6.5 PRC Seating Depth

[General RE LEE]

Are y’all loading mag length or seating close to lands on 143s and 147s? I wasn’t sure how much room the 6.5 PRC Tikka mag allows for COAL.

 

[waspocrew]

I generally load .020” off the lands or to max mag length if that’s shorter. I don’t own a Tikka 6.5 PRC, but seems my Seekins magazine has plenty of room.

 

[N2TRKYS]

I load to the tested COAL in the load data in every cartridge I’ve ever loaded. I don’t know or care how far off the lands I am.

 

[mlevimadden]

Are y’all loading mag length or seating close to lands on 143s and 147s? I wasn’t sure how much room the 6.5 PRC Tikka mag allows for COAL.

I’m doing the same as @waspocrew above. I’m 0.020” off the lands in my 6.5 PRC with a CBTO of 2.353”. The boat tail is sill below the neck shoulder junction but not by much.

It’s a tikka with plenty of room left in the mag. I don’t pay any attention to COAL once I make sure it fits in the mag, since the 147s vary by a few thou in length. From my old notes, I’m only about 30 thou longer than SAAMI.

 

[General RE LEE]

I’m doing the same as @waspocrew above. I’m 0.020” off the lands in my 6.5 PRC with a CBTO of 2.353”. The boat tail is sill below the neck shoulder junction but not by much.

It’s a tikka with plenty of room left in the mag. I don’t pay any attention to COAL once I make sure it fits in the mag, since the 147s vary by a few thou in length. From my old notes, I’m only about 30 thou longer than SAAMI.

The Tikka 6.5 PRC mag allows that much extra COAL? Sweet.

 

[mlevimadden]

The Tikka 6.5 PRC mag allows that much extra COAL? Sweet.

I’ve mostly just been running tikka long mags, so I should’ve made that disclaimer in my previous post.

I do have two 6.5 PRC mags I recently bought and just put a few of my reloads in those mags and they fit fine. I wouldn’t call it tons of clearance like the long mags. I didn’t get out my calipers, but I prolly have a 10-20 thou gap from the bullet tips to the front of the mag.

 

[coast range]

Are you guys running long action bolt stops in your tikkas?

 

[stevie]

Are you guys running long action bolt stops in your tikkas?

Check your rifle bolt stop before purchasing one. My T3X 6.5 PRC lite already had a long in it.

 

[sr80]

Started doing load development with my tikka 6.5 prc, and i was able to load 147 eldms and 140 berger EH at 3.000" that is the maximum I can fit in the factory 4 round magazine that came with my rifle. If i remember correctly i was still 40 thou from the lands.

 

[General RE LEE]

Started doing load development with my tikka 6.5 prc, and i was able to load 147 eldms and 140 berger EH at 3.000" that is the maximum I can fit in the factory 4 round magazine that came with my rifle. If i remember correctly i was still 40 thou from the lands.

Hornady 147s are pretty jump tolerant. I read somewhere over 0.035 is optimal.

 

[mthunter1989]

I am right under 3.000" COAL with my Roughtech in the 6.5 PRC mag it came with, with 143gr ELD-X. I can look at my notes and get exact measurements, but it put the ogive approximately .060" off the lands in my chamber. I think I measured the max COAL in the mag at around 3.020".

 

[Harvey_NW]

I had mine throated out for the 143 to be ~.040" off the lands when boat tail is seated to neck shoulder junction. Also using a flush 3rd 300WM magazine with plenty of room.

 

[justin davis]

I’m shooting 156 Berger’s. But have them loaded .010 off the lands. It’s in a tikka.

 

[mthunter1989]

Reviewing my notes, I actually measured the max OAL in the factory mag at 3.060".

 

[TaperPin]

Are y’all loading mag length or seating close to lands on 143s and 147s? I wasn’t sure how much room the 6.5 PRC Tikka mag allows for COAL.

If loading to magazine length it’s always a good idea to fill the magazine completely to make sure they feed. Over the years it’s a common point of malfunction for guys to work up a load shooting one case at a time and opening morning they can’t get the magazine fully loaded.

 

[jlchester5045]

If loading to magazine length it’s always a good idea to fill the magazine completely to make sure they feed. Over the years it’s a common point of malfunction for guys to work up a load shooting one case at a time and opening morning they can’t get the magazine fully loaded.

Very sound advice!

Also, pick a starting point and load at different lengths. I’ve seen rifles shoot better at factory COAL than 20 thou off or even at the lands and vice versa. Every rifle is different. I start at factory COAL and work out till it shoots the best. Seating further has its benefits but isn’t always what shoots the best.

 

[Harvey_NW]

Also, pick a starting point and load at different lengths. I’ve seen rifles shoot better at factory COAL than 20 thou off or even at the lands and vice versa. Every rifle is different. I start at factory COAL and work out till it shoots the best. Seating further has its benefits but isn’t always what shoots the best.

IME this went away once I understood the statistics of sample sizes and how the cone of fire is established. You will most definitely see this with 3-5 shot groups, but it doesn't mean you're actually making a difference. Next time you're done with load development you should take the best and worst seating depth results and compare 10 shot groups and post them up.

 

[jlchester5045]

IME this went away once I understood the statistics of sample sizes and how the cone of fire is established. You will most definitely see this with 3-5 shot groups, but it doesn't mean you're actually making a difference. Next time you're done with load development you should take the best and worst seating depth results and compare 10 shot groups and post them up.

Couldn’t agree more. Once I “finalize” a load, I always run 10-20 not to only verify group size but also velocity for ballistic calculations.