CZ 455 Accuracy, Barrel Float vs No Float...

[rcmark]

Looks like DJ was right!

Stock CZ 455 with plastic stock.
Sightron SIII SS 6-24x50 LR MOA

NF = No Float
F = Float

[jaia]

(it's ok, I don't float either )

[timberbeast]

Free floating a CZ barrel should only be done after shooting it a lot in a single session and noticing a distinct POI change as the barrel heats up. Or, over temperature and humidity changes, you see a POI change.

I have many CZ rifles that are Trainers, Full Stocks, Luxes and Ultra Luxes with barrel and stock contact or barrel lugs and screws and they are very accurate.

I've floated 452 Americans and gotten good results. But the 455 is a different design.

All that being said, the OP's experiences may not hold for all CZ 455 rifles. Float or not, be prepared for good, bad, or no results, there are no guarantees.

[RickBaum]

Originally Posted by rcmark

Looks like DJ was right!

NF = No Float
F = Float

Just curious..
What range?
What rifle/bbl?
When you say float and no float, is float fully floated and no float bedded the full lenth of the bbl?
There must have been another discussion that i missed that would have had all the floating vs no float information.

I personally tried a 2" bed just forward of the action and it trashed my groupings. My groups at the time were around .3-4" at 50 fully floated. After the partial bedding it doubled the group size, much like your photos. This was using the same ammo/lot, conditions and range.

[jaia]

A few years back, dj and I were swapping ideas regarding 455 barrel bedding.
He was an advocate for receiver and an inch or two forward of the the receiver.
I was into trying anything that I could find on line to try.
Barrel shimming was an old school technique from centerfire,
I started with a single shim at the center of gravity of the receiver/barrel
then kept adding more and more. Results on target kept improving.
Dj laughed at me, then decided to go full length bedding to see if it made a difference.
He stopped laughing when the 455 he was working with, started shooting consistent 0.2x groups.

I decided to go one step further and build a full length barrel block rifle.
That's where Fuglie and Son of Fuglie came from.

I figured if an actual gunsmith could no-float, I ought to go can't float.



You can't tune a fully bedded barrel.
Accuracy is limited by ammo quality, wind judgement and rifle/setup.

[wkd]

I have 2 Americans and a Varmint, all 3 shoot best free floated. Plus, zero doesn't change with the seasons.

[djdilliodon]

In all the full length bedding I've done and now doing just an inch with custom fits, if you got a solid barrel, a match chamber, and headspace correct, full length bedding is not needed. Full length works as your using the bedding as a form of tuning and to do it right, it's a lot of work and epoxy! You gotta be fast when that epoxy is squeezing out the entire length of the stock!

[gstaylorg]

So presumably, the "no float" option simply locks down the part of the barrel in the stock channel and dampens harmonic vibration? If so, I can understand why it might have the effect shown in rcmark's post above; you'd largely be confining harmonic vibration to the portion of the barrel out of the channel, which would be analogous to having a much shorter and stiffer barrel.

[jaia]

Son of Fuglie was my attempt to produce a stocked rail gun.
Barrel and stock 1 object, minimal harmonics.
No barrel whip, no stock flex, heavy, stable, the kids love it.
Maintains point of aim with minimal control.
When a youngster can put 5 rounds touching at 50 yards
with minimal instruction, it's a good thing.

[rcmark]

My feeble attempt at bedding!

When I tested I had the rear and middle of the stock bedded and temporary shims in the front of the stock.
After testing the temporary shims in the front of the stock was replaced with 'real' bedding.

Filled the bays with Rockite in a attempt to 'stiffen' the stock.

The used JB Steelstick for the bedding.

[rcmark]

Testing Aguila Subsonic: