Question on measurement off the lands for a .260 Rem Shillen match select 26 in
I am working up a new load and since I shot the ever forgiving .308 smk forever, I never measured off the lands. Now that I have a brand new 26 stainless Shillen match select barrel, where should I start with my measurement off of the lands. I will be loading 142 SMK, H4350 and new Remington brass.
Re: Question on measurement off the lands for a .260 Rem Shillen match select 26 in
Go get yourself a Hornady Lock-n-Load OAL gauge with a 260 Modified Case to find your jam length. Start with .020" off, and go from there. If you have a set of digital calipers, you can zero them out on the gauge. The measurements are usually referred to as BTO, or Base To Ogive. This is a much more accurate measurement with regards to seating depth consistency than measuring from the base of the case to the tip. Bullets can vary considerably in their overall length, but the ogive profile of a bullet is the characteristic you're looking for in regards to consistency.
Kevin
Re: Question on measurement off the lands for a .260 Rem Shillen match select 26 in
Quote:
Originally Posted by Aircraftmech76
Go get yourself a Hornady Lock-n-Load OAL gauge with a 260 Modified Case to find your jam length. Start with .020" off, and go from there. If you have a set of digital calipers, you can zero them out on the gauge. The measurements are usually referred to as BTO, or Base To Ogive. This is a much more accurate measurement with regards to seating depth consistency than measuring from the base of the case to the tip. Bullets can vary considerably in their overall length, but the ogive profile of a bullet is the characteristic you're looking for in regards to consistency.
Kevin
+1
Re: Question on measurement off the lands for a .260 Rem Shillen match select 26 in
Thanks guys, thats exactly what I have to measure, although I had the Lock and Load set up for .308 and no one had the .260 rem modified case in stock, so I ordered directly from Hornady. Should be here anyday
Re: Question on measurement off the lands for a .260 Rem Shillen match select 26 in
I always try to start at the lands during initial load development, that way once I find a powder charge and start with final tuning, pressure can only go down. A load on the very edge when .020 off the lands will be unsafe if the load is accidentally loaded on the lands or jammed. Just a safety issue to think of.
Re: Question on measurement off the lands for a .260 Rem Shillen match select 26 in
To everyone that has a StoneyPoint/Hor setup Sinclair now sells their own bullet comparitor inserts and headspace inserts. http://www.sinclairintl.com/.aspx/pid=34014/avs%7CCaliber_1=AAU_9xzzx3%20mm%20(xzzx366)%7CAAH_ 264zz1zz6xzzx5%20mm%20(xzzx264)/Product/Sinclair-Insert-Style-Bullet-Comparator
To SMK Shoe: to start at the lands is like starting with a max load of powder. If it didn't blow a primer or setback the lugs then a smaller load is safe. I see the lands as something to load to not away from.
Re: Question on measurement off the lands for a .260 Rem Shillen match select 26 in
I agree with SMK.
Work up your powder charge with the bullet kissing the lands. When you find pressure see how it shoots. If it shoots great (and it likely will) then you're golden. If not then you know you only have one direction to go with the bullet and that is deeper. Since you found pressure on the lands anything off the lands will be lower pressure.
Doing it any other way just seems foolish to me.
Re: Question on measurement off the lands for a .260 Rem Shillen match select 26 in
Always better to keep safety in mind. But what about those bullets that shoot better jammed? Other than the obvious of adjusting powder charges from min to max for each jammed length? Just wondering how others handle this situation.