Burn rate of H4350 compared to IMR 4350

[urbanrifleman]

What is your experience interchanging these powders?

 

[shoot4fun]

Your question leaves a lot of "gray area".
IMR and Hodgdon powders of same number are not completely interchangeable.
I think you could better derive the answer, especially for what ever your purpose will be, by looking at the Hodgdon Reloading Center data for the caliber you are loading. They usually provide data for both powders where applicable. H4350, being part of the Extreme powder line, is less temp sensitive than the IMR number. This could make a big difference in your climate or particular load.

 

[onelastshot]

These are two completely different powders, the only thing they have in common is the name. Load maximums will vary by as much as 3-4 grains. IMR is a slower burning powder than H4350. I corrected this post; when you get online with only two hours of sleep you sometimes make mistakes. I inverted my powders and initially said that IMR was a faster burning powder.

 

[MrBottleneck]

IMR 4350 (#117) is a faster burning powder then H4350 (#115)
You get a fast lot of IMR and a slower lot of H and you will be in for a surprise if you interchange without testing.
So, work up each powder accordingly as its own.

 

[xswanted]

My experience is you can start the same and work up each accordingly.

I like IMR better personally.

Both are great choices for many guns!

 

[joed49]

Both are great choices but are not identical in charges. I prefer IMR as I've found it to be more accurate at the higher charges in my rifle.

Bottom line, if I were out of IMR4350 and all that was available is H4350 I'd pick it up.

 

[urbanrifleman]

I never said I was going to interchange them without testing. I just noticed that there is no solid burn rate correlation between them in any reference I have found so far. Which, I have to admit is pretty bizarre considering its popularity. And now, after reading these comments there really is no consensus. And if lot to lot variance is so much that a new lot would require a new load work up, I would choose a different powder.

I am currently testing IMR 4350 in 243 with Berger 108s and found the low node at 40 grains is quite nice. The upper node was not as nice and got the gun smoking hot.

 

[urbanrifleman]

My experience is you can start the same and work up each accordingly.

I like IMR better personally.

Both are great choices for many guns!

Why? Just curious your take.

 

[DIBBS]

Not interchangeable at all, likely a grain or three difference in loads, always start low and work back up when changing brands or lots of powder...

 

[Rob01]

IMR 4350 (#117) is a faster burning powder then H4350 (#115)
You get a fast lot of IMR and a slower lot of H and you will be in for a surprise if you interchange without testing.
So, work up each powder accordingly as its own.

Vice versa.

 

[joshb]

I always just look at the burn chart like Robo1 posted. One way to deal with lot to lot changes is to buy a lot of the same lot. If you get a lot of different lots, mix them before you do your testing.

 

[xswanted]

Why? Just curious your take.

It's more of a "I'm tired of the H4350 cult" kind of thing for me.

Secondly it's always been around and it's always worked. Not to the H4350 wouldn't but it's just what I use!

R17 and 4451 are also close enough to both of these a guy can do some basic extrapolation and find similar loads with all three. Simliar. Not same.

 

[fourpower]

What is your experience interchanging these powders?

what ever your gun likes. I have a 6.5x47 laupa that is in love with h-4350 but hates imr-4350! let your gun tell you want it wants.

 

[dsculley]

For me they are inter-changable. Not on a gr for gr basis for the same use. Either works well in my 6.5x47. Just as with any other powder, you do your workup in a safe manner. The final charges for the 2 powders may be very similar, but probably not the same.