6.5x47 : IMR 4350 or H4350

[gtl1946]

I know the two are not the same but why do people use the H series of powders over the IMR series in this cartridge ? Is the IMR 4350 just a "non working" powder choice ?

 

[ShootDots]

The IMR "series" of powders are excellent powders. However, all but one (IMR 8208 XBR) are not "EXTREME" powders. Which means they are a bit more temperature sensitive to changes in temps. Example: This past Saturday I went to Beaumont, Texas for a 600 yard F-Class shoot. When we arrived it was 26degrees! By the time we finished at 12:30 it was approaching 70degrees. This is where the "extreme" line of powders shine. Having said that, there are some "non-extreme" IMR powders that are "pretty stable" temp wise if not pushed to the ragged edge. Of those, IMR 4895, IMR 4320, IMR 4007 and IMR 7828 are decent in temp swings. Ball powders, generally speaking, are VERY temp sensitive, although the "Western Powders" I.E. Ramshot, are supposed to be "extreme" as it were. But as far as "shootability" or accuracy etc.. the IMR powders are every bit as good as the Hodgdon powders that are your "H" powders and the producers of the extreme line of powders. I hope this clears things up a bit..

 

[schumi]

ShootDots, Thanks for the very thorough info. I always wondered the same thing.

 

[stubbicatt]

Too IIRC the granules of the H4350 are not those long twigs as with the IMR offering, so in theory you can get more in the case, as in the "case" of the 6.5x47 the limiting factor on velocity with that powder choice is case capacity, not pressure.

--Or at least that's what I have read on the internet!

 

[Syncrowave]

That's interesting stuff, ShootDots. Do you know what the "EXTREME" designation refers to, be it a coating and/or granule size/shape/perforation?

Just curious what differentiates "EXTREME" from non-extreme powders, if anything other than performance.

 

[ShootDots]

That's interesting stuff, ShootDots. Do you know what the "EXTREME" designation refers to, be it a coating and/or granule size/shape/perforation?

Just curious what differentiates "EXTREME" from non-extreme powders, if anything other than performance.

I surely do not Syncro... All I know is that it is Hodgdon's "designation" for the property of "temperature stabilization". I use it as a general reference to powder temp stability and apply that "esoteric lingo" to all powders that are stable like IMR 8208 XBR... LOL!!!

 

[stacy]

Nothing but H4350 out of my 6.5x47 130gr VLD'S Hunting Bergers

 

[Mega]

That's interesting stuff, ShootDots. Do you know what the "EXTREME" designation refers to, be it a coating and/or granule size/shape/perforation?

Just curious what differentiates "EXTREME" from non-extreme powders, if anything other than performance.

I surely do not Syncro... All I know is that it is Hodgdon's "designation" for the property of "temperature stabilization". I use it as a general reference to powder temp stability and apply that "esoteric lingo" to all powders that are stable like IMR 8208 XBR... LOL!!!

I think you will find that the word "Extreme" is just a name that Hodgdon came up with to describe the series of Single Base Powders that are manufactured here in Australia by Thales (ADI or Australian Defence Industries) that have always been very temperature stable compared to other manufactured single base and especially double base powders. Way back the main interest was to produce the best smokeless powder for our military use in all conditions. Someone over the big pond of water discovered our secret and wanted some....the rest is history. Now the whole show is owned by the French, enough said.

Hodgdon do not produce these powders and never have. They simply import them from Australia in bulk and then re-label them in their own small container to suit your local market. In fact you pay less for the entire range than we do.

Hodgdon also do all the load testing and data collection and supply the information back to ADI who produce their own reloading manual available on-line. The only testing done by Thales here in Oz is for a new batch of production to confirm it complies with the standards of the previous batch / production run. All the paper pulp used to manufacture the smokeless range of powders is imported from Europe.

You will find all the details on the Hodgdon Web Site under Products - MSDS information sheets.