GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Bill G on May 21, 2016, 07:59:59 PM
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(http://i27.photobucket.com/albums/c179/BillGreathouse/20160521_140632_zpsuc1qmtuh.jpg) (http://s27.photobucket.com/user/BillGreathouse/media/20160521_140632_zpsuc1qmtuh.jpg.html)
Just finished a rechambering of my .25 GM barrel. and have been working on some stuf to shoot through it. You all know about my swaged and knurled slugs that I've been working on and this is a new addition to the test list. I REALLY hope that these shoot well. What is pictured here is a 46gr. partitianed HP with flat base. Check them out.
Bill G
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Those look like they would leave a nasty hole in something. Are they accurate?
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Don't know yet. Got to get the barrel back on the rifle and gas it up. I'll keep you posted. Just discovered that both my tanks are under 2200psi. Grrrr that works fine for the boys 1200psi reged 2245's but no good for a M-rod.
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"Petal Bombs"....
Bob
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LOL.... That might be a fair assessment Bob. I was just putting things together and getting it ready to shoot some. In my hast, I apparently forgot to tell the mill to do a little circle interpolation. This left me with a 1/4" spot face instead of a .281". yea really. If you could see them up close. You can see into the nose cavity with light shining through the sides. If it sheds all 4 petals upon penetration, it will probably still weigh ~35gr+. I'm thinking that ='s big wound channel but still good penetration.
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Very interesting. Looking forward to your results. Let me know if you can part with some that I could run some tests with.
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These fit the GM barrel pretty loosely imo. The choked portion isn't as tight as a standard TJ barrel. They feed into both cambers very nicely and the TJ liner is just superb. The o-ring is a PAIN and doesn't give a true feel. These things start out as a .2437 slug and end up .2517 after the knurl.
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They look cool Bill. I hope they shoot well for you.
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Thanks..... ME TOO.
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those look absolutely devastating
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I can tell just by looking at whatcha got there, they will expand and shed those petals for sure. I like the concaved nose design there which should aide in expansion with the help of the HP opening and the cuts.
How fast it opens and sheds will be the main question. I think they look awesome.........
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Just a thought, but I wonder how loud they whistle at 850 FPS and if they do, that might be a good thing! Aim Fire and the varmint freezes and looks over at you to see where that crazy noise is coming from and it pops it one right between the eyeballs :o
Sorry just had to put a little fun into it lol
Anyway those may just work out pretty good, as long as they are balanced and they slide through the air without any turbulence affecting them.
I see a nasty hole is going to be made with those thats for sure.
Good luck and let us know how they group.
William
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Just a thought, but I wonder how loud they whistle at 850 FPS and if they do, that might be a good thing! Aim Fire and the varmint freezes and looks over at you to see where that crazy noise is coming from and it pops it one right between the eyeballs :o
Sorry just had to put a little fun into it lol
Anyway those may just work out pretty good, as long as they are balanced and they slide through the air without any turbulence affecting them.
I see a nasty hole is going to be made with those thats for sure.
Good luck and let us know how they group.
LOL I wondered if they'd whistle myself. The boys have some nerf guns that have these small openings at the leading edge is the rubber tip and they whistle when they are sent flying.
William
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I can tell just by looking at whatcha got there, they will expand and shed those petals for sure. I like the concaved nose design there which should aide in expansion with the help of the HP opening and the cuts.
How fast it opens and sheds will be the main question. I think they look awesome.........
Thanks Cedric. The nose is obviously lighter and the weight is a bit more behind center. Hope they shoot well to around 100yrds at least. After 100yrds the energy might be too low to effectively deform the slug.
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Just a thought, but I wonder how loud they whistle at 850 FPS and if they do, that might be a good thing! Aim Fire and the varmint freezes and looks over at you to see where that crazy noise is coming from and it pops it one right between the eyeballs :o
Sorry just had to put a little fun into it lol
Anyway those may just work out pretty good, as long as they are balanced and they slide through the air without any turbulence affecting them.
I see a nasty hole is going to be made with those thats for sure.
Good luck and let us know how they group.
LOL I wondered if they'd whistle myself. The boys have some nerf guns that have these small openings at the leading edge is the rubber tip and they whistle when they are sent flying.
William
oops got my reply inside the quote.
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Man those things look like they will do some damage. As long as the nose holds together until impact loosing those petals in the critter would be a good thing imo. Creat 5 wound channels instead of 1. Lots of bleeding and damage that way. Got some pb ammo set up like that. They are nasty. Looking forward to how these perform for you.
