IMR4198 vs. H4198


March 13, 2013, 07:27 PM
I'm sure there are some sighs out there ("not again") However my searches on this site haven't addressed this in my specific situation, and some are 6+ years old. At any rate, I'm shooting a bolt action .223 w/a 1:12 twist with 50 gr. SIE SPT's. the latest Hodgdon/Win/IMR manual I've got (as well as the Sierra manual I've checked) give heavier charges, higher velocities with IMR, but at a higher pressure, but IMR is listed in PSI, where H is still using CUP. Most folks say they "are very similar, but not the same" Intuition tells me I'm probably splitting hairs here, but anyone ever actually had the opportunity to do any side by side comparisons on a similar platform? I'll be using CCI 450's, since that's all my shop had, if that matters.

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March 13, 2013, 08:08 PM
The two are right next to each other on the powder burn rate chart.
I realize that you can get plenty of conflicting data. Remember that data reflects what the developers found in their testing with their test guns.

Since we have our own guns, we are responsible to work up safe accurate loads for our guns. The data gives us a safe place to start. Always Start Low and Work Up!

I would not hesitate to use any load for 4198 regardless the manufacturer, as long as I started on the low end of the charts.

As far as pressure. I have no way to test it. I can however look for tell tale signs of excessive pressure. This is a must.

March 14, 2013, 12:57 AM
Both 4198 powders are not the same or Hodgdon would now admit it. I like the H variations of all the powders that have the same numbers as their IMR cousins because the pressures are usually lower while generation similar velocities.

That said, I have a Howa 1500 bolt action rifle in .223 with a 1:12 twist barrel and I get very accurate loads using a slower powders than 4198. I like H335, BL-C(2), AA2230 and Varget much better than IMR/H4198 or even IMR3031. I have found when a powder fills the case accuracy and consistence is better than with powders which don't fill the case.

March 14, 2013, 02:29 AM
In that case, I'm gonna load that mutha' up to the base and then some!

March 14, 2013, 02:37 AM
Seriously, before I get thrown outta here. I've used A2230, BL-C(2), Varget, and even H4198 before. The ball pwdr's here do seem to peak rather fast, as I've gotten some pressure signs even at just a pinch overload. The extruded 4198 and Varget (even though I think that's a double base powder) seem more forgiving. Though Varget is so bulky, a real overload is unlikely. That's really why I asked if there's a real differenct b/w IMR Hodgdon.

March 14, 2013, 11:47 AM
Hodgdon was reprocessed military powder, at least when it started.

March 14, 2013, 07:49 PM
ive used them both. and if i remember right. i dont think you can get enuf of either in a 223 case to do any mind yu, im not talking compressed loads!

4198 of either brand is a very nice powder for 223,or has been in my experience.its all i use for 223.

March 14, 2013, 09:27 PM
IMR 4198 is pretty fast and peaks out at 20.4 Gr for a 50 Gr bullet. Difficult to get much beyond 2900 fps with a peak load. I get mild pressure signs at peak out if a 1/9 barrel bolt gun. It is very accurate stuff though.


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