243win/115gr DTAC/RL17 Load development part 1: Pressure testing

[InkedIan]

I couldn't find any great info on this combination so I thought I would share my findings as I go...

Rifle:
Savage 10fp
Bartlein 6mm 5R 1/7.5" twist 28" chambered in standard 243win
No barrel nut
Remmy recoil lug
Xlr chassis
YHM 7.62 QD Muzzle brake
Bushnell 3.5x21x50 DMR

Load Components:
115gr Dtacs BNC
RL17 powder
Federal brass
Federal 210m primers
Loaded to touch lands at 2.289 oal off ogive

Step 1 pressure test 2 cartridges for each load with FPS and description:
39: 2877, 2915 slightly flattened primers
39.5: 2942, 2941 slightly flattened primers
40: 2981, 2977 slightly flattened primers
40.5: 3025, 2995 slightly flattened primers
41: 3060, 3063 slightly flattened primers
41.5: 3104, 3099 slightly flattened primers
42: 3134, 3135 slightly flattened primers
42.5: 3167, 3163 slightly flattened primers, slight primer cratering
43: 3206, 3202 mildly flattened primers, slight primer cratering, very slight ejector mark, slight primer gas leaking
43.5: 3243, 3225 flattened primers, mild primer cratering, very slight ejector mark, primer gas leaking
No heavy/sticky bolt for any of the loads
Thinking I will start at 41grs for accuracy testing

Pictures of brass go from left to right 39 to 43.5grs of RL17

 

[Scotch_egg]

And how we're your groups?

 

[JGorski]

Ill be testing 41-43grs RE17 in my 6 Creed in May with 105AMP Hornadys, tried 40.5 and below last year, not even close to having a flat primer, Im thinking around 42grs might b optimum, we shall see. FYI, your 243 holds 5 grs more powder than my 6 Creed.
<a href="http://s1113.beta.photobucket.com/user/JGorski80/media/6creed_zps63452480.jpg.html" target="_blank"><img src="http://i1113.photobucket.com/albums/k513/JGorski80/6creed_zps63452480.jpg" border="0" alt=" photo 6creed_zps63452480.jpg"/></a>

 

[InkedIan]

Scotch_egg, Group testing is next. Loadings will be
41
41.2
41.4
41.6
41.8
42
42.2
42.4


JGorski, I've found that fed brass and primers are kinda soft so the pressure signs can show with lighter loads but it's what I have soooo.... I'm sure some CCI primers and Win or Lapua brass will tolerate some higher loads.