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More powder less FPS???
Posted by DT400 on September 28, 2015 at 11:01 pmOK this seems pretty backwards.
Stats
New Tikka T3 Lite 30-06 shoots very accurately
Nosler Accubond 180 gr
Hodgen Superformance58.5 gr 2814 fps
59.0 gr 2794 fps
59.5 gr 2771 fpsThe only thing I can think of is there is too much of this slow burning powder and the extra powder is actually hurting the burn rate sort of like running a gas engine too rich.
That's my only idea.
Has anyone experienced this before? Any explanation?Thanks
Darrell
Jason_McHann replied 8 years, 6 months ago 3 Members · 3 Replies -
3 Replies
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1 Bullseye
How long is the barrel? It's also only 43 fps and not much sample size provided. How many at each charge weight did you chrono?
You're on the right track with the burn rate making a difference though, if the bullet's already exited the barrel while the powder is still burning because there was more of it to burn, then you'd lose speed. A lighter charge in the same space means there's more room for the existing powder to burn.
Of course, I'm not a ballistician, and don't know the sorcery involved.
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1 Bullseye
It's a Tikka T-3 lite stainless with the 22″ fluted barrel. Can't find it on the Tikka site for some reason.
EDIT it is a “Superlite” not just “Lite” A Sportsmans Warehouse (where I bought it) special.
Sample size is about as small as you could get…it was the last round left over from doing group checking…1 round of each powder weight was used for the fps test. Granted it was small but a definite fairly linear drop in fps as the powder weight went up.
If I had had a 26″ barrel maybe the results would have been different.
Nice thing is the lowest powder weight giving the highest fps also gave the best group of .4″ @ 100 yds.
Really liking the Superformance so far. Since it is slow burning it seems to give lower recoil while still giving high speed and accuracy. The low recoil is nice in a gun that, in hunting trim (gun, scope, sling), weights 7lbs 2 oz…
Darrell
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15 Bullseyes
DT
I had this happen doing load development for my 270WSM. There is a point in which the densely packed powder cannot burn efficiently. If oxygen cannot readily get to the powder, you actually slow the burn.
In a longer barrel, there is time to equalize this issue. But in a 22″ barrel, the bullet is long gone before a stiff load of powder can burn.
Superformance is an odd duck for powder. It packs tightly with a medium-fast burn rate. Similar to 4831 but you can load it more dense.
My 30-06 shoots the 190 SMKs extremely well with Superformance.
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