H4895 vs. IMR4895

BOBTAILS

BOBTAILS

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How much difference is there between these 2 powders? Has anybody tried to see if one will shoot well in your gun the other does also or not?
 
The IMR powders seem to have a bit faster burn rate. That being said, you should treat them as different powders and work up loads for each. Your rifle will tell you what it wants.
 
and h4895 is an extreme powder(not temperature sensitive)
and IMR 4895 is not an extreme powder(temperature sensitive)
and according to the powder burn rate chart,IMR 4895 is slightly faster burning then h4895
 
I'm not a powder expert, but I just looked in my Hodgdon 2010 manual and it has H4895 as a faster powder than IMR4895. Also any loads using H4895, for any cartridge, seems to shoot faster with the same charge and bullet weight than with IMR4895.
 
I believe that the IMR is a bit slower, but I have loads that transfer over pretty close. I have a 223 77 nosler load in IMR that is unbelievable and the same load in h4895 shoots almost the same.
 
Originally Posted By: K-22hornet.The IMR powders seem to have a bit faster burn rate. That being said, you should treat them as different powders and work up loads for each. Your rifle will tell you what it wants.

+1
In one rifle, I have tested both 4895 powders, the "H" version shoots best. Not conclusive due to only one sample test, but that's what happened with my 222 Mag.
As said, treat them as different powders when working up loads. Good advice by K-22Hornet.
 
I've only used IMR4895 simply because that's what has been locally available over the years and it has given me excellent results. It seems to be an accurate, versatile and reliable powder. I've used it in 204, 222 mag and a 243. I'm sure H4895 would have served me just as well. The problem I have with IMR4895 and small cal cases like 20 cal is that it may and occasionally will bridge rather than flow freely into the case. I have read that H4895 is a finer powder and hence will probably flow better into the small cases and probably meter better as wwell. But I don't know for sure. Dave
 
IMR 4895 is a classic powder, was loaded in the original 30'06 M1 Garand loads. It's been very consistent for me from lot to lot (as have all IMR powders), but does fall victim to a little temperature sensitivity, and it is a bit long for sub-22 calibers.

H4895 is one of Hodgdon's Extreme Powders. It's temperature insensitive, and has a shorter, fatter kernel which shouldn't bridge as often. H4895 shoots so well in my .223 that I don't think I'm going to experiment with anything else.
 
I have had troubles with H4895 bridging in my .204 cases. I have since changed powders in my .204. It shot great but I didn't like the occasional problem of bridging. I still use H4895 in my .223, .22-250 and .243. I have not tried the IMR version.
 
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Originally Posted By: dozernomoreand h4895 is an extreme powder(not temperature sensitive)
and IMR 4895 is not an extreme powder(temperature sensitive)
and according to the powder burn rate chart,IMR 4895 is slightly faster burning then h4895
I'm reading everyones post here,thinking I'm an idiot for stating that imr4895 is slightly faster then h4895,,,so I double checked my hornady manual,,and is say's imr 4895 is slightly faster then h4895,,,,so then I grab my lee manual and it states it the opposite as the hornady manual,,,and agrees with everyone else's statements.Now I do realize every load manual are slightly different in load data,but I would have thought the powder burn rate chart would have been standardized,,,GO FIGURE ?? eh ??
 
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Quote: you are going to have to explaing bridging to me, what does that mean?

The powder kernals get stuck sideways in the drop tube (making a bridge) and you only get a partial fill of the case.
Then, the next case, it drops a full charge plus the jam-up amount.

That can be bad. It's why I check every case with a flashlight before I start seating bullets.

Never had a bridge (yet) but long extruded powder in a small ID drop tube has the potential.
 
imr4895 being tempeture sesitive.just exactly how much diff.can temp.make on point of impact? i have a custom built ar with a 1-9 twist kreiger barrel, i had the gun built around 50 grn hornady v-max bullets,when i shot it at the gunsmiths house before i took it home i had 5 shots touching at 100yds, not one hole, butt touching, ive acomplished that one time since then at my house. im in northern Va. it has been very hot and humid, i shoot in the evening before dark and use a single feed mag, to try to keep it as cool as possible inbetween shots, what should i expect?
 
As the temperature goes up for the cartridge and components, the pressure in the chamber rises and therefore the muzzle velocity will increase.. Your point of impact can change a little or a lot..

Your harmonics in the barrel will change to a different pattern when the bullet exits the barrel,,,sometimes not always in the same point of the pattern...Your groups may get substantially larger, or not at all...

A standard bull, or fluted bull barrel will generally have less distortion than a 'sporter'/lightweight contour due to the heat factor, but excessive pressure due to overly heated ammunition can be dangerous, or at the very least damage your firearm..

That's one of the reasons that people that sit out in the sun shooting Prairie Dogs will usually wind up keeping their ammo in an ice chest to reduce the heat build up..Leaving a cartridge in a really hot chamber can lead to a "cook off" where the chamber heat ignites the powder...
 
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