Ken,
I got that information from the guy that ran the Douglas Barrel machineshop (the one that you also ordered from, back in the 80's and 90's) you also knew and talked to him at that time. Although I don't remember his name now, you were the one that told me to talk to him and give your name, when I ordered barrels from them.

I think also they say something about it on their web site and that it may also say they guaranty their twist to 1/2" but, I can't say that for sure.

As a machinist, I can tell you that if torque is applied to a a rod to push or pull anything, it will flex and even though a button has a pitch to it, it's path can vary while being pushed or pulled, the more force, the more flex and variation can occur. Wear will case more force to be need and that can also cause variation.

But, basically, that what Douglas told me about their barrel making process and twist guaranty.

Frank 

"the journey is half the fun"

actually we do the same all the time in in verbal conversations we just don't usually see them laid out in a black and white linear format so its not obvious.

Some of the most informative information I've enjoyed here on the site over the years has been in the digressions; which regrettable are not usually accessible for later reference.

My method for determining a load on a new rifle is to start at .065” over case length. I breech seat a lubed bullet and then push it out and check it. I want to see two things that the rifling engraves into the base band of the bullet and that on the base band I can see contact all the way around. Then I start shooting at 100 yards I start with a load about 10% shy of recommended and work up until the vertical stringing is gone. At that point I know I am close so I move out to 200 and start again. Now the changes are more subtle and the wing has more time to play with the bullet. Over the course of 5 or 6 shooting sessions I will settle on a load. Then and only then I will adjust seating depth. I move out .005” at a time, again the changes are subtle so go slow. Once I have the best seating depth I never vary from it again, I make all my adjustments to the powder charge.
When I go from my home range (high elevation, different temperatures) to, lets say to Beeson’s range there are very real changes in conditions. After shooting a few targets if the groups are good I leave it alone, if not its time to add powder it’s usually only a click or two to close the groups up to what they should be. 

40 Rod

I believe the OP's question was answered several times before the subject moved off into another direction so I fail to see any wrong doing in it doing so? Other than it makes it impossable to do a search should the new subject have something also very useful in it.

Well, Travelor, have you tested the advice to increase the speed of the bullet? Did it reduce or eliminate the yawing? 
I get it a little now and then when experimenting, and if the bullet is at all suitable that speed increase will fix it. Not always retaining the same accuracy, though. Sometimes a little wiggle in a bullet's rear end is as pleasing as a wiggle in a shapely girl.

Schuetzendave wrote on Mar 7^th, 2017 at 9:19am:


Excuse the piggy back.

Dave, where you getting that info?  Your calculations or a table/calculator somewhere?    Either way I'd be very interested if it carries further.  Best I could measure my Original Ballard is a 17.5 twist.  Have wondered if another mould would improve on my LBT bullet.    I think that drops at 164gr.   One of the most accurate rifles I've shot but had been thinking I should have a heavier bullet.   Your table of numbers makes me think different.   Maybe you saved me money:-)   Thanks,  John

If I missed something, Forgive me for asking
but is the Miller Stability Factor mainly for 200yds or so?
Or is is applicable to estimate twist for long range, such as BPTR, with cast bullets at say 1300-1400fps, out to 1000yds.
I do know that in the Greenhill formula, one can get closer
to correct twist for BPTR in one substitutes 120 or 125 for the constant.
thanks
beltfed/arnie

rafter3c wrote on Mar 11^th, 2017 at 12:14pm:


Yes, I bought my first target rifle from you in 1985. I drove from Orange to Cajon to shoot it before buying it. I won many matches with it in the following two years. All my rifles untill resenty have been Doulas barreled.

I talked to Arlie several time and bought about 10 - 12 barrels from him between '87 and '90.

Frank