tl;dr: Skim the summary to see my major time-saving choices. I spent more time typing up my rationale here than I did making the choices in the first place haha, but I could do it during the dark hours
Summary:
Hey all, in case anyone can benefit from this, I recently rebarreled my main rifle, which is coming deer hunting with me this season. This meant I needed to do a new load workup for my hunting round, and I’m just slammed for time between now and opening day. The shortest path to an acceptable load is always of interest to me, but it was a pretty critical consideration for me this time around. I have access to some longer-range shooting zones on public land, but I have to set up targets each time to use them, and because the zones are mostly across drainages in the mountains, it’s about an hour for full setup and teardown, days are getting short, it’s an hour to get out there, I work, and I have other commitments outside of shooting. I have a local range that’s an hour round-trip, with much faster setup, but it’s only out to 200 yards.
I was getting pretty stressed about being able to do jump testing, a charge ladder, MV validation at 400-600 yards, and scope swap and re-zero all in the limited post-work daylight I have left, since almost all of those steps require a trip back home to the reloading bench in between (yes, I can do the scope swap somewhere in there, but it’d be a pain to accommodate it in the middle of load testing). However, as I went through the process, I realized I could cut some major corners and get an acceptable load based on my load’s MER and using some existing data I already had. I thought other folks might be in a similar position either this year or in the future, and wanted to lay out my thought process in case someone else can benefit.
Here are my components; not really looking for debate about my choices, just laying out what I’m working with and why I’ve already narrowed it down to these:
1. Find the lands: I use the gutted-bolt method. Works great, although it’s kinda a pain in my Bergara because I have to pull out the ejector each time.
2. Establish jumps to test: Most all-copper bullet mfgs recommend minimum 0.050” jump, I didn’t want to load a ton of test rounds, and lots of folks have had good results with surprisingly long jumps. So I did 0.070” to 0.120” in 0.010” increments.
3. Pick a powder charge: I had old load data for the factory barrel, andwas just gonna use that. However, it was Hornady LRP brass, which has more case volume than the Lapua, and I managed to think of that before I loaded the rounds up. I backed off a full grain (~2.5%).
- I also did some googling to figure out where other folks were with similar components, and felt I wasn’t crazy overboard with my starting charge. It was towards the upper end, which was fine with me because I aim to push the bullet as fast as I reliably can.
4. Load ‘em up: I don’t have any heart burn compressing extruded powders to some extent, but in hindsight I accepted too much compression on the longer-jump rounds (more discussion below). My first sign of this was that I was getting a bit of crunch on my longest rounds; I should’ve backed off 0.5-1.0 grains then started over when I got that sign.
5. Clean the rifle: It’s been awhile since I’ve touched the gun, so I figured I’d start with a clean slate and a few foulers
6. Shoot ‘em upShot five foulers of my target load, which also let me ensure I was reasonably on-target at 200 yds
So, out to the mountains, and I know I need to drop the powder charge. It’s fine at 0.080” jump, but only 0.020” more compression makes it a too-hot load, and I want more safety margin than that, especially since I’m doing this development in a cool, high-humidity environment, so my load is only going to get faster when environmentals change. Here’s where I cut all my corners.
I figure I don’t need to drop the powder charge much, since I’m only buying some safety margin (my load is currently “safe” at 0.080” jump). But what if it changes the MV appreciably? There are three HUGE simplifying considerations here. First, I have to keep 2000 fps at impact, which means I’m only shooting out to 400-435 yards, based on my old factory barrel load at 2830 fps. Second, deer are not tiny; at 400 yds, the boiler room is over 2 MOA, so I have some elevation variability margin there. Third, at 400 yds, changes in MV won’t hugely affect POI, especially relative to the boiler room size.
To make sure though, I gamed it out in the Hornady 4DOF. I find a zero/zero profile extremely useful for comparing stuff like this; set your sight height and zero range both to zero, so you can compare “raw” drop data for different loads. So, fill in all the info for the load and expected environmentals, and then just pick a random pair of very different MVs to see how they compare. I chose 2830 fps and 2750 fps; I’m already thinking I’ll drop the charge by 1% or so, which based on my old load data should cost me maybe 40-50 fps, so let’s double that and see how bad it is.
So! Yes, these are different, and if I had all the time in the world, I’d make sure I verified my DOPE out to at least 400 yds to validate my MV. However, this comparison makes it clear that even if I’m WAY off on MV, I’m still inside the boiler room, assuming I have a solid zero and break a good shot. And it’s not like I’m flying blind on MV, I’ll just slap the MS on and get a solid number at the range, I just won’t have outer-limits validation of the DOPE.
Well now I don’t have to do a powder ladder at all, much less haul my keister out into the mountains after work and try frantically to set it all up and get the ladder fired off before dark. All I have to do is swap the scope, zero it with the final load (1% reduction in powder charge, 0.080” jump), and grab a quick 5-shot MV average using the MS. All of that can be done at the local range in less than an hour, and inside my MER of 400 yds, the results are functionally the same as doing the Whole Enchilada Approach with DOPE/MV truing out to 600+ yards. Since I’m not punching paper, I’m just trying to hit a pie plate, this approach is good enough.
