Bullet seating depth - where to begin?

[artist]

Caliber: .257WBY
Bullet: GS Custom 92gr SP.

Just wondering if some of you more experienced reloaders can share a bit about how to determine optimum seating depth. I am able to seat touching the lands if necessary but am wondering if there are any general methods useful to help find the so called "sweet spot"?

Much appreciated!

 

[chino69]

bullet seating depth

Caliber: .257WBY
Bullet: GS Custom 92gr SP.

Just wondering if some of you more experienced reloaders can share a bit about how to determine optimum seating depth. I am able to seat touching the lands if necessary but am wondering if there are any general methods useful to help find the so called "sweet spot"?

Much appreciated!

For factory rifles or chambers I begin with the bullet touching the lands and go back in .010 increments until I find the sweet spot.

For custom match grade chambers I begin with the bullet touching the lands and try both; i.e. going further into the lands and further away in .010 increments. It really helps to have a Wilson in-line seater, an arbor press and perform this at the range. You'll get to the sweet spot quickly doing it at the range.

Lou Baccino

 

[Montana Pete]

This Mr. Baccino seems to have the right idea. My A.O.L. guage recommends backing off from 2 to 4 hundredths. Works for me.

Some guy was on the forum a month or two back, claimed he was measuring at thousanths, and then backing off a couple of thousanths.

Personally, I have never gotten the A.O.L. guage to measure at such precision.

I measure the same bullet in the same rifle four or five times, and --at the thousanths level-- I never get the same reading twice.

There's a difference between "precision" and "accuracy." Look the words up. You can have precision beyond the possibility of accuracy. Or a lot of hot air . . . . .

This guy apparently puts holy water on the barrel before he inserts the guage.

 

[chino69]

Seating depths

This Mr. Baccino seems to have the right idea. My A.O.L. guage recommends backing off from 2 to 4 hundredths. Works for me.

Some guy was on the forum a month or two back, claimed he was measuring at thousanths, and then backing off a couple of thousanths.

Personally, I have never gotten the A.O.L. guage to measure at such precision.

I measure the same bullet in the same rifle four or five times, and --at the thousanths level-- I never get the same reading twice.

There's a difference between "precision" and "accuracy." Look the words up. You can have precision beyond the possibility of accuracy. Or a lot of hot air . . . . .

This guy apparently puts holy water on the barrel before he inserts the guage.

Pete,
Using Wilson in-line seaters has given me more consistency than conventional seating dies. Once I establish my overall length for a particular cartridge I use a Stoney Point O.A.L. gauge and the overall length can be maintained @.001 with quality bullets using a Wilson in-line seater.

Taking my original measurements in the chamber of the rifle to arrive at my initial O.A.L. is never repeatable. I'm within .005 in my measurements due to how far I push the bullet into the lands, etc. This method only gives a reasonable starting point and I do the fine tuning at the range.

I've tried using a dummy cartridge and using the bolt to seat the bullet which, more often than not, gets the bullet jammed into the throat. I then have to remove the bullet with a wooden dowel from the muzzle end. There are people who claim this method works for them but I've never had success with it. I've even cut a slit in the neck with a Dremel tool, as recommended by several books, and have still been frustrated. My current method works for me.

Lou Baccino

 

[DR4NRA]

This Mr. Baccino seems to have the right idea. My A.O.L. guage recommends backing off from 2 to 4 hundredths. Works for me.

Some guy was on the forum a month or two back, claimed he was measuring at thousanths, and then backing off a couple of thousanths.

Personally, I have never gotten the A.O.L. guage to measure at such precision.

I measure the same bullet in the same rifle four or five times, and --at the thousanths level-- I never get the same reading twice.

There's a difference between "precision" and "accuracy." Look the words up. You can have precision beyond the possibility of accuracy. Or a lot of hot air . . . . .

This guy apparently puts holy water on the barrel before he inserts the guage.

The stoney point will give you a good place to start, to say that down to the thousandths with one is not obtainable you are not entirely correct. After initial measurements with the stoney point came up with a good starting point, I was able to consistently back off and find where the rifle likes to shoot well.

220 Swift, norma brass at 2.197 trim, 2 thousandths over minimum trim, 52 grain Sierra match seated to 2.333 to 2.3335 with the stoney on a good digital micrometer, which comes out to 2.668 C.O.L where by factory specs say 2.680. While this may be taking it a little to far, I have been able to consistently seat to a plus or minus .0005.

It takes more time but can be done. And I dont use holy water, I take the rifle out start banging on a drum, sprinkiling magic dust in the air, dancing in feathers while chanting, all in an effort to appease the shooting GODS, and to provide the other shooters with some entertainment as I look like a total fool.