Riddle me this - 4831 IMR vs. Hogdon

[DUSTY NOGGIN]

dont pull anything, yet ... the compressed on the staring low is not normal .. check scale .. what is your seating

next time get 3 data sources for your load before you start loading , i usually lean toward the powder manufacturers data , but will usually average the starting load of each data source and go from there

this conflict of data happens because of 2 things ,
they want you to use more consumables & they print it so low that you will learn why they print it so low , because you verified that it was too low by using up their too low data ...

i found lyman manuals data to be fairly realistic ..
look at different years of the same brand reloading manuals same parts same everything except lower charges.. you can find old reloading manual in classifieds for cheap .. there is also plenty of online data sources for free

ive had problems with horanadys data in my experiences, hornady data never gets used in any decisions in my loading , but i still have their manual just for their bullet seating measurements ..IMO ,they print data so low that is unsafe in the low side

 

[DUSTY NOGGIN]

i think your buddies 1/3 of a pound left over was a different lot

if your buying in pound bottles .
you kinda gotta calculate how many rounds you estimate its gonna take .. your 7rm is only gonna get 100ish rounds out of one bottle .. if you have to shoot 50 of em for load development that is only gonna leave you 50 before you have to test the next bottles speed vs the previous

you dont wanna buy 3 pounds of something your not sure of though.

same with the h1000 and retumbo , gotta know what the lot date is

 

[gte901m]

IMR4831 and H4831 are materially different. The IMR4831 load you developed will not translate directly to H4831.

The H1000 discrepancy you referenced is typical for 7mag data. Early 7mag data was optimistic with velocity, and modern data seems to be anemic.

Using case head expansion as a guide, 160 partitions maxed at ~71 grains in my rifle, and the accuracy nodes was ~69 grains. A 160 AB should be similar. Start 8-10% below 71.

As was mentioned above, calibrated your scale; a compressed load with a starting charge weight is abnormal.

 

[Lefty7mmstw]

dont pull anything, yet ... the compressed on the staring low is not normal .. check scale .. what is your seating

next time get 3 data sources for your load before you start loading , i usually lean toward the powder manufacturers data , but will usually average the starting load of each data source and go from there

this conflict of data happens because of 2 things ,
they want you to use more consumables & they print it so low that you will learn why they print it so low , because you verified that it was too low by using up their too low data ...

i found lyman manuals data to be fairly realistic ..
look at different years of the same brand reloading manuals same parts same everything except lower charges.. you can find old reloading manual in classifieds for cheap .. there is also plenty of online data sources for free

ive had problems with horanadys data in my experiences, hornady data never gets used in any decisions in my loading , but i still have their manual just for their bullet seating measurements ..IMO ,they print data so low that is unsafe in the low side

Hornady's (and a few others) data starts conservative for a very good reason. There are outlier rifles (my current 7rum is one) that anything above a relatively low start charge may actually be excessive. I blew a primer a few weeks back with retumbo and a 175 Hornady (85 grains) in a load that would be considered a start charge in some of the less conservative books. The rifle will do 3,000 fps on a 183 with a measly 82 grains of retumbo. It's got a 8" twist and a rather tight Brux barrel and a rather tight chamber. Hodgdon's online data starts at 86 grains for a 175 and retumbo.
Once you have a handle on what a rifle can handle you don't need to start as mild, but the first few rounds out of a rifle should be taken with caution.

 

[Country Bumpkin]

Thanks everyone. I pulled them and started down at 69.0 and topped out my ladder test at 73.5.

 

[Heavyiron]

I've got a 280ai (pre-nosler version) that will shoot one hole groups with imr4831. 58 grains behind the humble 139 hornady interloc. I keep both the imr and hornady version in stock. The h version seems to work better in my 270 and really for you to know. If you are like me, i have usually have several reloading projects going on so one powder will work good one time in a project and the other in .the next project..
Currently working with rl 26 on a new project with the 165 gr sierra , in my 7mm rrem mag. It shows good potential signs with velocity and accuracy to boot.

 

[Country Bumpkin]

Well, I had a chance to get out and try some of the H4831 today.

It was okay, I put it behind some 160 AB's in my 7 RM.

The real fun was seeing what H1000 did behind my Barnes 150 TTSX.

I still have some more messing around to do, but I'm
Just about to a point where I'll start with seating depths.

 

[gte901m]

Keep moving up the ladder with H4831 and 160AB. Between 64 and 65 works well in my rifle. Nosler does not list H4831 with 160s, but does list 65 as max with 168s.

 

[Country Bumpkin]

Keep moving up the ladder with H4831 and 160AB. Between 64 and 65 works well in my rifle. Nosler does not list H4831 with 160s, but does list 65 as max with 168s.

I'll give it a whirl. Are you at a standard saami chamber?

 

[gte901m]

Yes, saami chamber.