Greetings all,
I feel like I want to try something different and I'd like some input on my plan. I've got a 175 MK/RL-15 load worked up that works fairly well in my rifle. It is a Savage F T/R with a 30 inch 12 twist Brux barrel chambered with a 308 Fullbore 2011 reamer.
175 MK
43gr. RL-15
Lapua brass, length - 2.210, 55.4 H2o vol.
CCI BR-2
OAL 2.800
Chrono'd av. 2650 fps, ES- 12.5, SD-3.5
I'd like to be able to get a MV closer to 2800 fps.
I've reduced the Ba value by %6 for RL-15 in QuickLoad and set the temp. to 60 F. to match the chromo results. This gets me a QL prediction of 2656 fps and a barrel time of 1.486 ms. Chamber P Max is a gentle 47074 psi.
As far as I can tell this is the way it's supposed to be done. Correct?
According to OBT theory my 1.486 BT for this load is about -%3 away from the closest node of 1.530, slower. Conversely, the next faster node at 1.368 is about +%8 away from where I am now.
If I plug in 45.7 gr. of RL-15, adjusted for this lot of powder, into QuickLoad I get a BT prediction of 1.368 with a MV of 2809 fps and a P Max of 57009 psi.
I plan on checking my 43 gr. load again this weekend and verify the QL calibrations against perhaps another different load, say, 44 gr. before going up. I have some 42.8 gr. loads ready to try as well. These should put me pretty dang close to my next slower node. Don't ask me why but I've never tried less than 43 gr. t see if it would improve my accuracy. I guess I figured that was the wrong direction.
Does this seem reasonable to try working up incrementally to 45.7 gr. of RL-15? It's more RL-15 than I've ever used, or hear being used on a regular basis. 45.7 gr. is way over book max.
I'm skeptical of OBT theory and how well it describes the real world. I think it would be great if It worked for me. As much shooting as I do I suppose I'm not very scientific about my load development. I wonder if I'm leaving some accuracy on the table, so to speak.
Thanks
B
I feel like I want to try something different and I'd like some input on my plan. I've got a 175 MK/RL-15 load worked up that works fairly well in my rifle. It is a Savage F T/R with a 30 inch 12 twist Brux barrel chambered with a 308 Fullbore 2011 reamer.
175 MK
43gr. RL-15
Lapua brass, length - 2.210, 55.4 H2o vol.
CCI BR-2
OAL 2.800
Chrono'd av. 2650 fps, ES- 12.5, SD-3.5
I'd like to be able to get a MV closer to 2800 fps.
I've reduced the Ba value by %6 for RL-15 in QuickLoad and set the temp. to 60 F. to match the chromo results. This gets me a QL prediction of 2656 fps and a barrel time of 1.486 ms. Chamber P Max is a gentle 47074 psi.
As far as I can tell this is the way it's supposed to be done. Correct?
According to OBT theory my 1.486 BT for this load is about -%3 away from the closest node of 1.530, slower. Conversely, the next faster node at 1.368 is about +%8 away from where I am now.
If I plug in 45.7 gr. of RL-15, adjusted for this lot of powder, into QuickLoad I get a BT prediction of 1.368 with a MV of 2809 fps and a P Max of 57009 psi.
I plan on checking my 43 gr. load again this weekend and verify the QL calibrations against perhaps another different load, say, 44 gr. before going up. I have some 42.8 gr. loads ready to try as well. These should put me pretty dang close to my next slower node. Don't ask me why but I've never tried less than 43 gr. t see if it would improve my accuracy. I guess I figured that was the wrong direction.
Does this seem reasonable to try working up incrementally to 45.7 gr. of RL-15? It's more RL-15 than I've ever used, or hear being used on a regular basis. 45.7 gr. is way over book max.
I'm skeptical of OBT theory and how well it describes the real world. I think it would be great if It worked for me. As much shooting as I do I suppose I'm not very scientific about my load development. I wonder if I'm leaving some accuracy on the table, so to speak.
Thanks
B
