just a thought

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bruno

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looking at the manuals, and thinking, the tests were shot with a 26"bbl, and my bro's is a 20" (270 win)
he is short of listed velocities by about 275 fps with IMR 4350, which makes sense to me.
do you think using a faster powder, maybe the fastest powder listed, would be more beneficial, as in get closer to the listed speed? IIRC, that powder used 15 less gr. and only 100 fps slower.
I was thinking this powder may end up giving me the same speed as IMR 4350 due to his short bbl.
will try to see how it shoots with the faster powder, but curious if my reasoning is sound?
 
140 gr hornady btsp
In my gun with a 22"bbl, i'm getting 2900, which i'm happy with, and i get it with IMR 4350, and w760, both are listed in the manual at 3000.
just thought the faster powder might get me the same vel. using less powder.
i guess i'll have to ry it, but i just thought i'd ask.
with 90 gr sierra's i'm still 10 fps slower than the manual in my gun, have'nt tried them in his yet, but will soon.
 
bruno said:
140 gr hornady btsp
In my gun with a 22"bbl, i'm getting 2900, which i'm happy with, and i get it with IMR 4350, and w760, both are listed in the manual at 3000.
just thought the faster powder might get me the same vel. using less powder.
i guess i'll have to ry it, but i just thought i'd ask.
with 90 gr sierra's i'm still 10 fps slower than the manual in my gun, have'nt tried them in his yet, but will soon.
Click to expand...

Hodgdon show's 53.2 gr. of IMR 4350 gave them 2916 fps as a max in their test rifle. - 51 000 CUP

Im not sure how much you have in your case but it would seem you are around max for that powder.

If you want to go faster maybe try a slower power like H 1000 .

check the hodgdon site for more info.

http://data. hodgdon.com/
 
Magnum primers ?

What kind of primers are you using ?
I have been using magnum primers for all my 270 loads with very good results.

In light of the fact that you are setting off a lot of powder, usually more than
50 grains, fast and hot ignition is important. Even more important in a shorter 20 inch barrel where you want complete powder burn for max velocity.

You might want to try magnum primers. But remember magnum primers are equivalent to 2 grains of powder so reduce your start powder charge and work up in half grain increment watching for pressure signs.

Big G
 
My 300 WBY has a 24" on it and the fastest(speed) listed powder which was a slow burner got me a speed the same as a 7mm. I switched to a faster burning powder, one not usually recomended, and the speed picked right up and accuracy was still good. 150 fps with 2gr less powder. And faster than my 7mm Whew!
So try different powders and you may be suprised.
 
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