Same EXACT load as last years load shoots like crap

[tony d willIiams]

Are you using the same processed brass as you were using?
Same box of bullets and primers?
Has the powder bottle been tightly sealed since you loaded up last September load?

I've been chasing my tail on a 22-250 load. I don't have it totally figured out yet but one thing I learned is the last bit of powder in the bottle that has been used over the last year will give a higher velocity than a fresh, sealed, bottle with the same lot number. Like 80 fps for this 22-250.

Interesting, the info on last of a bottle of powder.
I always rotate and turn upside down a bit before I add to powder loader. Thinking the fines would mix with full size pieces of powder.

I am going to take some from top of container, and bottom to run some tests. For my pistol, standard rifle and extra long distance powders.

I am a bit anal, and I often do things on the "just might be" notion. Or I test for each bit of possibilities.

 

[Shootin4fun]

Velocity....
So maybe;
Your original loads were on the edge of a good accuracy node.
Your new loads are now out of that node by a lot.
If you don't have velocity data, start over on your load development just below your stated powder charge and work up with a chrograph and watch for velocity flats wide enough to start testing 3-5 shot groups.
Maybe your seating depth is widely varying (and make sure your using the correct comparitor Guage).
It certainly needs remeasuring of every component and velocity on the range.
You'll find it.

Exactly, this is why I originally brought up velocity measurements. We know it's not the rifle, scope, or any of that! A/B tests during the same shooting sessions tell us that. If the new loads are not in the velocity node you already established in the old loads...well that's why we call it an accuracy node.

 

[ShtrRdy]

Interesting, the info on last of a bottle of powder.
I always rotate and turn upside down a bit before I add to powder loader. Thinking the fines would mix with full size pieces of powder.

I am going to take some from top of container, and bottom to run some tests. For my pistol, standard rifle and extra long distance powders.

I am a bit anal, and I often do things on the "just might be" notion. Or I test for each bit of possibilities.

I could be wrong but I thought the dimensions of a gradual of powder were fairly consistent.

The reason why powder that's at the end of a bottle causes different velocity is because of the moisture amount it can take on. Drier climate can cause the powder granules to be lighter and vice versa.

How does humidity affect powder?

You may have heard about a relationship between humidity and bullet velocity either in a book, on a reloading forum, or from a crusty benchrest shooter right after saying they get better ES/SD&#821…

chronoplotter.com

 

[LVJ76]

Start with the easiest switch.....
Pull 5 bullets from old load and put in new loads...
Put 5 new bullets in old loads....
If still shooting odd........
Make sure powder used in new was used in old loads....
Lastly try switching the primers....
Other than oal and brass problem...only logical test.....
Especially since.....'old loads still shoot'

Maybe the powder container cap was left a bit open, and lost some of its properties?

Can you try powder from another container?

 

[Jeff Heeg osoh]

If you still have a few of the old rounds that still shoot great groups today compared to the new reloads, try this Make sure your scale you used is zeroed and pull a few bullets or even one of the old great shooting rounds and measure the powder from that case. Then see if it still compares to your notes as to what your using.

also if the old loads were using new brass and the reloads today are using brass that has been fired - resized and prepped you will need to back the charge off a bit since the brass now is matching your chamber better then when it was new and undersized allowing expansion prior to building pressure.

it will be intresting to see if the weight of the powder in your old great shooting rounds match your records used today. I seen where we forgot to write down a change to our recipe and or the scale lost its zero and was giving you bad feedback.

JH

 

[NW NM hunter]

Any chance your primers got accidentally mixed between LR & LRM. Otherwise I agree with the above and would chono one of each. Seems to be bullet component related. Do you have kids than could have been messing with the powders just have to ask.

 

[LongBomber]

Did you check the speed of the new loads vs the old loads. Humidity the powder has been stored at can change the burn rate significantly.

 

[Les in Wyoming]

Have you chronographed both loads? Old and new? Temps will make a difference in velocity, but with last year's ammo shooting better than this year's, you need to verify speeds between the two.

There has to be something different.
One thing different, could be that ammo built last year had a bit more neck hold due to a very slight bullet weld to the case neck. But, if last year, you shot your ammo fairly soon after loading, that should not be it.

Verify primers are the same
Verify primer seating is the same
Pull apart a loaded round from last year and reweigh the powder charge. Scale might have drifted, so this year's loads are a bit different.
Try a new bottle of powder and see if that changes anything
Neck tension
Check headspace from last years loaded ammo to this new batch
Verify seating depth (CBTO) is the same between last year's and this year's ammo. Maybe your die got adjusted or bumped inadvertently

I have not chronographed either load. Both are shot in the same temp, right next to each other. The idea of bullet weld could be the only difference, though they were loaded 6 months ago. Head space and weigh scales are the exact same. I measure CBTO on each. Exactly the same.

 

[Calvin45]

I have not chronographed either load. Both are shot in the same temp, right next to each other. The idea of bullet weld could be the only difference, though they were loaded 6 months ago. Head space and weigh scales are the exact same. I measure CBTO on each. Exactly the same.

Def not bullet weld haha…this is actually getting very interesting to me at this point. Same lot of powder?

 

[Indian7953]

Something changed in the load as it's not possible for it to be the exact same and have two different results. Is the new load the same jug of powder? Same lot of primers? Something is different. Or the old load just happened to shoot well but will it repeat several times? It's very strange and I hope you get it figured out.

It might be bullet to case corrosion

 

[LVJ76]

It might be bullet to case corrosion

Def not bullet weld haha…this is actually getting very interesting to me at this point. Same lot of powder?

If I understand correctly, the previous load shot fine right after loading, and after a while as well. So corrosion and bullet weld would not be the issues.

Definitely interesting.

 

[RidgeTop]

The problem is in the loads you are making this year.
Get some factory ammo of similar weight - Remington or Winchester Core-Lokt or PowerPoint. See how they do.
Nobody has mentioned primers - what is your story with the primers?
If factory shoots good, take all your old brass of same make,, and if good to reload, full size and load with new powder and primers to standard specs, same bullet to same COL.
If a friend has a bore scope make a visual check on bore condition. I thought my rifles were clean until I got a bore scope. Dirty on left.

 

[turnerfarms2011]

Indian 7953 do you still have the 264 for sale?

 

[choprzrul]

I'm betting velocities are different between the two. Better get the fps of the old load before you run out of them....or that data will be lost....