Home Forums Reloading Big Game Rifles IMR4350 vs H4350

I'm going to be hunting elk at tree-line soon. The bullet cartridge combination I've chosen would have been IMR4350 written all over it before I started reading about temp sensitivity.

So I've bought a few pounds of H4350. Then prairie dog shooting and a lot of other things got in the way. so I'm hoping to gather information to quicken my testing...

First looking at manuals, there's fewer H4350 loads in manuals it seems. Second the newest Nosler manual says IMR4350 is the most accurate powder in this combination.

I understand that H4350 is a little slower but Hodgen reloading site has less H4350 than IMR4350 and it's loaded to a way lower pressure.

Does H4350 have red hair? Is it as good as IMR4350?

For those of you that use this powder, is it as accurate as the IMR version? Can you get the same or similar velocity?

Thanks

What cartridge and bullet?

Years past I shot scads of IMR4350 and still shoot some. It was the first powder that brought the temperature issue to light for me.

Sometime ago I switched to H4350 and have not used much else in the 30/06 since then...and strictly with 165 gr bullets. Far as I can tell one is as accurate as the other.

Yes I get the same velocities with both powders; usually around 2900 fps with H4350.

A buddyy knocked off a bull elk in the San Juans in 30 degree temperatures at around 500 yards,after shooting his 30/06 all summer back here with a max load of IMR4350 in temps of 80-90 degrees.

Go figure.

40-60 foster swing in my 300wsm with imr4350. 25-degrees to 80-degrees.

I would worry if was shooting 500 yards but out to what most of my shots are it is not a big deal.

[quote=Bugger
Second the newest Nosler manual says IMR4350 is the most accurate powder in this combination.
[/quote]

But that doesn't mean it will be the most accurate in your rifle. It's quite possible H4350 will be more accurate in your rifle.

Bugger,

Both IMR4350 and H4350 vary slightly in burn-rate from lot to lot, but overall I've been using exactly the same charges as IMR4350 since starting to use H4350 at least 15 years ago, with very similar results in both accuracy and velocity in cartridges from the .243 Winchester to .375 H&H.

The "way lower pressure" you noticed on the Hodgdon site is probably due to some loads being tested with copper-crusher rather than piezo-electronic equipment. CUP (Copper Units of Pressure) aren't the same as PSI (Pounds per Square Inch): 50,000 CUP is approximately equal to 60,000 PSI in most bolt-action cartridges.

I've killed a BUNCH of big game with loads using IMR4350, much of it in relatively cold weather, with no problems out to 300 yards or so. If you don't intend to shoot much farther I wouldn't worry about it much. But H4350 does result in more consistent velocities in cold weather, so leaves only the increased density of colder air as a factor consider on longer shots.

When I was experimenting with a 25/06, I could load a couple of grains more of H4350 than IMR4350. Some bullets grouped better with one powder over the other, you just have to shoot them to see.

I actually switched from imr 4350 to h4350 as a price and availability issue. And yeah, this was before the 6.5 Creedmore, and the swarm of guys who will use nothing else in it.

Nowadays I can find either A4350 or imr 4350 at least a couple of places that I frequent. But to use them I'd need to work up different loads. If I'm gonna work up new loads I wanna go forward rather than backwards. I wanna try the 4451 Enduron stuff.

Easy for a guy to overthink some of this stuff. Use what you can find, and enjoy the trigger time...

Worst powder that I've used for temp sensitivity is RL22. It's also THE most accurate powder i have found in a couple of rifles. Gotta say that I tend to stick on what works and don't care to experiment as much anymore. If I could find h4350 I'd never try the enduron stuff. Most of the newer generation powders just don't mean anything to me.

I shot imr 4350 in my 243 for years. A great powder. I had a poi change with this powder below 20 degrees,although some of it was due to denser,colder air. I switched to h4350 and did not notice the poi problem nearly as much.It really is temp resistant. Probably 3000 to 3500 rounds on these 2 powders,at all temperatures. Both are very accurate. If you are not hunting in really cold temps,you will never know the difference.

thanks. That makes me feel much better.

bugger, someone asked what cartridge and bullet. Care to fill us in? As for your question about H4350 being a "red headed stepchild", no it is not. It's damn good stuff. It's just hard as hell to find in these parts. I run across IMR4350 in every LGS I visit. My long time elk load used IMR4350 with a 250gr. pill. It worked wonders on elk. I develop loads in the winter time for my elk rifles, so temp sensitivity isn't an issue. Let us know what cartridge and bullet you intend to load up and we can help more...

