Reloading velocity issue: I can't figure that one out!!!

Hi All,

This is the situation: I'm reloading for a 243Win and I use H4350 and some 70g Nolser and 100g Sierra.

I use 40g of H4350 for the 100g and I get a velocity of around 2930fps. Exactly what the book tells me....
I use 43, 44 and 45g of H4350 for the 70g and I get roughly 2450fps/2600fps/2700fps, so almost 800fps less than the book.

I also shot at paper around 300+ yards and the 70g was dropping much much more than what it should so I think the chronograph is not the cause.

I measured the diameter and weight of the bullet, all good.
I used the same primer, shell, measuring gauge and all......

Anyone as an idea on this matter?
Thanks

That powder isn't listed in Hodgdon manual for 243....

You sure that is the right powder you are supposed to used for 70 grain pills?

Does not seem suitable.

Quote:

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Originally Posted by Big Jack

That powder isn't listed in Hodgdon manual for 243....

You sure that is the right powder you are supposed to used for 70 grain pills?

Does not seem suitable.

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Correct but it's in there and other load data book.

https://load-data.nosler.com/load-data/243-winchester/

See attached:
Attachment 35326

It could be your barrel isn't as long as test barrel and powder may not be burning completely

Quote:

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Originally Posted by Big Jack

It could be your barrel isn't as long as test barrel and powder may not be burning completely

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Good point but my barel is 22", 2" shorter than the rifle used for the test, and 1" of barrel length is roughly 50fps. Also, load with the 100g was also with a barrel 2" longer and velocity was really close from the one published.

Please, keep them coming as I really want to figure it out.
Thanks

Pressure builds quicker in barrels as projectile weight increases. Land grove diameter verses bullet diameter also plays a huge part.

Try a different powder.

Varaget.

Varget

My 223 loves CFE 223 and works well in 30-30 as well.