Building the Big Dog

[Big Al]

Further to my original post on the building of my first bench rest heavy gun Ive put together a 5 minute slideshow which pretty much takes you through the whole of the build in a step by step way.

 

As things stand I have now used the rifle twice in competition winning the second and third rounds of the UKBRA Heavy Gun Championship which I am currently leading after also winning round one with a customers rifle that I built.

 

 

You can select 720hd from the settings menu.

[Danpd]

Superb,

 

A colossal amount of work and something to be quite proud of in my opinion.

[The Gun Pimp]

Was that a tuner Al?

[Big Al]

Was that a tuner Al?

 

 

Yes Vince, Ive made a tuner and done some initial testing with good results.

 

So far though Ive shot the gun without it in competition as the load which I tuned (although very accurate at 100yds) didn't have as good an ES as my current comp load which isn't quite as accurate. I felt that the vertical dispersion from the poor ES would negate any small group advantages the tuner gave. I just need to get the ES down as my current comp load is well under 10fps and is working quite well.

 

The tuner is my own design but based on a one of two common themes, it appears that tuner weight relative to barrel stiffness is very important. A 30" long 1.250" parallel profile is not as stiff as you would imagine, a shorter barrel will be stiffer even if its of a slimmer profile, there are barrel stiffness calculators out there which helps though.

 

 

Small adjustments make huge differences, this was a random powder charge sat 0.010" off the lands, hence not the best ES. Its clear to see groups sizes shrinking with the tuner adjustments. Im also playing about with adding a similar adjustment option to a moderator for field use.

 

 

It tuned the barrel harmonics well though without too much fuss.

 

 

There you go, you've got just over two weeks to make one and I wonder if we will start seeing more of them soon at Diggle?

[The Gun Pimp]

I've made a couple for other shooters but never tried one myself. You could set a trend - if you reduce your group size!

[trucraft]

Very impressive!

There's a lot of skill and hard work gone into that and great to see the results are worth it.

[Dellboy]

Brilliant with i could get a mill in my garage

[Big Al]

Not a lot of recoil from a 46lb gun - 6 Dasher - 105 Hybrid combo.

 

There is just a little more than an inch under free recoil and it comes to its own stop before it touches my shoulder

 

[Chris-NZ]

I can imagine a huge pile of alloy chips building up under that mill Al.

She's a munter!

[Big Al]

I can imagine a huge pile of alloy chips building up under that mill Al.

She's a munter!

 

 

The floor was littered Chris, Im still sweeping them from places weeks later

[Ronin]

I've made a couple for other shooters but never tried one myself. You could set a trend - if you reduce your group size!

 

 

 

There are several of us in the F Class league who use tuners - they do work!

 

Though fine adjustments to locate a harmonicaly "sweet spot" can have quite dramatic effect on group size.

[ejg223]

Fantastic work. What always interests me, would be making a heavy stock that would be balanced on the line of the bore. I am convinced it helps with consistency on my lightweight hunting rifles. Might not need a barrel tuner then.

edi

[Big Al]

Fantastic work. What always interests me, would be making a heavy stock that would be balanced on the line of the bore. I am convinced it helps with consistency on my lightweight hunting rifles. Might not need a barrel tuner then.

edi

 

Go for it Edi

[Chris-NZ]

Fantastic work. What always interests me, would be making a heavy stock that would be balanced on the line of the bore. I am convinced it helps with consistency on my lightweight hunting rifles. Might not need a barrel tuner then.

edi

 

It might reduce the muzzle flip Edi but I doubt it'd have any tuning value.

As Al said, feel free to experiment

[ejg223]

The main reason for muzzle whip or movement in general is the way it recoils due to where the centre mass is located in reference to the line of recoil. Take the up down acceleration of the barrel out of the equation you will also have less launch angle change within you speed/pressure variations of loads.

edi

[ejg223]

 

Go for it Edi

I did not mean to criticize your design more just as an idea or point of discussion. I have been building my rifles since several years after this theory and don't need to convince myself. Just never built a very heavy rifle with this in mind.

edi

[Big Al]

I did not mean to criticize your design more just as an idea or point of discussion. I have been building my rifles since several years after this theory and don't need to convince myself. Just never built a very heavy rifle with this in mind.

edi

 

 

I didn't feel you were criticising me at all Edi, to be perfectly honest I was lost in the technicalities and headed off with a lengthy post at a tangent which I later deleted

 

This rifle I built doesn't need a tuner, it shoots very well without one, so much so that I will continue to use it in competition without one until I can see a good reason to switch. My interest in barrel tuners has a lot to do with the fact I think they will make it easier and faster to develop an accurate load while still giving me the option to make subtle changes to barrel harmonics as and when required, seasonal temp changes for example or when a new batch of powder has to be used.