Diana & Broughton

I have been one of "godfathers" to newbie RFBR shooter and this Broughton barrel goes threw my hands.

Many people in the world loves free vibration barrels but my favourite is also free vibration action in same gun....

Now the newbies project looks like real RFBR gun and endless good lot hunting is beginning.

This Broughton is good one and it is very intresting to see how this old Diana is doing amongst Turbos,Stillers etc.

Few pictures. Also 2 x 10 shot groups to 50 m from test bench from this Broughton.Lapua Center X. Also seems that it eats RWS R 50 also...







BR, Timo

Friend gun fool Timo

Friend gun fool Timo


Timo, you walk your own path in life.....like someone else I'm kinda familiar with.

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I'm not familiar with the Diana......


But...................


It looks like it's got some 37 Remington in it.


The split rear receiver......for bolt handle passage....


What's good about this, is, that there's bolt body behind the locking lugs, to ride the breech bolt raceway.


This supports the breech bolt body both in front of, and, behind the locking lugs....like the 37 Remington.


It also looks like a dual lug, 180 degree opposed action, as I can see the raceway for the secondary locking lug cut in the tang.....




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What kind of ignition? SAP or PAS?


The 37 Remington is PAS, of course.



Also, where does the trigger sear catch the cocking piece of the firing pin......behind the locking lugs, or, in front of them?



How's the barrel attached?



Your gun fool friend, BC

Hi Bill and my other Gun Fool friends!

Those Diana 820 Prone RF.s history here is something like that:

*On 60s and 70s here comes only 20-30 pieces of them in Finland.To prone shooters.

*I think factory was Krico in Germany (East Germany?)

*They have good barrels,excellent feeding ramps,good triggers

*But few issues too:

*Barrels were put to actions with "brazing"

*When barrels goes worn out, shooters & gunsmiths changed actions & barrels with threads.

*Also many times they changed timing and ignition same time.

*Diana action is very long and not so stiff as many nowadays RFBR actions.
(This newbies Diana action in picture is shortened,because of LV weight limit)

*This very long action gives possibility to make extra hole/thread to action and make 2 short bedding area (under action screws) and left big part of action "free vibration".

*I fall in love to free vibration actions on year 1978 when I got to my hands customized Tanner 300 m prone rifle.But I dont like barrel blogs.This old very clever now retired army gunsmith has made the customizing to this Tanner.Made this free vibration action system without barrel blog.

*Also Dianas very long measure between loading ramp and thread end gives possibilities to make constructions which put barrels "ring vibration" frequency little down.

Everybody can have different thoughts of those Chris Longs vibration ideas,but there are few important points among story:

www.shootingsoftware.com/barrel.htm

*I have always thought that it is better to take care of disease,not for symptoms.

*With tuner we take care of symptoms.Disease is beginning in the other end of barrel....

Diana 820 model picture:



Gun on the top is my 6 JMS wildcat with barrel blog. Same time I love and hate it. Love the accuracy and hate the weight.If needed I can put 68 grain bullets goes over 4000 feet/s and it gives ofcourse very straight flight to bullet.



BR, Timo

Barrel Block Rifles

Timo,

I also like the idea of the floating action. I haven't shot this yet (and it needs a lot of refinement) for any kind of accuracy work but am hoping that I can learn something from it. This is a rimfire and most of what I've read indicates that the barrel block arrangement isn't ideal for the .22 rimfire. The plastic clamping surface is HDPE. I may try Delrin if this shows any promise at all.

Tony

Friend aslap

aslap said:

Timo,

I also like the idea of the floating action. I haven't shot this yet (and it needs a lot of refinement) for any kind of accuracy work but am hoping that I can learn something from it. This is a rimfire and most of what I've read indicates that the barrel block arrangement isn't ideal for the .22 rimfire. The plastic clamping surface is HDPE. I may try Delrin if this shows any promise at all.

Tony

Click to expand...

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Friend aslap:


I enjoy folks who are willing to try things.......like you're doing...



Now.....................


This is just an old man rambling......so take it with a grain of salt....



Barrel blocks for RFBR guns.........verses barrel blocks for CFBR guns.....


(These are in no particular order.........just rambling....)


1....A barrel block must not restrict the bore....and maybe the soft material you're trying will keep that from happening.

And easy way to determine if the bore is being restricted, is to slug the bore.



2. The front of the barrel block becomes the new face of the action, as far as barrel vibrations are concerned, and what it takes to control them.


3. Controlling barrel vibrations with a muzzle device is determined by the stiffness of the barrel.


3. A 20 inch X 900" barrel is much stiffer than a 24 inch x 900" barrel..... etc.



4....On a CFBR gun, no MD, a barrel block does, in effect, stiffen the barrel, which moves the exact center of the parallel node closer to the exit of the crown....

This in turn causes the part cycle oscillations at the muzzle to be less severe, which can result in better accuracy.


But........................


On a RFBR gun with a barrel block, which also in effect stiffens the barrel, moving the exact center of the parallel node closer to the exit of the crown actually makes it more difficult to stop the muzzle, with most MD's as they are currently weighted.


Friend aslap, all this is determined by exactly how long your barrel is from the end of the barrel block to the muzzle, and what diameter your barrel is.


