Brocock Concept Lite accuracy issues; need input/tuning advice

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A Pull through and patches has a hard time removing built up lead in the choke. Matter of fact, it wouldn't. Had a daystate (same barrel I believe) that needed a bronze brush to get it clean. I wouldn't be afraid to make a few passes with with a brush and pull a few more patches to see if you end up with silver flakes on the patch. After a good polishing with JB bore paste, a brush was no longer needed.
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Interesting point and something I hadn't considered. I guess I can pull the barrel off and run a brush through it properly and find out.
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Id be interested in what you find. The LW barrels usually shoot decent with a variety of pellets. Thats what's a little puzzling. There chokes can run tight though. And lead quickly with the harder alloy pellet like h&n and crosmans. The softer jsb seem to perform the best in my barrel.
 
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I re-tested all my current pellet selection indoors and applying all the suggestions from everyone thus far. Everything except scrubbing the barrel for lead at any rate. I shot the groups indoors at 25 yards, no wind (and no HVAC etc.), single loaded with loading tray. Numbers next to the notes are pellet weight in grains and pellet head diameter measured with my calipers. Yes, I have micrometers but calipers will have to do for now.

Anyway, you can see the results below:



1586706022_14954869355e9336668ca5b6.74577930.jpg




The 2 JSB Monster groups are one on medium power and one on high power settings on the gun. All other groups are shot on high power.
 
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So you are way under 1 MOA indoorsat 25 yards. What are all those holes for the FTT? Sighters? How fast is high power for the lighter pellets like the 8.64 HN FTT? Wouldn't they group better on Medium for 830 to 860 fps. How fast for the Monster Redesigns? Do the Redesigns fit really tight at the skirt? The head drops right in to my .177 Marauder magazine but the skirt is so big I had to push them in with a pencil. And they chamber hard and didn't group as well as the 10.34 JSB Heavies. My max energy setting with those gave only 775 fps. High amount of barrel drag. The .177 Piranhas were also ridiculously tight in the Marauder and the FX. Baracuda hunters grouped poorly also.
 
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So you are way under 1 MOA indoorsat 25 yards. What are all those holes for the FTT? Sighters? How fast is high power for the lighter pellets like the 8.64 HN FTT? Wouldn't they group better on Medium for 830 to 860 fps. How fast for the Monster Redesigns? Do the Redesigns fit really tight at the skirt? The head drops right in to my .177 Marauder magazine but the skirt is so big I had to push them in with a pencil. And they chamber hard and didn't group as well as the 10.34 JSB Heavies. My max energy setting with those gave only 775 fps. High amount of barrel drag. The .177 Piranhas were also ridiculously tight in the Marauder and the FX. Baracuda hunters grouped poorly also.
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No, the FTT holes are a group with that pellet. That's how bad they are in my gun lol. I think the FTT are around 900 but I haven't chronoed them in a while. I'll get some updated data. The Monster Redesigns drop right in to my magazine and don't chamber particularly hard.

I cleaned the barrel today and took the whole thing apart down to the bare barrel. I made a really interesting discovery: about 9" down the barrel it had significantly less drag on a plastic jag than it did the rest of the way. I was pushing patches out the end of the barrel and as I withdrew the bare plastic jag once I got past the choke the drag decreased significantly and then for the last 9" of the barrel (toward the chamber end) the drag *increased* significantly but to a constant point until the end of the barrel/chamber. Is this normal? I think something really weird is going on. I've never seen a barrel behave like that before, choked or otherwise. I think I might have a bad barrel.
 
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Your measurement of the FTT is written as .1770 but looks closer to .24 if those are .25" squares. I would hope that any barrel would feel uniform past the leade up to the choke when pushing a patch through.
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The number isn't the group size, it's the measured pellet head diameter. The group size is about 1" which is about 4 MOA. Which is horrible.
 
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If it isn't lead build up In the first half of the barrel, I think you found your problem. Did you brush it? I'd send it back if possible.
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I brushed it with a bronze wire bore brush. Zero leading. I looked at the bore before I cleaned it and it was just mirror clean before I did anything with it. The first few patches were dark gray with dirt and oil but no lead really. If it were a centerfire rifle the bore looked like a newly cleaned bore *before* i started cleaning it. I bought the gun from Baker Airguns. I'll see if I can't get it exchanged or something.
 
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