GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Big Bore AirGun Gate => Topic started by: rsterne on October 13, 2015, 06:50:23 PM
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I have been contacted by Al Nelson of NOE Bullet Molds and I am supplying them with a bunch of my latest designs for Bob's Boattails.... They made be found here, there is a separate thread on each design....
http://noebulletmolds.com/smf/index.php/board,24.0.html (http://noebulletmolds.com/smf/index.php/board,24.0.html)
All these designs follow the concept used in the "Whiteout" with only two points of contact with the barrel.... the rear of the nose Ogive and a driving band at the back, just in front of the boattail.... All designs 2.0 calibers and longer use the new 8* boattail, while shorter bullets have the older 10*, as they are too short for the shallower BT to fit.... I am supplying Al with designs for several weights in different calibers.... If you are interested in any of them, please register on the NOE Forum and comment on the thread for each mold you might be interested in getting.... That way Al can measure the interest on the various weights....
The drive bands will be enlarged to 0.002" over the caliber (thanks, bluethunder!), plus all designs can be made to whatever diameter you want, within reason.... I am not receiving any compensation from NOE, my only interest here, as always, is to increase the quality and availability of boattails for airguns....
Bob
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I really hope this works out. Any chance they'll make the Whiteout bullet as well?
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Anyone selling the cast boolits yet?
Not much interest in casting, but I do want to shoot them.
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Good deal Bob. Glad it worked out for you. I'll defiantly be ordering one soon I hope.
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Great stuff Bob!!! I am going to "MOZEY ON OVER" to the forum and register to put my 2 cents in!!!! ;)
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Once Al has all the lighter SD designs on the website I will request the Whiteout, plus a 172 gr. .308cal I have drawn up.... and also a 111 gr. in .257.... and maybe a 7mm or two if I can, also some .224s.... He is working on the .40 and .45 cal drawings now, and I will be sending him some for airgun barrels in .217", .250", and .300" next.... What gets produced will depend on feedback....
Bob
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Let's hope NOE can follow the print LOL. One thing I've from several casting experts is that Veral makes the bullet he wants which often doesn't match what was asked for. I assume that NOE doesn't have the limitations of Accurate regarding the metplat and boattail diameters. Good stuff to follow :)
Tom
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NOE can make Spitzers or small Meplats, no problem there.... They can do narrower Boattails than Accurate, Al will be having speaks with his toolmaker to see how small they can go.... None of my designs are smaller than 70% of the caliber, so hopefully they can do that....
Bob
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I hope bullet casters from here jump in because lately it is been very hard to people get interested small calibers like .257, 223, etc
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I'd be in for a .224...:) I have the 14" twist TJ barrel so that perhaps puts a crimp on my OAL/weight...going to get a .225WFN from NOE as soon as he has made a 3-cav with one HP pin( love that huge meplat ). A BBT would not be unwelcome.
cheers,
Douglas
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Teemu, part of the problem is that Accurate wouldn't do molds smaller than .30 cal.... or bases smaller than 0.25"....
Douglas, the problem is that once you add a boattail, your twist rate may not be enough.... I drew up a 39 gr. in .217 cal last night, that would fit a Hatsan (or MRod .25) magazine, and it needed a 12" twist....
Bob
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Teemu, part of the problem is that Accurate wouldn't do molds smaller than .30 cal.... or bases smaller than 0.25"....
Douglas, the problem is that once you add a boattail, your twist rate may not be enough.... I drew up a 39 gr. in .217 cal last night, that would fit a Hatsan (or MRod .25) magazine, and it needed a 12" twist....
Bob
Size it up to about a 1.7-1.8 caliber .224 and I bet 1:14 is just about right, at 2 calibers and 41 grains it was a 1:12 twist in this thread
http://www.gatewaytoairguns.org/GTA/index.php?topic=83019.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=83019.0)
I am crazy enough I would try it in my Marlin barrel 1:16 twist (which a friend said stabilized the 60g subs out to the 50 yards he was shooting)( found a y-tube vid of that also)
I think that a .224 (35-40g)that did not need big power mods just a barrel to work with a stock Mrod and such might be a big seller because of being an easy path to cast... would even be hand pumpable...
another big seller would be a light .25 that worked in a stock Mrod .25 barrel... tall drive bands with a body right about choke size?
Hmm I think we need a New Gate ;) Cast boolits for PCP.......
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Teemu, part of the problem is that Accurate wouldn't do molds smaller than .30 cal.... or bases smaller than 0.25"....
Bob
That's why I have about 40 NOE's mould. And that is only place at this moment who makes spitzers...But even if You find nice mold we need 10 buyers to get that mold if that isn't already on NOE's list. Inventory runs need only 5 buyers
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Al has been my "Go To" Mold maker for the .257, and I couldn't be happier! Superb in all respects. Good looking molds, bullets, and stellar accuracy 8)
Knife
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Yeah that's true. I got all .257 mold's which NOE has made so far ;D...ouch, wait one version hasn't got both PB and GC version..
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There is not much attention what should wish to get those BBT-molds... or I'm just impatient. But still wish that bullet casters here who are interested those Bob's molds would come and say they words on NOE's forum.Really liked to get those in NOE's version..Thanks
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More calibers and weights now posted.... Designs are there in .224, .257, .308, .357, .408 and .458 calibers for those using PB barrels, plus .217, .250, and .300 for the airgun only barrels.... I have sent Al some 7mm (.284 cal) as well.... Anyone interested in 6mm (.243 cal) make a post over there and ask, and maybe Al will let me add that....
http://noebulletmolds.com/smf/index.php/board,24.0.html (http://noebulletmolds.com/smf/index.php/board,24.0.html) .... Just don't say I prompted you.... :P ;D :o
It is important that anyone interested in cast bullets post in that gate, in every thread that has a bullet you would like to own or have a serious interest in.... The ones that are the most popular will likely proceed either to production or to a group buy.... If you don't say anything, this will all just fade away, I would imagine....
