GTA
All Springer/NP/PCP Air Gun Discussion General => Projectiles => Boolit and Pellet Casting => Topic started by: EdinGa on October 18, 2018, 09:58:19 PM
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I'm happy to report that the Urban likes the 30 grain FN. They cycle smoothly through the magazine and accuracy is acceptable too. I have the hammer spring tension at 13.5 turns and I'm getting an average of 633 fps and 27 ft lbs. Accuracy was a little under an inch at 25 yards and about an inch and a half at 40. The flattened bullets in the pic below hit my steel spinners at 35 yards.
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A recovered bullet... I'm no expert but it looks like the size is about right as cast to me. Opinions?
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IMO that looks like a perfect fit, as cast.... just like it was designed that way, huh?.... ;)
Bob
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IMO that looks like a perfect fit, as cast.... just like it was designed that way, huh?.... ;)
Bob
I'd say so, my friend. We're lucky to have you and your talents. The more I shoot them, the tighter the groups are getting, too. I have no idea what the bhn of this lead is but I can scratch it with a fingernail. I'm casting them from range scrap that I've collected from the SASS lanes at our club.
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I’ve found that the 30 gr bbt gets better the faster you shoot them . I’m using a 1:17.7 LW barrel at just over 900fps.
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When I was around the SASS guys they shot mostly subsonic, usually around 800 fps and iirc the lead hardness they tended to prefer was from about 8-15 Bhn..? and the fingernail test usually works up to about 12 Bhn..? I do think with the choke it is best to keep the hardness down about 8 or less... both for accuracy and leading...may even gain a few fps, that is just my gut feeling though... I do not think wear is a prob with the hammer forged barrel tho...
I think all BSA barrels are 1:19 twist which I think is about perfect... The Kolbe twist calc says different because of the short boattail but I think the rear band sort of negates the effect adding just a touch of drag and adding a bit of aerodynamic stability... Bob believes the twist calc but this is one time I will go with my gut feeling... plus 30g grain .22 short have done great with 1:20 twist for a long time...would love to see you take it out as far as you could hit a cardboard box and target just to check stability... I think it will be fine especially down sub 700 fps... but i do also think it will be fine up towards 900 fps also...
Sizing well if that was a non choked barrel I would say yep that looks pretty durn good but it looks like you have room to try sizing down... and honestly it may do better sized down a bit to help it get thru the choke...
so bore groove ratio looks to be about 75 groove and 25 bore with sloping sides.... and the nose looks to have .001- .0015+ engagement with the lands... so if you size down just enough that you have light engagement( just barely past bore size(bore riding) the base band should swage out enough to seal well... I do feel choked barrels are more sensitive to sizing and it may help accuracy...
Thanks to Bobs work talking with NOE, LBT etc and getting these made we are the ones exploring small bore with air... what works best is what we are learning...
see what happens when you ask for opinions.. ;)
Man This Makes me want a .22 Buccaneer to go with my .177...
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I am assuming the round was chambered and then pushed back out of the breech... not a full push thru...
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I bet those suckers penetrate really well. Would love to see the results on a mid sized critter, like a good sized raccoon.
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I’ve found that the 30 gr bbt gets better the faster you shoot them . I’m using a 1:17.7 LW barrel at just over 900fps.
I wish I had something that would push them that fast. 😊
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I greatly appreciate all of your efforts. I'm excited about the possibilities in this area. I will study everything that's said here, and I've been devouring everything else I can find on the subject. I've been loading subsonic for my powder burners, but I think this a much better alternative.
This was a fired bullet that was recovered from a water jug. It penetrated to the 3rd gallon but didn't have enough energy to peirce the plastic. Any rifling marks you see did pass through the choke. I will do my best to shoot at longer ranges soon.
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I bet those suckers penetrate really well. Would love to see the results on a mid sized critter, like a good sized raccoon.
They made it through 2 gallons of water at about 10 yards. I haven't shot anything else with them. I'm due for an armadillo or a possum soon...
