[nigonjac]

At a local shop the other day, and noticed they had some powder in stock. I usually use IMR4350 for my 270 Winchester, but am currently down to about a 1/4 pound left and haven’t seen any on the shelves for months. I saw they had IMR4955 and figured I’d give it a try. Does anyone have any personal experience with 4955 and loading for a 270 Winchester? Looking to work up a load with the Hornady 130 grain SST. Hornady does not list this powder in their manual, I contacted them and they said they have not tested with it-yet. I checked the Sierra manual for their 130 SPBT, and they have it listed with 45 minimum and 54.8 max as the extremes. Hodgdon has it listed as 55.8 minimum and 61.0 max compressed. I contacted Hodgdon about the rather large discrepancy and the only thing they sent back to me was was the load data I already had from their website. No explanation as to why data could be so different. I understand powder/bullet companies generally aren’t the same as far as published loads, but they generally are close. This does not seem to be the case with this powder which has me concerned as to where to even start safely. There are some conflicting reviews online which doesn’t help either. Hoping some of you may have experience with the 4955 “enduron” powder.
Would be using Winchester cases and CCI 250 primers.

Thanks,

 

[GSP7]

Never heard of it..... But Id use it, after I looked it up and read about it

IMR Enduron® 4955

IMR Enduron 4955 is a versatile, match-grade propellant with a mid-range burn speed that is in between IMR4451 and IMR7977. It is an extruded powder and provides top performance for big game cartridges like 25-06, 270 Winchester, 280 Remington and 300 Win Mag, among other cartridges. The main...

shop.hodgdon.com

This propellant performs comparably to Hodgdon H4831 but charge weights are materially different.

 

[jimboro]

. I wouldn't do this without a croni though. .. I hope you know how to read pressure signs. . If not .. learn to .. read up on it .. before you load anything. . ..but as always start low ..

 

[MikeG]

Wow, never heard of it, another "powder of the week." Good luck......

 

[Darkker]

Essentially all extruded powders had a few ingredients, which are reported as being less healthy than Kale.😉 In order to be able to sell to markets across the globe such as ball powders can; those ingredients had to go.
So General Dynamics rebuilt the extruded facility in Quebec for the change. "Enduron" is the buzz word Hodgdon markets those new formulation products under.

Cheers

 

[GSP7]

Huh ?

 

[Darkker]

What would you like clarified, the ingredients?

The removed products were:
2,4 Dinitrotoluene
Dibutyl Phthalate

The mover behind it is the EU and a CE certification stemming from the REACH program.


Nigonjac:
To your original question about the discrepancy. I wasn't aware of Sierra having done actual pressure testing in quite some time. Be interesting to know if this is calculated or what.

No it's not unthinkable for them(Hodg) to have some serious lot variations, especially given what was happening during the GD plant rebuild. But that is a bit excessive, so I suspect it's a calculation Vs testing issue.

Cheers

 

[unclenick]

I think Sierra has their max loads tested to be sure they don't exceed SAAMI numbers, but the loads themselves are developed in production guns and they don't change them if the pressure test comes out on the low side. These sorts of discrepancies are not uncommon among load manuals.

 

[recoil junky]

I think I'll stick with H4350, I have about 12 pounds left between one opened and one "sealed" 8 pounder. 😉

RJ

 

[MikeG]

Yes, I toured the Sierra plant a few years ago including the underground firing tunnel. Fascinating.

Was told that they work up loads, then send the max ones off to be pressure tested somewhere.

Their test guns were production receivers, with a heavy barrel that gets clamped into some sort of fixture.

 

[nigonjac]

After talking with Sierra they strongly recommended starting at 50 grains and working up. Said they used multiple lots of the stuff along with different barrels/brass/primers. I will start there and report back when I get a chance to have a nice range day.