Just how close are the two 4350's (IMR asnd H) to each other? To hear some folks talk they are practially interchangeable. Others are of the opinion that the IMR tends to be a touch faster that the H and loads with it should be reduced slightly. It also seems to me that more peole favor the H version over the IMR. Maybe just more lot to lot variations than anything. What is the opinion of the reloaders here on AR?

I have some of each to test in a Remmy .270 with a Hart barrel, and will see what falls out from that, but was just curious what others experiences were.

JTP, I think you'll find the Imr to be more than a touch fasted burning. Both of them have worked for me, but I have not and will not use loads for one in the other or vice versa. I've always loaded my 270 w/ Imr 4831. I think you might like the H4350 better due to it's slower burn rate. As one of Hodgdon's extreme powders,it's supposed to be temperature insensitive also.

How much faster? Roughly a grain or so, or more than that? So far, it seems I am seeing the node with IMR about a grain below where I would expect it to be with the H, but my data needs to be refined better. Those were just initial impressions.

+1 to IMR being faster and not interchanging them without stepping down a bit.

The Hodgdon manual, which I printed online, shows 130g Hornady sp---55g Imr4350, 54.3g H4350
140g Sft sp-------53.2g Imr4350, 52g H4350
150g Horn sp------51.6 IMR4350, 49g H4350

24" barrel, win brass & primers

quote:

The Hodgdon manual, which I printed online, shows 130g Hornady sp---55g Imr4350, 54.3g H4350
140g Sft sp-------53.2g Imr4350, 52g H4350
150g Horn sp------51.6 IMR4350, 49g H4350

That would indicate H4350 was the faster powder.

alive in cc: I saw that data, it was one of the things that sparked this thread, as I believe that is backwards from nearly everything I have ever heard. I'm going to have to look at my other manuals tonight and see what they say.

Go look at the data on that same site for the 30-06. The 150 BT looks right, but then you go to the 165 and it is flipped again. Plus some of that data has a C behind it which I believe means it was calculated, not actually tested.

IDK, their data looks kind of squirrely to me.

Based on the numbers, I agree.I concentrated on typing the numbers correctly and did not snap. I reverified and I typed them correctly. This is from the 2008 manual. The Hodgdon website currently has similar numbers, but does list the same amount of I or H for the 135g Sierra bullet. I'll look at the old free paperback manuals that I have from 1995 for the Hodgdon data and an older Imr paper manual. I wonder if things may have changed some when Hodgdon acquired the Imr line?

JTP, I think the "c" indicates that it is a compressed load.

I've always found IMR4350 slightly faster, it appears on burn rate charts that way too, but the current Hogdon data seems to conradict that, depending on caliber (30-06 or 338wm).

Ahh, I'll buy that on the "C".

Using several 30-06s, my standard load is 57grs of IMR4350 behind a 165gr bullet.
If I'm using H4350, I go to 59grs of powder to acchieve the same results.
The general opinions, right along, has been that you needed a couple more grains of H4350 to do the same work as IMR4350.
I bought a 8#er of both several years ago, and so, haven't bought any for a while. They may have changed the H4350, I don't know, but according to the numbers posted in here, that would be a 4-5gr swing from what usta be and what is. That's a lot.

I'm seen people take what was a max load of H4350 and replace it with IMR 4350. The result was blown primers....so the difference is significant.

On my burn rate chart the IMR-4350, H-4350 and AA-4350 are in a row which indicates nothing at all.

When we throw in the AA-4350 to the discussion it really makes me wonder.....

I have no information that these three powders are identical....to the contrary, Hodgdon does not show loading data identical as they do H-414 and Win-760 so I'm assuming that they are not the same.....Until it is proven they are not identical, they must be loaded using separate loading data.....I wish they would change the name of two of the powders as it just confuses folks!

A lot of this goes back to when everybody was selling milsup powder (how Hodgden got their start) Back then 4895 was 4895 regardless of who was selling it cause it all came from the same place.
Only when they started new manufacture of say 4895 and 4350 etc did the differences occur.

I agree with Vapo on this one. Since I have been loading for quite a while, I have always used the "IMR" offerings of whatever. I see no advantage to having a "bunch" of various powders, with the same name, and different specifications. I wonder if Hodgon, will eventually change and standardize the powders?

Jerry

ive seen as much lot to lot variation of the same brand as ive seen between the differnt brands.

Lloyd: Funny thing, in my experience, the only powder, with which I have had any lot variations, at least that were significant, were with IMR4895. IMR 4350, 4064,and 3031, I am using the same loads and data I did in the 70's. Groups and velocities remain about the same.

Jerry

From the information I have seen, IMR and AA are exactly the same powder with different packaging. My AA manual even says it is identical in every way, as is the 4064 versions. (It is an older version, but I read it again recently, in Handloader I believe)

H4350 is a different story.

In my 7mag,65.3grs of IMR-4350 gives me 3225fps with a 140gr bullet.That same charge of H-4350 and a 140gr bullet,gives me 3060fps.So yes,I'd say there is quite a difference.

In a 1982 American Rifleman that I have, in the Hodgdon ad for the powder, they state that H4350 is identical to IMR4350. What ever it is now, they sold the stuff as being a cheaper version of IMR 4350.

I have a lot of H4350 from the 80's. It takes one grain more of H4350 to reach the same velocities than IMR 4350 in 30-06. That is probably within the tolerances of the manufacturing process.

The manufacturing process is highly varible. Then powders are blended, but within tolerances. Lot to lot variations provide the illusion that powders are different when infact they are the same.

Look at old data for HP38/W231, H110/W296. These powders have always been the same and yet reloading manuals show different pressures for same loads.

