The switch barrel competition rifle is my HG that we've talked about in the past with the 338 Yogi chamber and now a 6.5x55 Ackley barrel also.
My original 338 barrel was a Lilja 1.850" dia x 32" and is now 30 1/4" after being setback and a slight taper put on it after 2.5yrs. Muzzle measures around 1.600" approx now.
The 6.5 barrel is also a Lilja 30" 1.450" untapered.
Both are screwed into a 2" x 10" BAT action. I think you've seen the pictures before on this site. The BAT action has 1 1/4 dia x 1 3/4" long tenon threads. If you would like another picture let me know.
When the rifle was originally built, it was planned around the switch barrel concept. The scope comes off by loosening the 4 screws that clamp the rings onto the tapered dovetial base and it slides right off. It was setup so the rear scope ring would mount flush with the back of the dovetail base to be able to somewhat repeat my scope position.
All of my rail plates on bottom have clearance holes so that an allen wrench will go up into the action guard screws and they will drop out without removing anything else from the rifle. Clamp the barreled action in a "c" block, insert the action wrench and snap it off. Screw on the new barrel and snap it tight and a little extra, insert the barreled action back into the stock, tighten 3 guard screws, slide scope/rings down the dovetail and clamp in place. Ready to go.
As far as blocks. Most any of the known long range 'smiths have blocks premade or can make you one. Don't know of anyone close to you up there though. Know of some around me if your interested there. contact me if your interested.
I really can't see in the pictures as how the barrel is "free floated". If the sleeve is around the barrel and the sleeve in touching the block then nothing is "free floated", is this not right? My way of thinking would be that if the barrel is not touching anything then it would be "free floated".
Please correct me if this is wrong.
Out of curiosity, if the barrel is blocked and the action is floated then would having a single shot action be an advantage? What I am getting at is if the receiver is just hanging there and the block is providing the rigidity then would you be able to use an action with a magazine without any loss in accuracy? If there is no loss in accuracy then it might be an advantage to have a repeater in a long range hunting gun, at least to a lazy guy like me who misses allot. [img]images/icons/wink.gif[/img] What do you think?
If you can see it, you can kill it.
If the sleeve is around the barrel and the sleeve in touching the block then nothing is "free floated", is this not right? My way of thinking would be that if the barrel is not touching anything then it would be "free floated".
Think of the block system as your threaded area on a standard action.
In that situation you would have 8 to 12 Lbs of barrel actully "hanging" on 1" to 1 1/2" of threads on the action.
The block is now your threaded area only moved forward onto the barrel further.
"Everything" in front and behind the 6" to 10" block is "free Floated".
With conventional bedding and with heavier barrels "hanging" on that 1" to 1 1/2" of threads, it was found that, through repeated firing especially benchrest, the flexing of the barrel caused a slight crushing effect on the threads holding that barrel in the action and accuracy started to slip. They went to the barrel blocks to eleminate this effect and it works well especially for the benchrest shooter who usually fires many rounds rapidly and with large cases and large barrels.
What's nice with the split blocks is, as long as you have the SAME barrel diameter and action, you can replace an entire barreled action even at a match if you desire.
I have 4 barreled actions in different calibers that fit the same heavy benchrest aluminum stock and can make the switch quite rapidly.
They are all 1.450" diameter barrels with the Remington 721 actions on each.
Barrel blocks are the way to go if your firing many rounds in 1000 yard competition especially in the Heavy gun class.
Here is the pic on my Ultra mag. 35" no taper barrel hanging off a P14 Enfield action. I bedded under the first 7" of barrel is it seems to hold the weight. So far getting consistent 1/2MOA groups (5rd groups) at 180yds. Not a bench rest rig so not too concerned that accuracy is not tighter. Will shoot at LR hopefully soon to see if accuracy holds.
So far no obvious strain on the action doing things this way. however, the Enfield action has a larger thread then most actions. A larger diameter receiver too.