Powder Question?

[CyaN1de]

I am sure there is a logical explanation to this.....

I am basing this question on 22-250 loads.

Why is it that the 2 4895's (Hodgdon and IMR) are only 4 slots apart on the burn rate chart (H4895 being the faster of the 2)but max loads and pressure vary a great deal between the 2 but velocities are only 35 FPS in difference?

50 GR. SIE SP IMR 4895 .224" 2.350" 37.6 3862 61,500 PSI
50 GR. SIE SP H4895 .224" 2.350" 36.5 3827 50,200 CUP

Can I assume that IMR 4895 might be a better powder choice based on the fact that it would have better case filling capacity and leave less air space between the bullet base and the powder?

 

[JasonYuke]

I know it does not make sence either to me i just never asked the question, However from experience loading the 22-250 IMR 4895 has been much better than H 4895 as a choice for me with 52 and 53 grain bullets.

I have also played with H-380 with good results and Varget.

 

[maynard]

PSI and CUP are not the same and are not convertable.

 

[proonur]

I'm about to run an experiment in my Garand with those two powders.
I substituted the H4895 for the IMR successfully already, and now I'll see what the IMR does to the accuracy.
On the Hodgdon website it has them right beside each other #64 and #65. I don't think there's really enough difference between them, but we'll see.

 

[sunray]

"...Can I assume that..." Not really. As you know, the two powders are close, but not the same. Use the one that gives you better accuracy.

 

[updatelee]

quickload sais
37.6gr IMR4895 will be 61700psi, 4125fps

and

36.5gr H4895 will be 53900psi, 3907fps

quickload isnt allways bang on, but from what Ive seen with my 22-250 and 300wm its usually pretty close. and its showing 200fps difference, that could defn account for the difference in pressure.

 

[CyaN1de]

PSI and CUP are not the same and are not convertable.

Yep...I missed that part

"...Can I assume that..." Not really. As you know, the two powders are close, but not the same. Use the one that gives you better accuracy.

As these are for gopher loads, I am willing to sacrifice 1/4 min accuracy for more velocity for the sheer joy of an extra few feet of airtime.

Seriously though, I want a balance of decent accuracy with max velocities and I do know that load density plays a role in accuracy as well.

quickload sais
37.6gr IMR4895 will be 61700psi, 4125fps

and

36.5gr H4895 will be 53900psi, 3907fps

Well I will have to pick up some IMR 4895 as that extra 200 fps (if the max load is accurate enough) is what I was looking for.

 

[Mystic Precision]

I bet that if you took the H4895 load and raised to the same 61700psi, the velocities will be very similar if not the same.

I like the Hodgdon powders as they burn cleanly and are temp stable. If running toasty loads now, when things temps start to get hot, the IMR load would need to be readjusted as you might go over your accuracy node.

As was said, shoot the one that gives you the most accuracy vs air time.

Jerry

 

[CyaN1de]

I bet that if you took the H4895 load and raised to the same 61700psi, the velocities will be very similar if not the same.

I like the Hodgdon powders as they burn cleanly and are temp stable. If running toasty loads now, when things temps start to get hot, the IMR load would need to be readjusted as you might go over your accuracy node.

As was said, shoot the one that gives you the most accuracy vs air time.

Jerry

I do have some loaded up with H4895 that are a little over max recommended loads, but I have not had a chance to take them out for a grouping/chrony session. I believe I loaded 37/37.3 and 37.7 to try out, but I only got 3/4 of the way through the 36.5 loads which is the book max and is not showing any signs of pressure.