Lot to lot variations.

Of course the manufacturer is free to change the formulation, pressure curve, anything. That is why it is best to use the data that was new when that lot was new.

I have AA-4350 and H-4350 as well as IMR 4831 and H-4831. My particular 8# keg of AA-4350 is much slower than H-4350. It almost as slow as the IMR-4831 that I have. I usually have to use about 2 grains more of the AA-4350 than I do of the H-4350.

quote:

Originally posted by JTPinTX:
alive in cc: I saw that data, it was one of the things that sparked this thread, as I believe that is backwards from nearly everything I have ever heard. I'm going to have to look at my other manuals tonight and see what they say.

Go look at the data on that same site for the 30-06. The 150 BT looks right, but then you go to the 165 and it is flipped again. Plus some of that data has a C behind it which I believe means it was calculated, not actually tested.

IDK, their data looks kind of squirrely to me.

It`s been reported often that powders can flip flop in burn between different cartridges. The 30-06 and 270 win (IMR-H)4350 data on Hodgdons site appears to back this claim.
I`m not sure what the reason is for the switching of the burn rate but recommend one stays with the data for that cartridge and components.
BTW I`ve never noticed much if any difference in the two powders as far as temp resistance or consistency of burn from lot to lot in my rifles. Both powders perform well within their range and results are very similar

ADI AR2209 powder is marketed in the USA as H4350.
The ADI published powder equivalent chart shows AR2209 on the same line as H4350 and IMR4350.
In my 7mm-08 I load the same charge weight of AR2209 as Sierra publish for IMR4350 with their 140gr SPBT bullets and achieve the same velocity as they publish. So load for load with this particular bullet in the 7mm-08 AR2209 (H4350) appears the exact equivalent of IMR4350.

I have also read that where once the original H4831 was slower than IMR4831, the newer produced H4831 is much closer to or perhaps the same as IMR4831.
I think similarly ADI produced AR2213 is also marketed as H4831.
AR2208 is definitely marketed as Varget in the States.

Maybe because the Aussie company ADI is producing powders for Hodgdon, they have deliberately manufactured them with the same characteristics as IMR like numbered powders to avoid the confusion and potential problems reloaders have faced over the years. Certainly would seem the logical approach.

quote:

Maybe because the Aussie company ADI is producing powders for Hodgdon, they have deliberately manufactured them with the same characteristics as IMR like numbered powders to avoid the confusion and potential problems reloaders have faced over the years. Certainly would seem the logical approach.

Making a powder hotter then it's been over the last 60 years with out ample warning sounds like a good way to blow gas into the face of your customers, and maybe get sued.

Joe, I have heard that as well, about powders flopping burn rates due to varying applications.

It is looking like to me, in my particular lots, that the IMR is noticeably faster than the H version. It may be a few days, but when I get some firm numbers I will post it up. I appreciate all the input on the subject.

Years back I used to call Accurate Arms a fair amount, looking for specific information. I asked one of their techs about the difference between their powders and some of the others with the same numbers, and specifically about their AA3100. I was told that the Accurate Powders are one grain slower than the IMR powders with the same number, and that AA 3100 is the same as IMR 4831, with the exception that IMR powders are nitrocellulose based and the AA powders are nitrocotton based. But the 3100 was one grain slower than IMR 4831.

Based on that information, I went from 59 grains of IMR 4831 to 60 grains of AA 3100 behind a 130-grain Speer GS in my BDL 270 Winchester. I saw no POI change, difference in bolt lift, primer appearance, or anything else. I have since used the AA 4350 and 4064, and have the same experience.

Just my $.02...

IMR-4350 was my go-to powder for 40 years. About 5 years ago I got a chronograph and did an experiment with IMR-4350 and H-4350 in different rifles.

I found H-4350 gave higher velocity at max pressure and much lower "extreme spread." H-4350 is my new go-to powder.

quote:

Originally posted by armadillo:
IMR-4350 was my go-to powder for 40 years. About 5 years ago I got a chronograph and did an experiment with IMR-4350 and H-4350 in different rifles.

I found H-4350 gave higher velocity at max pressure and much lower "extreme spread." H-4350 is my new go-to powder.

All my 4350 is now Hodgdon as well

Seems like Sierra'a latest book shows XMR4350 as fastest, IMR as 2nd and H as slowest.

I like XMR4350 and Accurate's 4064 just fine

FOOD FOR THOUGHT
From the 1985 Gun Digest, Dean Grennell reported that the 24th edition of the Hodgdon Manual carried a complete listing of loads for their H4350. Dean goes on to state that as it turns out H4350 is rated slightly faster in burning rate than IMR4350.

He then also cites “but one example”; In the 300 Win Mag 74.0grs H4350 is the listed maximum charge with a 150gr bullet for 3244fps at 53,000CUP. According to Dupont’s recommendations 76.0grs IMR4350 in the same load puts out 3335fps at 53,900CUP.
Prior to the publication of Hodgdon’s H4350 data, says Dean, this powder was dispensed in loads recommended for IMR4350.

Of course if H4350 was slower than IMR4350 as we seem to know it today, this would be correct and perfectly safe. Maybe H4350 was faster back then or did Dean get completely mixed up and confuse the two 4350s in his writings, transposing one for the other.

As I posted earlier in this thread I do know that I can use AR2209 (sold as H4350 in the USA) in identical charge weights published for IMR4350 and for that matter I’ve used Nobels No 0 powder in the same charge weights for the same velocity and pressure indications (in the 7mm-08 anyway).

I treat the two as different powders when working up loads, starting low and working up.
Invariably, one of the two will shoot more accurately than the other as a result of testing.