Bantam .25 cal and Sniper XR .25 Cal Same Pellets different speeds for accuracy????

[Smitty911]

My first PCP was a Brocock Bantam (unregulated) in .25 cal from AoA, with a 3x9 scope. Shot really well, LabRadar and it starts at 200 Bar and and I shot down to 100 Bar, normally, in the 810 range down to 700+.
My Sniper XR (with a 5.5x25 scope) is new I've shot it a few times and the Reg pressure is 160 (on the gauge), and it shoots on the LabRadar around 910 to start and stays there until it falls off the regulator.
Now my Bantam around 120 Bar becomes a 1 MOA shooter, 0.50" at 50 yards (Laser ranged). My Sniper XR doesn't get to MOA.
Both have the same Barrel (I polished both the same way), Trigger, etc. etc and shooting the same pellet JSB Exact King .25 Cal 25.39 Grain.
After polishing the Bantam has about 100 shots and the Sniper about 20 at this point.

Why the accuracy difference and does this mean I need to lower the reg pressure on the XR to tighten up it's group?

I have a Altros Regulator for the Bantam, and I've put a Carbon Bottle on it, should I just set the reg pressure at 120 bar and install it and be done.

Smitty

 

[Ezana4CE]

My first PCP was a Brocock Bantam (unregulated) in .25 cal from AoA, with a 3x9 scope. Shot really well, LabRadar and it starts at 200 Bar and and I shot down to 100 Bar, normally, in the 810 range down to 700+.
My Sniper XR (with a 5.5x25 scope) is new I've shot it a few times and the Reg pressure is 160 (on the gauge), and it shoots on the LabRadar around 910 to start and stays there until it falls off the regulator.
Now my Bantam around 120 Bar becomes a 1 MOA shooter, 0.50" at 50 yards (Laser ranged). My Sniper XR doesn't get to MOA.
Both have the same Barrel (I polished both the same way), Trigger, etc. etc and shooting the same pellet JSB Exact King .25 Cal 25.39 Grain.
After polishing the Bantam has about 100 shots and the Sniper about 20 at this point.

Why the accuracy difference and does this mean I need to lower the reg pressure on the XR to tighten up it's group?

I have a Altros Regulator for the Bantam, and I've put a Carbon Bottle on it, should I just set the reg pressure at 120 bar and install it and be done.

Smitty

@Smitty911 Reg seems a bit hot on the XR at 160. I’m no master tuner so take what I say with a grain of salt. Also that’s a light pellet that can get bullied by the wind. At which other velocities have you attempted to shoot the Kings? What was your reg adjustment and HS depth on previous attempts before reaching the tune you’re discussing in this post? How about your ES, Avg, and SD on other attempts? I’m curious, why shoot Kings instead of King Heavies (33.95 grain)? It’s a bit unrealistic to expect similar performances from two different guns especially considering that one is regulated and the other isn’t. Have you tethered the unregulated gun at varying pressures in order to analyze and compare your shot string data? XR sounds brand new (as opposed to “new to you”) and hasn’t been broken in yet. I don’t know how many pellets you’ve put through it in shooting it “a few times.” About 20? Also kinda unreasonable to expect two different barrels from the same manufacturer to perform identically. Several variables to consider here.

 

[Smitty911]

Ezana4CE,
I just shot it how I got it. I only had the 25.39 grain pellets. I'll pick up some of the heavier ones. I'll start pulling some data and shot strings together.

Thanks,

Smitty

 

[Ezana4CE]

Ezana4CE,
I just shot it how I got it. I only had the 25.39 grain pellets. I'll pick up some of the heavier ones. I'll start pulling some data and shot strings together.

Thanks,

Smitty

@Smitty911 Not a problem. Please understand that these are thoughts and suggestions, not necessarily solutions. Trying some of these things may lead towards what you’re looking for. This was the first Brocock Bantam thread I read on AGN. https://www.airgunnation.com/threads/brocock-bantam-sniper-hr-information-thread.365686/
It’s pretty informative. There are pages of AGN posts and thread on these guns. Search the forums and you’ll find plenty more info.