I get as technical as the next shooter on the bench, but moving away from the bench and into the hunting fields, I think IMR 4350 will do everything you would ask H4350 to do. I like both powders and use both for me and others, but for my personal rifles, the IMR flavor has always shot a little better, so I use it. My 30/06 is a classic rifle, so I thought it would be cool to go with a classic load of 57 grains of IMR 4350 under a 165 grain bullet. It shoots well every time with no surprises. Here in the desert, I sight in as late in the fall as I can, but it's still 80 plus degrees much of the time. This past November, I took a mule deer on a morning that my truck read 16 degrees. I don't know if I lost velocity or not, and it was only a 200 yard shot, but that bullet landed exactly where I wanted it to go. That piece of brass went back in my pocket, and it will get some more IMR 4350. I say pick what shoots best, and go hunt.

Yeah, groups 1/4" smaller make a big difference on elk.

I'm in the same boat shooting IMR 4350 in both of my elk rifles. I sight in in rural San Diego County at about 4000 Ft of elevation and somewhere around 75 degrees. It will be close to 90 today. We hunt at 7800 Ft on average in Colorado at around 25 degrees any morning or evening.

One of my younger, very technical shooting friends who thinks you need a ballistic program to pull a trigger was terribly worried about the climatic differences. I explained to him that I'm the biggest source of inconsistency in the field shooting and that he was full of crap..... but feel free to run the numbers and let me know.

When he figured the difference it was .2 of an inch at 400 yards and I assured him that even though I've always thought my marksmanship is stellar - that I wiggle a heck of a lot more than that at 400 from a field rest. Last year at 550 yards my 2 shot group was middle of elk vitals with all that inconsistent powder, elevation, and barometric pressure working against me..... funny how those bullets keep hitting where the crosshairs meet hide.

FWIW, I went to CO and dropped a nice Mulie with a 270 and 52.0/IMR4350 under a 150 Partition. Seems that was max in that 700, 24" bbl. Range 275 yds, stopped just short of exiting the ham/hide after punched just to the side of the throat, head on.

Chrono'd 2850 mv - it was enough.......

Whatever you use, KNOW the POI/POA, and use a proper bullet.

No animal will know the difference.....

That said, in the 6.5s, alot of folks use "H" and it's reported to give about 75 more fps.

I found the difference in poi to be 1\2 m.o.a. at 200yds in the cold winter weather. This would make no difference to most big game hunters. It did make a difference to me, because that .5 at 200 grew dramatically on a coyote at 500 to 600yds. Enough to easily miss it.And since killing those little varmits is my job, I went to the more temp stable H4350. Air density is still an issue,but powder is not.

Yeah, that's the major advantage of cold-stable powders: You don't have to compensate for TWO effects of cold, just denser atmosphere.

On really cold days calling, I leave a couple of shells in my pants pocket. If I have to shoot a ways, I slide one of the warm ones in. Still have cold barrel, dense air, ect. Indecently, the leica geovid HD b s have been very accurate on giving me the correct clicks in extreme weather conditions,elevations,and angles. fww.

My first rifle in the early 60's was a Mauser 98 7.92x57. I only shot perhaps twenty rounds in it before the Sharon 6mm Remington arrived dad did the rebarrel and I bought a Herters C grade varmint stock. The IMR 4350 with 75 grain (both Speer and Sierra) bullets would shoot 1/4" groups. Thus the love affair with 6mm Remington and IMR 4350. Since then I've used that powder in many cartridges. I bought it in 8 lb containers.

I'm looking at 30-06 with Partitions for a cow elk tag in WY. I'm using lighter than normal (for me) bullets because I'm also loading for my son and I'm concerned on how he handles recoil. I will bring 3 ea 06's along. They all shoot under 1MOA with IMR 4350. When hunting out of state I normally bring a spare rifle. I often do so in state if away from home.

Since I live a little over 1,000 feet in elevation and am sighting in at 70 degrees. Plus, We will be hunting at tree line, perhaps 11,000 feet. At that elevation temperature could vary greatly, I think.

While shooting will likely be close range, I want to eliminate as much variables as possible. And in case I miss there's always "The sun got in my eyes and the rocks I was standing on moved about the same time as I was stung by something, and I heard a rattle that sounded like a timber rattler just behind me and...

Ive had better luck with IMR 4350 for 30-06 165 loads. H4350 seems to do better with 180's accuracy wise. IMR4831 for velocity behind the 180's.

The last time I hunted Elk in CO, it was close to Grandby, West side of the mountains just out of Rocky Mtn National Park. It was 45 below when I left camp opening morning.
That's 115 degrees below sighting in temperature. If it's that cold on this trip, I'm not going hiking to get where I want two hours before sunup.

I think that a lot of people over-think this temp thing. It might make a difference if you are shooting extreme range and small targets, but for normal ranges on large animals, it will be insignificant for the most part.

Sight in for 200 yards and hold in the upper third of the lungs out to 325 or so, and it won't matter if it drops a bit more.

