Gentlemen, I need a way to more accurately measure my seating depth, or distance to the barrel lands, than the old fired case, bullet, and magic marker routine. Makes me question the use of a micrometer seater with such an imprecise starting measurement. I've read about both the Sinclair Internation Tool and the Stoney Point OAL unit. Any suggestions?
Regards, Matt.
Posts: 525 | Location: Virginia | Registered: 26 January 2001
I was happy with the Sinclair tool because it is simple and usable on almost anything. It took me a few minutes to understand the directions, but once I understood what it was doing, it seemed like the perfect tool for the job.
The fun starts when you choose a comparator, and your seater doesn't seat everything the same. That's life. I prefer the Davidson comparator for ease of use, but they all work, and usually differently.
Posts: 2272 | Location: PDR of Massachusetts | Registered: 23 January 2001
I have tried the cleaning rod and the stoney point methods but have recently changed to seating the bullet I want very long and gradualy getting it so the bolt will just close on it. I take some wire wool and twiddle the seated bullet in it, when the bolt is shut and the bullet examined you can see light as day the land marks. Rewire wool the bullet adjust the seater down a tad and carry out ad infinitum until marks are gone or just apparent. It seems much easier and more accurate. Keep that as a dummy round and use it to set up your seating die.
Just shot a .34" 4 shot (wind and heat haze too)group using this exact method and Lee dies.
Posts: 2258 | Location: Bristol, England | Registered: 24 April 2001
quote:Originally posted by 1894: I have tried the cleaning rod and the stoney point methods but have recently changed to seating the bullet I want very long and gradualy getting it so the bolt will just close on it. I take some wire wool and twiddle the seated bullet in it, when the bolt is shut and the bullet examined you can see light as day the land marks. Rewire wool the bullet adjust the seater down a tad and carry out ad infinitum until marks are gone or just apparent. It seems much easier and more accurate. Keep that as a dummy round and use it to set up your seating die.
Just shot a .34" 4 shot (wind and heat haze too)group using this exact method and Lee dies.
On rereading this seems to be the method you use? Apologies but having tried the comparator this seems better.
Posts: 2258 | Location: Bristol, England | Registered: 24 April 2001
The method you describe is fine for finding seating depth (the original question) and having a dummy for setting up dies. Has advantages even over the Sinclair tool.
The comparator comes later, for checking the actual results of seating. This can be handy for seating depths deeper than .000", and in case they don't all come out like you wanted them.
Posts: 2272 | Location: PDR of Massachusetts | Registered: 23 January 2001
quote:Originally posted by Matt in Virginia: Gentlemen, I need a way to more accurately measure my seating depth, or distance to the barrel lands, than the old fired case, bullet, and magic marker routine. Makes me question the use of a micrometer seater with such an imprecise starting measurement. I've read about both the Sinclair Internation Tool and the Stoney Point OAL unit. Any suggestions?
Regards, Matt.
I love Sinclairs equipment and use their comparator but the Stoney Point OAL case setup is fast and repeatable in my use in 22cf to 30cal rifles and works in my small diameter actions as well as large actions....you do need the modified cases but they are worth the effort....as the other post states the Sinclair works fast for standard actions and you don't need the modified case....I also have the comparator and headspace gauges for the stoney point setup and they also work well for me.....good luck and good shooting!!!!
Posts: 687 | Location: Jackson/Tenn/Madison | Registered: 07 March 2001
RCBS has a great little tool for this. I have the stoney point set up and Sin also but find the RCBS does a great job with finding bullet seating depth and also with checking and setting for different bullets.
I've used the Sinclair. Following the directions to the letter I find that I get different readings with the SAME components -- a specific case and specific bullet.
Variations are only a few thou, but then that's what we're attempting to sneak up on in relation to the lands. Hard to know if you're 0.001" off the lands if the tool won't give you a consistent reading.
Machine shops have "marking" or "indicator" fluid. It's blue stuff that goes on the stock so the machinist can see when the tool is touching the surface. Basically it's the "magic marker" technique, only this fluid is designed for the purpose.
I use the Sinclair and have found it to work quite well. I put a cleaning rod down the muzzle and with the bullet seating tool pushing from the bolt side and the cleaning rod from the muzzle I can get a consistent feel for how much pressure I apply to the bullet as I seat it in the lands. Using this method I have gotten results that are very repeatable, not just with the same bullet, but with multiple bullets from the same box. I suspect that with equal care I could have gotten the same results from the SP. In any case you will be happy to have this tool, because until I got this tool it felt like I was flying blind when it came to seating bullets.
I use a couple cases, that I've decapped, sized, and slit the necks with a Dremel grinder. I stick a bullet in the neck, and chamber the round. The lands push the bullet into the neck, and I measure with a caliper and Sinclair comparator. I push the bullet out of the case with a pin punch. I'll measure it 3 or 4 times, just to be sure. I keep these "measurement" cases in the boxes with the die sets. Regards, George.
