Brocock Sniper HP in the house

Thanks folks. Further details and LOTS of pics to come

I will say that it's a really neat size. I have had "normal" rifles (hatsans, fx, air airms, rws, etc) and now also a cricket. This is a really good feeling rifle. I'll be swapping a scope off another rifle (for the time being). Hopefully I'll have more to report on this tomorrow!

@dreamweaver, those are great shots! Have you found any H&N pellets (i.e. Baracuda Match) that shoot well in yours? Is it worth testing anything other than JSBs?

Here are a couple of pics:



5 shots at 37 yards jsb monsters redesigned:





Accuracy?

Umm, I realized I left the rings only finger tight. And I still was able to shoot the above group with monsters. The 18.1 and 14.3 are not impressing me yet (even with semi-loose rings). As @Dreamweaver mentioned, I may need to be patient and just pump a couple of tins through it to see how it comes with other pellets. 





Velocity testing

JSB 25.4 Redesigned on high = 875 fps / 43.2 fpe
JSB 25.4 Redesigned on high = 890 fps / 44.7 fpe (velocity is going up slightly - no change to HS or reg)
JSB 25.4 Original on high = 898 fps / 45.5 fpe

JSB 25.4 Redesigned on high (after resetting reg to 155)
HS 2 turns = 850 fps / 40.8 fpe
HS 3 turns = 896 fps / 45.3 fpe

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NSA .217 21 grain = 935 fps / 40.8 fpe

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H&N Baracuda Match 21.1 on high =960 fps / 43.2 fpe (5.51, 5.52, and 5.53 all similar speeds)

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JSB 18.1 on 2 = 690 fps / 19 fpe 

JSB 18.1 on 3 = 885 fps / 32 fpe

JSB 18.1 on 4 = 950 fps / 37 fpe

JSB 18.1 on 5 = 990 fps / 39.9 fpe

JSB 18.1 on 6 = 1005 / 41 fpe

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JSB 14.3 on 1 = 735 fps / 17.2 fpe

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Crosman Premiere Ultra Magnum 14.3 (155 reg / 2 hammer spring)


CPUM on 1 = 730 fps / 16.9 fpe
CPUM on 2 = 850 fps / 23.0 fpe
CPUM on 3 = 930 fps / 27.5 fpe
CPUM on 4 = 1005 fps / 32 fpe
CPUM on 5 = 1030 fps / 33.7 fpe
CPUM on 6 = 1050 fps / 35 fpe



Trigger adjustment

Just over 1/2 clockwise turn on the rear screw with a 1.5mm allen. Gun would not cock at 3/4 turn clockwise. Making this change also eliminated a small step that I felt as you increased pressure on the 2nd stage. This brought the trigger to a very crisp state. I would estimate that making this change turned it from a 2.5 to 3 lb trigger to 1.5 to 2 lb trigger. I still have a little more room to further lighten it if needed.

I have updated my earlier post with more velocity tests and some trigger adjustment info.

A few updates regarding the gun:

I notice when shooting down to about 150 bar that the reg drops further. It shows about 125.





Here are the gauges at a higher working pressure. The reg looks to be set at about 160 bar:



I have NOT adjusted the hammer spring preload. The adjuster head is turned in 3.54 mm:





Here is some testing with JSB Monster Redesigned (by far its favorite food) showing changes in impact at the lower settings. I am calling high power "5". I began and ended in top-left group so that is 10 shots while the others are 5-shot groups. The lowest power shots hit too low and were not on paper.

Power 5 = 890 fps / 44.7 fpe
Power 4 = 830 fps / 38.9 fpe
Power 3 = 770 fps / 33.5 fpe
Power 2 = 687 fps / 26.6 fpe
Power 1 = 580 fps / 19 fpe



NSA 217 21 grain vs Monster Redesigned 10-shot groups @ 50:



Monster Redesigned vs. Monster Originals vs. H&N Baracudas (5.51, 5.52, 5.53). 5-shot groups at 50:





Note: No changes have been made to the hammer spring or regulator so far. All set as delivered. It is now wearing a SightMark Citadel 3-18x50mm:

I finally took the time to chrony a full string. This is with all the original settings after running about 300 or 400 pellets through it to break it in.

• 250 bar fill 
• Regulator gauge setting = 155-160 bar
• JSB Monster Redesigned (25.4 grain)
• 60 shots
• Power adjuster (transfer port) on high
• Extreme Spread = 15 fps (1.7%)
• High / low velocities: 899 fps / 884 fps
• Average fps = 891
• Average fpe = 44.8
• Ending tank pressure after 60 shots = 170 bar

I did shoot another 10 shots that are NOT included in the above string. Shot velocity dropped below 880 fps by shot 64 and by shot 70 the velocity was around 860 fps and the tank pressure showed 150 bar.

Simply going by the sound of the gun, it does feel like it can be tuned to be more efficient. I decided to turn down the regulator. I used the technique mentioned here in AGN (in another thread) of taking a shot while simultaneously turning the regulator's external adjuster. This was pretty easy to do. I took four shots and was able to move the adjuster a little bit each time. 

While I did not do a full string at this setting, I did begin to test hammer spring settings. I found that turning counter clockwise (backing out the adjuster) lowered velocity. Backing out the adjuster until it is flush with the receiver and then turning one turn in is my starting point here. The regulator gauge now shows about 140 bar.





HS 1.0 = 775 fps
HS 1.5 = 830 fps
HS 2.0 = 850 fps
HS 2.5 = 860 fps
HS 3.0 = 860 fps

So two turns on the HS seemed about right at 140 bar. Going to 3 turns gained a little velocity. I did do 3.5 turns and saw no gain in velocity and the shot sound got noticeably louder. So 850 fps with the monsters still leaves the gun shooting at 40.8 fpe.

It's reasonably quiet. Louder than my FX Royale and Air Arms S510 but much more quiet than a Kral Bigmax that I had. I am OK shooting it without a LDC in my yard. However, with a LDC it's phffft quiet. I have shot it without the shroud and it's as loud as my Kral. So the barrel shroud is certainly effective. I do have a couple of acres where I live. If I was in more of a residential area, you would probably want a LDC on it.