The postings by Doubs & Unspellable concerning the reboring of 30 Mauser Broomhandles to 9mm aroused my curosity, as I recently had this done by Redmonds. First, let me state that this was the first experience that I have had with reboring and I have no vested interest in Redmonds Reboring. I quote from their brochure:
"When the 7.63 Mauser bore is reamed to 9mm, this reams out the bottleneck of the existing chamber, and what is left of the existing chamber is the correct length and diameter for the 9mm cartridge. No chambering is necessary. This may seem strange, but I have rebored hundreds of these Brooms and I know what I am talking about.
Some Brooms that have been shot out, may have excessive chamber wear at the front of the chamber, which may cause the 9mm case to go too far forward, giving an excessive headspace problem. There are three ways to remedy this problem. If you hand load, longer cases can be used such as the 9mm mag and the cases can be trimmed to the proper length. The other alternative is to control the headspace by seating the bullet out from the case a little longer so as to set the case back against the bolt face taking up the excessive headspace. This method is described by Finn Agaard in an American Rifleman article, Aug.1988, pg.32. If you do not hand load there are various commercial loads that vary in bullet seating and can be matched up to your pistol. To check your Broom for proper headspace, you need to remove the barrel from the receiver and strip the bolt of extractor and firing pin. Insert a sample dummy cart. in the chamber and see if the bolt comes all the way forward, and if it does, check for excessive gap between the bolt face and cartridge. The third alternative is to chamber to 9mm export. I cannot guarantee this cart. to feed properly and some action alternation may be necessary. I do not do any action conversion.
In the conversion of your Broomhandle, I only rebore the barrel and do no chambering. I have no control over your existing chamber and therefore cannot be responsible for its condition."
Contrary to the experiences of Doubs & Unspellable, I experienced no difficulty in dropping a 30 Mauser cartridge in several of my 9mm Lugers and having it chamber easily. According to my micrometer, the shoulder on the new Old Western Scrounger 30 Mauser cases measure .0370" dia. The mouth of my WW 9mm loaded rounds mics at .0375". I fired 5 of these 9mm loads in my rebored Broomhandle, which appears to have no headspace problem. These fired cases measured .0377" at the mouth. The taper remained the same, and there was no bulging anywhere on the case, they looked as if they had been fired in one of my Lugers.
I can only surmise that the problem experienced by Doubs was due to excessive chamber wear in his gun. As for Unspellabe being unable to chamber 30 Mauser in his 9mm, and mine chambering ok, there must be a difference in dimensions of his cases and the ones that I have.
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