20.5" Lilja bull barrel on CZ 455, Harrel tuner too heavy?

[done111]

I have a CZ 455 with a Lilja barrel that was made before Lila incorporated the shimming provisions of today. It is 20.5" long and is a straight 0.900" outer diameter. The barrel does well with Lapua Center-X and SK Long Range. I was thinking of getting a Harrell tuner to squeeze out a little bit more hopefully, but I have been hearing that for heavier bull barrels, that a Harrel may be too heavy? It's counterintuitive to me but I heard that heavy barrels may need LIGHTER tuners (if they benefit much at all). I was hoping to get some advice on the Harrell tuner and 20.5" bull barrels. Any other good information before taking a plunge like this is also appreciated. Stay warm out there!

Don

 

[Hi-NV Shooter]

I have a CZ 455 with a Lilja barrel that was made before Lila incorporated the shimming provisions of today. It is 20.5" long and is a straight 0.900" outer diameter. The barrel does well with Lapua Center-X and SK Long Range. I was thinking of getting a Harrell tuner to squeeze out a little bit more hopefully, but I have been hearing that for heavier bull barrels, that a Harrel may be too heavy? It's counterintuitive to me but I heard that heavy barrels may need LIGHTER tuners (if they benefit much at all). I was hoping to get some advice on the Harrell tuner and 20.5" bull barrels. Any other good information before taking a plunge like this is also appreciated. Stay warm out there!

Don

How does it shoot without a tuner? if you have very little vertical then probably need less weight. but if you have a lot of vertical say 1/2" or more then weight might be needed.

Lee

 

[done111]

I'm less than 1/2" at 50 yards with the good ammo, 0.3ish. Does the amount of vertical to remove determine more or less weight for a tuner? It would seem intuitive to me that a heavier tuner would work too and would be able to cover more situations (like different lot of ammo with larger group). If I need less vertical correction, largely because I'm using ammo the gun likes currently, then I use a lighter tuner only?

Sorry for all the words, just trying to understand and learn

 

[Lesloan]

FWIW, my primary bench rest rifle is a 40X with a 28" heavy Lilja barrel and an Accushot tuner. The tuner does definitely make a difference. The Harrel tuner is lighter than my Accushot, and I can't imagine it'd hurt your accuracy. If you need more weight you can always add weights to it.

 

[gunsandgunsmithing]

I have a CZ 455 with a Lilja barrel that was made before Lila incorporated the shimming provisions of today. It is 20.5" long and is a straight 0.900" outer diameter. The barrel does well with Lapua Center-X and SK Long Range. I was thinking of getting a Harrell tuner to squeeze out a little bit more hopefully, but I have been hearing that for heavier bull barrels, that a Harrel may be too heavy? It's counterintuitive to me but I heard that heavy barrels may need LIGHTER tuners (if they benefit much at all). I was hoping to get some advice on the Harrell tuner and 20.5" bull barrels. Any other good information before taking a plunge like this is also appreciated. Stay warm out there!

Don

IME, the tuner you have is not too heavy and should work just fine on your bbl, but good question and yes, it's counterintuitive but the stiffer the bbl is, the sooner you run into issues, to a point. One, I'm talking typical target bbl contours, not pencil thin hunting bbls. And two, you're bbl is relatively stiff compared to some longer bbls commonly seen in rf br but in the big picture, it's not really that stiff as compared to say a 1.450 rail gun bbl. You aren't even close to the point that the weight of a std harrell's tuner would be any concern to it working. Go shoot! Merry Christmas!

 

[Hi-NV Shooter]

I'm less than 1/2" at 50 yards with the good ammo, 0.3ish. Does the amount of vertical to remove determine more or less weight for a tuner? It would seem intuitive to me that a heavier tuner would work too and would be able to cover more situations (like different lot of ammo with larger group). If I need less vertical correction, largely because I'm using ammo the gun likes currently, then I use a lighter tuner only?

Sorry for all the words, just trying to understand and learn

Look at vertical being caused by velocity differences of the ammo the more it has velocity variances the more vertical will occur.
Because tuning is about bullet exit timing you are using the weight forward of the crown/muzzle to time that exit. weight will alter the speed in which the barrel will move in its upward range. so, knowing how much vertical the barrel will produce without a tuner with your best lot of ammo gives an indication of where the exit point is within that natural range. very little vertical will mean you only need to alter the exit point within a narrower range of the barrel's upward movement. so, if weight alters the speed in which the barrel moves and the range of vertical dispersion with your best ammo is small logically you need less weight. opposite of this if you use too much weight you will never be within range of the barrel's natural highest POI with your best ammo. in finding the correct bullet exit range you are trying to bring the low and high POI to be as close to each other as possible doing this will shrink the vertical dispersion. achieving this will have the effect of POI matches POA on a more consistent basis.

Lee

I'm less than 1/2" at 50 yards with the good ammo, 0.3ish. Does the amount of vertical to remove determine more or less weight for a tuner? It would seem intuitive to me that a heavier tuner would work too and would be able to cover more situations (like different lot of ammo with larger group). If I need less vertical correction, largely because I'm using ammo the gun likes currently, then I use a lighter tuner only?

Sorry for all the words, just trying to understand and learn