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H4350 vs IMR4350 (Powder)

Just how much difference is there between the two?

It just doesn't seem probable that Thales would make a powder like H4350 that would vary much from IMR 4350, However one never knows, therefore the question?

Has anyone noticed any difference, or have information concerning the two powders?
 
I did some research on this when I was looking and not finding H4350. No firsthand experience but there is some literature way back when someone claimed that the two are in fact the same but more recently this appears to have been debunked. My understanding is IMR4350 is more temperature sensitive.

I ended up finding H4350 and so did not follow-up. Would be interested in what you find.
 
jlow said:
I did some research on this when I was looking and not finding H4350. No firsthand experience but there is some literature way back when someone claimed that the two are in fact the same but more recently this appears to have been debunked. My understanding is IMR4350 is more temperature sensitive.

I ended up finding H4350 and so did not follow-up. Would be interested in what you find.

Hi jlow, I've heard the same thing but have NO idea where the truth lies.
I would really appreciate any information anyone has on the subject.
 
I've used both powders in my 6XC and haven't noticed any over pressure problems with IMR4350 due to temperature. I'm running a pretty hot load so I would think I would see some evidence of high pressure if present. The load was developed in the spring when the temperature was between 45-50 deg. F. Both loads are within a 1/2 gr of one another for approximately the same velocity. I'm using IMR4350 at present due to its lower velocity spread.
 
jlow said:
I did some research on this when I was looking and not finding H4350. No firsthand experience but there is some literature way back when someone claimed that the two are in fact the same but more recently this appears to have been debunked.

They don't even look the same?

In overall burn rate they are sufficiently close that lot to lot variation is probably greater than the make to make burn rate. Doesn't mean they are interchangeable, just close.
 
For competition shooting the more important question would be is one as consistent as the other in a given cartridge loading. I know lots of people who have great success with the H version getting very consistent ES numbers. The question then is does the IMR (or AA for that matter) give the same consistent MVs, if not then the burn rates are academic.
 
PRS competitors. Data from Precision Rifle Blog...

"Hodgdon’s H4350 dominated the scene with almost 75% of the shooters using H4350. H4350 along with all of the other Hodgdon powders used are from their Extreme Series line. That means the Hodgdon Extreme Series Powders combined for a staggering 93% of powders used. All of the powders in that line have Hodgdon’s thermally desensitive coating technology, which has been proven to have significantly less temperature sensitivity and lot variation than other powders."


From...

http://precisionrifleblog.com/2013/09/28/precision-bullets-powders-what-the-pros-use/


Great website if your not familiar with it. Tons of good info, scope test, what the pros use, etc.



Dan
 
I've tried both H and IMR4350 in both my 6xc's and a 243 that I have. In the xc's there was literally no difference in speed or group size. In my 243 the H was just slightly more consistent on group size...... so I just stuck with the H4350.

From what other reliable shooters / reloaders have told me they DO see a difference..... so it might be a thought to try both in your rifle and see what it likes. JMHO :) WD
 
I can't remember the temp ranges used, but a user had the data posted on here not to long ago. In the two extremes temperatures that the used I believe IMR 4350 was like a 67fps change, H4350 was A LOT less but can't remember the exact number off hand.

I have been using IMR as I haven't been able to find and Hogdgon, the IMR manages tiny groups out of my 6XC still. :)
 
Danattherock said:

PRS competitors. Data from Precision Rifle Blog...

http://precisionrifleblog.com/2013/09/28/precision-bullets-powders-what-the-pros-use/


Great website if your not familiar with it. Tons of good info, scope test, what the pros use, etc.

Dan

Dan,
I happened to read the same article last week. I found it interesting but the first question that came to mind was: Who are the pros that Cal is talking about?

So I e-mailed Cal and asked him. He said that because of confidential reasons he couldn't give me any names. So, as another user here so aptly puts it in his signature: Don't believe everything you read on the internet - Mark Twain.

