Gents:
I'm new to handloading the TSX's and am not sure on bullet seating depth vs. C.O.L. Am I supposed to seat to the 3rd and final (closest to bullet tip) groove or load to a distance of the lands. I do not have a gauge to determine this. Any suggestions. Anything past 3.325" tends to be tight when I close the bolt, yet I believe M.O.L. is spec'd at 3.34" in Barnes and 3.321" in Lee reloading manuals. Not sure why the disparity, but any info would help. Thanks.
ScottW

The grooves are only to reduce pressure. To determine seating length I usually partially size an empty case, seat a bullet in the case, but leave it long. Then put the case in the chamber and close the bolt (takes a bit of effort). Once you remove the case measure the overall length, and from there I usually seat the bullets about .02" deeper. I hear that Barnes bullets like to be seated more like .03 to .05" from the lands.

I'm not an expert on Barnes bullets, so maybe someone else can add better advise.

quote:

Originally posted by ScottW:
Gents:
I do not have a gauge to determine this. Any suggestions.

Yes. Get one. You'll need it and they're cheap.

You'll find different recommendations on seating depth because every bullet is different, then you have the SAAMI standards.

What you need to do is find the absolute overall length with your bullet of choice, then reduce it to 50 thousandths off the lands of YOUR rifle to start, while using a Barnes bullet. Most of my rifles like the TSX about 5-10 thousandths off the lands.

Let us know what happens.

Doc:
Which gauge do you recommend?

The Stoney Point Tool is not bad. You'll also need the modified cases for each caliber you want to measure with this tool.

What you have to realize is that bullet types vary greatly in ogives. A bullet seated to a certain COAL may be off the lands, and another bullet (with a different ogive) may be in the lands at the same COAL. If you want to be aware of the position of the bullet with respect to the lands for different bullet types, you really have to measure max seating depth with each bullet. Luckily, it takes less than 5 minutes to do so, once you get the hang of it.

To properly measure your seating depth, you should measure using a bullet comparator (like this one), to be sure you measure off the ogive of the bullet, as opposed to the tip. The ogive will normally vary less than the tip of the bullet.

- mike

Will strongly second mho.
The Stoney Point rig is really easy to use and very helpful with the Barnes line of bullets as the best accuracy varies with different rifles as to how much "set back" from the rifling. I have a couple that like the ogive set off around .007 but one that is best at .012.
Find myself usig it on everytihing i reload if nothing else but for information to see what is digested best by that gun.

Scott,

I "fourth" Doc's, gab's & mho's recommendation on the Stoney Point Tool. I use one also and like mho says, after you've done this once - it's easy.

Cool thing about this tool is that you'll very quickly find out interesting seating depths for evry bullet is different and see that just a little bit either way with a bullet can make a remarkable difference.

Having said that and only having expereince with one Barnes bullet, a 120 gr. .284" TSX, I found that using the "just behind the third groove/driving band" spot you mentioned with a crimp form a Lee Factroy Crimp Die was just exactly what turned out to be the best AOL for my barrel/bullet combination was anyway.

There are two parts to the Stoney Point system, the OAL Gauge and the Cartridge Comparator. The former goes into the chamber to determine where your lands are and the latter allows you to convert that measured bullet into inches and thousandths on your caliper.

IMO, the Comparator is much the more useful part, as without it you must work with catridge overall length, a much inferior measurement than the Ogive Length the Comparator yields.

In fact, I have given up using the SP OAL Gauge at all because of problems with the system, and returned to looking for land marks on smoked bullets. I still use the Comparator, though, for Ogive Length.

Jaywalker

I use a stoney point and the sinclair comparator.

Every post above is sound advice.

They have good seating instructions on the Barnes web site. They are typically longer than other bullets being 100% copper so your magazine box may be the limiting factor on seating depth depending on the rifle. I can't get anywhere near the lands with my sendero but they shoot good anyway.

Great info...thanks, Gents! Oh, goody! More tools to clutter up my reloading bench!
ScottW

Scott

When you buy a box of TSX they will have seating instructions inside, my 06 COL is 3.420.

I use the stoney point system but drill and tap my own cases as I have way to many CF to buy threaded cases for all you need is a good drill press and a machinest vice, the drill and tap will run you about $12