100yd Benchrest Pellet Velocity

[Joe Shooter]

Question...

For competing in 100yd benchrest; what is the best velocity or velocity range to tune for to obtain that distance, with accuracy and best wind deflection? Thanks.

 

[Julez]

What caliber your talking about?

 

[18.13]

And what pellet

 

[Joe Shooter]

44.75 gr .30 JSB Exact

 

[tommyb]

Joe

We need a lot more information here. 

What gun/brand do you have, what type of barrel, indoors/ outdoors, are you using wind flags, what type of competition are you looking to do, bipod, front and rear rests you will be using, etc

100 yard BR accuracy with an air rifle involves a lot of variables.

My suggestion - Spend a few days researching posts on the BR Topic area and you will learn a lot.

 

[18.13]

According to Chairgun with a 10 mph cross wind........880 had a wind drift of 6.17 and 940 had 6.13 any higher than that or lower your wind drift increased



At 50yrds 800 to 880 had the least drift

 

[JungleShooter]

One (just one!) factor to consider is the BC at different velocities, taking account the MV and the different velocities until the projectile reaches the target.

Bob Sterne tested the BC of .22 JSB domes at different velocities and (for his gun and conditions) came up with the following variable BC chart.



Matthias



PS: Strelok Pro allows us to enter up to 5 different BC values, each with its appropriate velocity.

 

[Joe Shooter]

Hello Tommy,

I appreciate your response. While I'm new to airgun benchrest shooting, I am not a novice shooter. I know what it take to shoot with precision...calculating the wind, etc. What type of rest or bipod I am using, what barrel, or whether I am using wind flags or not; while they may have an effect on my accuracy or personal performance, really have no bearing on what velocity I will need to effectively reach a 100 yd target. 

 

[steve123]

I've had the best with 45gr at 860 to 885 in two different rifles.

 

[tommyb]

Hello Tommy,

I appreciate your response. While I'm new to airgun benchrest shooting, I am not a novice shooter. I know what it take to shoot with precision...calculating the wind, etc. What type of rest or bipod I am using, what barrel, or whether I am using wind flags or not; while they may have an effect on my accuracy or personal performance, really have no bearing on what velocity I will need to effectively reach a 100 yd target.

Joe

i gotcha. But, there is a big difference between ‘reaching’ a hundred yard target and shooting accurately with an air rifle. I don’t doubt your experience or skills, but optimum velocities vary greatly with caliber, barrel types and pellet weights. 

The optimum velocity for a 44 grain pellet in a 30 caliber rifle can vary by manufacturer and barrel type, in terms of achieving the best accuracy. I have found that I need to try and achieve this knowledge by trial and error. 

I had a RAW .30 cal HM1000x and it took me a lot of chrono runs and adjusting HST to find optimum velocity. 

 

[Joe Shooter]

Yes, I agree that I will need to do alot of shooting, chrono runs.

But to give you abit of what you asked for previously,,,, my gun has a 20" TJ Hammer Forged barrel, 1:26" twist, unchoked, optimized specifically for JSB pellets. Regulated @ about 2000 psi.

 

[Jayson]

Not knowing anything about your set up personally, but have shot a lot of 100 Br, I would start at 860 and move up to 930ish, in 10 FPS graduations. 30-50 shots at each,You will see patterns that should really help you dial her in, that’s what I would do! If you get tired, quit and start up the next day, best if you do it indoors at first, then go outside and see if the wind spirals those indoor settings Stock up on pellets if you can find um right now? Also, with that twist rate, she might really like the 50’s over the 44’s? That would be cool.good luck! 

 

[crazyhorse]

Not knowing anything about your set up personally, but have shot a lot of 100 Br, I would start at 860 and move up to 930ish, in 10 FPS graduations. 30-50 shots at each,You will see patterns that should really help you dial her in, that’s what I would do! If you get tired, quit and start up the next day, best if you do it indoors at first, then go outside and see if the wind spirals those indoor settings Stock up on pellets if you can find um right now? Also, with that twist rate, she might really like the 50’s over the 44’s? That would be cool.good luck!

Good point...we were caliber restricted so it was .22 cal and my case was 940 FPS....

 

[stoti]

Dial in your gun for accuracy, I would assume somewhere between 850-920fps and then worry about calculating your holds for wind drift. 

Stoti

 

[Joe Shooter]

Much appreciated guys; that is exactly what I was looking for. Thanks for all your responses!

 

[tommyb]

Joe

You never did tell us what gun you had. 

I’m curious now that you have what you want in terms of feedback. 

 

[Joe Shooter]

I have a custom .30 Benjamin Marauder...4500psi bottle, W.A.R. bottle regulator, Cothran valve, 20" TJ Hammer Forged barrel, in the back half of an Armada stock. I'm going to swap the barrel for a 24" and a different buttstock soon.

 

[tommyb]

Awesome. I don't know much about Marauders, but looks like you jazzed it up quite a bit. Nice!

Does it have a single stage or two stage trigger? And, what release weight do you typically adjust for when you shoot it?

 

[Joe Shooter]

Thanks! It does have a 2-stage trigger. I have the first stage at about 1.5lb and the second stage at about 10oz.

 

[tommyb]

Thanks! It does have a 2-stage trigger. I have the first stage at about 1.5lb and the second stage at about 10oz.

Thanks Joe.