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I am assuming the round was chambered and then pushed back out of the breech... not a full push thru...
It was a fired bullet that was recovered. It did pass through the choke.
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well having gone thru the choke that looks really good.. do you have a micrometer..? if so if you could chamber a round and push it back out and compare the two would give an idea how much the BSA .22 barrel are choked... heck even pics with out measurement would help...
It does look like the round is about perfect to bore ride the nose pre choke with minimal engagement as is... but if the round is dropping .217 nose and .219 base band like drawn you may be able to size the band down a bit and still seal well at .218... mine drop just a bit small at 790* and about 1.5 sn...
I also have the .220/222 mold... but I poured those really hot and they dropped a good bit small... but it fit my crosman .219" ish barrel just about perfect...
some are using light silicon oil and other lubes when sending cast from what I have read it sometimes helps accuracy & helps prevent leading...
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well having gone thru the choke that looks really good.. do you have a micrometer..? if so if you could chamber a round and push it back out and compare the two would give an idea how much the BSA .22 barrel are choked... heck even pics with out measurement would help...
It does look like the round is about perfect to bore ride the nose pre choke with minimal engagement as is... but if the round is dropping .217 nose and .219 base band like drawn you may be able to size the band down a bit and still seal well at .218... mine drop just a bit small at 790* and about 1.5 sn...
I also have the .220/222 mold... but I poured those really hot and they dropped a good bit small... but it fit my crosman .219" ish barrel just about perfect...
some are using light silicon oil and other lubes when sending cast from what I have read it sometimes helps accuracy & helps prevent leading...
I'm pouring these hot too. I've got some liquid alox, I'll lube some and give them a try. I'll mic them tomorrow too.
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I bet one of those would take out 2 possums if you lined em up right.
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I bet one of those would take out 2 possums if you lined em up right.
If I can get a couple of them to cooperate, I'll give it a try. 😊
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I do consider .5-.75 hunt-able but will always look for ways to get as close to moa as I can... yep that nice flat nose will hit hard at 28 fpe... bout like a .22 short...and much more consistent velocity than the CCI cb cap
https://www.youtube.com/watch?v=KhTyih9T9vg (https://www.youtube.com/watch?v=KhTyih9T9vg)
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I like the CCI cb longs over the shorts. 22lr in general isn't all that consistent. I do wish CCI would give us a nice flat nosed small game bullet. They do hit hard.
Is that your YouTube channel?
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yep air is like good match ammo in these small bore consistency wise... we just need to learn to use that consistency...
will be calling a gunsmith on Monday about a few 22 lr(used)- 22 WMR (Marlin new)-22 hornet(Heym blank new) barrels to convert for my .25 Mrod...
The one I planned on using retired next I check out did no machining... just found one about 40 miles away has machine and gunsmith in the name... am hoping for about mid 40s for the fpe with 22""-24" long Barrels... do have a 1950's 28" Hakim .22lr(Berreta hammer forged) barrel
but the Heym .22 hornet barrel is the highest quality of them all they hone the bore after drilling before hammer forging... so no machining marks/artifacts to get transferred to the bore and grooves... should not lead up... it is also not choked that I can feel...
BSA Barrels are know to be very good pellet barrels but I am pretty sure they are not honed after drilling...
edit nope no ytube channel and my youngest is 24...
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I like the CCI cb longs over the shorts. 22lr in general isn't all that consistent. I do wish CCI would give us a nice flat nosed small game bullet. They do hit hard.
Is that your YouTube channel?
Cci sgb- is flat nosed, almost like a truncated cone sort of.
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Cci sgb- is flat nosed, almost like a truncated cone sort of.
I haven't seen those. I'll have to check them out.
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I did a few more tests today. The first image is a chambered bullet the was pushed back out next to a fired bullet. The following 2 images are the fired vs unfired diameters as measured on the driving band.