Changeling:
See http://forum.accurateshooter.com/index.php?topic=3810502.0

Kindest regards,

Joe
 
This is how QL list these powders,

Powder Name...........Burning Rate-(fast to slowest)
IMR 4350..................0.5150
Hodgdon H4350.......0.5130
Accurate 4350..........0.3810

Powder Name...........Heat of Explosion ( hot to cold)
Accurate 4350..........3790
IMR 4350..................3760
Hodgdon H4350.......3760

Powder Name...........Ratio of Heat to load volume (hot to cold)
IMR 4350..................1.2403
Hodgdon H4350.......1.2403
Accurate 4350..........1.2410


Tia,
Don
 
Remington and DuPont set up the ADI Mulwala explosives and Footscray ammunition plants during WW2 to assist Australia in manufacturing ammunition used in the South West Pacific operations theatre and thereby reduce shipping requirements of heavy loaded cartridges from the USA. Naturally, Mulwala made powders were in effect identical to those manufactured under the IMR name and used for the same purposes. Over the intervening years, the products have diverged due to R&D work, and both companies have changed ownership, IMR also moving north of the US / Canada border.

IMR and ADI / H versions of the same product number, eg 4350, 4831, 4895 do roughly the same jobs, but aren't the same things. Some are shown as having identical rates on burning speed charts, some vary slightly. The 4831s have the greatest difference inh this respect due to a historical accident. The early Hodgdon operation started with surplus US manufactured propellants, mostly DuPont IMR extruded grades, but the occasional Winchester Western ball type (Ball Lot-C manufactured for a British contract for .303 Mk7z ball, later more or less replicated as BL-C(2) for Hodgdon). When the surplus products ran out, Hodgdon had to find alternative manufacturers, and DuPont was opposed to supplying the handloading market at the time. Hodgdon went intially to ICI Nobel in Scotland and when that plant was closed, to the now privatised ADI. In each case, the remit was to make similar grades, so today's 4350 is two removes from that of the 1950s and might vary considerably. The 'accident' with the 4831s was that this was the last of the first generation of surplus numbers to run out and over the considerabler number of years that Hodgdon stored it, it gradually changed its moisture content and became slower burning. When Hodgdon then went to ICI Nobel, it asked for a slower burner than the still in US production fresh IMR version as handloaders would be confused and very likely run excessively high pressures by using pet loads worked up on the surplus stuff.

ADI / Thales has put a great deal of R&D into its Mulwala powders and the greatest advance for many handloaders as weell as military users is the temperature countering work. That's mainly why the H versions have become more popular, plus a lot of good marketing work by Hodgdon powder before it took on the same job for IMR (General Dynamics owned these days). ADI responded earlier to customer requests for shorter grain sizes to allow more consistent metering in both home and factory reloading. Also, VarGet hit an almost unique niche that guarantees excellent sales and excellent brand loyalty to the H. brand - IMR has had no direct equivalent. IMR now appears to be upping the ante - it likely has to as it's not recreational requirements that drive expensive R&D programmes here, more often military - and soldiers want complete temperature stability as well as very consistent charge weights in their ammo these days, so everybody's trying to catch up with Hodgdon, including IMR.

As all IMR grades are single-based types, they're mot particularly temperature affected anyway, but the new Enduron grades should cancel or at the least reduce the gap with ADI.

IMR-4895 is not faster burning than H4895 in most cartridges (Relative burning rate is variable according to application, not fixed.) In most mid sized cartridges, it allows the use of slightly higher charges and achieves higher MVs. It's also very flexible with a huge range of uses, and as such partuially compensates for ADI / H. having two useful grades in this bracket, 4895 and VarGet.
 
Laurie,
The latest Hodgdon Reloading Manual's cover features IMR's new Enduron powders, with separate articles inside for each - 4166, 4451, & 7977. I found the manual on the newsstand while buying groceries - after I'd purchased 18lbs of 4451. Turns out these new extruded powders are double-based, & are advertised as being very temperature stable, plus having an ingredient that's purported to reduce copper fouling.

I've been loading 4451 in a couple of 6x47s, along with using it in a new 6.5x47 & 260 Improved 30*, and have been very pleased with accuracy, velocity, & consistency in all three rounds. We had a warm spell earlier in February, so I was able to get out & do some chronographing while shooting at 600yds. On a day with a high of 82*F, the 4451 loads I'd worked up & chrono'd on a 42*F day were running within 2-3fps of the same speed, while the 123gr loads with 4007SSC were nearly 50fps faster in the heat. Didn't have any IMR4350 loads to compare, though I'm wishing I'd have worked a bit to have made that happen. I'd be very interested in finding out if IMR 4350 is more temp stable than IMR 4007SSC.
 
Turns out these new extruded powders are double-based, & are advertised as being very temperature stable, plus having an ingredient that's purported to reduce copper fouling.

