Load development - groups

[bpk1982]

I'm curious about number of shots per group when developing loads for a hunting rifle. I always start with 3 shot groups. Typically I'll move up to 5 per group when I feel I'm close. More times then not, the first 3 shots are acceptable but with the inclusion of 4 and 5 the group spreads more then I'd like. Not always, but typically. Some times I'll scrap that load and start over. But it's got me thinking, for a hunting rifle, should I only be looking for 3 shot groups and if they spread after that, who cares? Curious what others are doing. I'm currently working on a tikka 7mm rem mag, H1000 and 162 eldx. For 3 shots it'll mostly print groups 1/2" to 1 & 1/8". That is acceptable to me for a hunting rifle. When I get into 5 or more shots into the group it'll spread to 1.5" plus. Heat must be a factor but I dont ever let the barrel get too hot. Thoughts?

[TBark]

I hit our range with a few odd loads for my 25 yd sight in (remounted scope) Then my work-up loads, 25 or so, 5 -6 of ea differing .5 gn.
Trying to recall, Retumbo I think for my 7MM RM.
What u say about groups and heat, sounds good, I let er cool for a bit after ea group of 3 anyways.

TBark

[bpk1982]

Groups referenced in OP are shot at 100 yards.

[Dubious]

I do 3 shots for load testing hunting rifles I rarely use 5 rounds on non relieved non match grade barrels. Factory barrels can do odd things in larger strings when hey heat up. There nothing wrong with 5 round groups if that what you like keep using it. The more rounds you fire the more data you will collect group size will increase your extreme spread and std d will have more points to compare and you’ll be able to have a rounder data set to plug into your ballistic software if your using an app like shooter or isnipe.

.5-1 1/8 size groups at 100 are good groups for a factory tikka I’ve built loads for 2 friends with the tikkas and ended up with similar result. Same results with factory Remington 700’s.

[Nyksta]

You are looking for consistently accurate shot load, so let your barrel cool a bit between each shot, even in the same group. You dont want the potential of barrel heat stringing to interfere with testing what load works well.

And to tell if a load is consistent, try 3 or 4 groups of 4 shots groups.

I initially load 8 rounds per charge weight. .4 grains steps for my 46 grain max

Start shooting groups with low charge and progress up to the high charge. Then start high and proceed back low.

This will be a better tell at what is a great load, and will better help rule out flukes.

Once i have a idea of what loads i want to narrow down on, i load 8 more at the new test weights. .2 grain steps.

Then again with .1 grain steps if im unsure how wide my node is.

[Redneck 7]

I do most of my reloading based off 3 shot groups for my hunting rifles and never have had an issue. Are you seating the bullets to the cartridge overall length? That seating depth variance may be the culprit, or how accurate are your powder charges?

[260 Rem]

I spent several years shooting three shot groups at paper. All too often, load development could be frustrating. Can’t count the number of times I got a nice three shot group ... loaded a couple more to the same spec ... only to find the good group could not be repeated. For a time, I fully bought into the idea that for a hunting rig, three was enough. After all, the barrel heated up or I waited too long for it to cool and conditions changed, and yada yada yada ....
It was not until a buddy convinced me I would get better information about a load with five shots that I reluctantly increased the number. Bottom line is that after years of shooting longer strings, I am comfortable with what 5 shot strings tell me.
A couple of years ago I shot a number of side-by-side three and five shot groups. Different days...one three...one five. In the end, the comparison revealed that (for me), 5 shot groups averaged 40% larger than 3 shot groups.
Another self imposed “rule” I have, is that four consecutive groups are necessary to “prove” a load.

[6.5 shooter]

Originally Posted by 260 Rem

I spent several years shooting three shot groups at paper. All too often, load development could be frustrating. Can’t count the number of times I got a nice three shot group ... loaded a couple more to the same spec ... only to find the good group could not be repeated. For a time, I fully bought into the idea that for a hunting rig, three was enough. After all, the barrel heated up or I waited too long for it to cool and conditions changed, and yada yada yada ....
It was not until a buddy convinced me I would get better information about a load with five shots that I reluctantly increased the number. Bottom line is that after years of shooting longer strings, I am comfortable with what 5 shot strings tell me.
A couple of years ago I shot a number of side-by-side three and five shot groups. Different days...one three...one five. In the end, the comparison revealed that (for me), 5 shot groups averaged 40% larger than 3 shot groups.
Another self imposed “rule” I have, is that four consecutive groups are necessary to “prove” a load.

Agreed

[bpk1982]

Originally Posted by Redneck 7

I do most of my reloading based off 3 shot groups for my hunting rifles and never have had an issue. Are you seating the bullets to the cartridge overall length? That seating depth variance may be the culprit, or how accurate are your powder charges?

Thanks for the thoughts so far guys.