Bob
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It is important that anyone interested in cast bullets post in that gate, in every thread that has a bullet you would like to own or have a serious interest in.... The ones that are the most popular will likely proceed either to production or to a group buy.... If you don't say anything, this will all just fade away, I would imagine....
Bob
I have sent Al some 7mm (.284 cal) as well.... Anyone interested in 6mm (.243 cal) make a post over there and ask, and maybe Al will let me add that....
Bob
I'm interested that 6mm...
Usually it takes 10 serious interested people to make new designs to get Group Buy...I've seen exceptions but that's different case. So if some timeline designs don't get needed attention then it is frosen... That why I'm making noise for these topics because it is sad if this goes gutter
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I too wish more people would be open to Bob's BBT concept. I really believe he is onto something... Advancing the sport is what it's all about... Great job Bob! I will have every BBT mold I can get my hands on! 8)
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The Whiteout showed me where I wanted to be, and when I used the McDrag program to optimize the relationship between bullet length, ogive and meplat, I knew I had the ability to scale bullets between calibers.... Al came along just at the right time, and we ended up with a repository for all my designs in one place.... Who knows how many will actually reach production, that will depend on interest, and ultimately performance, which will generate more interest.... For me, it's great just to see them all developing the way I always hoped....
Bob
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I'm very interested in the 135 and 154gr in .308. I just can not commit to buying anything right now. I will get a mold of each as soon as I can afford it.
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I understand about not committing right now.... but please indicate your interest, and then when/if there is a group buy you can jump in if you want.... This is to give Al some indication where to start....
Bob
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OK I'll go ahead a register and post on each mold.
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I'm very interested in the 135 and 154gr in .308. I just can not commit to buying anything right now. I will get a mold of each as soon as I can afford it.
It may take several months to get that 10 buyers. Main thing is there is coming interested buyers now and then...There is so many molds at on lists that when it goes on mill that even takes week or so. tooling ordering take several days. There is plenty of time to wait I promise You.And that just says You are interested that not mandatory thing...Some people draw back even when group buy is on going but like Al ones says better jump of then that GB than not paying that mold when it is ready. And if I remember correctly there is 60 days timeline to pay that mold when it is ready
Edit: OK I see You find that topic.
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I have posted my interest there! 8)
Thanks Bob! ;)
Knife
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Bob
I am comparing the .408 252 gr boattail on the Accurate Mold site to the 266 gr boattail on this post. I have a 40 cal Extreme from Brent. Which of the two should be more accurate and effective on deer.
Thanks Ray
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The NOE bullet is slightly longer, with a narrower boattail, a longer ogive, and a bit heavier, so it should have a better Ballistics Coefficient.... It will, however, require a somewhat faster twist because of those changes.... I am recommending a 23" or faster twist for the new NOE bullet.... the Accurate had a recommended twist of 26" or faster.... I do not know what twist rate Brent uses in the Extreme .408.... They both have the same diameter Meplat, and the weight is close, so there should be no difference in their performance on game.... In the proper twist barrel, there should be no particular difference in accuracy.... although the better BC will mean less wind drift with the NOE bullet.... They both have the same length supported by the rifling, greater than one caliber....
Bob
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Thank you Bob for your reply. This is very helpful and much appreciated. I think the twist rate is one in 22
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Thank you Bob for your reply. This is very helpful and much appreciated. I think the twist rate is one in 22
Hello Ray...You may want to check with Brent...pretty sure its 1-32 twist...kind regards, Al.
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My Extreme .408 has a 1:32 twist
FredSG
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I think you guys are correct. I must have been thinking of another gun
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I'm interested. Where can we get faster twist barrels to stabilize the longer boolits?
I know that my ballistics program recommended that I use a 1:13" twist barrel for stabilizing the H&N Piledriver.
What is the lightest. 217" BBT that could be produced with one of these molds? I would like to try some in my springers if I can get them at a light enough weight.
Also interested in .30 or 7.62mm slugs in the 50+ range.q
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It is not practical to create a boattail in a really short bullet.... there is not enough length left for the bearing area.... The absolute minimum length I can do is 1.25 calibers, although 1.5 calibers is better....In .30 cal, there is a 1.25 cal long design, it weighs 68 gr.... If that bullet was scaled down to .250 cal it would be 39 gr.and require a 22" twist.... and in .217 cal it would be 26 gr. and need a 19" twist... At 1.5 calibers long in .30 cal the weight is 80 gr.... In .25 cal that would be 46 gr. and require an 18" twist.... and in .217 cal it would be 30 gr. and need a 16" twist.... If anyone wants cast bullets of those weights, please post in the Airgun Board at NOE, giving your reasons, and I will submit them to Al and hopefully he will include them in his catalogue....
Bob
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Bob do you use G1 or G7 on the ballistics calculators for this bullets?
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The program that Al at NOE uses calculated the BC using the G1 Model.... I usually use that as well because it is much more commonplace.... Since we are not interested in Supersonic, and both are relatively flat in terms of the Cd in the Subsonic range, there isn't a huge difference in the shape of the curves, only the baseline, in other words the value of the BC.... Nobody else uses G7 for the types of bullets used in airguns, they are all using G1, so I don't see any point in comparing apples to oranges....
The only proper way is to use a Doppler Radar to determine the Cd over the entire velocity range as the bullet slows down, and I hope someday to have a LabRadar to collect that data.... Then I will be able to develop my own Drag Model for the BBTs....
Bob