50 BMG primer seating depth

[secondofangle2]

Having some trouble with my 50 BMG SDs. Dunno if it's the cold weather, or that fact that I now have a 2250 yard target and a GARMIN measuring shots that makes vertical stringing more obvious, or it is a new problem that sneaked in that I'm not aware of yet.

So as to not turn this into a giant referendum on all things 50 BMG reloading, I wanna focus on one variable: Primer seating depth.

I'm using a ($450!) M2 precision primer seating tool that indexes off the base of the case, not the rim. (RWS brass so almost perfect rim uniformity, but still - there is no better way to seat a primer than M2 in RWS brass). For years I've been using 0.007" seating depth, kinda the same as that guy who will not be named recommends for large rifle.

I no longer have access to FCSA, but a buddy said he saw on there that at least one dude is using 0.0175", which is over double mine, 0.010 more in fact.

Anybody have EXPERIENCE in this domain? Obviously, I'm going to try deeper seating, and I've already changed my setup for 0.015" depth, but I'm wondering how much is too much?

 

[Alan Warner]

Having some trouble with my 50 BMG SDs. Dunno if it's the cold weather, or that fact that I now have a 2250 yard target and a GARMIN measuring shots that makes vertical stringing more obvious, or it is a new problem that sneaked in that I'm not aware of yet.

So as to not turn this into a giant referendum on all things 50 BMG reloading, I wanna focus on one variable: Primer seating depth.

I'm using a ($450!) M2 precision primer seating tool that indexes off the base of the case, not the rim. (RWS brass so almost perfect rim uniformity, but still - there is no better way to seat a primer than M2 in RWS brass). For years I've been using 0.007" seating depth, kinda the same as that guy who will not be named recommends for large rifle.

I no longer have access to FCSA, but a buddy said he saw on there that at least one dude is using 0.0175", which is over double mine, 0.010 more in fact.

Anybody have EXPERIENCE in this domain? Obviously, I'm going to try deeper seating, and I've already changed my setup for 0.015" depth, but I'm wondering how much is too much?

I use an M2 also and set them at .012.
Run a side by side of your .007 and some at .012 and see what the chrono says.
Just an fyi- the newest lot just in is running rim thickness a thou or two larger than what we've all seen for the past four years.
The .675 undercut is now running at .677.
According to Mark C. The new lot is new production where as the older lot was all from stored inventory. Thus the long wait to get the newest shipment.

 

[secondofangle2]

Thanks, Alan