That's interesting Dennis. It's the first time I've seen it said that they are 'high-energy' (added nitroglycerine) types. ADI's secret seems to be out of the bag though as several recent introductions are less temperature sensitive including double-based types (Belgium manufactured Ramshot is far less affected than other older ball types, again due to intensive R&D to meet military requirements.) I used to get the Hodgdon Annual Manual in the past, but haven't seen a copy for a couple of years now.

We've still to see the new IMR Enduron types in the UK - they'll arrive soon I'm told. Meanwhile we've recently got the Reload Swiss range from Nitrochemie Wimmins ag, a mixture of single-based and 'high-energy' types also sold to and branded as some of the recent Alliant introductions (Re17 = RS60 for instance) which are looking very good. H4350, H4831sc, and H. VarGet have arrived here over the last year but in such small quantities that they're sold out on the day they arrive in a gunshop. As a result, many people have become fed up with the Hodgdon / ADI situation and as the IMR equivalents have been promised in larger quantities have turned to them (and to competitors such as Ramshot which we get directly from Belgium). The two big problems / issues in this have been VarGet which has made its own niche and for the .284 / Shehane / 7mm short magnum shooting F-Classers 'shortcut' which again seems to suit that application so well that replacing it is difficult. The IMR4831 version is noticeably faster burning and just doesn't suit the 180gn bullet loads so perfectly. Reload Swiss RS52 has turned out to be a superb alternative to VarGet and Re15 (also short here) and usually gives higher MVs, but it is 'high energy' and may be more temperature affected (although temperature variations are much less of a problem here than in North America). It'll certainly reduce barrel life if the full performance increase is utilised (as per RS60/Re17 replacing H4350).
 
According to my research IMR 4831 was the original powder for the 20mm anti-aircraft round used on Navy ships prior to and during the first years of WWII before they switch to Bofor's type guns for AA.
 
Laurie,
Well, that's the word - from the horse's mouth, so to speak. Hodgdon's paid writers all three mentioned it in their individual reviews of the Enduron powders, which was quite a surprise to me, since I'd made the purchase of two 8lb jugs based on the results of load development with a single 1lb can of the stuff, and had no clue that the formulation included nitroglycerin. But so far at least, it's all good - 4451 is certainly less temp sensitive than 4007SSC, and at least in my rifles, produces a bit more velocity than IMR4350. A bit more time will tell more - I'm a bit concerned about bbl life, and would very much like to see 4451's flame temperature published. At this point in time, I'd guess it's very similar to that of any of the other 4350s, and will be a bit harder on throats than cooler burning numbers like Viht's N160 & 165.
 
Here is my 12/19/14 response to the H4350 vs IMR 4350 question. For me, they are readily interchangeable.

Reloading Forum (All Calibers) / Re: Differences between H 4350 and IMR 4350
« on: 10:06 PM, 12/19/14 »
My results mimic those of M99.

"Oak Ridge. Late Sunday afternoon 11-09-14. Sunny. Twitchy 0-4 mph wind. Low 60's. 600 yards from bench. Did not hold outside x ring to compensate for wind.

30-06.

32" Bartlein cut with Manson reamer. Barnard action. Ten times fired Lapua Brass (pockets still tight). Tula primers. 215 Berger hybrids .012 into lands.

15 shots H4350 followed by 5 shots with IMR4350. 53 grains for both.

H4350...2 sighters, then one 9, 2 tens, 10 x's.

IMR4350...one 10, 4 x's.

This was the first time I had tried the IMR. For same volume out of my powder dispenser as the Hodgdon, it weighed about 3 grains less, thus filled the case more to bring it up to 53 grains.

I trashed the brass that shot the 9."

I should add that while bullets loaded with the same weight of the 2 powders shot to the same point of impact at 600 yards, they are definitely different powders....and are very different in grain size and color. My rifle is happy with both of them.

Frank B.......
 
When I first received my 6.5-284, 8-10 years ago I had both IMR 4831 and Hodgdon 4381. I tested both and the IMR shot better. After all the reading I had done about how much superior the H4831 was I surprised that it wasn't.
 
Tagging in here, just to get some more views on this new powder and the old IMR, which I use in my 06 pushing 190 smks to 1k plus.

The "Pro" are really people that compete for money, some use weapons as part of their job I would guess most dont they just compete, and 90% are probably on this forum.
 

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