Conflicting Data for 168 gr. Amax Loads (.300 win mag)


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TonyM
October 11, 2011, 09:42 AM
I have two questions: I'm loading 168 grain Hornady Amax bullets in .300 win mag. According to old data I have the max load for IMR 4831 is 72 grains, IMR 7828 is 76.8. However, using the online Hodgdon/IMR website, it lists a max load of 75.5 for the IMR4831 and 80 for IMR7828- this is for the 168 grain BTHP. What gives?

2nd question I did test loads using aforementioned bullet and RL22 worked best. I then reloaded ten rounds with RL22 at 79.1 (max load). Five rounds were in new Remington brass (resized, trimmed to identical length) and five rounds were once fired federal brass sized to exact same length. The group with the Remington was not as tight as the Federal-- do you suspect this is due to position I was firing from (prone for Remington, bench for Federal) or likely from the brass itself?

I shifted positions as when I got to the range the prone bench was the only one open, later, the regular bench opened and I switched to it......

Any other recommendations for loads of 168 grain Amax in .300 win mag?

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USSR
October 11, 2011, 11:59 AM
TonyM,

First, a 168gr Amax is not a 168gr BTHP. Second, different makes of brass would account for different listed Max charge weights. Since you should never start off loading a Max load anyways, I would start at a grain or two below the lower listed Max charge, and run it through a chronograph to see what you are getting velocity-wise, before increasing your charge weight.

Don

redbullitt
October 11, 2011, 12:39 PM
They are just guide lines and a typical range to work with, not anything more than that. The loads worked in the test rifle. That's all.

Were I you, I would get access to a chronograph. Velocity and watching pressure signs are going to be better indicators of where you should be most of the time. Hodgdon has had pretty accurate data from what I have seen most of the time (ie sierra can be super conservative). I have always had the best luck starting low and working up and finding where it shoots the best. This will give you the best load workup. FWIW I don't often end up at a max load.

Why not try a mid weight charge? May be more accurate in your rifle.

What distance were you firing prone v bench? If it was not far, then it was probably shooter issues. I use mixed brass a lot and until you get out to some distance it does not really show up at all.

ranger335v
October 11, 2011, 02:45 PM
The books only tell us what they got, no book can tell you with any certainlty what your rifle needs or is safe at. So, it's up to YOU! Good luck.

MEHavey
October 11, 2011, 03:43 PM
I'm loading 168 grain Hornady Amax bullets in .300 win mag.
According to old data... However, using the online Hodgdon/IMR website, it lists a....

Hornady (whose bullet this is) says:

IMR4831 MAX 72.0gr (QL says 100% case fill/62,000psi - which is cartridge max)
----------------------------------------------------------------------------
IMR7828 MAX 76.8gr (QL says 105% case fill -edge of compressed- and 57,000psi)

I'd go with Hornady's recommendations unless/until you work up well-read brass signals.


As to another powder, I'd suggest N560 for the 165 through 190gr projectiles

TonyM
October 11, 2011, 07:42 PM
Thanks for all the info. I realize a BTHP is not an AMAX, however Hornady lists them the same, whereas Hogdon lists it as Hornady BTHP, rather than all 165-168 Hornady's lumped together (as Hornady does). I didn't start at max load, however I did find groups improved while approaching Hornady's listed max load, and therefore wondered if going over (per Hodgdon data) would be acceptable. I'm trying to use powders I already have- IMR 4831, 7828, and RL22. I have a chrony and will use that next trip to the range.

I was firing at 100 yards- I dont normally shoot prone, unless hunting. I'm comfortable with it, but less so when shooting from a lead sled, which is what I was using at the range.

Thanks for all the input!

murf
October 11, 2011, 08:19 PM
the amax has a larger bearing surface. you should use the old data. imop

murf

45ACPUSER
October 11, 2011, 08:37 PM
First off you might want to trace back an look at the details....ie brand of case that was used to generate the data....usually the key factor....

TonyM
October 13, 2011, 03:31 PM
Thanks for all the input-- any thoughts as to using this as a load for antelope???

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