I'm considering purchasing a S.I.A.C.E. double rifle in .45-70 and having it rechambered to 450 #2. Is this a good idea? What problems may happen.
Do you believe that I would be able to regulate it to a usable effective African gun?

Help... Any advice welcome.

bearhunter,

See my second to last post on the double rifle action strength thread on the big bores forum. I would not recommend this conversion for strength and endurance reasons. If all you want is to be able to duplicate a 45-70 Ruger No1 load in the 450 NE this conversion may be ok. In other words, if you want to push a 480 grain bullet 1900 fps then the 450 NE conversion will probably be OK. That particular load (480 grains bullet @ 1900 fps) would produce around 40,000 CUP chamber pressure in the 47-70 and would be around 33,000 I suspect in the 450 NE.

I recommend strongly against firing full 450 NE loads out of that rifle. By full 450 NE loads I mean 480 grain bullets at 2150 fps muzzle velocity.

The hinge pin diameter is too small to withstand the beating.

Todd E

Todd E,

I'm still wondering??? All load data that I've seen for the .450 #2, using a 480 grain bullet, range 21,000 to 26,000 CUP pressure at 2100 to 2200 fps.

As for strength of the hinge pin. All of the old English double rifles were based on shotgun actions, with no alterations for added strength. Their actions seem rather weak, but have survived many years of use???

Have you seen the S.I.A.C.E. actions? I have not, but shall soon, I've been told. Complete guns go for $4,000 with an added cost of $250 for the rechambering. May or may not be a good deal???

Bearhunter---

There's considerable difference between British shotgun actions and those used for double rifles. Bushed firing pins, side clips, oversize hingepins, and, most notible, reinforced frames are common.

When contemplating rechambering of doubles use the British pressure measurements of "tons". They measure the force on the standing breech, which is what tears up actions, instead of per square inch.