I've seated to mag max and scale is supposed to be accurate to .1

[bpk1982]

Originally Posted by 260 Rem

I spent several years shooting three shot groups at paper. All too often, load development could be frustrating. Can’t count the number of times I got a nice three shot group ... loaded a couple more to the same spec ... only to find the good group could not be repeated. For a time, I fully bought into the idea that for a hunting rig, three was enough. After all, the barrel heated up or I waited too long for it to cool and conditions changed, and yada yada yada ....
It was not until a buddy convinced me I would get better information about a load with five shots that I reluctantly increased the number. Bottom line is that after years of shooting longer strings, I am comfortable with what 5 shot strings tell me.
A couple of years ago I shot a number of side-by-side three and five shot groups. Different days...one three...one five. In the end, the comparison revealed that (for me), 5 shot groups averaged 40% larger than 3 shot groups.
Another self imposed “rule” I have, is that four consecutive groups are necessary to “prove” a load.

Good info here. Thanks for the input. I too have found that all too often shots 1-3 are acceptable but the extra shots make it unacceptable. There must be something to the 3 shot guarantee with the tikkas lol.

[Sashi]

During load development I'll start off with 2 shot groups, those groups which are acceptable, I'll work around with 3 or 4 shot groups, of those groups the ones that are acceptable, I'll play with other parameters, primers, seating depth etc. The group will never get tighter than the first 2 shots.

[heretohunt]

For me I do 3 shot groups at 200 yards until I find the promising combinations. Then make 3 sets of 3 of each and pick the best. Maximum acceptable group size is 1.5”@ 200 yds.
I’m fairly new to load development but it seems to me that you can’t tell much at 100 yds?

[260 Rem]

Getting prep’d for a Reloading Demo I’m doing at SPFGA tomorrow so thought I would share my last set of load development that is part of the presentation. Explanation:
Top panel explains the information on each of the target panels,
Groups are numbered in the order shot showing increasing charge weights each day.
Group #1 was only three shots as it took more than anticipated to get on paper. All other groups are five shots.
Unfortunately, I waited until this morning to shoot the “bracketing” charge weights around the “sweet” formula and it did not work out perfectly. (I’d like to blame the nasty wind gusts for the high shot in the last group, but wind is always part of the equation and when a shot separates from the group ... 9 times out of 10 it is pilot error). NOTE: The “hole” by group 8 is a tear from a knot in the target board

[32-40win]

I've always used 5 shots groups to prove a load to start with, some guns will change a lot with heat, some won't. I take my time with big game guns, may be 5 min between shots. And I've shot at one target every day for a week with 5 rd sessions just to see the overall average. That seems to tell the truth about what you can expect. With a varmint gun and a heavier barrel I'll run 5 in less than 5 min. Once I have the general area for the load, for a varmint gun, I'll run some 10 shot groups to see what the real picture looks like. As long as it stays minute of gopher, even with a slightly vertical pattern, without horizontal stuff, at 200, it is good to go for me.
If you shoot a round or two at the same target once a day for a while, you'll see how you shoot, the gun does what you tell it to do. Once in a while conditions will mess with you, be it wind or light, other days it is all you, other days you can do no wrong. I don't expect a mass produced factory big game hunting gun to shoot bugholes suitable for benchrest, especially when it is in an '06 size or magnum type chambering under about 9 lbs. A heavy barreled varmint gun should be able to hold a 1" or less wide and 1-1/2" or less high, reasonably quick, 10 shot string at 200 though.

[catnthehat]

I used to do my load development at 100 yards for my hunting rifles but for the last 25 years or so I have worked up loads at 200 then checked them at 100 and 300 .
I generally shoot 5 shot groups .
Cat

[bpk1982]

Thanks again for the input gents. Nice to see what others are doing. Keep it coming. I need to really slow down my shooting according to some of the comments here. I'd like to get out tomorrow, we'll see if this snow let's up

[Pathfinder76]

It’s kinda fun to think minute of lady bug accuracy is needed in a hunting rifle. It’s fun to tinker, and mess around with load development. It’s great to impress the internet fraternity with pictures of little groups. But it’s a bit overblown. Wednesday evening I decided to switch up a load while hiking around looking for a bear. I thought the 160 Partition in my 280 might just be the ticket for bouncing bruins on their nose.

With this in mind I dug through my collection of bullets and happened to find what I was looking for. I then prepped 10 cases, went to the Nosler Manual and found a powder that I had a bunch of, loaded 5 rounds of 52gr, and 53grs of said powder (no Martha it is not necessary to load develop in tenths of grain increments) and went to the range. I ran two of each weight through the chronograph and threw the remaining six down range.



I then loaded ten and went hunting Thursday night. Friday I decided I could add one more grain of powder so I prepped five cases, added 54grs of powder, added the bullets and back to the range this morning. Again, two across the chrono to make sure nothing weird was happening, and then three down range (yes there was a vertical scope adjustment between groups). All three groups look the same (can’t find my third target grrr).

Now, this is not gnat accurate, but I’m not hunting chipmunks. Five shots might prove different, but I’m confident it will make zero difference on game out to 400yds. We make far to much of this.

[catnthehat]

I can’t shoot bug holes from field positions do do worry about it.
If I can can hold MOA at 200 prone I’m happy.
Cat

[NinjaHunter]

I just use a laser thermal gun to check barrel temp when doing my load testing.

