| 470Rigby |
| (.333 member) |
| 09/05/04 10:07 AM |
|
Re: HELP!! Amateur question Re: Army/Navy 450/400 3 1/4
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DUGABOY
In reply to:
If this is a NITRO rifle it will be stated on the bottom of the barrel flats, and will usually give you the regulation distance as well as, whether it was regulated/proofed for full Nitro loads, or Tropical loads. The full load will be 60.0 grs Cordite,
Just need to clear up a few of the issues raised here,viz;
Nitro Proof - the tricky thing is, before Nitro Proof became mandatory in 1925, a Gunmaker could make a rifle that withstood full nitro loads and shot to regulation, but could legally sell the gun with Black Powder proof, presumably to reduce costs. This happened rarely, but there are examples floating around, incuding a very nice Dan'l Fraser 450/400. Also, during this period a gunmaker could have a rifle prooved for whatever "Nitro" load he wished, and one may encounter rifles carrying "Riflite" proof marks, with no mention of Cordite at all.
Regulation Distance - I have never seen this. Could you amplify?
Tropical Loads - were actually "full nitro" loads, when shot where most of these rifles were intended for use - the tropics. For example, the pressure generated in the 55 grain 450/400-31/4" Cordite "TROPICAL" load was held to 17 tons when shot at 120 deg.F, compared to the 60 grain load's development of 16.5 tons at 60 deg. for the same muzzle velocity. (from "The Field", 1904). In this sense, rifles carrying "tropical" proof marks cannot be viewed as anything less than "Full Nitro" rifles.