ebiggs said:I made the rookie mistake of buying way too many extra touch hole liners. :shocked2: I have since found out they last a very long time. But with that surplus supply, I was able to try different drill size holes. :hmm: I have a chronograph and I know velocity suffers slightly as the hole gets larger but a few grains more, 5 or 6, evens that out. The larger size is as Roundball suggests in my experience. Besides, if the touch hole requires “cleaning”, it much easier to do. The larger size touch hole does not require cleaning, at least as often, as a very small hole.
I will restate, reliability is the key. :thumbsup: Clean as needed.
Does the standard deviation go up as the vent size is increased?
All comments to the contrary a properly designed and installed 1/16" vent is not any less reliable or slower than a .070 vent.
This is why. http://i72.photobucket.com/albums/i199/DPhariss/Gunsmithing/IMGP0785.jpg
Many misfires are caused by insufficient priming. The fallacy that a light layer of priming is faster has fostered many problems with reliability.
The level of fouling or type produced by the powder or lower pressure loads will often cause problems with fouling blocking the vent.
Powder that produces flakes of fouling in the bore can result in a flake falling to the breech and blocking the vent.
Dan
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