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Bill,
Just save me some for testing on game and some new CLEAR test media i'm dying to try.
Hopefully here soon (friday) my new 25 (.250 cal) will be complete so i can start tuning and shooting her.....ARRRRGH, the wait!
And you had to come out with these like right now.....lol
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Bill,
Just save me some for testing on game and some new CLEAR test media i'm dying to try.
Hopefully here soon (friday) my new 25 (.250 cal) will be complete so i can start tuning and shooting her.....ARRRRGH, the wait!
And you had to come out with these like right now.....lol
Cedric are you using the TJ liner on this .25 build? they fit so good in the TJ liner that I've pushed them through. What weight are you panning on shooting through this build?
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Bill,
Just save me some for testing on game and some new CLEAR test media i'm dying to try.
Hopefully here soon (friday) my new 25 (.250 cal) will be complete so i can start tuning and shooting her.....ARRRRGH, the wait!
And you had to come out with these like right now.....lol
Cedric are you using the TJ liner on this .25 build? they fit so good in the TJ liner that I've pushed them through. What weight are you panning on shooting through this build?
Bill,
Not 100% sold on whether its going to be a Diabolo shooter ONLY or if BOTH slugs and Pellets. Yes, its a 14" twist TJ 250 liner with no choke. I heard they shoot pellets pretty well. So we shall see when its all done. I also plan on shooting slugs at about the weight your making and lighter as a possibility. The barrel should in theory perform well with both.
Accuracy and shot count well determine it for me. Actually, that's a lie, if pellet do extremely well, i'm still going to shoot slugs no matter what.......lol!
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Are GM barrels choaked?
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Are GM barrels choaked?
Yes sir. These slugs go into the chamber at ~.2517 and come out the choke end at .250. the resistance is extremely low when pushing one through the bore and increases for the last couple of inches. The TJ barrel liner has a constant resistance once seated and the slugs that I've measured are in the .2499 .2501 range upon exit. My current .25 cal slugs are made to fit a .243 lans and knurled up to fit a bore up to .2515.
My Green mountain barrel had a chamber size of .258 and had little to no taper going into the lans. I have since re-chambered it to better accept slugs. .258 allowed the slug to yaw as it seated and that is unacceptable. My new chamber is ~.252 and tappers in at 1.5 degrees included. Not what is typically used. My reasoning is to have a taper but allow, perhaps, a more versatile leade in. An attempt at comprimise for the sake of shooting pellets and slugs of various weight. By having the throat at .253, I think that the deviation from center axis will be minimal if at all. There been lots written on this subject and articulated far better than I might.
Bill
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Bill,
Just save me some for testing on game and some new CLEAR test media i'm dying to try.
Hopefully here soon (friday) my new 25 (.250 cal) will be complete so i can start tuning and shooting her.....ARRRRGH, the wait!
And you had to come out with these like right now.....lol
Cedric are you using the TJ liner on this .25 build? they fit so good in the TJ liner that I've pushed them through. What weight are you panning on shooting through this build?
Bill,
Not 100% sold on whether its going to be a Diabolo shooter ONLY or if BOTH slugs and Pellets. Yes, its a 14" twist TJ 250 liner with no choke. I heard they shoot pellets pretty well. So we shall see when its all done. I also plan on shooting slugs at about the weight your making and lighter as a possibility. The barrel should in theory perform well with both.
Accuracy and shot count well determine it for me. Actually, that's a lie, if pellet do extremely well, i'm still going to shoot slugs no matter what.......lol!
HAHAHAHAHA! Cedric self awareness speaks volumes.. You are an honest man.
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I hope you post some pics, here... this is interesting
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Bill, you might want to send some of your rounds to this DJ guy...
http://www.gatewaytoairguns.org/GTA/index.php?topic=109425.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=109425.0)
He has the cameras and gel.
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Thanks Scott, I will consider that for sure.
Did some experimenting last night and the evening to see just how light they can be made. 31gr is as short as I can go and maintain sufficient bearing surface. At that weight, they look like they will just break apart. Especially if they were launched from one of these hot rods out there. Estimating the required twist, it looks like 79gr is where the 1:14 twist requirement is. That leaves a lot of lead as the base.
I managed to get the spot face for the TP cut this afternoon and will assemble for accuracy testing through he GM barrel, hopefully this weekend. I'm skeptical though. The GM is a lot looser than the TJ. I'll keep everyone posted
Bill
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Very interested in the outcome. CCI makes a partitioned subsonic 22lr and they are brutal
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Ooooh I need to see those CCI's.