I've been using the fired case and magic marker formula for determining the OAL in my rifles but finally decided that I would do it 'right' and buy a sinclair OAL tool. I started off with a pre-war M70 in 30.06 and with 150gr accubonds my readings arrived with .001 of each other so I decided that was fine and dandy and went on to my a-bolt in 7mmRM. I've tried it with both 140gr accubonds and 140gr corelokts probably 30 times combined and arrived at the same numbers two or three times for each bullet. I let my brother give it a whirl and he's had the same problem with his .243 a-bolt. Anyone have any advice on how to go about this?

Thanks,
Matt

This isn't very scientific. I have a Stoney Point OAL guage, and almost went nuts the first few times I used it. Couldn't get 2 readings to come out the same. Another piece of junk I surmised. Then along about the 4th day my readings were much closer to each other. Now I feel like a whiz with it. There is indeed a learning curve involved in using these things. I've never used the Sinclair tool but can't imagine it's much different. Just take your time and be patient. Best wishes.

Cal - Montreal

Hey Matt, That "variance" is why I don't like them myself. A buddy of mine, Don, bought one and couldn't get accurate readings. So, he "tried" to give it to me. I attempted to use it for a few days and took it back to Don. As we laughed about it, Don considered giving it to someone he didn't like, but I believe it now resides in a swamp next to his house.

Of course you will now be refered to as "Mechanically inept" by the folks that use them and accept the poor readings as OK.
---

Just go back to the old Cleaning Rod Method, cause it ALWAYS works and you can repeat it with excellent accuracy:

1. Put the Flat Tipped Jag in the cleaning rod.
2. Close the Bolt on the empty rifle.
3. Slip the cleaning rod in the muzzle (being careful not to wham the crown) and let the Jag rest against the Bolt-face.
4. Place a piece of tape as close to the muzzle as possible around the cleaning rod and remove the rod from the barrel.

5. Take a single bullet out of the box and think of it as the "Set-Up Bullet"(SUB). It will be used for a few things.
6. Remove the Bolt, drop in the SUB and hold something against the Base of the SUB to keep it from sliding back.
7. Slip the cleaning rod back in the barrel until it touches the SUB.
8. Take a 0.001" Capable Caliper and measure from the Muzzle to the leading edge of the tape. This is the "Kiss-the-Lands" distance for the SUB which can be thought of as the Overall (possible) Cartridge Length(OCL).

9. If you do not intend to "Crimp", put an empty Case in the Press Shell Holder.
10. Raise the Ram and screw the Seating Die into the press until it contacts the empty Case, then back it out one turn and set the Lock Ring.
11. Make sure you can remove and replace the Seating Die, then screw it back in until the Lock Ring touches the Press.
12. Using that empty case, Seat the SUB to the OCL and set the Seating Stem Lock Nut.

13. Remove the Seating Die from the Press and measure across the length of it with the Calipers from the top of the Seating Stem to the Base.
14. Record that number on the Bullet Box as the Overall Die Length(ODL). Since the Seating Stem touches the bullet on the Ogive, it eliminates most of the variations in length of the bullets in the box.

Example: Let's say the ODL is 4.325" for that box of bullets. And you want to Seat some 0.025" "Off-the-Lands". You pre-adjust the Seating Die to 4.300" screw it into the Press and begin loading bullets.

If you try to measure the OCL at this point, it may create some confusion because it will vary slightly from cartridge to cartridge. This is because of variances in the individual "Bullet Lengths" within a box and should be ignored. The main thing is they are all Seated so the Ogive is the same distance off-the-Lands and that is assured by Seating them slowly and smoothly.

Each time you open a new box of bullets you need to do this. It compensates for the Throat Receeding and variations in the Bullet Manufacturing process from Lot-to-Lot.

Best of luck to you and please don't throw any of the "Tools" in my direction.

Are talking about the Chamber All?

Thats too bad. I havent had any problems with mine yet. Very consistant. I did have variances with the other methodes mentioned. Thats why I bought it.

Maybe I lucked out.

quote:

Originally posted by boilerroom:
Are talking about the Chamber All?

