Been Gone For a While

G

gilream

Mike
I have been out of the shooting hobby for about 10 years and am now getting ready to devote some time to it again. (Finally retired.) I remember this forum as the one of the best sources of information and I have a few questions.

What's it the best measuring device/technique for determining the Lands Engagement Point. I have the Sinclair 'lug nut' with various caliber holes drilled in it to use along with my caliper. Has there been an improvement in this area? Any new user friendly measuring devices?

Is Ken Turner still on this thread? If so, Ken please e-mail me (gilmw@bellsouth.net)

Mike
 
It's not new, but Sinclair makes a device that you use with a fired case and a bullet to determine where touch is. It has a rod, two stop collars, and an adapter that goes in the back of the action. There is also the Stoney Point tool that takes a case that has been drilled and threaded through the primer pocket. Hornady bought some of that line. It may be under their name. Beyond that Hornady(Stoney Point) has some attachments for calipers to measure shoulder bump when setting a FL die, and the same adapter takes inserts that do what your "nut" does. Sinclair makes their versions of both of these. In Benchrest, I venture to say that most work back form "jam" (where an overlong seated bullet is pushed back to when the round is chambered) rather than worry about the problems inherent in determining precisely where touch is. Welcome back.:D
 
If you are as anal as I am

you will do as Boyd sez and then continue to push your bullet back into the case a couple of thou each time, polishing your bullet with 4 ott steel wool, until you can just barely see land marks. In my opinion, you can not achieve this with any measuring device available to us.

You can use your "Nut" as a comparitor but I prefer the comparitor that can be attached to a jaw of a caliper. They are available from Sinclair.

Depending on neck tension, bullets seated by jamming will be pushed into the lands quite a bit. Sometimes a bullet will stick. You have to be beyond .012 to stick a bullet into the lands.

I use this method because I want to know exactly where my bullets kiss the lands. The process must be done with each make and lot of bullets you use. Of course there are lots of folks who simply jam and then add or subtract powder to tune. It works but it is a "Blind" way to tune, IMHO.
 
Mike ...

In addition to the above comments, call Sinclair and ask for a catalog: http://www.sinclairintl.com/. Also, they have techs on staff that shoot benchrest. Ask for one of them if you have specific questions on benchrest tools and equipment. They're very knowledgeable and helpful. :)
 
Pete... I'm too anal for my own good

Could you go a bit more in depth as to what you mean by 'blind' tuning? (I am going to attempt to tune a 22 PPC load for my varmint gun using Watson 52 grain match bullets. I have determined what I believe to be the correct charge of H322 and i did that using the 'jam' method with the bullet seated out to be pressed into the case as the bolt closes. I'm wondering if i need to go back, find the kiss point as described and work the powder charge up again. BTW..thanks to you and others for the good information.
 
Where I came to in this process

is I wanted to know how far into the lands I had to go to make my rifles shoot their best groups. I began to realize that neck tension would allow bullets to go into the lands in different amounts depending on a number of things. I realized that finding where the bullets just make a mark would be the best starting point for the person who wants to know how far they are in.

This is the way I have proceeded for years now. I advance the bullets by .003 each advance and I shoot three shot groups. I shoot mostly 30 Cal rifles and have found that I can usually find a round hole when I am in either .006 or .009. I have had a couple of barrels that liked .012 in, IF I have the right powder and bullet combo.

A person can go in the oposite direction as well. Some folks find great accuracy jumping their bulles. I have seen that work as well. It is probably the best way to go becaues one can open their action at any time without worrying about pulling a bullet. I don't know why I haven't done this in the past. Guess being a creature of habit is the reason.

To me, it is absolutely necessary to have exact seating depths to achieve the best possible accuracy. It isn't easy to achieve this but I find it worth the effort. It isn't easy because one must measure every loaded round and be certain that they are exactly the same measured where the bullets will engage the lands. That requires some work.

I use threaded dies in a turret press to size and seat bullets. Among the dies is a bullet puller, I use it often and adjust the seating die accordingly.( I have micrometer seaters) I also measure all of my bullets after coating to segregate them by their ogive length.

All that said, those who jam and play with powder get good results most of the time I think and tuners seem to be able to help take out what the powder won't. Another alternative is have a number of barrels chambered and choose the best one using the one load one bullet method. That is probably the best way to proceed but I haven't yet seen fit to committ those kind of resources to my hobby. I like to do other things too.

That's is pretty much it as far as seating depth is concerned. I have been weighing every powder charge way before it became popular. There is some satisfaction in Pioneering, I must say.
 
Mike

Haven't heard from Ken in a long time. He used to be a regular.

As for what is new in finding seating depth, most of us use the old tried and true method of polishing a bullet, seating it, looking at the marks with a magnifying glass, and then adjusting accordingly. Once you find what the Rifle likes, then you can measure the loaded round using something as simple as your "lug nut" from Sinclair.

Granted, there are all sorts of devices out there that are designed to do this, but most have their own particular quirks that make them no better than just checking it in the way I described.........jackie
 
Jackie...could you elaborate on the process of finding the most accurate seating depth? I'm guessing that most competition shooters pretty much shoot the same cartridge and that you don't have to worry too much about working up to the right powder charge from scratch. I worked up a charge for my 22 PPC varmint gun by letting the bolt close on a cartridge with the bullet seated out passed the jam. Should I drop back to the point where the bullet just kisses (as mentioned above) and try working up the powder charge again, or would you simply just begin backing away from the jam say .005" at a time and shoot test groups? With my current set up I have fired 8 five shot groups and the average of those 8 groups is .469". It may be that I will not be able to improve and it may not be worth the trouble. What do you think?
 
seating depth

I told awhile back to take one piece of brass ready to go and take a fine wheel on a dremel tool and cut the neck to shoulder 3 times fairly evenly arround. This will allow you to take any bullet put it it long and when chambered it will come out with a light "touching" distance. You have to be carefull not to push it in when handling and measuring but I have had good luck with it. I have done one for every cartidge I load for.
 
You must log in or register to reply here.
Back
Top