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The difference is the choke in your barrel....I am pleased that the midbody is clearing the lands, even at the choke.... 8)
Bob
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The difference is the choke in your barrel....I am pleased that the midbody is clearing the lands, even at the choke.... 8)
Bob
You've got a winner there. It's a great bullet. I did the test to find out how much choke these BSA barrels have. I can also report that they fly straight. These shots were from my Urban at 75 yards. Impact was about 7 inches below point of aim, but I managed a decent group with nothing but a front rest. I'm sure it would do better from a bench. Note the nice round holes in the second image.
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Hmmm been thinking about the band... have you done much reading on the Urban here... When I first got my Buccaneer .177 it was not super impressive... Had two small probs... one was the stock was just a touch loose so I tightened the bolt... the second was the Barrel band it was pulling the barrel down slightly and that caused poi shift over the psi drop and caused harmonic probs... after those fixxes it stacks most pellets at 30 yards and it is .5" at 50 with Sniper mags(full fill) and 10.3 Cpum(2400 psi fill)...gotta do my part of course... 50 yard groups are about .75 if a full fill down to about 2500 psi with the Cpum... point is for accuracy may need keep it in the sweet spot in the fill with the light stuff....
and Many of the Buc, Yote, and similar will benefit from removing the Barrel band... especially with that big ole can on the end... lay it on it's side and it will want to push it to the side and the band will want hold it there...
https://www.google.com/search?rlz=1C1GNAM_enUS688US688&biw=1366&bih=626&ei=YQ_OW56eN4PYsAXyk67wDw&q=gamo+urban+barrel+band+&oq=gamo+urban+barrel+band+&gs_l=psy-ab.12..0i22i30.8850.8850..23297...0.0..0.82.82.1......0....1..gws-wiz.Q53ugP9Nvfc (https://www.google.com/search?rlz=1C1GNAM_enUS688US688&biw=1366&bih=626&ei=YQ_OW56eN4PYsAXyk67wDw&q=gamo+urban+barrel+band+&oq=gamo+urban+barrel+band+&gs_l=psy-ab.12..0i22i30.8850.8850..23297...0.0..0.82.82.1......0....1..gws-wiz.Q53ugP9Nvfc)
So yeah it may be worth you time to try taking the barrel band off... on my Buc it was easy but the Urban with the can you will have to destroy the band or degas and pull the barrel... But free floating the barrel seems to me the right way to go...
speaking of the can do not try to fire a double feed out cause that will kill the can and these will double feed...
Thanks for sharing the results with your QB and Urban...you and I have shown that even down at ~20 fpe these 30 grainers will work for 30-40 ish yard hunters... I love the independence of that thought...
sub 1.75" at 80 yards with a 105cc air tank, when you think about it... is amazing... if the barrel band is tight as the pressure drops in the tank it should/could be causing wandering poi issues... had a strong feeling the round would be stable...
as far as barrel fit just wow they do fit your Qb and BSA barrels very well...as they drop... you may be able to size to 218-2185(it would just size the rear band) with the BSA.. but no guarantee of improving results... same with sizing to same then knurling... may help may be worse... heck just to cover bases I would try lightly knurling them with a fine file as is...
that and cutting the range scrap with 50% pure pb are the only other things I can think of that I would be trying long/short term...
Do not know how far to trust digital Vernier calipers as far as absolute accuracy... but do believe they are consistent enough to show the amount of choke... one of my kids got me a Fowler 52-229 Series mic that make me just a bit more confident about measuring to .0005...
Wish I was doing more myself right now but ran into some health issues a few months ago and it has slowed me down some...
If I was hungry with your results I would chance a 80 yard body shot on mister bunny as is... and every shot in the group would have made a chili can dance.. :D
Like I said thanks for sharing your results I think they are the first from a Qb and Urban and add just that bit more to the knowledge base...
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wish ya lived nearer to here... got about five dozen eggs that got left out to shoot at.. ;)... My youngest likes to draw quick vampire zombie faces on them...
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wish ya lived nearer to here... got about five dozen eggs that got left out to shoot at.. ;)... My youngest likes to draw quick vampire zombie faces on them...
