Load Development

smoothie25 · Mar 3, 2017

I shot a ladder Test and found 57 grains of h4350 with a 180 AB to be in a node. I shot two separate three shot groups at ~100 yards. They both produced near identical patterns. Two touching and one flyer about an inch away. All the shots felt good, no pulled shots. I'm puzzled as to why this happened twice. Thoughts?

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c. schutte · Mar 3, 2017

I'm a novice at loading so for that reason I shall not give any advice. Surely one of several dozen experienced hand loaders will have that answer. It could be nothing more than adjusting the seating depth a tad.

Now, I've a couple rifles that will shoot the 2nd and 3rd shots a little lower. I've always thought it might have something to do with a warm barrel not being as fast as a cold one?

Again, I look forward to hearing what others have to say.

chs

Billyram · Mar 3, 2017

When I'm accuracy testing I like to shoot two 5 shot groups. 3 shot groups won't tell you anything. I don't know what kind of accuracy you're looking for but 57 grs of H-4350 behind 180grs is a stiff load. Max loads rarely produce the best accuracy so I would back off the powder by 1 gr and go shoot two 5 shot groups. If you can't achieve the accuracy you want @ the velocity you want with the 180gr Go to a lighter bullet. For a hunting load I like to balance accuracy with velocity. I work up to the velocity I want and stop at the point where the accuracy is with in my requirement.
Billy

OU812 · Mar 3, 2017

Which shot was the flier? If 3rd shot is the flier I would look at barrel heating up. Other causes could be seating depth, cheek weld, trigger pull, rifle not recoiling straight back, not having the rifle in the same place on your rest to name a few.

Dwh7271 · Mar 3, 2017

Fwiw, I'd turn the seating stem down a quarter turn. If that doesn't bring them together, a half turn.

smoothie25 · Mar 3, 2017

The first group I wasn't keeping track of the order. The 1st shot for the 2nd group was the flyer.

Dwh, if I seat the bullet deeper should I decrease powder charge as well?

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Guy Miner · Mar 3, 2017

Guessing that this is a .30-06 rifle?

Just from the load data.

Guy

smoothie25 · Mar 4, 2017

Yep, 30-06

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waveslayer · Mar 4, 2017

smoothie25":9o43diba said:
I shot a ladder Test and found 57 grains of h4350 with a 180 AB to be in a node. I shot two separate three shot groups at ~100 yards. They both produced near identical patterns. Two touching and one flyer about an inch away. All the shots felt good, no pulled shots. I'm puzzled as to why this happened twice. Thoughts?

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My first thoughts are: you may be in a node, but not the optimal node for your gun. What's the chrono saying?

Looks like you need to work on the load development a little more. Also, check scope torque as well. Have you used the OCW test before?

My wife thinks I only have 3 guns

Billyram · Mar 4, 2017

I haven't loaded any 180 AB but have loaded 150, 165 AB and would believe the 180 would behave the same as the others. I have some data for 180 gr BT in 2 accurate rifles. One was a H-S Precision Pro-Hunter That shot the 180 gr BT quite well with a average 5 shot group .692". The load was:
W-W case
WLR primer
H-4350 @ 56grs.
LOA 3.310" .010" from the lands
2804 FPS

The favorite load in this rifle was:
W-W case
GM210M primer
H-4350 @ 55 grs
Hornady 178 gr A-Max
LOA 3.305" .010" from the lands
2747 FPS
.510" 5 shot average
1/2 gr more powder opened op the groups to .553" and only gained 8 FPS.

The other rifle doesn't like 180 gr BT as well but shot .801" average 5 shot groups with the same load .010" of the lands LOA 3.300". This rifle was built with a shorter throat and 11" twist for shooting 150-165 gr bullets. To me this is acceptable hunting accuracy.
I've shot a few deer with the 180gr BT and found it to work well but don't recommend using the A-Max on deer. The biggest exit hole I've ever seen was made with the A-max on a medium sized buck shot @ 50 yds. "And the deer ran 25 yds!" I wouldn't trust The A-Max for deer hunting.
I load the AB .010" from the lands just like I do with the BT. At this time I'm not getting quite the accuracy from AB as I get from BT but it's only about .100" difference if that much.
Hope this helps.
Billy

SJB358 · Mar 4, 2017

Dwh7271":3f2r940c said:
Fwiw, I'd turn the seating stem down a quarter turn. If that doesn't bring them together, a half turn.

Amen to that. Keep turning that seating stem in a 1/4 turn at a time. With those two touching I bet you'll walk that flier into the others easily. That's about to be a great load.

