Easier way to load a buffer?

[ToddAndMargo via perl6-users]

Hi All,

I am looking for an easier way to load a buffer.

I know about this way

[4] > my Buf $b=Buf.new(0x2A, 0x54, 0xFF, 0x53);
Buf:0x<2A 54 FF 53>

I would like to do it on one big blast:

my Buf $b=Buf.new(0x2A54FF53A5F1D36F1CEA7E61FC37A20D54A77FE7B78);
Cannot unbox 170 bit wide bigint into native integer

But do not know the proper syntax.

Any words of wisdom?  Am I stuck with the hard way?

Many thanks,
-T