Home Forums Reloading Big Game Rifles Yet another old component vs new data question- IMR 4350 for 30-06

IMR-4350 is a long stick powder that doesn't stack that tight in the case,so even it the powder is in the neck,you can push it back into the case when seating the bullet without it being over compressed with the bullet backing out after seating.I've run 60.0grs with 150gr bullets in Winchester cases that have been fired with no problem and that is a good load.With 165gr bullets,I've had best accuracy with 58.0grs.Remington cases seem to have a little less volume,you might want to back off a grain if you use those cases.I've loaded the three 4350 powders,Accurate,IMR and H,when using the same charge,Accurate was the lightest weight powder by volume using up the most space in the case.H was the heaviest taking up the least space.And IMR fell between the other two,maybe being closer to Accurate than H.One thing I've noticed about loading the 30-06,it seems like most loads are going to fill the case at the bottom or just into the neck of the case.The long neck of the 30-06 allows you to seat a lot of bullet weights without taking up powder space.You can shoot powders from Varget to Reloader-26 and usually find good loads.A couple of other powders I like in the 30-06 are Win 760 and Ramshot Big Game.Those two powders are ball powders and will give you more case space because it stacks tight leaving less air space between each grain.I like using a magnum primer with those two and get very good accuracy and velocities too.

I sent an email to Hodgdon questioning whether or not the 60.0grs of IMR-4350 with a 165gr bullet was an error.The response I got back was no,it was a long tested load.I would not shoot that in any of the five 30-06's I own.All my rifles seem to max out at around 58.5grs.
This is on Hodgdon's data
IMR
IMR 4350
0.308"
3.300"
56.0
2,746
48,100 PSI
60.0C
2,934
57,600 PSI

Get a plaster vibrator from a hobby store or your Dentist. These are used for getting bubbles out of the mix to get smooth models. Even with big size stock powders you can vibrate a full case down to the base of the neck. If you use a drop tube and a slow pour with the vibrator you came get even more of a settled fill. Been doing this for years and most of my loads don't "crunch" when bullet seating. JM

A few comments:

First, as somebody already hinted at, new cases have less capacity than fired cases, even after fired cases have been full-length resized. Have never encountered any problem getting up to 60 grains of IMR4350 in fired Winchester cases with SOME 165-grain bullets, even without "settling" the powder--and also never encountered any pressure problems with 60 grains with SOME 165-grain bullets.

Which brings up my second point: Different bullets result in different pressures. Which is one reason why various sources of loading data list different maximum charges with 165-grain bullets. The Sierra boattail that Hodgdon lists with a 60.0 grain max is one that produces less pressure, due to less bearing surface. (I used 58.5 grains of IMR4350 for many years in Winchester cases with the 165 Nosler Partition, with zero problems--and the Partition results in MORE pressure than most bullets.)

Third, there is no major difference in the burn-rate of H4350 or IMR4350. Back when H4350 was newer Hodgdon adjusted the data for it fairly often, and it could indicate burning a little faster OR slower than IMR4350. But that's pretty much settled down. The data for the two 165-grain bullets they provide data for show 1.2 and 1.0 grains difference in maximum loads. That's well within the normal variation of different manufacturing lots of handloading powders.

Fourth, firm compression is usually good for powder charges, especially extruded powders. They burn more consistently, and also tend to be less temperature sensitive with noticeable compression. A good example is the load I've been using in my .375 H&H for almost 30 years with both Nosler Partitions and Sierra GameKings, 80.0 grains of IMR4350. It is heavily compressed, but far less temperature sensitive than 58.5 grains of IMR4350 and the 165 Nosler Partition in the .30-06, which is only lightly compressed with that bullet. (It would be more firmly compressed with some other 165-grain bullets, such as the Barnes TTSX, Hornady GMX or Nosler E-Tip.)

John, I know that hearing this gets tiresome, but I still think that a comparison list of bullets as to bearing surface would be an interesting (and useful if viewed with intelligence) thing.

Overall, IMR 4350 has always been more accurate in my '06 with 165's than H4350, but not by much. Find what is best for you between 56-58 grains and call it good. IMHO, the velocity difference between the high and low or even trying to push a 165 faster with more powder is not worth a second thought. I'm not a competition shooter and I don't shoot game much past 400 yards. With that, I've shot good groups (typically an inch or better) and game from 100+ degree temperatures to down into the teens and IMR 4350 has always worked very well.

I have found the same accuracy difference in 180s in my '06. There is nothing scientific about my conclusion, just my observation.