Load change advice; 30-06 National Match Brass

[Laguna Freak]

I have a really accurate load in my 06 shooting 150 Accubond @ 2900 FPS +/- 3 FPS; 57 gr RL16 WLRM primer. This load is very consistent in both Hornady & RP brass.

I have 280 once fired FA and LC National Match brass 1958 to 1967 that I want to switch to now. Weight sorted into 2 Lots within 3 grain weight spread. Looking for advice on starting load to get back to 2900.

Thanks in advance for sharing your experience.

 

[Rosebud]

Back off a grain from what you're shooting now and chronograph it. Work up from there.

 

[Laguna Freak]

@Rosebud that's looking like pretty good advice. Thanks.

It seems fire forming the FA/LC NM cases to my chamber is required prior to re-working the load back to 2900 fps mv, because their exists a wide variance in base to shoulder dimension of the FA/LC NM cases. Maybe 20% of cases reached my chamber's required shoulder set back. Atleast half of the shoulders are 6-10 thou short with the balance in between.

After annealing, fl sizing, trimming, & re-priming 40 pieces of my 3 grain weight variance Lot 1 FA/LC NM cases, I have the following interesting results compared to
R-P brass that fits my chamber:

3 random cases of each chosen

FA/LC vs R-P
Case weight variance
0.6 gr 2.5 gr
Case average weight
200.67 gr 199.7 gr
Water capacity variance
0.2 gr. 3.4 gr
Water capacity average
269.1 gr 269.73 gr

 

[338 dude]

I have a really accurate load in my 06 shooting 150 Accubond @ 2900 FPS +/- 3 FPS; 57 gr RL16 WLRM primer. This load is very consistent in both Hornady & RP brass.

I have 280 once fired FA and LC National Match brass 1958 to 1967 that I want to switch to now. Weight sorted into 2 Lots within 3 grain weight spread. Looking for advice on starting load to get back to 2900.

Thanks in advance for sharing your experience.

 

[Rosebud]

If you need to form your cases to the chamber find some cheap bullets and midrange powder charge and shoot everything. Then start load development. Or find better cases.

 

[Laguna Freak]

If you need to form your cases to the chamber find some cheap bullets and midrange powder charge and shoot everything. Then start load development. Or find better cases.

Thanks. I ordered 300 cheap 150 factory second bullets.

 

[Laguna Freak]

So, its been a long hot summer and I finally got 40 cases fire formed to my chamber. I selected a 10% random sample to compare water weight capacity. Water weight capacity =
68.5 gr
67.4 gr
67.5 gr
67.5 gr

Looks pretty good to me.

 

[Laguna Freak]

Thank you to everyone who offered sage counsel! Its looking like I got this load dialed back in. 3,4,5 are 55.7 to 55.9 gr = 2870 fps 8 fps ES. FWIW; Brass is FA and LC 60, 61, 62. This old Steyr Pro Hunter still driving tacks after 25 years.