Measuring a bore on a rifle
I have an 1895 German Commision rifle. 8mm. I was alerted to the notion that some were not bored to accomidate a modern shell and some not. I could not find an alter mark anywhere. Would using a set of dial calipers on the end of the barrel be acurate enough to find proper diameter or any suggestions. I really do not want a bomb in my hand or face.
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You need to "slug" the barrel ! Take a small piece of lead slightly bigger than the bore, (small fishing weight, ect.) and push into the bore a couple of inches. A little oil will make this easier, then push it back out the other way. Measure the slug with a micrometer, not a caliper. That should tell you if it"s a .318 or a .323 bore. 0 -
Well actually the rebored ones have an S stamp on the reciever, but be warned even they generally measure .321" which is still tight for a .323 bullet. But if you handload there are .321" bullets available whereas .318 are harder to find.
"...hit your enemy in the belly, and kick him when he is down, and boil his prisoners in oil- if you take any- and torture his women and children. Then people will keep clear of you..." -Admiral of the Fleet Lord Fisher, speaking at the Hague Peace Conf0 -
Here's kind of a neat trick I was shown lately. In the past I always slugged bores using a cast lead bullet of the next larger size. For some of the odder sizes finding an appropriate bullet took more time and effort that the actual job. But if you have a well-stocked fishing tackle store in the area they probably sell lead wire for making fishing weights. It is about as large in diameter as a yellow wooden pencil and comes in a roll. A roll will last you for many years. Using any snipper tool, cut off a piece about 1 1/2 inches in length. Stand it on end on a hard surface and begin gently tapping the end that's up. As you shorten its length you increase the diameter and create the slug of desired diameter. So far I haven't used this on anything larger than 8mm (but it works just fine for that and the .30 Cal. range), and I suspect that larger diameter wire can be obtained. Anyway, in your case, all you'll have to do is expand it to about .35-.38 Cal., remove your rifle's bolt, hold the rifle vertically with the breech up, and drop the slug into the chamber making sure it goes in lengthwise. Then, using a solid rod of the appropriate diameter, pound the slug through the bore from breech to muzzle. Use no lubrication. Arrange something to catch the slug when it exits the muzzle to give it a soft landing and avoid any deformation. I have a W.W.II G.I. "barracks rod" with the cleaning tip cut off which I use for bores of about .30 Cal., but long ago purchased some solid brass rod stock from a local metal company for other bore sizes. You may find the first 4-6 inches in the bore to offer a little resistance, but once you get the slug started in the bore it doesn't take much to get it the rest of the way through; this because the slug is swaged down to size in the first few inches. You'll want to pass the slug completely through the bore, because it will be squeezed down to the smallest diameter of the bore, and if the bore has a tight spot the slug will be reduced to that diameter. With some practice you'll get a "feel" for the progress of the slug and a sudden looseness in its travel will indicate an oversized area in the bore. When you examine your slug remember that you are looking at a mirror image of the bore and the high spots represent the grooves; so you must mike across the high areas to get a groove to groove reading (which is what you want). 0 -
Thank you gentlemen for your insight and knowledge. It is appreciated.
"The only fences we need to worry about are those we put in our minds"0 -
Unless the rifle was rebarreled after 1905 or so, you almost assuredly have one of the .318" 8mm Mausers. 0 -
I bougt mine 1888 Commission rifle made by Steyr in 1904 from my
coworker 17 years ago. He told me that he had it checked and it has
the larger .323inch bore. I shot US made ammo in it for years. This rifle even bagged couple of mule deer. In September I was going to take this gun to our "Vintage military bolt action" event sponsored
by Browning Co. here in Utah and I was planning to use full power
military surplus ammo. So, just be safe I slugged the bore, it meassured .318inch. It was a shock to me, I'v been shooting this thing for years. So be carefull !0
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