Can I mix H4895 with IMR 4895?

[mikepro8]

As the title states...
I have been reloading for my M1 Garand, but am just about out of H 4895, which calls for 49gr. of powder with a 150 gr. bullet.
I went to my local shop today and they were out of Hodgdon's 4895, but said they had IMR's 4895. I bought two pounds at a decent price.

Load data for the M1 Garand calls for 49 gr. of either powder (4895).

My question is, I have a bit of H4895 in my tube at home, can I mix the two powders or should I empty the tube before using the IMR 4895?

[Bama Man]

Empty the powder in the tube before putting in the other.
I don't know why the loading data shows that it takes 49 grains of either powder.
My loading data shows that for a .308, 180 grain bullet, IMR4895 loads 38.2 grains, and H4895 loads 40 grains.
This data is just an example of a difference in these powders.
I don't know which is which, but i was told by a long time handloader and benchrest shooter, that one of the powders shoots about one grain hotter than the other, but I can't remember which on does.
I just know that I would never substitute one for the other at the same weights.
I asked him the same question as I had IMR4895, and my data called for H4895. I was looking to maybe get by without another powder purchase.
NEVER mix any powders.

[rwilson452]

As always when starting a new load, start with a lighter charge and work up.

[knight0334]

IMR and H 4895 powders have slightly different burn rates. They are close substitutes, but aren't the same. Dont mix, and readjust your charges for each given powder.

[mikepro8]

Thanks for the replies...
Did a little more research and found this: http://data.hodgdon.com/cartridge_load.asp
Per your reponses, there is a bit of difference (3 grains!) in the load data for .30-06.

Thank you!

[Bama Man]

I just looked up the load for the 150 grainer .308 in my Lee's modern reloading 2nd edition book, and it shows that the IMR 4895 loads at 42.1 grins, and the H4895 loads at 43.0 grains.
The IMR powder gives 2880 FPS with 59000 PSI chamber pressure, and the H4895 gives you 2870 FPS with 60808 PSI chamber pressure.
NOTE that, in the Lee manual, all data is listed for the NEVER EXCEED load, which are: H4895, never exceed 45.5 grains, and the IMR4895, Never exceed 45.5 grains.
I don't know what data your using, but, always look up your own data, and never trust ANY data you find online unless it is the powder manufacturer site.
I'm just telling you what I found in my Lee data.
My Speer manual doesn't show a load for H4895, but shows a start load of 41.0 grains of IMR 4895, with 2489FPS ,and a max load of 45.0 grains of IMR 4895, with 2717 FPS.

[knight0334]

This chart comes in handy for seeing the difference in burn rates versus two like named powders.

http://www.reloadbench.com/burn.html

[mikepro8]

Right from Hodgdon's (who bought IMR a few years back, from what I read) site....
150 GR. NOS BT IMR IMR 4895 .308" 3.250" 49.0 (min) 2856 49,400 PSI 53.0 (max) 3009 56,700 PSI

150 GR. NOS BT Hodgdon H4895 .308" 3.250" 46.0 (min) 2806 44,400 CUP 51.0 (max) 2976 48,500 CUP

In all actuality, I could use 49 grains of either. The 49 gr. of IMR 4895 is the starting load, and 49 gr. of the H4895 is a mid-way between the min and max load.

According to that burn rate chart Knight posted a link for, they are VERY close, but obviously not quite the same.

I LOVE reloading!!!

[knight0334]

Right from Hodgdon's (who bought IMR a few years back, from what I read) site....
150 GR. NOS BT IMR IMR 4895 .308" 3.250" 49.0 (min) 2856 49,400 PSI 53.0 (max) 3009 56,700 PSI

150 GR. NOS BT Hodgdon H4895 .308" 3.250" 46.0 (min) 2806 44,400 CUP 51.0 (max) 2976 48,500 CUP

In all actuality, I could use 49 grains of either. The 49 gr. of IMR 4895 is the starting load, and 49 gr. of the H4895 is a mid-way between the min and max load.

According to that burn rate chart Knight posted a link for, they are VERY close, but obviously not quite the same.

I LOVE reloading!!!

Just wait until you experiment with duplex and triplex loads.. lol

If you think the IMR/H 4895 thing is messed up, try loading for a 45-120 in smokeless which was designed for blackpowder, but trying to keep pressures below 42K PSI, but be able to use an entire 32" barrel.

I use a duplex/triplex powder charge which the first layer(closest to the primer) is a faster burn rate, then the next is slower, and then slower to effectively utilize the long barrel. (300gr .458" slugs at 3000fps, 500gr+ @ 2300-2400fps)

[mikepro8]

Just wait until you experiment with duplex and triplex loads.. lol

If you think the IMR/H 4895 thing is messed up, try loading for a 45-120 in smokeless which was designed for blackpowder, but trying to keep pressures below 42K PSI, but be able to use an entire 32" barrel.

I use a duplex/triplex powder charge which the first layer(closest to the primer) is a faster burn rate, then the next is slower, and then slower to effectively utilize the long barrel. (300gr .458" slugs at 3000fps, 500gr+ @ 2300-2400fps)

Dude.
You are giving me a headache.

One powder charge is enough for me for now.