So that was my system this year for load development for my hunting round. This isn’t news to a lot of folks on here I’m sure, but if there’s even one person out there who’s in a similar position to me, I thought they might appreciate a perspective that saves tons of effort/time and is still fit for purpose.
Let me know if you can think of anything I could do better! I know the starting powder charge thing is a good takeaway from this, but I’m all ears if there are other time-saving steps anyone can think of to incorporate. And to all those hunters out there, good luck, if you still have season left!
Summary:
- I did a standard jump test, using a semi-known load (it ended up being too hot, lesson learned and explained below). If you don’t have info on what charge to start with, google what others use and back off 2-3% or simply use the manual starting load, whatever you’re comfortable with.
- Since I’m using an all-copper bullet in a 6.5CM, my max ethical range (“MER”) is limited to ~400 yards, which means my accuracy needs for minute-of-deer are not extremely stringent.
- Since my accuracy needs aren’t extremely stringent, my MV validation doesn’t need to be super accurate. I used 4DOF to confirm that even a huge MV drop (80 fps) didn’t dramatically change my POI at MER, so all I need is a decent MV estimate. I’ll use a MagnetoSpeed, and so what if the true DOPE is a bit different.
- Instead of having to go out into the mountains to shoot out to 400-600 yards to verify DOPE, I took two trips to my local range (200 yds), less than 2 hours each, and have a load I trust out to MER.
- This is BY FAR the fastest/easiest load development I’ve ever done, and it works because I only need it to hit a ~10” target at 400 yds or closer. Don’t spend your life chasing ¼” groups for a mid-range big game hunting round!!!
Hey all, in case anyone can benefit from this, I recently rebarreled my main rifle, which is coming deer hunting with me this season. This meant I needed to do a new load workup for my hunting round, and I’m just slammed for time between now and opening day. The shortest path to an acceptable load is always of interest to me, but it was a pretty critical consideration for me this time around. I have access to some longer-range shooting zones on public land, but I have to set up targets each time to use them, and because the zones are mostly across drainages in the mountains, it’s about an hour for full setup and teardown, days are getting short, it’s an hour to get out there, I work, and I have other commitments outside of shooting. I have a local range that’s an hour round-trip, with much faster setup, but it’s only out to 200 yards.
I was getting pretty stressed about being able to do jump testing, a charge ladder, MV validation at 400-600 yards, and scope swap and re-zero all in the limited post-work daylight I have left, since almost all of those steps require a trip back home to the reloading bench in between (yes, I can do the scope swap somewhere in there, but it’d be a pain to accommodate it in the middle of load testing). However, as I went through the process, I realized I could cut some major corners and get an acceptable load based on my load’s MER and using some existing data I already had. I thought other folks might be in a similar position either this year or in the future, and wanted to lay out my thought process in case someone else can benefit.
Here are my components; not really looking for debate about my choices, just laying out what I’m working with and why I’ve already narrowed it down to these:
- 6.5 CM
- All the usual reasons; there are other hunting loads that are “better,” but none for which I have a barrel or reloading setup haha
- Barnes 127gr LRX bullet
- I used to hunt in CA, so I have these stocked up
- I like all-coppers anyway, great terminal ballistics at every range between “bad breath” and the outer impact velocity limit. I hold to 2000 fps minimum impact velocity, although some mfgssay 1800 fps is ok. Too many reports of penciling at that velocity, so I like to keep it safe.
- I expect a healthy blood trail if I need it, although I don’t think I will based on my intended terrain
- There are multiple great bullets available that would let me stretch my range; however, they can blow up if you’re too close or hit solid bone, and I don’t trust my LR shooting well enough at this point to feel it’s ethical to try to take a 600-800yd shot at this point anyway. I also like the idea of getting close, to try to maximize the “fair chase” ethic. On top of that, I don’t have any on hand, so that’s that.
- CCI 41 primer
- What I could find recently, so I’m committed to these for the next 5k rounds ; normally I use CCI 450s because they’re cheaper
- LapuaSRP brass
- Once-fired in the old factory barrel for me, but fresh or more-fired would work fine too so long as it wasn’t near end-of-life
- I bumped the shoulders back 0.002” after they were fired in the factory barrel; while this isn’t as good as getting a 0.002” bump from the new chamber, they chamber fine in the new barrel so whatever
- Annealed (brass .308 brush through the necks after), FL sized (0.002” bump), 0.002” tension with a mandrel, didn’t touch the primer pocket, didn’t need to trim or rechamfer (still good from first prep session)
- Reloder 16
- Similar to H4350 in 6.5CM performance, better temp stability, less competitive to try to find
- I have a ton because I’m tired of load development, and just want one load for a long time at this point
1. Find the lands: I use the gutted-bolt method. Works great, although it’s kinda a pain in my Bergara because I have to pull out the ejector each time.