I have killed a number of elk with loads that were supposedly temp sensitive and the elk rode home in the truck anyway.

The big problem isn't reduced velocity at 300 yards. Instead it's assuming the rifle will retain the same point of impact at ONE HUNDRED YARDS in really cold weather.

I have tested a bunch of rifles and loads at zero after sighting-in at "normal" temperatures, and they will shift POI significantly at 100--and there's no way to predict how it will change unless you try it.

One .30-06 shifted POI two inches UPWARD at zero after being sighted-in at 70 degrees--and by a not-so-odd coincidence was a load using a 165-grain bullet and IMR4350.

But if Bugger checks and, if necessary, checks the point of impact at 100 yards in what should be much cooler weather after he arrives, then he will indeed be easily good to go to 300.

"But if Bugger checks and, if necessary, checks the point of impact at 100 yards in what should be much cooler weather after he arrives, then he will indeed be easily good to go to 300."

Yes, it is the point of impact that I'm concerned about. Not the drop in velocity. The more variables a shooter can control the better, IMO.

I'll be checking POI the day or maybe two before opening day at location. I suspect/hope that no one including the elk won't care. However, I really hope the temperature behaves.

If I remember right my favorite load for my 338 is with IMR4350 too. That was my go-to elk rifle/load. As it turns out, even though I have had good opportunities to drop the hammer at 300 yards or so, I have not yet shot an elk at over 150 yards.

Having a less temperature sensitive powder makes sense in all hunting/shooting I think, even prairie dogs, because the temperature on the prairie may climb quite high and shooting a hot rifle on a hot day with the wrong powder is not a good thing.

Now if we (I) could get a famous writer to test loads at tree line with the temperatures on the south side of negative 20 degrees, then we'd (I'd) have it made...

Too late this year though.

Took the three 06's and shot H4350 57 grains and some factory second bullets to get the rifles close. As it turns out they were not to far off. These rifles have cheaper Leupolds -friction adjustments. 2 are 2x7 and one is 4x.

After adjusting two just a little bit I shot the following target. 2 shots from one and three from the other two. I'll load up some good bullets next.
t

This reminds me of the angst that is sometimes expended on the virtues, even the "virtual need", for controlled round feed rifles and then negating whatever reliability you gain from that by making ammo which may not chamber easily 100% of the time, or throwing some other problem at it.

I know various fillers, strengtheners, and stabilizers are added to synthetic stocks in the form of glass, carbon, and/or kevlar fibers, but synthetics... plastics, are notorious for expansion variances, often much greater than wood, with temperature changes.

Stocks have evolved. The very worst artificial stock that I know of was Reminfton nylon 66's stock. That would/could change poi by a foot in an hour if one side got wet.

Next was Remington's attempt with their center fire stocks which reminded me of sponge rubber. Not even good for a fire. I think they have come a long way.

The artificial material used for stock that I believe in is Kevlar. I believe, but I could be wrong there's little movement with that material.

As far as wood goes, not all different woods are created equal either. Though I prefer it to all artificial materials except I think Kevlar is near equal.

JB, is the change in POI due to the load itself, or as much in the stock as others are discussing? I was wondering this before reading the comments.

Very good point, and Great insurance on a hunt where you spend alot of time and money to get there, shoot the rifle on location before opening day....could prevent a lot of bad memories.

I suppose if the test is performed with the two powders in the same rifle the stock may be eliminated since it doesn't know which powder is burning.

I count myself fortunate or lucky. To the best of my memory, I've had Wby Fiberguard, Rem Syn, Win Syn, Ruger Syn, & Tikka Syn stocks. I can swear that NONE of them have shifted POI in temperatures from 80* down to 0* or even -4 & -8*.

Klik, I'm not trying to dispute/argue with you but this has been my real life experience. I'm not sure synthetic = plastic.


Jerry

Yeah, I don't believe it's the stock. Or at least I've never seen any evidence pointing in that direction in my rifles, whether the stocks are synthetic or wood.

Instead, I've noticed rifles that change 100-yard POI in cold weather are the same rifles that change POI with powder charges only a grain or two different when working up handloads. Usually they're rifles with relatively lightweight barrels.

However, have never seen 100-yard POI shift noticeably in any rifle when muzzle velocity changed less than 40 fps from 70 to zero. Of course, that doesn't mean it can't happen--but so far it hasn't happened in any of my tests. Which is one reason I'm pretty fond of cold-resistant powders for hunting here in Montana.

H4350 is almost universally preferred to the IMR version by the long range target guys for the reasons Mule Deer stated. I use it in my 6.5x47 Lapua behind a 142 matchking. The accuracy at 1000 yds is pretty incredible.