Not many airgunners around me. It would be nice to have someone to shoot with.
I appreciate all the knowledge you've shared. I cut my barrel band off awhile back. The Urban has been a tackdriver so far. It loves the 15 and 18 grain JSBs and the Crosman ultra mag. I'm not giving up on squeezing some more accuracy out of these bullets. I lubed some with Hornady Unique case lube this afternoon and the results were promising. I'm going to try Lee liquid alox tonight and see how it does. I'm having so much fun casting and shooting them that I refuse to give up until I know I've done everything I can to stack one on top of another.
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Had to take a look at the MSDS for the case lube...mainly mink oil and tallow and some glycerol esters... Eley Tenx uses tallow and bees wax base... bet they work about the same... the Tenx may leave a bit of wax residue tho...
They like to brag about the flat nose being better for stability...
"
The iconic flat nose projectile of ELEY tenex is one of many innovations pioneered by ELEY engineers. As it cuts through the air its revolutionary design pulls the centre of pressure forwards, aerodynamically stabilizing the projectile and increasing accuracy at the target.
"
Eleys misspelling of center not mine.. ;) I copied and pasted...
I can not say for sure(not an scientist) but I did drink that koolaid a while ago... I also think it moves it forwards at lower velocities about 600 fps or so... it is not the only factor but I do think it does play a part...
just for histories sake;
Bob has worked on perfecting these for a good while now... in the below thread is I think the earliest version... a .25 50g that he came up with in 2013...
https://www.gatewaytoairguns.org/GTA/index.php?topic=54796.40 (https://www.gatewaytoairguns.org/GTA/index.php?topic=54796.40)
This is the thread in which Bob decided to draw up the 30g .217 and 40g .250.... I also talk about buying into the flat nose stability stuff then .. ;) Oct... 2015
https://www.gatewaytoairguns.org/GTA/index.php?topic=98605.40 (https://www.gatewaytoairguns.org/GTA/index.php?topic=98605.40)
then with NOE being willing and able to produce a slightly larger size of the same designs it helped us and our non standardized barrel sizes...
Me I started really believing in the concept when he went to the bore riding nose and rear band... my gut says that is a good stable design... with all the right compromises to work with air still have a good B.C. and have enough meplat to hit hard for hunting... There are some good powder burner 22-223-224 and even .227 molds out there but none that were designed for air and none that were light weight enough to send out of a 20-35 fpe stockish rifle or a some what modded 40+ .22 Mrod(or other some what inexpensive rifle) based power plant...
I think the .25 50g BBT is a better round than the 40g if you have the fpe... but with only 50 fpe of a stock Mrod I think the 40g is a better choice as a 25-50-75 yard hunting round...in my mind it is basically a rebated boat tail semi wad cutter that has the potential to out perform any of the available pellets... especially if hollow pointed.. ;)
But yep Bob has put some real effort into getting these perfected and made... and am glad he did...
It is catching on bit by bit and gathering momentum imo...Sending cast rounds started years ago with the big bores .257 and up... I am hoping we can help the momentum by making the smaller bore stuff work...Making it work with a stock Gamo Urban sub 30 fpe and with a Qb at about 20 fpe shows just how accessible it can be... do not need the big tanks and $$ to make big power with big bores for it to be useful...
Do not get me wrong accuracy at 400 yards with a .257 and up is important too...but the accessibility factor of the small bores will help move things forwards I hope...
Looking back at the one thread boy my concentration probs really show at times and in the process of typing things out sometimes I get some stuff backwards and unclear or just wrong.. :-[
in the end I am just glad when things work to a useful degree.. ;)
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Sorry just have to post a bit more because there were many that say that you can not send slugs out of a choked barrel and some still do... I have said you can from the beginning... just takes more care...and a lot depends on how much it is choked, how abruptly, how stiff of a barrel etc... Do not get me wrong a good un-choked barrel is not worse than a choked Barrel... But if you can get the choked barrel working with cast...the choked barrel tends to be less pellet picky than many un-choked pellet barrels... and there are many choked .22 lr barrels... the 1956 Beretta is.. ;)
also in the thread there is some about the BBT .217 from a Modded discovery...plus a chart I made with chair gun showing the BBT .217 vs JSB and just how much of an advantage the BBT has in Knock down power and in the wind... Pretty sure it is true down at 27-30 ish fpe also... maybe I will make a chart at that fpe level... what velocity are you getting best accuracy with the 18s..?
