Part 15 (1/2)

It has been found that the erosive effect is in direct proportion to the nitro-glycerine present The cordite MD, which contains only 30 per cent nitro-glycerine, gives only about half the erosive effect of the old service cordite With regard to the heating effect of cordite and cordite MD on a rifle, Mr TW Jones es in fifteen minutes in the service rifle Cordite raised the temperature of the rifle 270 F, and cordite MD 160 F

only

With regard to the effect of heat upon cordite, there is some difference of opinion Dr W Anderson, FRS, says that there is no doubt that the effect of heat upon cordite is greater than upon black powder At a teun is considerably affected as regards pressure

Colonel Barker, RA, in reply to a question raised by Colonel Trench, RA (at the Royal Artillery Institution), concerning the shooting qualities of cordite heated to a te it hot undoubtedly does disturb its shooting qualities, but as far as we can see, not unpowder I fear that we must always expect abnorunpowder or cordite; and when fired hot, the increase in pressure and velocities will depend upon the heat above the nor takes place” Colonel Barker also, in referring to experin climates, said: ”Climatic trials have been carried out all over the world, and they have so far proved eminently satisfactory The Arctic cold of the winter in Canada, with the temperature below zero, and the tropical sun of India, have as yet failed to shake the stability of the co qualities” Dr Anderson is of opinion that cordite should not be stored in naval azines near to the boilers

Professor Vivian B Lewes, in his recent Cantor Lectures before the Society of Arts, suggests that the azines of warshi+ps should be water- jacketed, and maintained at a temperature that does not rise above 100 F

~Axite~--This powder is manufactured by Messrs Kynock Lihah the proportions are altered; ingredients are added which impart properties not possessed by cordite, and the methods of its manufacture have been modified The form has also been altered Axite issimilar in shape to a double- headed rail It is claimed for this powder, that it does not corrode the barrel in the way cordite does, that with equal pressure it gives greatly increased velocity, and therefore flatter trajectory That the effect of temperature on the pressure and velocity with axite is only half that with cordite That the maximum flame temperature of axite is considerably less than that of cordite, and the erosive effect is therefore considerably less That the deposit left in the barrel after firing axite cartridges reduces the friction between the bullet and the barrel It is therefore practicable to use axite cartridges giving higher velocities than can be employed with cordite, as with such velocities the latter would nickel the barrel by excessive friction It is also clai results have been obtained with this same ties with 200-grain bullets

Velocity 2,726 FS

Pressure 2095 tons

~Axite~ Cartridges with 215-grain bullets

Velocity 2,498 FS

Pressure 1924 tons

~Axite~ Service Cartridges

Velocity 2,179 FS

Pressure 1576 tons

~Cordite~ Service Cartridges

Velocity 2,010 FS

Pressure 1567 tons

Five rounds from the Service axite and Service cordite were placed in an oven and heated to a temperature of 110 F for one hour, and were then fired for pressure The following results were obtained:--

~Axite~ ~Cordite~ Before heating 1576 tons per sq in 1567 tons per sq in

After ” 1673 ” ” 1721 ” ”

_____ _____

Increase 97 = 61 154 = 98

Average Velocities-- Before heating 2,150 FS 2,030 FS

After ” 2,180 ” 2,090 ”

_____ _____

Increase 30 FS = 1-1/2 600 FS = 3

In order to show the accuracy given by axite, seven rounds were fired froet fixed at 100 yards from a rifle Six of the seven shots could be covered by a penny piece, the other being just outside In order to ascertain the relative heat imparted to a rifle by the explosion of axite and cordite, ten rounds each of axite and cordite cartridges were fired from a 303 rifle, at intervals of ten seconds, the te taken before and after each series:--

THE RISE IN TEMPERATURE OF THE RIFLE BARREL

With axite was 71 F

With cordite was 89 F