I recommend buying one if you plan to do load testing.

[Pathfinder76]

We make far to much of this.

[Deer Hunter]

As much as I prefer magnum primers in my hunting loads, I have had significant improvements in group size running standard rifle primers in 270/284 size cases recently. Primer choice also can change velocity as well.

[Salavee]

here's a link for you to check.. http://optimalchargeweight.embarqspace.com/

It's all about what you want to do with your hunting rifle .. and the system works well.

[Buckhead]

So, basically, start with the tried and true loads - most of which have been around for at least 50 years and move forward from there.

[Salavee]

Originally Posted by Buckhead

So, basically, start with the tried and true loads - most of which have been around for at least 50 years and move forward from there.

That all depends on what you want to achieve. If you're happy with what's worked OK with millions of different rifles and particular powders over the span of 50 or 60 years, that method will work.. sometimes exceptionally well. On the other hand, if you are looking for the optimum load for your particular rifle,cartridge and barrel the OCW method is the way to go. It's not quite as simple as the Audette ladder method but I believe you would be well rewarded if you give the OCW method it a try.

[Homesteader]

I usually do 3 for hunting rigs and 5 for target rifles. Last time out I did 3 shots with the little Montana then shot a couple other rifles then laid another 3 down on the original target with the Montana. A far better group then I’d ever get shooting 6 in a row, lol

And I totally agree we make too much of bench groups and not near enough field practice, whether that means bipods, prone off a pack, whatever practical real world shooting that can be expected.

[260 Rem]

There is truth in the old saying “practice makes perfect” and when it comes to shooting, the more you pull the trigger (regardless of whether the rifle is benched, bipoded, or backpacked)...the better (chance) there is of improving. Even offhand improves with lots of bench practice.
A few years ago there was one of those pesky “challenges” started on CGN and later brought here to AO. Think it was called the “cold bore challenge” and required the shooter to shoot a cold round followed by two more from a “field” rest ... on five different days ... inside a 1” diameter circle at 100m....I was game, given that I had been told that a hunting style bipod could not come close to grouping like a a traditionally benched rig ... so I gave it try. Much to my (initial) surprise, I was able to do it with my “too tall” (hunting) Harris bipod. No doubt in my mind that all my bench shooting helped with the bipod. I would even hazard a guess that if I shot off a backpack, that cold round and even the next two would land pretty darned close to the target dot. The point being, that there is a lot of transfer from bench technique to rested field positions.
Now, with respect to this thread, the theme is “load development” ... and there is no more reliable spot from which to test for the sweet spot than off a bench.
EDIT: Just did a search and the cold bore challenge was never brought to AO. I asked if there was interest and since there was not, did not borrow the idea for this site. The CGN challenge comes up under a search in the precision rifle forum...it was back in 2015.

[Buckhead]

There are time tested loads out there for a lot of cartridges that will give good accuracy and velocity. I start with one of those. It's easy enough to find one with a little reading. No need to overcomplicate things for a hunting rifle.
And 3 shot groups are what I use for a hunting rifle. If I can't decipher what my rifle is telling me from shooting half a dozen or so 3 shot groups at various powder charges maybe I should learn how to do needlepoint or some such.

[Buckhead]

Originally Posted by Salavee

That all depends on what you want to achieve. If you're happy with what's worked OK with millions of different rifles and particular powders over the span of 50 or 60 years, that method will work.. sometimes exceptionally well. On the other hand, if you are looking for the optimum load for your particular rifle,cartridge and barrel the OCW method is the way to go. It's not quite as simple as the Audette ladder method but I believe you would be well rewarded if you give the OCW method it a try.

I'm not saying I don't find the optimum load for my particular rifle and cartridge. I'm saying it's not that complicated. There's no need to try and reinvent smokeless powder (or the wheel).

[Salavee]

Originally Posted by Buckhead

I'm not saying I don't find the optimum load for my particular rifle and cartridge. I'm saying it's not that complicated. There's no need to try and reinvent smokeless powder (or the wheel).

We know it's not complicated but there are a Lot of great new powders available that are not listed in any manuals. Many of them are superior to some popular powders that go back to WWII. If you're happy with those, so be it . Others simply like to try the new stuff in case they might find something special... and they often do.

[260 Rem]

IMO, attention to detail with reloading and load development ... produces results directly proportional to what is put into it. I can rely on the formula established by others and who knows, maybe I’ll get lucky, but more often than not those (untuned) results are mediocre in terms of accuracy.
And as a side note, I have never found a magic shortcut to load development. I start with a fixed seating depth, establish the optimum charge weight (the proof of which is on paper downrange)....and then tinker with seating depth. There is typically enough shot dispersion with 100m (5 shot) groups to determine vertical stringing. After establishing the sweet spot, a couple of 300M (5 shot) groups showing a minimum of vertical will provide better information ... without the use of a chrony. More often than not, when I practice at 300m, I shoot ten shot groups.