But yep it has dime sized grouping at 900 fps in the wind at 50 yards out of a choked L.W. barrel just for some inspiration...
https://www.gatewaytoairguns.org/GTA/index.php?topic=121728.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=121728.0)
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I love to plink and I'm a tinkerer at heart, so the development of what I see as a better alternative to diabolo pellets has my full attention. I've been building low velocity, quiet loads for my powder burners for a while now, but I think air power is the solution I've been after the entire time. I get my lead for free, and I have the satisfaction of creating an accurate projectile with my own hands. It doesn't get much better than that.
If I remember correctly, the 18 gr JSBs were running around 740 fps. I turned up the power when I switched to the 30 gr bullets. I need to try the JSBs at this power level and see how they group.
I'm grateful for all the time and effort you put into your comments. I don't have much to add right now, but I'll contribute to the cause any way I can. I'm a hand pumper, and I don't have the budget for a big bore or a compressor. If we can prove this concept with stock pcps, I think more guys like me will get on board.
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wish ya lived nearer to here... got about five dozen eggs that got left out to shoot at.. ;)... My youngest likes to draw quick vampire zombie faces on them...
Not many airgunners around me. It would be nice to have someone to shoot with.
I appreciate all the knowledge you've shared. I cut my barrel band off awhile back. The Urban has been a tackdriver so far. It loves the 15 and 18 grain JSBs and the Crosman ultra mag. I'm not giving up on squeezing some more accuracy out of these bullets. I lubed some with Hornady Unique case lube this afternoon and the results were promising. I'm going to try Lee liquid alox tonight and see how it does. I'm having so much fun casting and shooting them that I refuse to give up until I know I've done everything I can to stack one on top of another.
Following.
Nice group. What distance? Thank you.
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Eddie when I'm shooting these bullets from my SPAM16@42FPE they're like a laser!
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Following.
Nice group. What distance? Thank you.
20 yards. I'm going to stretch it out further this afternoon if I have time
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Eddie when I'm shooting these bullets from my SPAM16@42FPE they're like a laser!
That's good to hear. I've been looking at those since I saw your posts about them. I want something with more power as soon as my budget allows.
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Ok so I see Chairgun not as gospel just a pretty decent useful estimate...Did a comparison chart using a .5 sight height(advantage of not having the Magazine stick up like on other budget multi shots)... I like low mounting scopes is best for point blank range...
So I set zero for optimum PBR for each round and that set zero range... .5" kill zone...
Red is 30g BBT at 633 fps(~27fpe) zero is 20 yards with a PBR from 2.5-23.1 yards...
Blue is JSB 18.1 at 820 fps(~27fpe) zero is 25 yards with a PBR from 3.1-28.8 yards...
Green is JSB 18.1 at 740 fps(~20fpe) zero is 23 yards with a PBR from 2.8-26.4 yards... original setting with JSB for longer shot... count(part of the beauty of being able to send BOTH CAST and PELLETS).. ;) 8) ;D
Now the BBT does not shine so bright as it does when both are able to be sent around 900 fps but it still does show very well especially when you consider how hard that flat meplat hits compared to the lighter round nose projectile... like I said at these fpe levels I consider it a really good 40 ish yard hunting round...
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For me estimating range is a strength I am pretty good at it out to about 60 yards or so...no range finder just trained my self over the years starting when I was young using football fields, string with knots, small flags, angles and such... and drop is predictable... wind well sometimes it drops or rises suddenly and other factors... terrain cased turbulence etc... point is wind has a larger uncertainty factor for me in real life...
I did chart out the below just am not posting them...
