Help with load dev, Where's my node?

[sheshotme]

I'm new to reloading and load development. Just shot my first OCW test at the range. Can someone help me read the results?

Remington 700P
.308
Varget powder, CCI 200, 168gr Sierra GMM BTHP, Lake City brass (3rd firing)
2.800 OAL
Tested at 100 Yards (access to anything more is limited)

47F, 12mph gusts but shot at 6mph, 65% humidity, Pressure 30.06

#5 looks fantastic at .192 but from what I understand I still have to look at the prior/post grain increment for temperature stability. #7,#8,#9,#10 looks consistent with #8 being the best.

What's your diagnosis and what's my next step?
20160102_308_OCW.jpg

[bsumoba]

Can you help with a few more details on your load?

What is your overall length and if you know it, what were you jumping the bullet, and do you know what charge weight you saw pressure signs at (assuming you worked up higher than the pics you have in the post)?

With the 168s in a bolt action, guys have gone higher, but I'm a big on accuracy over speed.

Given your picture, I would look around 43.8-44.1 gr. Reason being, the POI are about the same over a 0.3 gr spread. I would choose maybe 44gr and work different seating depths to see if that tightens up the groups. Go in 0.010" increments. If it doesn't help, then start working 44gr more and shoot 5-shot groups to see what it can do with 5-shot groups and if it can hold 1/2" groups. Then, I would chornograph your loads to see if you can maintain an ES (exteme spread) in the high teens to mid-20's or smaller. That would be decent for a factory rifle with handloads.

That's pretty good for a factory rifle. I would look into a better trigger (Jewell or Timney) as well. That seems to help a lot of people get their loads smaller as most people cannot squeeze off consistent shots with the factory Rem triggers.

[CSACANNONEER]

My questions are: How did you shoot these? Did you use a sandbags, bipod, a quality rest system, a lead sled type rest? Why didn't you shoot 5 shot groups to help eliminate the possibility of flyers? What ype of stock are you using? Is it bedded? Are you using the OEM trigger? Are you using quality glass? Your group for 43.2 appears to be labelled 0.192" but, it's obviously bigger than that.

I agree with bsumoba that around 44.0 would be a good place to center your next testing around.

[sheshotme]

Thanks so much!

OAL is 2.800. I haven't measured my maximum length to touch lands yet. I don't have the equipment. No pressure signs. and I stopped at what you see. I was nervous about going above max load which consensus seems to be 45 grains.

Chrono and trigger are on the To Buy list.

[sheshotme]

My questions are: How did you shoot these? Did you use a sandbags, bipod, a quality rest system, a lead sled type rest? Why didn't you shoot 5 shot groups to help eliminate the possibility of flyers? What ype of stock are you using? Is it bedded? Are you using the OEM trigger? Are you using quality glass? Your group for 43.2 appears to be labelled 0.192" but, it's obviously bigger than that.

I agree with bsumoba that around 44.0 would be a good place to center your next testing around.

bipod with sandbags, Leopold 10x scope. I wish I had a lead sled. But I tried to set it up as stable as I could with minimal human input. why not 5? thought 3 would suffice. HS precision glass bedded. OEM trigger.

43.2 came in at .5. subtract .308=.192

[CSACANNONEER]

bipod with sandbags, Leopold 10x scope. I wish I had a lead sled. But I tried to set it up as stable as I could with minimal human input. why not 5? thought 3 would suffice. HS precision glass bedded. OEM trigger.

43.2 came in at .5. subtract .308=.192

I finally bought a lead sled (the cheap "solo") a couple weeks ago and am impressed with it. It's not ment to replace high end bench rest rests but, it does a great job taking the human error out of the equation. Sandbags and bipod are OK IF you do everything very consistently but, they still leave space for human error. Since you are using a bipod and bags, 5 rounds will help you determine if one shot was a flyer or not.


43.2 clearly shows that the group is larger than .192". Just think about it a minute. If each bullet hole is .308" and there is space between two holes, the measurement between center of each impact has to be further than .308". Each hole is .154" on either side of center. Let's assume that there is .100" between the two furthest holes. So, the group would measure .100" + (2 x >.154") for a total of .408". There is no way that you correctly measured .5" from outside to outside of the two furthest shots.

