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PostPosted: Wed Dec 14, 2016 12:48 pm 
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Location: Coalmont BC
As detailed in my thread on my .257 Monocoque PCP, I had NOE make moulds for my 101 gr. and 112 gr. Bob's Boattails.... I asked Al Nelson if there was any way he could convert them to a HP, and the best he could do would be to make one cavity a HP using a Lyman style pin, the next time he ran some moulds.... So, I contacted Erik Ohlen at Hollowpoint Mould Services in Oregon, and he agreed to do his Inset Bar HP conversions to a pair of 2-cavity NOE Moulds.... I had them sent directly from NOE to him, along with the drawings below, showing the changes required....

Image


Image

The lighter bullet was originally 101 gr. with a 40% Meplat and the heavier one was 112 gr. with a 30% Meplat, but the smallest HP pin practical in a .257 is a 1/8" OD pin, so that requires pushing the Meplat back to that diameter on both bullets, making the Meplat nearly 50%.... I left the actual dimensions of the cavity up to Erik, but told him that these are for Varmint hunting, so I don't care if they disintegrate on impact, so to use as large a cavity as he thinks will cast properly and allow the bullets to release from the mould without issue.... At this time, I don't know what the finished weights will be, my guess is somewhat lighter than shown on the drawings....

Anyway, my wife decided these would be a good Christmas present, so we ordered them and they have just been shipped from Erik as he has completed the HP Conversions.... I'll update this thread when I get them....

Bob

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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal;
Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!


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PostPosted: Wed Dec 28, 2016 5:30 pm 
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Location: Coalmont BC
I got my HollowPoint conversions back from Erik today, and they look AMAZING.... He is such a skilled craftsman it makes up for the $100 per mould cost, just in looking at the finished product....

Image

The converted 101 gr. is on the left, and the HP version of the 112 gr. is on the right.... He used (as requested) a 1/8" HP pin, which pushed the Meplat back to just under 50%, shortening the bullets slightly.... The "Inset Bar" conversions hold the heat in the HP pins nicely, so once up to temperature I am sure they will cast just great.... I'm really looking forward to trying them out....

Bob

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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal;
Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!


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PostPosted: Thu Dec 29, 2016 9:12 am 
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Joined: Mon Dec 19, 2016 4:04 am
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Location: Calgary
I have a 65 grain Lyman .257 mold and was hoping to get a barrel for my airforce condor in Canada. Been watching videos of people hitting targets out to 1km with these casted bullets.

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PostPosted: Thu Dec 29, 2016 11:31 am 
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If your mould is a Lyman 257420, that is one of the great bullets in .257 cal.... but they do cast at about 73 gr. in pure lead....

Bob

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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal;
Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!


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PostPosted: Thu Dec 29, 2016 3:31 pm 
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Joined: Wed Jan 05, 2011 12:35 pm
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Location: P.G. B.C.
What twist is mathematcially required for that 73gr. bullet at such low velocity? 12" might also work in the PCP. A standard 10" might work considering it still works for 120gr. jacketed in the .257's.

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PostPosted: Thu Dec 29, 2016 3:32 pm 
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Bob- that is a VERY nice looking mould. NOE moulds (have 2 now) and their HP system is also nice.

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Daryl


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PostPosted: Thu Dec 29, 2016 5:59 pm 
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Location: Coalmont BC
The 73 gr. Lyman 257420 (also available from Arsenal as GC or BT) works perfectly in a 14" twist at all airgun velocities.... from too low to bother to Mach 1 and beyond.... The 14" twist TJ's 25-20 liner is the standard used by most quarterbore airgunners.... It is 0.250" land and 0.257" groove, and available in 1/2" and 9/16" ODs.... That bullet and barrel is a proven combination to 400 yards and beyond, in the right PCP....

The HP conversion you see was done by Erik Ohlen at Hollowpoint Mold Service.... http://www.hollowpointmold.com/ .... It is his "Inset Bar" style, which casts easily.... a real joy to use.... Unfortunately, NOE cannot use their "RG style" HP system on a bullet with a Meplat under 0.200", below that they can only supply HPs with a Lyman pin in a single cavity.... They normally don't like going below a 5/32" pin, because as you mentioned elsewhere, a small Lyman style pin cools too quickly.... but if you catch them when they are making the moulds in the first place, you can maybe convince Al to make a Lyman style with a 1/8" pin.... It was too late for these two bullets, as the moulds were already done and off the mill, so Erik was my only chance.... and he came through in Spades.... :twisted:

Bob

_________________
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal;
Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!


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