I’m working on this experimental mindfuck for a while now. Really wanted to wait until I can post more data, but just can’t wait longer.
!!!This is just a fun project, not planing to bring it in serial production!!!
Let’s start with the basics.
What is an LRB? It stands for “long range barrel”, an oooold way to create/improve hopup effect. There are some ways to make it, the most common is a slightly bent barrel. That makes the bb friction more against the top of the barrel and increase backspin. If you want to know more give a shot to google it.
The LRB itself is a good idea, but brings up “some” questions:
-How much bend is the best?
-Where I should start to bend the barrel?
-How it correlates with bb velocity/mass/barrel bore/barrel lenght/surface?
-How the bend affects the shape of the barrel?
See? More questions than I could answer with years of testing… And there are probably even more.
We already know how mostly the bb acts in the barrel, it spins mostly on the top (based on the worn coating tests), but it touches other parts of the wall too. It’s possibly because of the imperfections of the bore and the bb or simply because of the pressure of the gas behind the projectile. (This is what we try to reduce by increased quality)
Could we make the bb roll more, or entirely on the top of the barrel?
If the bb is magnetic, yes.
All bb which dark contains some magnetic metal powder.
In my experiment the parts are the following:
-SRS sport barrel
-Lambda 6.05 509
-Custom 3D printed spacers
-100% seal & r-hop
As you see there is a chanel over the top of the barrel, strong neodimium magnets placed on in it.
These pull the bb up all along its movement.
It does not affect the velocity, or the consistencity.
What it does?
The bb rolls much more on the top, also the airflow concentrated below the bb, that pushes it up against the barrel too.
It provides waaaay more backspin than the hopup just itself.
My testing begin with Longbow .50 and .48.
.50 is magnetic, .48 is not.
Set the hop to lift .48, obviously .50 would need more hop.
When shot the .50 was not visible at all, usually it’s traceable between 60 and 90m.
My conclusion was it overhops a lot…
Took .45 white, adjusted the hop to it, shot the .50, it was still heavily overhoped, straight to the moon at ~50m…
Back to .43 white, hop set to it, .50 shot, still overhops but I can follow the flight path.
The hop set to .40 still overhoped .50, backed up a little, would assume the hop set somewhere to list .36-38 (I don’t have lighter bb here)
This way the bb flies really straight and flat to ~100m, at 110 aimed shots are possible without holdover. I had no chance to shoot it further since at that range I can only hear the impact but can not see. (These shots placed at 3.3J)
Grouping wise the results are comperable with my best PDI setup, with a nice internal group that beat all others I shot so far. 50% of hits at the PDI level, 50% of shots are with less than half spread. (Will give it a shot with measured and cleaned bb again, suspecting that will tighten it all up)
The fun part is, when tested it indoor at 100m when Csypa and Panther shot to 100m too, I had to hold ~1.5m below the target to hit it insted if holdover.
I will continue testing with this setup, not because I expect much more, but because it is a lot of fun… 😀