BallisticsGuy
Well-Known Member
I had an issue with H4350 availability and a match tomorrow but I have a ton of IMR-4350 on hand. IMR4350 is a little faster burning but has a little bit less energy content and about the same bulk density. The difference between them is very small for this use case.
Not wanting to do it the hard way, I searched and searched fot 6XC load data with 105+gr bullets but found exactly nothing. So I looked at 6CM and 6x47L data and burn speed, bulk density and energy content for H4350 & IMR-4350 and made an educated guess. My guess worked better than I'd hoped.
The load below was safe in my rifle. Your mileage may vary. Start at least 2 grains lower and work up.
Case: Norma LRP
Bullet: 115gr DTAC
Powder: IMR4350
COAL: 2.74
Primer: Federal 210
Charge: 39.5gr
MV: 3050 avg
SD: 7FPS
Barrel: 25.5" Columbia River Arms 3-land polygonal
I see the question asked constantly about IMR-4350 vs H4350 in fast short action 6mm's and 6.5's. Nobody ever has the answer for IMR4350, they just say, "go get H4350." but that's both glib and unhelpful. So, here you go. The actual answer to the actual question.
With an identical load using H4350 instead of IMR4350 I get 2980fps with similar SD's and an identical POI. Group size with both powders was the same, 5 shots into half an inch, 10 shots into 3/4" from a bench.
Now you have the information, do with it what you will. IMR-4350 is a great powder choice for 6XC and other fast 6mm's like 6x47L and 6CM with bullets from mid-weight to heavy for caliber.
As always with my load data, this is information not advice. You are responsible for your actions and your safety. I provided data as an EXAMPLE of what can/will happen. It's not a prediction or your results and you should exercise reasonable amounts of caution.
Not wanting to do it the hard way, I searched and searched fot 6XC load data with 105+gr bullets but found exactly nothing. So I looked at 6CM and 6x47L data and burn speed, bulk density and energy content for H4350 & IMR-4350 and made an educated guess. My guess worked better than I'd hoped.
The load below was safe in my rifle. Your mileage may vary. Start at least 2 grains lower and work up.
Case: Norma LRP
Bullet: 115gr DTAC
Powder: IMR4350
COAL: 2.74
Primer: Federal 210
Charge: 39.5gr
MV: 3050 avg
SD: 7FPS
Barrel: 25.5" Columbia River Arms 3-land polygonal
I see the question asked constantly about IMR-4350 vs H4350 in fast short action 6mm's and 6.5's. Nobody ever has the answer for IMR4350, they just say, "go get H4350." but that's both glib and unhelpful. So, here you go. The actual answer to the actual question.
With an identical load using H4350 instead of IMR4350 I get 2980fps with similar SD's and an identical POI. Group size with both powders was the same, 5 shots into half an inch, 10 shots into 3/4" from a bench.
Now you have the information, do with it what you will. IMR-4350 is a great powder choice for 6XC and other fast 6mm's like 6x47L and 6CM with bullets from mid-weight to heavy for caliber.
As always with my load data, this is information not advice. You are responsible for your actions and your safety. I provided data as an EXAMPLE of what can/will happen. It's not a prediction or your results and you should exercise reasonable amounts of caution.
Last edited:
