.243 win and h4350 questions!

[Savagebien]

Hey i recently ordered some h4350 and have found conflicting load data... for example for the 107gr smk sierra says max is 39.6gr of h4350 ext.... and hodgdon says that the max for that bullet/ the hornady 105amax which i shoot is 37.5gr of h4350..... is there some difference in the ext and just the h4350? i cant find where they make 2 different h4350's.... whats the deal just one more conservative? sierra and hodgdon match max amounts, or very close for imr4350 and those bullets... what gives?

 

[lever-hed]

I think the 'ext' stands for extruded, no difference, Both the same powders. However, the main diff is in your bullet style and weight as tested.
Just cuz the bullet style and weight are close dont assume, each manufr tests under their own procedures and there is a diff science for each mfr .

 

[Savagebien]

thanks i'll go with the hodgdon 105amax data!

 

[Winchester 69]

... is there some difference in the ext and just the h4350? I cant find where they make 2 different h4350's....

Extreme. Indicates less sensitivity to temperature extremes. No difference in load data. Hodgdon re-formulated several of their powders several years back and labeled them "extreme."

 

[johnnyk]

Savagebien,
The reason there are differences in the data is there are differences in the bullet metallurgy and differences in chambers and barrels. Some bulets are harder than others and some rifles reach max pressure sooner than others. Make sense?
When I have conflicting load data like you're seeing, I average the two out (39.6 + 37.5 = 77.1 / 2 = 38.55). I then take this number and reduce it by 10% (34.70), then I have my max and min load 38.5 - 34.7gn. This has worked for me in the past. JohnnyK.

 

[Alaska Dave]

Doubt if this is much help but with the 105's in my rifle 41 gr. IMR4350 is impressing me Dave

 

[Clark]

43 gr H4350 100 gr HNDY RN jammed into the lands has a threshold of long brass life at 43 gr.
24" barrel 2975 fps

 

[Junkyard220]

I have a question as well just piggy backing on this question.

Barrel 26" Mcgowen Barrel

.243win
I am running 41.5gr H4350
Lapua Brass
107SMK
CCI BR2 primers
2.950OAL

400Ft ASL of evelvation
91deg F
71% humidity
29.62 HG pressure


i should be getting 2900+ FPS according to a reloading guide and several other sources. But my DOPE says other wise , i was shooting this past weekend ZEROed the rifle with a 300yard zero. my program stated that i need 8MOA give or take to get out to 600yard. Atmosphere conditions taken into account.Now real life i was more like 11MOA to get from 300 to 600. i dont know what is the issue with the load not pushing 2900FPS. ANyone have thoughts at all on this?

 

[243Lapua]

I used 40.5 - 40.6 grs of 4350. With no issues. Excellent load with 105vld and 107 SMK, in a 243win that gun)i have.