So if I misjudge the range say I hold for 35 yards when it is 38 yards(about the very worst I would do imo) with the 27 fpe BBT it will be low about .4" (still in the .5 Kill zone)... the 27 fpe JSB is only low about .2"... Now I have to say usually I am within a yard +/-... especially on level ground...
now add 10 mph gusting wind that rises and drops very quickly... gotta make the shot before Mr squirrel/rabbit moves so may not be able to wait for calm or consistent wind... so it ends up I hold for the 10 mph and it is really 3 mph cause it dropped... with the BBT will hit about 1" right... the JSB hits 1.5" right...
Now add for ~half your group size(for the 40 yards) in dead calm conditions... say .25" with the Urban... so for a head shot need to get closer... and will need to get even closer for the JSB than the BBT(if getting same size groups at 40 yards calm)... If I was hungry would do the 35 yard body shot with the BBT but not the JSB... That flat meplat and a 2+ fpe advantage will hit a good bit harder...and the BBT can be hollow pointed...
Back when I hunted with a Benji .22 and green tin Benjamin at 18fpe the wind/mildish breeze took my range for a shot down to about 15-20 yards from 30-35...
So just trying to show even at lower fpe as long as I get them accurate... I would still prefer the BBT... even without the big factor of the independence of it...
Boy I talk a lot some times... but I do like the idea of being able to send cast and pellets from the same hardware with no adjustments... or just some adjustment for shot count with light pellets...
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Boy I talk a lot some times... but I do like the idea of being able to send cast and pellets from the same hardware with no adjustments... or just some adjustment for shot count with light pellets...
I'd love to sit down and have coffee with you sometime. I would bring a pen and a notepad.
I didn't have time to do any testing today, but I'll try to respond to some of this tomorrow.
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I like my coffee... right now I am on a fancy kick and drink a high altitude Peruvian med dark roast mixed with 1/3 chicory 1/2 tsp each of Stevia & sugar.. ;) from a french press(wake up treat)... got store brand( Fred Meyer) too for the rest of the day... The chicory thing is from when I was young... sometimes I will just get a can of https://www.walmart.com/ip/French-Market-Coffee-Chicory-Dark-Roast-12-Oz/46142532?wmlspartner=wlpa&selectedSellerId=0&wl13=3167&adid=22222222227000000000&wl0=&wl1=s&wl2=c&wl3=42423897272&wl4=pla-51320962143&wl5=9033625&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=local&wl12=46142532&wl13=3167&veh=sem&gclid=EAIaIQobChMIqNTnz6qi3gIVDH1-Ch0F9AvFEAQYASABEgJoGvD_BwE (https://www.walmart.com/ip/French-Market-Coffee-Chicory-Dark-Roast-12-Oz/46142532?wmlspartner=wlpa&selectedSellerId=0&wl13=3167&adid=22222222227000000000&wl0=&wl1=s&wl2=c&wl3=42423897272&wl4=pla-51320962143&wl5=9033625&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=local&wl12=46142532&wl13=3167&veh=sem&gclid=EAIaIQobChMIqNTnz6qi3gIVDH1-Ch0F9AvFEAQYASABEgJoGvD_BwE)
From the above 20 yard group can extrapolate a group of about .75-.80 ctc at 40 yards same conditions... bad conditions 3-7 mph wind(with practice) eh about .75"-1"...imo...
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Centre looks perfectly spelt to me :)
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Well it rains a lot there so I guess the water tort-your has affected your minds.. ;) like the Washingtonians on the other side of the Cascades... I is on da udder side O' da hill in the rain shadder...
Doy werrit I woe throo a wobbly abart it... it is a brummie rifle senden the boolit... So spelling it centre...I wull gie it a goo!
Not all yaouw lot am yampy as Ozzy ...
;)
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the post #34 charts were conservative on the B.C. of the 30g BBT... I used .0634... well turns out it is .08 ish... so expect a bit better performance than shown.. ;)
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charts show B.C. used for the JSB...