No one can really say without comparing them in your rifle, but I'd bet on H4350 outperforming IMR4350 any day. The loading manuals publishing "most accurate powder tested" is usually BS. It, like COAL, is rifle dependent & I wish they wouldn't publish it, it's misleading.

In short, use the H4350.

In a couple of .260s, a 6.5 Creed, and a 6.5x47 Lapua... I've seen virtually no difference between IMR4350 and H4350. Identical loads shot essentially identically in terms of accuracy, velocity, POA/POI, and temp sensitivity. I've shot 24 pounds of H4350 and about 10 lbs of IMR4350 in the past 4 years out of the above rifles, mostly with 123s but some 139/140s have been mixed in... and I shoot the exact same charge of each powder and very little changes.

I haven't seen velocity vary between the two powders more than about 30 fps...

I have't seen POI vary by more than about 1/2"...

I haven't seen accuracy degrade/improve by more than about 1/4" or so...

I haven't had any POA/POI issues in temps between 0-90 degrees...

I'm sure some guys can quantify the huge difference between the two powders... but I certainly can't. That's only over the course of about 5000 rounds of mid-size 6.5s though....

Dogshooter,

As I've mentioned a number of times before in various places, temp-resistance is to a certain extent cartridge dependent. Instead of testing IMR4350 and H4350 in several 6.5mm cartridges of similar case capacity, I've tested both in a wide variety of rounds from the .243 Winchester to .375 H&H. Have seen the velocity lost with IMR4350 from 70 to zero degrees range from very little to around 100 fps. (H4350 has remained consistent in all cartridges, usually losing less than 15 fps over the same temperature range.)

IMR4350 turned out to be very cold-resistant in the .375 H&H with 300-grain bullets, but it lost considerable velocity in the .30-06 with 165-grain bullets. In one particular .30-06, impact shifted a couple of inches at 100 yards from 70 to zero degrees--and overall that rifle tended to be very consistent in POI with widely varying loads.

In fact it would shoot full-power handloads with 165 and 200-grain bullets to so close to the same place at 70 degrees that I could use them interchangeably--as long as temperatures weren't too cold. But once the temperature dropped to near zero, the 165/IMR4350 load shifted POI two inches, and the 200-grain load did not. The powder in the 200-grain load was not IMR4350, but H4831.

I agree... different cases/bores will cause different results. I truly believe load density makes a huge difference in temp sensitivity... though I can't quantify that other than with empirical evidence.

I'm just saying in my application (6mm-6.5mm bores and .308ish size cases) they are virtually interchangeable. All of the loads are in the 90+% load density range... probably a coincidence... but I'll take it

That doesn't surprise me.

And my experience also tends to indicate that load density can make a difference. The IMR4350 load I use in my .375 H&H with 300-grain bullets is 80-81 grains, exactly how much depending on the lot, which DEFINITELY fills the case!

As scenarshooter pointed out recently on another thread on the same subject, you never know what any load will do at different temperatures until you test it at different temperatures.

Some 'plastics', like nylon, will absorb moisture which can cause dimensional changes. (Anyone who has used a nylon tent in rainy weather has seen the 'wilting' effect that moisture can cause.) I don't have any idea if the "Nylon" 66 actually used nylon or some other 'plastic' but it's quite possible that moisture affected its stability.

And I wasn't intending to cast aspersions on any and every synthetic stock, but simply pointing out the fact that it can be a factor to be aware of. There are many factors which are affected when temps get cold. 'Correcting' one might be somewhat helpful, but it really isn't a make-or-break factor if there are several others which trump it.

Klik -

Thnx for clarifying about all syn. stocks. Gotcha


Jerry

Klik - I may be wrong, but thought the Nylon 66, used Nylon bearings in the action for smooth lubricity....

I saw evidence of this load density and temp stability business years ago with IMR4831. It did better in the 270 than the 7 RM once temps got into the 0-10 degree range.

This was in the days before there was an internet so no one to really bounce it all off on. I stored it in memory and moved along.

The 'sensitivity' of powder can be some what negated by loading small batches of ammo, enough for a specific hunt. Consider the temperature range of the hunt and the most likely time of day that will produce a kill as temperature can vary through out the day.

For me I load hunting ammo that is most effective in the 32-45 degree range which is essentially 40 degrees. Most kills come in the first 2 hours of daylight and the last hour of daylight.

For targets consider historical temperatures for the time day and location of a match.

I think it was a polymer called Zytel, /www.google.ca/#q=zytel

Zytel was/is Dupont's trade name for type 66 nylon.

I suspect "Nylon" 66 was a better marketing name and choice than "Zytel" 66.

Little research - from what I can gather - seems it was the 66th R&D try which they settled on for the material. Used it in the stock and bearings inside the action. Has Moly D in the material.