2. Establish jumps to test: Most all-copper bullet mfgs recommend minimum 0.050” jump, I didn’t want to load a ton of test rounds, and lots of folks have had good results with surprisingly long jumps. So I did 0.070” to 0.120” in 0.010” increments.
3. Pick a powder charge: I had old load data for the factory barrel, andwas just gonna use that. However, it was Hornady LRP brass, which has more case volume than the Lapua, and I managed to think of that before I loaded the rounds up. I backed off a full grain (~2.5%).
- I also did some googling to figure out where other folks were with similar components, and felt I wasn’t crazy overboard with my starting charge. It was towards the upper end, which was fine with me because I aim to push the bullet as fast as I reliably can.
4. Load ‘em up: I don’t have any heart burn compressing extruded powders to some extent, but in hindsight I accepted too much compression on the longer-jump rounds (more discussion below). My first sign of this was that I was getting a bit of crunch on my longest rounds; I should’ve backed off 0.5-1.0 grains then started over when I got that sign.
5. Clean the rifle: It’s been awhile since I’ve touched the gun, so I figured I’d start with a clean slate and a few foulers
6. Shoot ‘em upShot five foulers of my target load, which also let me ensure I was reasonably on-target at 200 yds
- No need to make sure I’m dead-on, since the LRX load won’t have the same POI, I just need to see the group size/shape
- I shot one round of each jump length, cycling through until I had five rounds on paper for each jump. I’m not the best shot in the world, so this eliminates later groups artificially improving as I “warm up.”
- This is when I got my second and third signs that I had made a poor powder choice: stiff bolt lifts at 0.100-120” jump, with a few in the 0.090” group as well, and a visible POI shift upwards on the 0.100-120” groups to boot. Obviously too much compression. Still, no ejector marks or case head swipes, so I just went with it. Not advocating this approach, quite the contrary actually, but there you have it.
- Pick a jump: My 0.070-90” groups all looked reasonably similar, fairly well-distributed, and were all sub-MOA. So, take the middle, at 0.080”, and drop the powder charge a bit. But how much?
So, out to the mountains, and I know I need to drop the powder charge. It’s fine at 0.080” jump, but only 0.020” more compression makes it a too-hot load, and I want more safety margin than that, especially since I’m doing this development in a cool, high-humidity environment, so my load is only going to get faster when environmentals change. Here’s where I cut all my corners.
I figure I don’t need to drop the powder charge much, since I’m only buying some safety margin (my load is currently “safe” at 0.080” jump). But what if it changes the MV appreciably? There are three HUGE simplifying considerations here. First, I have to keep 2000 fps at impact, which means I’m only shooting out to 400-435 yards, based on my old factory barrel load at 2830 fps. Second, deer are not tiny; at 400 yds, the boiler room is over 2 MOA, so I have some elevation variability margin there. Third, at 400 yds, changes in MV won’t hugely affect POI, especially relative to the boiler room size.
To make sure though, I gamed it out in the Hornady 4DOF. I find a zero/zero profile extremely useful for comparing stuff like this; set your sight height and zero range both to zero, so you can compare “raw” drop data for different loads. So, fill in all the info for the load and expected environmentals, and then just pick a random pair of very different MVs to see how they compare. I chose 2830 fps and 2750 fps; I’m already thinking I’ll drop the charge by 1% or so, which based on my old load data should cost me maybe 40-50 fps, so let’s double that and see how bad it is.
- 2830 fps: MER = 435 yds, “Raw” drop at 400 yds = 3.05 mil (43.9”)
- 2750 fps: MER = 400 yds, “Raw” drop at 400 yds = 3.24 mil (46.6”)
So! Yes, these are different, and if I had all the time in the world, I’d make sure I verified my DOPE out to at least 400 yds to validate my MV. However, this comparison makes it clear that even if I’m WAY off on MV, I’m still inside the boiler room, assuming I have a solid zero and break a good shot. And it’s not like I’m flying blind on MV, I’ll just slap the MS on and get a solid number at the range, I just won’t have outer-limits validation of the DOPE.
Well now I don’t have to do a powder ladder at all, much less haul my keister out into the mountains after work and try frantically to set it all up and get the ladder fired off before dark. All I have to do is swap the scope, zero it with the final load (1% reduction in powder charge, 0.080” jump), and grab a quick 5-shot MV average using the MS. All of that can be done at the local range in less than an hour, and inside my MER of 400 yds, the results are functionally the same as doing the Whole Enchilada Approach with DOPE/MV truing out to 600+ yards. Since I’m not punching paper, I’m just trying to hit a pie plate, this approach is good enough.
So that was my system this year for load development for my hunting round. This isn’t news to a lot of folks on here I’m sure, but if there’s even one person out there who’s in a similar position to me, I thought they might appreciate a perspective that saves tons of effort/time and is still fit for purpose.
Let me know if you can think of anything I could do better! I know the starting powder charge thing is a good takeaway from this, but I’m all ears if there are other time-saving steps anyone can think of to incorporate. And to all those hunters out there, good luck, if you still have season left!