As an extreme example:


Say you had a 1.000" diameter barrel, which was 19 inches from the end of the barrel block to the exit of the crown.


Stopping the muzzle for a barrel this stiff would take a custom made MD, of some sort.


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A barrel block for a CFBR gun, no MD, is most certainly a benefit, since the part cycle oscillations of the muzzle are less severe.


But on a RFBR gun with a barrel block, stopping the muzzle with an MD can most certainly be a challenge.



If I were going to spearment with a barrel blocked, RFBR rifle, I'd use a 30 inch barrel, no more than .875-.900" in diameter, and keep the length of my barrel block to about 5 inches, or so.


This way I could stop the muzzle with a standard HH/MD.



Just an old man rambling.....



Good luck with your project.


Your friend, Bill Calfee


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PS:


One other point about CFBR verses RFBR guns.



There's a big difference between a 6PPC at 3200 FPS, and a rimfire at 1050 FPS, when it comes to how a standard deviation of 15 in the ammo, as an example, relates to performance on the target.

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I want to add one additional thing, here.....


CYA members are sharp....and very observant....


I know some of you folks will be thinking:


"Won't the soft material that friend alsap is using for his barrel block allow the barrel to vibrate normally?"


The answer is, no.


CYA friends, all it takes is your thumb and finger to interrupt barrel vibrations......


This is the easiest thing in the world to demonstrate.

Thanks, Bill!

Thanks for the suggestions! I might just have too much time on my hands. I think what I'll do is try it without a tuner. If it looks like it has potential, then I'll go forward. If the groups look more like a shotgun pattern, then I'll write it off as a lesson learned. Maybe.

Timo - from your description of the Diana-actioned rifle, it sounds like the action is sort of just sitting on a couple of pillars. Is that anywhere close to how it's put together? it sure looks like it likes the arrangement however it's done.

Tony

Bill wrote very good of few warning words or issues of barrel blogs.Also if barrel block is different steel than barrel,then it is possible to get rifle which poi is changing little when shooting more shots and barrel is going warm.
In one case I put very thin (about 0,2 mm) "rings" to both end of blog and this little poi changing disappeared.

There are different ways to make free floating action without barrel blog.When action is so long as original Diana is you can made 2 short bedding area under action screws.
RF:s forces are so small that it works enough and gives good accuracy.

Other one is "one point" system.Only tapered cone piece which tightening to stock with 1 action screw.Is frustum right word to this piece???

BR, Timo

Friend alsap

Friend alsap


I wanted to make a point about barrel blocks verses barrel bedding, so I took the liberty of doodling out your barrel block and showing a picture of barrel bedding.


Back when I started center fire bench rest work, barrel bedding was somewhat in vogue.


This system allows the action to float......like Timo advocates.


I first cast a Devcon F, aluminum composite block using the finished barrel as the pattern.....


I put this bedding area in white....in the doodle.


When the Devcon cured, I then cleaned the bottom of the barrel, where it contacts the bedding block, by sanding with 180 wet or dry paper.......same for the Devcon block.


Then glued the barrel to the bedding block.


The biggest advantage this system has, is that the barrel is solidly attached to the bedding block, for vibration purposes, without any fear of pinching the bore, like can happen with a clamp type bedding block.


Here's another benefit, for a CFBR gun:


The front of the bedding block, red arrow, becomes the new action face......as far as barrel vibration reduction is concerned.


This makes the barrel much stiffer, since it's technically shorter, which reduces the severity of the part cycle oscillation at the muzzle...


No MD's back then......so we worked with naked barrels, of course.



For a rimfire though, this system has the same issue as does a clamp type barrel block.


The barrel becomes so stiff, that it will take a one-off MD to properly stop the muzzle.


But again, this system allows the barrel to be rigidly attached to the bedding block, without worry of pinching the bore.


Keep us posted of your progress...


Your friend, BC

Hi y'all,i had a light bulb moment in 2013 when i fitted a barrel block to a model 1516 anschutz. This 1966 1516 action had a 54 match barrel installed which slugged good and it was also dated 1966. Barrel was cut to 25.25 inches and glued in with loctite. Eley EPS chamber with headspace set at 41 thou. Barrel block is 4 inches long leaving 19 .75 inches in front of the block and .50 inch behind. The block is aluminium and was glued in with devcon and goes 1.75 inches into the stock.This rifle is still being used without a tuner as it makes no difference what you hang on the barrel. I also made the stock out of Queensland Maple with an Anschutz profile. As a side note this rifle was sold to a fellow club member and he will not part with it. Scott.

Very nice!

Fred,

Nice work on the block job. Did the work improve the accuracy by some measurable degree!?Scores or groups getting better than without the block?

Leaving all of the barrel vibration stuff on the side for a moment (and it may very well be impossible to leave that on the side for any length of time) it always seemed to me that, with what seems to be a litany of issues with bedding, getting the action up and out of the stock would remove this variable.

Tony

Hi aslap,100% as the original rifle had a hornet's nest in the barrel and i only bought it for parts. I will say i am not a gunsmith but i have a friend who does small jobs. Sometimes he tells me to go away as this/that won't work. . I do projects to keep my mind busy (i am the same age as Mr Calfee) and most are passed on after completion. Scott.