VSR hop upgrades

[Drakker]

Originally Posted by cetane

This seems to be a good unit too if running vsr cut barrels...

https://s-media-cache-ak0.pinimg.com...98cc07993d.jpg


http://www.action-army.com/images/pa...er/chamber.htm


http://www.airsoftsniperforum.com/41...p-chamber.html

That chamber has all the drawbacks of the PDI chamber without any of the advantages. You are much better off with the stock hop-up chamber.

[daishi]

Okay,

Well I am going with a PDI w hold bucking, the stock chamber, a dangerwerx arm and a 6.03 435mm barrel.

Now to just figure out what heavy weight bb's are actually decent. Thinking .4s....but not sure what brand. Madbull?

[Drakker]

You should choose the BB weight in function of your air volume / power. Try a lot of different weights and calculate the joules you get with them. This will give you a progressive curve, chose any of the BB weights at the top of the curve and you are good to go. The "shape" of the curve will vary a lot depending on your air volume, barrel length, etc. This is a made up example, but it illustrates the effective power curve well.

BB weight and effective power
.20 1.2 joules
.25 1.3 j
.28 1.36 j
.30 1.42 j
.32 1.45 j
.36 1.47 j
.40 1.43 j
.43 1.35 j

With a theoretical effective power curve like this, your best choice of BBs are probably .32g, .36g and .40g. On my low power G-Spec (380fps with .20g BBs) my effective power curve tops at .32g BBs and drops sharply from there, so my best choice is .30g or .32g BBs.

Of course, if your rifle has a lot of air volume and a lot of joule creep, it's entirely possible that using heavier BBs will get you over field limit when you calculate the joules and compare it to the equivalent FPS on .20g BBs. A lot of players have abused joule creep in the past and are happy to chrono at say 420fps on .20g, but then use .36g BBs and shoot the equivalent of 500+ fps on .20g BBs.

With the same G-Spec setup in the past, but with a more powerful spring, my effective power curve would top at 0.40g BBs, but then anything over .30g BBs would be over field limit, so it wasn't very practical.

[Styrak]

Originally Posted by daishi

Okay,

Well I am going with a PDI w hold bucking, the stock chamber, a dangerwerx arm and a 6.03 435mm barrel.

Now to just figure out what heavy weight bb's are actually decent. Thinking .4s....but not sure what brand. Madbull?

0.36g Madbull whites. One of the only good quality WHITE heavyweights. Cause I think BB's you can't see are useless especially when sniping.
I use and sell them.

[ThunderCactus]

That's some good info.
Keep in mind bolt actions can joule creep like mad. What ever the field requires you to chrono on, it's up to you to not break the rules.
When I'm required to chrono on .20s with my M24, I always let the guys at chrono know it shoots low on .20s and much, much higher on .36s. (Actually with one previous build, it barely lost fps on .36s, shoots 380 on .20s and 374 on .36)
Remember we're out there to have fun, not hurt people!