rimfire ammo speeds

R

reelxprs

New member
I recently got some eley match with a posted speed of 1055. I usually shoot ammo in the range of 1065 fps and this ammo always shot good. I have a Benchmark 16.5 twist barrel.
The 1055 ammo will not shoot as consistent as my 1065 did. Is this due to my barrel twist or what? My rifle did not shoot well in the colder temps also ( below 55 degrees).
Is my rifle telling me I need to shoot higher velocity ammo or what? Or should I try to re-tune for the slower speed ammo?
Thanks
Jeff Fountain
 
You just cannot go by speed. First the speeds printed the last couple years vary from say 3-4 years ago because ELEY swapped out their test barrels. Then we get into machine variance and lot variance so you probably want to get a few boxes from different machines to reestablish a current baseline.
 
Jeff, I can't answer your question as I am still trying to figure it out myself! What I can tell you is I have a reverse tapered Benchmark with a 16.5 twist also & mine seems to hate hot weather & humidity. Odd that they are complete opposites in that respect.
Also I have some Eley with an advertised speed of 1062 I felt shot ok initially. Then it got hot & humid & it hated it. Temps fell & it seems to shot ok again. Your 1055 may shoot fine on a different day??
Eley speeds are done with their test barrels & are set as an average of what they see. Our guns may be, & probably are quite different.
Been told to take a few different lots to the bench in case one works better on that certain day. The other thing a gentleman said was to keep notes on it all. Sound advise.
Keith
 
A better place to focus;

I have not found much relevance to speed and what my rifles like. What both of them seem to prefer is the ammo from the #2 machine. I focus solely on the ammo from that machine and have been able to find good ammo right through everything that has come our way. It's a whole lot easier to simply do that than to be chasing all the machine #'ers lots and published speeds, IMHO. I found good lots in the fast and in the slow. I think the trick is to have a number of different lots on hand and try them when the rifles seems out of sorts, rather than focusing on one big lot of one single lot number; perhaps. :)
 
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Yep, you have to Lot test all of the Eley, including Tenex. I have gotten good Lots of Match off machine 5, but have also gotten bad Lots off 5. I don't think velocity has anything to do with accuracy. I have good grouping Lots from 1046 to 1065 fps.
 
Rimfire ammo speeds

I have found by chronographing over the last 7-8 years that printed velocities on ELEY tenex & match are approximate only. Actual speeds will almost invariably be higher or lower. All of which stands to reason because my barrels are not ELEY'S test barrels. My results are only occasionally within + or - 2fps. Having said that, I have noticed that if I test 3 or 4 lot #'s off the same machine at the same sitting, my numbers fall into the same relative order as ELEY'S printed numbers when ranked fastest to slowest whether they are higher or lower than ELEY'S ratings. All of which reinforces test, test, test, test.
 
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