243 Winchester +p

[Thejet]

Didn’t see any load data on here so here we go.
Tikka 243 Winchester +P, 15 inch 1-8 twist barrel with tacked brake so 16 overall (legal min length).
Starting with Hornady 108Ms.
Optic is NF atacr with UM tikka rings, torc and blue LT for instal.

 

[A382DWDZQ]

Why not start with published load data?

 

[Pickettpuncher]

And twist rate

 

[Thejet]

Starting point after barrel brake in.

Components.
Winchester brass, Hornady 108Ms, match LR primer, RL17 powder, seated at 2.8.

Ran powder charge starting at one gr under max (41) in one gr increments up to 46 gr to test speed and find pressure.

46. 3082 pop primer

1. 3025 little pressure

44 2818 miss read-retest later.
43. 2865
42. 2777
41. 2711

Loaded up same setup but at 43, 43.5, 44, and 44.5 gr to test ES.

44.5 2952-2974. 22es
44. 2916-2928. 12es
43.5. 2893-2897 4es
43. 2850-2880. 30es

 

[Pwb199]

That’s pretty impressive for a 15” barrel

 

[Mulyhuntr]

What's the point of such a short barrel but no can? I imagine that thing is insanely loud?

 

[ACHILLES]

It’s handy, easy to carry, and still very capable out to medium ranges. All braked guns are loud at any barrel length. It’s not like he could shoot it without ear protection if the barrel was longer.

 

[A382DWDZQ]

Assuming a 200fps increase for barrel speed up...
Quickload shows this load on a 15” barrel as 2,888 for a charge of 45.5, and 82,068 psi. That is pretty close to what the results above are showing.
A proof load at 1.3 x SAAMI (78,000) would be 44.8-44.9, with velocity registering ~3,050 on a sped up barrel (+200fps).
The blown primer at 46 was probably around 87,000-88,000psi.

 

[Thejet]

tested two other powders today, same components just swapped powders. Results below.

VV 560
43. 2458
44. 2579
45. 2651
46. 2679
47. 2804
48. 2853
49. 2942
50. 2995. Pressure

Loaded sets to test for ES.
47.5 2805-2831. 26es
48. 2861-2879. 17es
48.5. 2915-2918. 3es. W
49. 2943-2970. 27es

H4831SC
47. 2789
48. 2826
49. 2877. First sign
50. 2960.

Loaded sets to test ES

47. 2798-2813. 15es.
47.5. 2801-2805. 4es.
48. 2839-2840. 1es
48.5. 2864-2878. 14es

 

[Pwb199]

Makes me wonder what a 243AI or a 6creed +P could do

 

[Axlrod]

tested two other powders today, same components just swapped powders. Results below.

VV 560
43. 2458
44. 2579
45. 2651
46. 2679
47. 2804
48. 2853
49. 2942
50. 2995. Pressure

Loaded sets to test for ES.
47.5 2805-2831. 26es
48. 2861-2879. 17es
48.5. 2915-2918. 3es. W
49. 2943-2970. 27es

H4831SC
47. 2789
48. 2826
49. 2877. First sign
50. 2960.

Loaded sets to test ES

47. 2798-2813. 15es.
47.5. 2801-2805. 4es.
48. 2839-2840. 1es
48.5. 2864-2878. 14es

Your starting load for N560 is VihtaVouri's max load. Their max velo is 2749 fps with a 23" barrel.
You don't have a 243 +p, you have a 243 + Unsafe.

 

[A382DWDZQ]

It might make sense to just build a 6 SAUM or 6 PRC to get those velocities. Longer brass life, barrel life, action life and life.

 

[Pickettpuncher]

How do you make a cartridge +p anyway? Just load it hot? Or is there a better way

 

[Thejet]

How do you make a cartridge +p anyway? Just load it hot? Or is there a better way

It’s treating a portion of the barrel to allow it to build more powder before hitting pressure.

 

[Thejet]

Your starting load for N560 is VihtaVouri's max load. Their max velo is 2749 fps with a 23" barrel.
You don't have a 243 +p, you have a 243 + Unsafe.

I agree that it’s odd how much over their printed max is, but at what a i listed there was zero signs of pressure. No marks on brass, no hard bolt lift, no popped primers so on. H380 however still blows primers 1gr over book max.

 

[Thejet]

1 RL17 43.5. Top left 2874-2936 sd21
2 RL17 44. Top right. 2923-2980 sd21
3 n560 48.5. Bot left 2918-2943 sd 9
4 H4831SC 47 b right 2789-2829 sd14
5 H4831SC 47.5 n t L 2828-2846 sd8

 

[Thejet]

115 Dtac deep nose cut H4831SC
46.5. 2715-2747 sd15.
46. 2690-2710 sd8