Cleveland48 · Mar 4, 2017

I had very similar grouping while working up a load for my Creedmoor last year. Two were always touching or in the same hole and the third always opened up to about an inch. The deeper I seated them the better it got. At .090" off the lands it hit its sweet spot with Three consecutive groups that were in the .4-.5"

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Tommer23 · Mar 5, 2017

I have to agree with what has already been said about 3 shot groups. They rarely do anything for you. Dumb luck statistics state; the chances of 2 bullets hitting the relative same spot out of a 3 shot group is 66%. The chances of 2 bullets hitting the same spot in a 5 shot group is 40%.

Simply put, a 5 shot group is 25% more likely to show the accuracy of your gun than a 3 shot group.

If you shoot a 5 shot group, with 4 touching or closely grouped and one flyer, I would say the flyer is caused by you and not the gun or the load. The same may be true of a 3 shot group with one being a flyer, but statistically speaking, dumb luck has a high enough probability that it's hard to separate luck and true accuracy with only 3 shots.

SJB358 · Mar 5, 2017

I'll usually shoot 4 shots once I get a decent idea of what's going to shoot.

I use three at first to get speeds and ballpark accuracy. With the bigger rifles I'll shoot 3, 3 shot groups. If they are consistent I'll call it a day.

c. schutte · Mar 5, 2017

I'll do a 3 shot group to see if the load is approximately what I think it is. Once established I'll repeat that 3 shot group. If it goes that far then I'll shoot at distance (usually 300 yards) with two separate 2 shot groups. The reason for that is in hunting situations the first shot counts and a follow up might happen. Most likely a 3rd shot won't happen.

I always like to keep track of where shots hit and in what order. Especially 1 and 2 if shot in quick order. Keeping the same target for another outing also keeping track of which shot hits where.

Ideally, I like to have a pattern of where shot 1 and 2 hit. If you do this severaly times you get a really good idea where they will group in a real hunting situation.

Another thing I like to do with some is do a 5 shot group with about 1 to 2 minutes between shots. Allow the barrel to cool a little and then another 5 shot group with the same time between shots. That lets me know if a repeatable pattern shows with a warm barrel.

This is time consuming and might take many trips to the range to finally have enough info on a load or ammo. With the rifles I have done this with I know that a few will hit a little low on the 2nd shot and one will climb up and to the left as the barrel warms. Another rifle shot 9 inside 1" at 100 yards with one flyer which was me and I knew it before I saw the hit. Not bad considering that was a .340 wby that burns shovels of powder with each shot! Gotta love the accumark!

smoothie25 · Mar 7, 2017

Thanks for the input gents. Seems like the consensus is to shoot 4-5 shot groups for better verification and to see deeper. Problem is.. I'm already seating the bullet .13 off the lands. Do ABs typically need this much jump?

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SJB358 · Mar 8, 2017

smoothie25":1rjyp6c1 said:
Thanks for the input gents. Seems like the consensus is to shoot 4-5 shot groups for better verification and to see deeper. Problem is.. I'm already seating the bullet .13 off the lands. Do ABs typically need this much jump?

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Typically, I find the Accubonds to due their best for me from .070 to .15 off the lands. I have a couple rifles that are shorter/longer, but by and larger that is where they usually land for me.

Don't sweat the jump, once you find the spot they wanna be, the shot groups will be very consistent.

I do start them all .050 off. I haven't found working closer to work for me. Some guys have gotten great groups up close, but that hasn't been the case for me.

smoothie25 · Apr 1, 2017

Loaded up some ABs today with a shorter overall length. The pic in my first post was at 2.61" CBTO. I loaded 4 each of 2.60", 2.59", and 2.58" and shot at 100 yards.

2.60" shot a little over and inch. 2.59 shot under an inch. 2.58 opened back up at 1.3ish inches. I loaded 8 rounds of 2.59 to confirm my initial results and shot two separate groups. They shot .82 and .96 inches. I'm pretty happy with these results! Going to shoot further out next trip to see if they stay together. Thanks for your help gents!

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Billyram · Apr 2, 2017

I haven't found seating depth to make much difference when chasing accuracy. Powder charge makes the most difference and when you have a good load 1/2 grain difference either direction in powder charge makes little difference. I'm showing a load seated .010" from the lands averaging .418" groups and when seating the bullet .065" deeper to fit the magazine .470" groups. The .052" difference could be the difference in conditions from one day to the next. 1 grain less powder shot .348" group average for a difference of .070". Not much difference but more than seating depth.
Billy

truck driver · Apr 2, 2017

Once I have found my seating depth I will play with the powder charge up and down to see if I can draw it in if you are not showing any pressure increase charge a tenth at a time till you see pressure or it comes in if the group gets bigger just reduce the load a tenth at a time and see if it will shrink.