Author Topic: HP Conversions of NOE .257 cal BBTs  (Read 1167 times)

rsterne

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HP Conversions of NOE .257 cal BBTs
« on: December 14, 2016, 09:47:27 AM »
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....






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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Christopher

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Re: HP Conversions of NOE .257 cal BBTs
« Reply #1 on: December 14, 2016, 02:22:18 PM »
Wow.....those things will be devastating. IIRC, you've got a 34" barrel on your Monocoque project , right? How much pressure do you plan on putting behind these bullets?

Thanks,
Chris
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rsterne

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Re: HP Conversions of NOE .257 cal BBTs
« Reply #2 on: December 14, 2016, 03:58:22 PM »
I think it's 33", and I plan on using 3600-3800 psi.... The gun is safe to 4500+....

Bob
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rsterne

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Re: HP Conversions of NOE .257 cal BBTs
« Reply #3 on: December 28, 2016, 02:29:37 PM »
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....



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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