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Find barrel twist & chamber seating?

litetriggerlitetrigger Member Posts: 320 ✭✭
edited February 2011 in Ask the Experts
What is a good way to find what twist a bbl. is? Any good systems to find the depth of a chamber for seating bullets close to the lands without doing a casting? thanks
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    zimmdenzimmden Member Posts: 237 ✭✭
    edited November -1
    Yes, very accurate and no cost. Start a cleaning rod with rotating handle with a bristle brush and patch into the bore. Mark the rod with felt tip marker directly on top near the handle. Make marks 10,12 and 14 inches. Push rod into barrel until it rotates one full turn. (The rod will go around) When it reaches the top, it has made 1 turn. Note how many inches you pushed. This is rate of twist. To find the exact chamber length to the rifling, take a FL sized empty case and slightly seat a bullet into the neck. Slowly chamber the case and remove. The bullet will be pushed back into the neck by the lands giving the exact max length. Pull bullet and repeat. You should be able to see the rifling marks on the ogive of the bullet. Use a moly bullet or darken with a marker pen.
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    litetriggerlitetrigger Member Posts: 320 ✭✭
    edited November -1
    zimmden, thanks for the info. the seating the bullet worked fine. finding the twist is not working. the rod seems to slip (not turn) in places. also the tip starts to unscrew. I'll keep at it. thanks again
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    zimmdenzimmden Member Posts: 237 ✭✭
    edited November -1
    Tighten bore brush and use a tighter fitting patch. Rod will rotate 360 degrees for one twist in xx inches.
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