GTA

All Springer/NP/PCP Air Gun Discussion General => Projectiles => Boolit and Pellet Casting => Topic started by: mackeral5 on February 21, 2021, 04:17:25 PM

Title: Rolling the dice on MP 257-640
Post by: mackeral5 on February 21, 2021, 04:17:25 PM

I decided to roll the dice on this one, the gas check version.   I like the large HP/flat nose.  Hoping it will shoot well out of my 35" 1:14 twist Bulldog barrel.  Should be able to share some results in upcoming weeks.

(https://i.imgur.com/PTqlGyO.png)

Title: Re: Rolling the dice on MP 257-640
Post by: mr007s on February 21, 2021, 08:10:43 PM

Let us know how it performs

Title: Re: Rolling the dice on MP 257-640
Post by: mackeral5 on February 25, 2021, 06:29:46 PM

Casted a few of these, here is a pic next to a 257420 boat tail.  With the deep hollowpoint pin they drop at 68gr.  I haven't casted any with the dimple pin or the flat nose pin yet.


(https://i.imgur.com/sEqqwzU.jpg)

Title: Re: Rolling the dice on MP 257-640
Post by: mackeral5 on March 03, 2021, 03:19:46 PM

So far so good with this mold.  With the deep hollow point pin and using lead from my trap that is 80% NSA and JSB mix they cast in the mid-high 68gr range.  This target was shot with 68.7 and 68.8gr.  As-cast, they require little force to push through a .257 NOE sizing die.

this target is representative of the first 102 yard groups I've shot with this gun/barrel/bullet combo.    Bottom right group was a 7 shot group, shot while aiming for the top right.  Middle group was after a scope adjustment, then the top right bull was another slight adjustment and the last 5 shot group of the session.  Shot with gun resting with a tack driver bag on the bed cover of my truck, standing position. 


TJ 25-20 barrel, 1040-1050fps untethered. 

(https://i.imgur.com/YxgWwtW.jpg)

(https://i.imgur.com/3V9cOF5.jpg)

Shot from this contraption.

(https://i.imgur.com/CyOKFyU.jpg)