Savage308 chamber

[oldpahunter]

Lots of good info on this site. This is my first post but I have been reading old post and getting alot of great tips. working on loads for the 308 with seating 175 SMK off the lands, I tried the Stoney point tool with the modified case and had a wide variation of lenghts using a caliper and the comparator. I used the split case mouth method that I read in the reloading section and it worked and was consistant. I got a reading of 3.233 with closing the bolt to seat it. My question is does this sound right, measured off the ogive with the comparator.

[frank1947]

no, but did you zero your calipers when you put comparator on it, the comparator and body measure 1 inch so if you are 2.233 you might be good, that tools should work consistantly, put bullet deep into the modified case then push in tight to chamber then loosen screw push bullet tight to lands use a rod from the muzzle end and push to guide it out make sure bullet is snug still in case now measure

[oldpahunter]

Yes I forgot about the comparator you are correct. Will try using the modified case again. thanks for the help.

[frank1947]

sure No problem

[Bamboolongbow]

My chamber measured 2.290 to the ogive using the split case method.

[darkker]

Sounds close. Every throat is a little different.
My 10FP when using 175SMK's, get set to 2.9". That is .015625" off the lands in my gun.

[benfranklin]

you can not measure your chamber like your doing...Really all your
doing is getting the over all length of your bullet to the ogive..

[gotcha]

With a new bbl bullets will tend to stick to the lands & pull out of the case slightly on extraction. Take at least five readings. Ten would be better. If your measurements vary more than .003" bullets are probabley sticking. Run a wet patch into the bbl & try again. If after five measurements you get 3 or 4 that are within .001" go with the shortest measurement. If you end up using more than one bullet, sort for length as base to ogive measurements can vary widely even w/ SMK's........... You'll also need to re-check seating depth from time to time as the throat will lengthen based on the number of rounds fired. Just my 2 pesos :)

[GaCop]

With a new bbl bullets will tend to stick to the lands & pull out of the case slightly on extraction. Take at least five readings. Ten would be better. If your measurements vary more than .003" bullets are probabley sticking. Run a wet patch into the bbl & try again. If after five measurements you get 3 or 4 that are within .001" go with the shortest measurement. If you end up using more than one bullet, sort for length as base to ogive measurements can vary widely even w/ SMK's........... You'll also need to re-check seating depth from time to time as the throat will lengthen based on the number of rounds fired. Just my 2 pesos :)


+1!

[Grit #1]

There is another way of doing this that I used for years and still do. It may be a bit more involved but is it really quite accurate. It involves a candle and an over seated case/bullet combo. What you do is smoke the end over the bullet were the ogive is located and run it up into the chamber and extract it with out dragging the bullet along the side of the action. You will see were the lands have touched the smoked bullet. The lands will rub the smoke off in that area and the copper will shine bright. Wipe the bullet off run it up through the seating die to seat the bullet a little deeper re-smoke and repeat. Takes a couple of times to get close. Then go in smaller increments until the land don't touch the bullet and you will have a pretty accurate gauge round to measure. It sure beats waiting for a new Stonypoint case to come it the mail.
Best regards,
Grit