Thats too bad. I havent had any problems with mine yet. Very consistant. I did have variances with the other methodes mentioned. Thats why I bought it.

Maybe I lucked out.

No, I'm talking about this
http://www.sinclairintl.com/cgi-bin/category.cgi?catego...em=09-400&type=store

Tried it again today and still can't get any real repeatable readings.

what am I thinking, mines a Stoney Point. I just bought it from Sinclair

I suppose the Chamber All is a better design. I've heard no complaints as of yet...but I'm sure someone will respond within minutes to that comment.

Matt, now you know why some folks have micrometers, and others have calibrated C clamps

MVW

I just recently got the Sinclair tool because I always felt the Stoney Point was not exact, even though the repeatability was good. I tried it on 2 rifles that I had already loaded shells for to see how it compared.

The first rifle was a 30-06 that I'm trying to get to shoot the 200 grain Accubond. I had loaded them thinking I was .025" off the lands. With the Sinclair I got repeated measurements that were the same down to the thousands and calculated that I had actually loaded them .08" off the lands.

The other was a 300 WM that I had loaded some 180 gr TSX's and some 200 gr TSX's. I thought I had loaded them .05" off the lands as calculated by the Stoney Point. By the Sinclair (again repeated exact measurements down to the thousands of an inch on both bullets) I had actually loaded them .025" off the lands.

I have since shot those loads and the TSX's shot great and the Accubonds shot terrible.

I have tried Hot Core's method going so far as to get a single edge razor and a 1/4" dowel rod and laying the razor flat on the muzzle to make a very precise mark. Then using the razor again to create a ledge on the wood shaft of the dowel to set the blade of the calipers on. I got inconsistant measurements there by as much as .03" or so. Time consuming and uses a lot of dowels.

Now with the Sinclair I angle the muzzle down and gently drop the bullet in and then use a dowel through the muzzle to lift the bullet out of the lands and let it gently drop back. With the PFLR'd case I push it with my little finger in tight against the shoulder.

Again I have just started using it so I may change my mind later but right now I think it's the best yet. With it I will have confidence enough to load closer to the lands.

BTW

A tool was posted on another thread that looks like a Sinclair type rod with locking nuts that you insert into the muzzle and use Hot Core's method.

r_reeves61@bellsouth.net

The thread is now on page 3

https://forums.accuratereloading.com/eve/forums/a/tpc/f/2511043/m/106101903

I don't understand the problem. Do you mean the OAL calculation is the same for each bullet? If so, that is just a coincidence. The sinclair tool works off the ogive of the bullet and the shoulder of the case. If you have a sinclaire comparator,..you can check to see that the distance from case head to ogive is the same between any bullet you use. The ogive is the point at which your bullet will contact the lands,..so no matter the bullet,.the casehead to ogive measurement remains the same.

Woods, The tool I sell works just like the dowel pin method. I use a polished S/S rod with two aluminum collars that are CNC drilled to be square with the rod. then there are set screws in the sides of the collars. to use this tool close the bolt. close the bolt and stand rifle upright. slide rod down the bore till contact is made with the bolt face. with collars stacked out on the muzzle tighten the top set screw using only finger pressure. take the rod out of bore and open action, drop a bullet in the chamber and using a blunt object press the bullet up to lightly contact the rifling. slide the rod back in the barrel till contact is made.tighten the second collar with contact being on the muzzle. pull the rod out and measure between the collars with micrometer. that is the max col of that bullet in that rifle. It will take less than a minute to do it and It is accurate everytime.

quote:

Originally posted by JustC:
I don't understand the problem. Do you mean the OAL calculation is the same for each bullet? If so, that is just a coincidence. The sinclair tool works off the ogive of the bullet and the shoulder of the case. If you have a sinclaire comparator,..you can check to see that the distance from case head to ogive is the same between any bullet you use. The ogive is the point at which your bullet will contact the lands,..so no matter the bullet,.the casehead to ogive measurement remains the same.

The problem I'm having is I can't get repeatable results with any bullet I'm trying, I know that they probably wont read the same. Guess I should have been more clear on that Oh and I did order a sinclair comparator also, very nice little tool.