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rsterne
I have challenged Al with trying to come up with a method to make all mould cavities hollowpoint, where the Meplat is less than the 0.200″ diameter that is now his current minimum to use the RG pin system…. I have had the idea for quite a while of modifying the venerable Lyman 257420 to specialize it for airgun use by eliminating the lube grooves and making a parallel mid-body that just clears the rifling lands, while at the same time creating a small boattail in place of the original gas check stub…. The nose of the bullet and the front and rear drive bands remain exactly the same, as does the LOA…. If combined with a hollowpoint, to keep the same CG as the original Lyman GC design, I see no reason why this should not be an excellent upgrade to what is currently the “go-to” airgun bullet in .257 caliber…. Here is a drawing of what I propose….
I have checked the stability using the Kolbe Twist Calculator, and it should still work perfectly in a 14″ twist, which is the most common used in .257 PCPs, which often use the excellent and easily available TJ’s liner of that twist rate…. If you are interested in seeing this design produced, with replaceable RG style pins that would allow both the FN and HP configuration, please add your name to this thread and we will see if we can get Al excited enough to take on this project….
I’m in for an RG4 in aluminum, please….
Bob
rsterne
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Not recently, I’ll call him when I get a chance…. Last I heard was he was working on getting the small diameter RG pins working, I believe the first mould to have those available will the the .224 cal 57 gr. here….
http://noebulletmolds.com/smf/index.php/topic,2452.0.html
If that is successful, then I would hope we will see several other RG moulds for bullets with Meplats less than 0.200″ follow…. I do know that NOE had a production problem a couple of months ago, and are still digging their way out of the backlog….
Bob
These moulds are now in the Store…. 75 gr. FN or 72 gr. HP….
http://noebulletmolds.com/NV/index.php?cPath=26_603
In addition, a shorter, lighter FB version is also available…. 63 gr. FN or 60 gr. HP….
http://noebulletmolds.com/NV/index.php?cPath=26_604
All moulds are either RG2 or RG4, and come with three sets of pins for HP, Cup and FN…. in aluminum or brass….
Bob
owencoors1
I received mine this past week. These bullets are casting at 71.122 grains each, with my lead. I removed my 1:10″ twist barrel, sized some down to .253″ and shot them through a 1:15″ twist Green Mountain barrel, choke removed, but at 50 meters they were keyholing very badly. I have an Ideal 257420-GC that Erik modified to hollowpoint. On this particular mold he had to shortened the nose .009″ to make it work, or the bullets would be significantly heavier. Those bullets go 67.85 grains and sized down to .253″ , through the 1:15″ twist GM barrel, they will allow 6-shots to go into a 3/8″ group at 50M.
So I put the 1:10″ barrel back on and lo and behold, the Noe 257420-BT-HP bullets shoot well, 7/8″ at 100M. I have a Green Mountain 1;14″ barrel blank, 25″ long, 1.060″ diameter, but I need to turn it down and fit it in the Airforce frame before I get to see how they shoot through that. I’m quite pleased with the way that the 1:10 twist barrel is stabilizing this bullet. I would not have thought that they would group this well at this twist rate, but they certainly do.
thomasdeyo
denisbeaudry
owencoors1
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