# h4350 vs imr4350



## TomCat3367 (Dec 11, 2008)

Hello to all. I am currently using a Sierra Manual that does not list H4350 only imr 4350. I realize it is not the latest manual and plan to get updates. I have been using 52gr with 100gr bullets with great success in my 25-06. IMR has been hard to get here recently so I purchased H4350. Does anyone know if 52gr load will exceed the safe load for this powder?


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## ac700wildcat (Oct 30, 2006)

From my modern reloading book:

100 grain jacketed bullet

imr4350 start load 47.2gr @ 2934fps max load 53.5gr @ 3290fps 52900psi
h4350 start load 47.0gr @ 3038fps max load 50.0gr @ 3155fps 61217psi


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## ac700wildcat (Oct 30, 2006)

From my nosler manual:

H4350 start load 49.5gr @ 2968fps max load 53.5gr @ 3318fps
imr4350 start load 47.0gr @ 3142fps max load 51.0gr @ 3352fps

Quite a difference between the two manuals. I'd definately work up a new load if you are going to switch powders. You should never use data from one powder to load with another. Even if the powders have the same numbers like the h4350 and imr4350 do, they still have different burn rates and create different pressures.


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## TomCat3367 (Dec 11, 2008)

Thank you for your information and can see some confusion as to which manuel to believe. One shows 50gr as max and one says 53.5gr. I guess the 10% safety factor may apply as well as different test rifles. It would probably be safer to pull the bulletts and start over. Thank you again.


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## darkgael (Feb 10, 2006)

"One shows 50gr as max and one says 53.5gr."
To which manuals are you referring? For which powder?
Pete


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## Hunter_58346 (May 22, 2003)

100 GR. NOS PART Hodgdon H4350 .257" 3.200" 47.0 3038 47,800 CUP 50.0 3155 51,500 CUP

100 GR. NOS PART IMR IMR 4350 .257" 3.200" 48.0 2975 43,200 CUP 52.8 3257 51,200 CUP

This is from Hodgdons web site. A thing to remember is that just because a bullet is 100 grains, id doesnt mean that the same charge can be used for a different company's 100 grain bullet.


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## darkgael (Feb 10, 2006)

Oh. I thought the reference was to a three grain difference in max for *the same powder* and the same bullet in two manuals.
Pete


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## Savage260 (Oct 21, 2007)

The new Sierra book shows H4350EXT and 100gr Sierra bullets at min 45.0gr and max 54.0gr.

The IMR4350 shows 44.0gr and 53.0gr.


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## dakotashooter2 (Oct 31, 2003)

Starting over would probably be a good idea. Another factor to keep in mind is that the current H4350 is a powder developed to be less temperature sensitive than the IMR 4350. A good thing here in ND where you might be shooting prarie dogs on a 100 degree day or deer hunting at -20.


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## Csquared (Sep 5, 2006)

I'm surprised to see some info showing the two as close as they do. My experience with each in a '06 case has shown much more of a difference. I had pressure signs well before I reached optimum velocity with the IMR, but not with Hodgdon's.

Have you tried AA-3100 with 100gr bullets in your .25? I always used IMR-4831 until I stumbled across the 3100. Pretty amazing stuff!


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## TomCat3367 (Dec 11, 2008)

Thank you all for your comments and advise. I have only used 4350 and 4831 in IMR until now. The 52gr of 4350 with 100 gr speer hot-core has proven to be the most accurate and effective. My rifle does notlike nos part bullets as they are all over the place. I did break down and test fire some of the H4350 in 52gr and it was great. It showed no pressure signs and held a very good pattern. I must have gotten lucky this time but will upgrade my manual or buy a newer Sierra manual that has the current powders in it. What loads have you guys been most happy with for the 25? 
Tom


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## Csquared (Sep 5, 2006)

Never heard of a rifle that wouldn't shoot Partitions, so that's a first for me. My gunsmith sort of cringes when I judge his work by how well it shoots them, but as far as I'm concerned a hunting rifle should be judged by how it shoots hunting bullets, and neither him nor Nosler has failed me yet.

I use IMR-4831 in a 24" barrel and AA-3100 in my 22" barrel with 100grs, as stated, and IMR-4350 with 120gr Partitions. I get just a fuzz over 3000 fps in my 22" barrel with the 120's.

There have been several new slow burning powders introduced over the last few years and I haven't kept up with them in my 25's so my info may be somewhat dated, but 4350 is a very useful burn rate, and I could, if needed, load for most of my rifles with only that powder.

Have fun!

:beer:


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## TomCat3367 (Dec 11, 2008)

I am not really sure why it does not like the partitions. I at first thought it may be me so I had my son shoot them with a gun vise and he agreed that they were not very consistent. It is a shame because I have a couple of boxes of them and some loaded up and hesitant to take them hunting. Maybe it is the load I am trying to use. It is the same as the others that shoot well. I never experimented much with it due to the high cost of the bulletts. Thanks for sharing your information.
Tom


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## Savage260 (Oct 21, 2007)

If you like the partitions don't give up on them. I have talked to quite a few people that only try 3-4 loads then move on. I think that is crazy. If you want to use a certain bullet, but it isn't grouping up to your standards keep trying. Different powders, seating depths, grains of powder. If they still don't work then maybe look at changing bullets, or try it all again with a different primer. I went through a couple hundred rounds with my 25-06 before I found a good load with the 100gr Barnes TSX. I am very glad I didn't give up.


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## bwnelson (Oct 29, 2002)

Congrats on finding a good load.

FWIW and future reference, H4350 is slower burning than IMR4350 and can be substituted grain for grain in place of the IMR as a starting point and can usually be worked up to a higher charge but may not give as much top end velocity on a warm day. The greater temp sensitivity of the IMR formula usually ends up to approximately equal Hodgdon velocities during North Dakota/Minnesota November weather.

DO NOT sub IMR4350 for H4350 on a grain for grain basis. IMR is hotter.


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