[sheshotme]

your logic is sound. Is there something wrong with my way of measuring or perhaps my calipers (calipers are zeroed). I'm at home sick right now, perhaps my maths and logic skills are compromised.

[CSACANNONEER]

It doesn't look like you are measuring the furthest tangents on the two circles. It also looks like you are no including some of the paper that has overlapped where the bullet went through. Try carefully putting loose bullets in both holes and measuring them while they are both perpendicular to the paper.

Think about it for a minute. If you can put a bullet in each hole without them touching each other, the measurement between centers has to be greater than .308.

[bsumoba]

Take your calipers and zero them with the jaws closed. Then, open it to the desired bullet diameter (.308, .223, .264, .284, etc). Then, re-zero it.

Now, you can measure bullet hole edge-to-edge at the largest part of the group and it is easier to now get your "center-to-center" accuracy. No math involved.

[CSACANNONEER]

Take your calipers and zero them with the jaws closed. Then, open it to the desired bullet diameter (.308, .223, .264, .284, etc). Then, re-zero it.

Now, you can measure bullet hole edge-to-edge at the largest part of the group and it is easier to now get your "center-to-center" accuracy. No math involved.

Great idea but, he is using a set of dial calipers so, there will be some math involved either way. What do you see wrong with the picture of his measurement?

[kdsd731]

That caliper is showing .547" by the way.

[CSACANNONEER]

That caliper is showing .547" by the way.

And isn't even measuring the furthest two tangents or correcting for torn paper overlapping the bullet path.

[sheshotme]

.660-.308=.352 better?
20160104_192_loaddev.jpg

[CSACANNONEER]

.660-.308=.352 better?

I'd beleive that. It's still great shooting that most will never be able to achieve. If it was only a 5 shot group you would have much better feedback and know that it wasn't just luck. While I agree that I'd concentrate closer to 44 grains. I might also load a small batch at 43.2 just to see if you can duplicate this again.

[bsumoba]

bipod with sandbags, Leopold 10x scope. I wish I had a lead sled. But I tried to set it up as stable as I could with minimal human input. why not 5? thought 3 would suffice. HS precision glass bedded. OEM trigger.

43.2 came in at .5. subtract .308=.192

When you tell someone a 3-shot group does this, a lot of people go yea that was luck. If you can print 5-shot into the same group, then you know you had a very good group going there. that's all. For me, I need to hold good groups at long strings because of the type of shooting I do.

Here is a good example of one of my guns being able to hold 5 shots into essentially a big hole.. The holes are 0.284 (7mm bullet). If you also notice, I shot 54.8 and 55gr and the change in group size was minimal. This is a nice node where over 0.2-0.3 gr of powder charge, it still prints great groups...mind you, this is a custom competition gun though:

Great idea but, he is using a set of dial calipers so, there will be some math involved either way. What do you see wrong with the picture of his measurement?

The only thing I see wrong is that he should really measure to the edge of the "black ring" that surrounds the hole. This black ring is created by the carbon left on the bullet as it is passing through a dirty barrel. That stuff is then printed and left on the the paper and gives a good indicator of the "edge" of the bullet diameter. Usually the black ring is slightly bigger than the hole itself. I like to use cardstock paper or put a piece of paper glued to the back of a cardboard piece. This usually gives good looking holes without the paper tearing too badly.

I'd beleive that. It's still great shooting that most will never be able to achieve. If it was only a 5 shot group you would have much better feedback and know that it wasn't just luck. While I agree that I'd concentrate closer to 44 grains. I might also load a small batch at 43.2 just to see if you can duplicate this again.

The only problem with 43.2 gr is that 2 tenths of a grain above and below look horrible, which usually means that you might have gotten lucky and that there is a good chance you will not print another group in the same size. It also becomes an issue because now you have such a small window for it to shoot well and any changes in temperature might drastically change your groups. For a .308, if you can get a 0.3-0.4 gr window where it shoots decent, then load to the middle of that charge weight, then play a little with seating depths to tighten up the group. If you are loading to mag length, then maybe change the powders in very small increments to possibly get the same effect, and by little, I mean 0.05-0.01 gr changes. At some point, the accuracy is what it is and you will not be able to get it down more without a lot of effort, possibly even to no benefit. 1/2" group shooting factory rifles is about what you can expect at best, and that is consistent 1/2" groups...not a 3-shot group that printed into a sub-1/4" group one time.