Another Barrel polishing question
- Thread starter DaveT1
- Start date
Instead of posting a pic of one group I thought I’d post (8) five shot groups at 50m. 1/2 inch circles.
FX Impact M3 .25, JSB 33.95gr MK2. Reg 114bar around 900fps.
Box in red was off reg.
I’m not even sure these groups are great???
But have to say it has taken a long time and polishing the barrel with Autosol to get these groups. I posted 8 groups to show it wasn’t a fluke.
When I got the gun brand new pushing a pellet through the liner I experienced uneven pressure.
It was tight at the breech and the first 2/3rds and then got loose in the last third then tightening at the choke.
Something didn’t seem right. And I would constantly get flyers.
So I can only presume these more consistent groups are a result of polishing the liner until I got even pressure whilst pushing a pellet down the liner.
FX Impact M3 .25, JSB 33.95gr MK2. Reg 114bar around 900fps.
Box in red was off reg.
I’m not even sure these groups are great???
But have to say it has taken a long time and polishing the barrel with Autosol to get these groups. I posted 8 groups to show it wasn’t a fluke.
When I got the gun brand new pushing a pellet through the liner I experienced uneven pressure.
It was tight at the breech and the first 2/3rds and then got loose in the last third then tightening at the choke.
Something didn’t seem right. And I would constantly get flyers.
So I can only presume these more consistent groups are a result of polishing the liner until I got even pressure whilst pushing a pellet down the liner.
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I have just very recently polished and reduced a very tight Choke considerably. The accuracy has increased dramatically so much so i really cannot believe what I have done to this very inaccurate gun.
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Kral NP02 Still work in progress but very pleased with it now. It has gone from one
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The groupings posted by Josh9465 and Telephonepete are not good and frankly way below average.
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Like a pigeon, you swoop down and crap on everything, then quickly fly away.
The grouping before I polished had flyers in every group And were worse before.
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I will match my open sights groupings against yours any time you like Pal but dont show one flashy group lets us see the whole session at least 6 bulls every shot fired." In every flock of Sheep there is always one with a shxxty arse. Mine will be shot with a Springer."
Thats the way to post groups all of them. Consistency is the most important not the odd good group.
25 meters (27.3 yards) distance with JSB Diabolo 18.13Gr pellets.
The bull is 2mm (0.078 inch) in size
The bull is 2mm (0.078 inch) in size
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Lol ...
Sub Par, should have done better. Not enough sighter shots taken etc ... what were you thinking man !!!
Sub Par, should have done better. Not enough sighter shots taken etc ... what were you thinking man !!!
It's that there is a wide degree of opinions in this discussion.
Polishing with bore paste , then shooting slugs for accuracy , should be a tell all. As we all know , slugs a more finicky than pellets due to added surface area of the slug projectiles.
In my Crown mk2 600mm. .25 , I noticed that after 250 shots , my accuracy tends to fade with more fliers. Build up of excessive lead, I believe.
Any thoughts?
Polishing with bore paste , then shooting slugs for accuracy , should be a tell all. As we all know , slugs a more finicky than pellets due to added surface area of the slug projectiles.
In my Crown mk2 600mm. .25 , I noticed that after 250 shots , my accuracy tends to fade with more fliers. Build up of excessive lead, I believe.
Any thoughts?
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It very well may help extend cleaning intervals to spend a little time smoothing the bore. How much it helps will of course depend on the initial condition of the bore. Most of the common manufacturing practices for barrels will leave some appreciable surface fretting which tends to strip off lead and accumulate it. This sort of microscopic roughness can often be smoothed down fairly easily with something as fine as J-B Bore Compound on tight-fitting felts or jag+patch, done with a good ball bearing rod that follows the rifling spiral.
Do bear in mind this approach is only influencing the surface roughness. Any subtle dimensional variations will remain…tight spots and loose spots on the order of ten-thousandths (0.0001”) or hundred-thousandths (0.00001”). So if you have the knowledge and wherewithal to pour a cast lap and work that out—or better still, to a slight taper—the results will be even better.
Do bear in mind this approach is only influencing the surface roughness. Any subtle dimensional variations will remain…tight spots and loose spots on the order of ten-thousandths (0.0001”) or hundred-thousandths (0.00001”). So if you have the knowledge and wherewithal to pour a cast lap and work that out—or better still, to a slight taper—the results will be even better.
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