Working up a load

[oldgunny]

I am new to reloading so these questions may be old stuff to most of you, but I can not find the anwsers in any of the books I've read so far, so I'm hoping someone has the anwsers.

When working up a load, everything I've read says to start with a reduced powder charge and work up, keeping an eye on the chamber pressure.

Also, everything I've read says to start with the bullet "jamed" in the lands, with a reduced power charge, and work back to a "jump" of .10 to .20 to see what works best in any given rifle.

question 1: Which of these operations should be done first.

question 2: Is there anyway to test chamber presure when conducting these test.

Thanks

 

[billmo]

oldgunny, the bullets should be jam to lands while you are trying your first reduced powder charges and continue thru that shooting session. With your bullets jam to lands, you only have one direction to move with your bullet seating depth. Do not change more than one thing at the time. Decide which powder and charge your rifle likes first, then begin adjusting bullet seating depth as you described above in another shooting session.

Pressure test can be done but only with a "strain gauge" attached to the barrel as far as I know.

I hope this helps. Bill

 

[oldgunny]

Thanks Bill, this gives me a starting place. Do you know if the Stoney Point tool is the best way to find the correct bullet seating depth. I have also heard you can seat a bullet long in a non-primed case and the lands will push it back to the correct setting depth to measure. Is there a better method?

 

[2506]

If you are going to use this rifle for hunting you do not want to jam your bullets into the lands. I always start 10 thousands off the lands and work back. When hunting you have to unload you rifle sometime and with a bullet jammed into the lands you are most likely going to stick the bullet in the bore and dump a case full of powder down into your rifle. Been there and done that 30 miles from a cleaning rod to punch the bullet out. Work up in .5 grains first to see what you get for accuracy while watching primers and case stretch for pressure signs, then you can go 1/10 gr at a time to see if your accuracy gets better. It has been my finding over the years that your most accurate load will be from 1 grain below max up to the max load given in most loading data. Once you find the most accurate powder load if it is not a max load you can try different primers and then you can move the bullet seating depth to try to find more accuracy. That is what I do. A good place to start is the accuracy loads given in the Sierra manual.

 

[billmo]

Thanks Bill, this gives me a starting place. Do you know if the Stoney Point tool is the best way to find the correct bullet seating depth. I have also heard you can seat a bullet long in a non-primed case and the lands will push it back to the correct setting depth to measure. Is there a better method?

I use the Stoney Point tool. You can do it several ways as you mentioned but I have found the Stoney Point tool to be the most accurate for me. But, I make several trys before I decide where I was the most accurate. 2506 does have a point. If you are hunting with this rifle, you may want to keep about .003 to .004 neck tension on your brass so as to avoid that disaster or just stay away from the lands a little and work up your most accurate load at that seating depth. Bill

 

[oldgunny]

This rifle will be used for target shooting only. I started with a Model 700 Varmint rifle, and I'm building it piece by piece into a rifle I can shoot F-Class T/R with. It's a .308, and I have a mcmillian stock, jewell trigger, leupold scope, and plan to have it re-barrled and chamberd over the winter. This, by the way, is much more expensive then buying a gun already to go from a custom gunsmith, I have found.

I have found that with the factory chamber the case neck expands about .012. What should this be telling me about the chamber.

 

[billmo]

Well, it's certainly at the top of the SAMMI and then some if it is opening up .012. Your custom rifle chamber should definitely not be that big.