They always say "Your firearm may be different".

'...[that] powder may not be suitable for a semi-automatic...' M1 Garands seem to have a problem with slow burning powders bending the operating rod. Best analysis shows the slower powders tend to have a higher pressure when the bullet passes the gas port in the barrel. I do not know if any other semi-automatic rifles have the same problem. But there is some underlying problem somewhere. It's not an old wive's tale.

 

[jmorris]

Usually with my other rifles I’d pick a max powder charge and load down in increments of .2 grains to get a node.

That is backwards, only time you want to start high and go down is if you are reducing loads and worried about the bullet becoming stuck in the bore.

This time Hodgdon website gives me a max of 59 using the exact bullet I have but they’re using Winchester cases

nosler website gives a max of 56.5 but not differentiating between 180 and 175 grains

For a starting load “max” isn’t the place to be looking.

To avoid outliers you can load inside overlapped data. Are these are your two sources?





Those two would lean me towards 55.0 as a starting point.


If I looked at Nosler #3, Hornady 4th and Sierra 2nd





I would probably start even lower, most certainly would NOT start at 59 grains though.

Worth noting that IMR 4350 and H4350 are not the same powder even though Nosler shows the same starting and max loads for both.

 

[Skeptic13]

I use the same methodology as the OP. I don't ever start at minimum charge weight. It is certainly always safe but I have never gotten good results at minimum and it is a grand waste of powder. I have never had an issue loading down and shooting up the charge weight range. Normally that will put your first shots right in the middle of the charge range. You just have to pay close attention to pressure signs as you are shooting which you should be doing anyway.

As far as the OP actual question. In this situation where you have such a variation I would first disregard Hornady. They are notoriously conservative. I would take Hodgdon maximum and go down .4 or .5 gr and then load down from there in the same increments. Then once you have good results from one particular charge weight you can work from there and decrease you increments.

 

[BBarn]

I would give the most weight to the Hodgdon data since you are using the exact same bullet. And if using the same primer, even better.

But since other data sources tend to cite smaller charges, I'd reduce the starting charge below Hodgdon's recommendation of 55 gr., to 54 gr. or a bit less. Then I would work up from there, and probably stop at or below 58 gr. or if velocities were reasonable and there were no pressure signs.

 

[jmr40]

Often when you see such differences in max load data it is because one manufacturer simply stopped testing at 56.5 gr because they got the results they were looking for. That doesn't mean 56.5 gr is a max load. A different manufacturer may have decided to push things a bit farther and concluded that 59 gr was still a safe load.

FWIW 57 gr of H4350 with just about any 175-180 gr bullet I've tried gives me about 2800 fps or a tad more with the accuracy I want. But that is from bolt rifles. The problem with loading for semi's is that you have to work within a fairly narrow window of pressures to function reliably. I have no idea how well that load will work with your rifle.

 

[stillquietvoice]

@AbeS welcome to the forum.

The manual "A" researchers and checkers used different stuff than manual "B" used. Different cases, either manufacturer or lot; at least a different lot of bullets; different brand or something primers; different lot of powder. Different firearm. Different pressure testing machines. Different day with different ambient temperatures.

As @Archie posted the variable data is due to different equipment, conditions and components. Most sources of reload data site the type of arm that their tests were done in. Nosler data is usually tested in a rifle with a match chambered barrel, rifle, most have longer than standard barrel lengths as well. When I loaded for semi autos, rem 742, 7400,nd m1 garand I used imr 4064 because its operating pressure was "best" for the gas systems in those rifles and hot hood accuracy, velocities.