Just finished a 6.5-06 build on a 116 Stainless Savage Action. Wanted to experiment with this caliber so I opted for a cheap Shaw 26" SS Varmint Prefit from Gunshack which set me back a whopping $199. Sits in a Boyd's Tacticool Laminate.
I Had plenty of H4350 on hand so I made 3 round strings from 46g to 49g in .5 increments. Had a pound of Alliants PP4000MR I have been using for 7 RM which has been great so I figured I would try it too. Alliant only has data for 25-06 and 30-06 for the 4000MR so I emailed them. Their response was NO DATA. I am shooting the Hornady 140 Amax and the Max load for the 25-06 with the 120SP is 50g which I figured was pretty conservative so I made 3 rounds each from 49 to 53 grains in .5 increments.
Shooting at 100 rounds (all my club has) I shot each string off my Atlas bipod and a bag using my Gen 2 Magnetospeed Chrony. All were in new R-P .270 brass. Trimmed to 2.494 with a CCI BR2 primer. COAL was 3.320. Here are my results.
H4350
46 2739 ES 55
46.5 2776 ES 17
47 2834 ES 6
47.5 2839 ES 8 *.3 group - best
48 2856 ES 37
48.5 2880 ES 38
49 2900 ES 28
Power Pro 4000 MR
49 2887 ES 30
49.5 2911 ES 12
50 2949 ES 14
50.5 2961 ES 9 * .5 group - best
51 3001 ES 36
51.5 3032 ES 29
52 3051 ES 16
52.5 3077 ES 22
53 3120 ES 25
Holy crap this thing is the Hammer of God! What an awesome rifle and caliber. I think I'll go with the node at 50.5. There was a significant difference in recoil between 50.5 and 53. Although 3120 is smoking Ill want to go easy on the barrel and of course be more accurate. Interestingly there were no pressure signs at 53! The slight primer cratering must be my firing pin as it was evident on all shots fired. I may try to work up a few more grains from 53 to see if I can find another node or at least find the max where it starts to show pressure signs. I can't imagine a 140 moving at 3300! That is WSM speeds!
This is the 53g 4000 MR 3 round group.
Interesting how the string went horizontal. It was .48 MOA across and .28 verticle.
From left to right 51.5 - 52 - 52.5 and 53 grains.
New stick on the test bed.
Reply With Quote
Bookmarks