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turer, and state that he desires a barrel cut with an extremely tight chamber, or a chamber of some peculiar shape. The gunsmith might very properly refuse to cut such a chamber from the standpoint of safety alone. But he can also plead the cost of making the necessary reamers. Certainly the cost of making the two finishing reamers which will probably be necessary to cut a chamber to some special dimension would be not less than $40.00 in man labor, plus at least the same amount for machine labor, both doubled for overhead. To these we might add the day's labor of the highly trained man spent in figuring out dimensions as previously described. Indeed a complete set of chambering reamers today costs from $200 to $300 to make, and the customer who glibly talks about having a specially chambered rifle, hardly realizes what he is getting into in the way of expense if he really wants to go any further than bothering the gunsmith with many letters about it.

When one starts to chamber a barrel it is probably bored, reamed, and rifled all the way to the breech end. A series of about four to six reamers are used, graduated in size and diameter so that each succeeding one makes a shallow cut, and slowly and gradually enlarges the chamber to the desired size and shape. See Figure 113. The reamers are made bv hand, being ground from Anted reamer* purchased from gage and tool-making firms. They are usually used by hand, although in large arms factories they are operated for

Fig. 113

Fig. 113

convenience and speed in a special turret lathe. It is a principle of reaming that a reamer, if operated by hand, and if not forced unduly, will ream out exactly in line with the axis of the original bore. To assist in this, each reamer is provided with a pilot or cylindrical portion in front of the cutting edges, which, riding on the top of the lands, acts as a guide and a centering agent for the

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