NOE Version of 257420 BT HP - Plus Shortened FB Version

[rsterne]

Now in the NOE Store.... RG2 and RG4 versions only, in brass or aluminum....

http://noebulletmolds.com/NV/index.php?cPath=26_603

This bullet is as close as I could draw it to the dimensions I took from the original (steel mould) Lyman 257420, with the following changes:

1. I used a boattail base, starting at the same diameter as the front of the gas check stub, and tapered like the Arsenal version....

2. I changed the lube groove center section to a smooth cylinder, just small enough to miss the lands (ie 0.248"), like my BBTs….

3. The overall length was reduced 0.005" to make it fit one of the mags. mentioned during the development threads, which everyone had lots of opportunity to view and comment in....

https://www.gatewaytoairguns.org/GTA/index.php?topic=150246.

http://noebulletmolds.com/smf/index.php/topic,2676.0.html

4. Most importantly, Al used the new thin RG pins so that all cavities are HP, but there are optional pins to cast a flat nose or cup point.... There are no HP moulds available for any 257420 version anywhere else, that I am aware of, without sending the mould out to have them added at extra expense....  Are these bullets identical to the 257420?.... No.... They are a 257420 BT HP design, and hopefully the changes made will increase the BC....



NOTE: Al has also made a shortened version available, with the boattail removed.... (like removing the gas check shank on a 257420)….

http://noebulletmolds.com/NV/index.php?cPath=26_604

This is also made in the RG2 and RG4 moulds, and is 63 gr. as a FN and 60 gr. as a HP....



Bob

[steveoh]

I’ve been waiting for these! Ordered a 4 hole aluminum mould!

Happy dance!

[Loren]

Some results of the 60gr HP at 100 yards from my Texan.

[steveoh]

Some results of the 60gr HP at 100 yards from my Texan.

Did you get any chrony numbers? Where is your power wheel set at?

For the 257420 bullet at about 74 grains I’m set at about 1/4 power. That still gives me about 1047 fps on the first shot or two at 3,000 psi. If I fill to 2800psi I get a bell curve with slightly lower velocity. If I turn up the power wheel then groups suffer.

That last target looks good!

[Loren]

Tethered at 3000psi, hammer adjustment one tick past halfway mark and towards the butt of the stock.  They are smoking at 1220 fps.  I have the rifle set for shooting 86 & 92 grain bullets and just wanted to see how these would do at that setting.  The new 72gr HP's were all over the place. I will have to detune the rifle and try them again.

[Hobbyman2007]

Loren , when your pushing bullets faster than usual . You can play with your lead tin mix and harden the cast a bit . I found this worked quite well with the original BBT bullets when shooting them over 1100 FPS from a BT65.

[Loren]

My plan is to actually slow them down.  My thinking is they will destabilize out pass 100 yards as they slow below sonic speed.  I think that is why the 72gr shot crappy for me.  They are doing 1120ish out of the muzzle, but by the time they hit 100 yards they have slowed and destabilize dropping below sonic speed.