I understand...and I appreciate you clearing that up...and once again, it was a very very good video...I learned a great new method....thanks again
Finding your lands (video)
- Thread starter Alex Wheeler
- Start date
great video....i've been doing it wrong this whole time!
btw, what action is that?
btw, what action is that?
Alex Wheeler
Site $$ Sponsor
I've pulled the firing pin before but never torn down the ejector spring/pin on my bolt. I might consider doing it to give this method a try. I see there is a tool to assist with taking the ejector spring out but not sure I want to buy another one-time use tool.
Can it be done without special tools? How hard is it to get back together?
Can it be done without special tools? How hard is it to get back together?
Alex Wheeler
Site $$ Sponsor
Its just a pin that needs to be pushed out. You can use a punch and small hamer. Theres a notch on the ejector the pin passes through, line it up when you put the pin back in. Very simple job and no special tools needed.
That was a great video, thanks for posting!!
Thanks for sharing, always learning good stuff on this site.
Thanks, will give it a whirl.
i tried it and it WORKS! that little hesitation in bolt lift is very easy to feel,esp as you get just to touching the lands. my stiller bolt has no ejector and after removing the firing pin the feel is precise. i compared this measurement to the one i recorded by following the land's engravings on the bullet as i seated .002 deeper and i got a different value. my number was .009 more. i seated bullets .025 into my lands measurement(.034 by the bolt click method). my groups have been erratic and may be because some of my bullets may be seated deeper as they really engage the lands. i will use these new measurements and reload the bullet/powders that seemed to have promise and....
Alex,
This may be the "most useful" video ever put on this site....super job.
For people like me that are not machine or gunsmith savvy, I would be very hesitant to start removing bolt parts like the ejector (on a BAT MB) that I had to put back exactly like it was, not knowing if I did it correctly or not.
If I just remove the firing pin, how much, in your opinion, would the "true" reading be effected?
This may be the "most useful" video ever put on this site....super job.
For people like me that are not machine or gunsmith savvy, I would be very hesitant to start removing bolt parts like the ejector (on a BAT MB) that I had to put back exactly like it was, not knowing if I did it correctly or not.
If I just remove the firing pin, how much, in your opinion, would the "true" reading be effected?
Alex Wheeler
Site $$ Sponsor
Its really simple, I plan to make more videos as it seems guys really like them. I'll do one one ejector removal. Donavans idea would work too, but you wont get that precise feel with the ejector pushing on the case. I think it some thing that really should be removed.
Bats roll pin is a very light press fit, you can just push it out with a pin punch, no hammer needed.
That was sure more positive then my way, thanks a lot. Looking forward to more videos.
This definitely should be a sticky.
This definitely should be a sticky.
X-Caveman
Gold $$ Contributor
I did this and had a .011" difference than with my Hornady tool/ modified case.
As important for me was discovering and cleaning out all of the gunk inside my bolt. Evidently this needs to be done at more frequent intevals than about 2,500 rnds. Thanks for the video.
As important for me was discovering and cleaning out all of the gunk inside my bolt. Evidently this needs to be done at more frequent intevals than about 2,500 rnds. Thanks for the video.
So this video came out at just the right time for me, since I was in the process of working up two new loads in .308 for the Sierra 155g Palma and the Lapua 155g Scenar. I had previously checked the distance to the lands with my Hornady OAL tool on both bullets last week, so I had a reference point to compare to this new method.
With the Hornady tool I was going by feel to find the point where light pressure just barely engaged the lands. I used the cleaning rod method to go back and forth with the bullet to fine tune position. I measured three different bullets 5 times each for both the Scenars and the Sierras, then averaged the results to get my final number. This is about as accurate as I could make the Hornady tool.
With the method shown in the video I tried to select one bullet that was most representative. I did some quick measuring of bullet length and and base to ogive and selected a bullet that was a nice median measurement for both bullets.
Results were fairly close between the two methods. The Sierras measured about .002" shorter, and the Scenar's measured about .008" shorter to the lands with the video method. I noticed this with the Scenars when using the Hornady tool, there was a less definitive contact point with the lands due to the long sloping nose of the bullet making it harder to "feel" when to stop pushing on the bullet.
Overall I would characterize the difference between the two methods as this... The Hornady method measures "distance to first light contact with the lands", where as the video method measures "distance to first point of complete non-contact with the lands". I certainly think the video method is more accurate and repeatable, and easier once you take the time to pull the bolt firing pin and ejector spring apart.
As a side note, pulling the firing pin and ejector spring is a good exercise to helping feel brass chambering effort. I've been bumping shoulders about .0015 - .002" with a full length sizing die, but it turns out that still leaves some effort required to close the bolt on the brass. I had to size the brass down a fair bit more to get the bolt to close effortlessly. I may end up adjusting how much I size cases based on this experience... I'd never done it before and it was a good piece of info to learn.
Thanks again for putting this video together!
With the Hornady tool I was going by feel to find the point where light pressure just barely engaged the lands. I used the cleaning rod method to go back and forth with the bullet to fine tune position. I measured three different bullets 5 times each for both the Scenars and the Sierras, then averaged the results to get my final number. This is about as accurate as I could make the Hornady tool.
With the method shown in the video I tried to select one bullet that was most representative. I did some quick measuring of bullet length and and base to ogive and selected a bullet that was a nice median measurement for both bullets.
Results were fairly close between the two methods. The Sierras measured about .002" shorter, and the Scenar's measured about .008" shorter to the lands with the video method. I noticed this with the Scenars when using the Hornady tool, there was a less definitive contact point with the lands due to the long sloping nose of the bullet making it harder to "feel" when to stop pushing on the bullet.
Overall I would characterize the difference between the two methods as this... The Hornady method measures "distance to first light contact with the lands", where as the video method measures "distance to first point of complete non-contact with the lands". I certainly think the video method is more accurate and repeatable, and easier once you take the time to pull the bolt firing pin and ejector spring apart.
As a side note, pulling the firing pin and ejector spring is a good exercise to helping feel brass chambering effort. I've been bumping shoulders about .0015 - .002" with a full length sizing die, but it turns out that still leaves some effort required to close the bolt on the brass. I had to size the brass down a fair bit more to get the bolt to close effortlessly. I may end up adjusting how much I size cases based on this experience... I'd never done it before and it was a good piece of info to learn.
Thanks again for putting this video together!
Alex Wheeler
Site $$ Sponsor
I will eventually do one on sizing as well. The reason you experienced what you did is because the angle of the shoulder in your chamber is not exactly the same as in you die. And your comparator only measures one spot. The best way is to have your smith make you a comparator with the reamer used on your barrel.
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