Great groups when load testing... after not so much

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GcG166

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Recently worked up a load using the method discussed in this article:

http://www.longrangehunting.com/articles/load-tuning.281/

The load is for my savage model 10 in .223 with stock barrel sitting in a choate stock

Did one group of shooting and took the most horizontal group and did another test moving up .1gr per group and did 6 groups and got under 1 inch for all the groups with 3 about a half inch at 220 yard which is the longest distance I have avaliable for load testing. I picked the best group and loaded up 50 figuring I had my load.

One thing I shouldmention is that the bullets I did the testing with were older bullet's given to me still sealed in the box with a $19.99 price tag on them so they definitely weren't bought last year. When I was loading the 50 rounds of the load I got from the testing when I ran out of these older bullets and went to some that I bought my overall lenth went up 0.02 of an inch. I kept my seating die at the same setting and the bullet's remained just touching the lands so I kept going and marked what bullets came from what and hoped for the best



So i went shooting today in minimal wind and shot about 15 rounds and got cimsistant 3 inch group's at the same distance I did my load testing. not very impressive. Not really sure what to think or where to go now. When I did the load testing I realized that the bullets were seated out a little to far and actually jamming pretty hard into the lands so now they're loaded to just touch the rifling (done on the second load test also) just not sure why I was getting such bad groups here with great groupings before. Maybe the bullets? My shooting? Any advice of what to look into would be good or if I should redo the ladder test with the newer bullets? This is my first time really loading up for a rifle that I can't easily outshoot
 
Both were with 69gr seirra matching bthp. I just didn't realize that they would have changed. I was told that if I kept my distance to land the same they should shoot pretty much the same.
 
Maybe 100 rounds since last cleaning so I doubt it's fouling.

I'm thinking I'll try shooting what I have loaded again on the next good day. If I get the same results I'll know it wasn't just me. If I get the same results I might have to redo the first ladeer test and see what that gives me

It also just came to me that this was the first time firing this brass in the rifle so it was FL sized instead of just neck sized. Would this cause the difference?
 
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Send the OEM an email and list the batch numbers on the box:they can tell you if it changed compared to late model projectiles of the same type. At least you can confirm or eliminate that theory.
 
The bullets DE definitely have a different shape. The projectiles were measured and have different overall lengths. I emailed Sierra and they told me to just seat so the jump to the rifling is the same. Which I did
 
Well then there you go. You are shooting a different projectile. Sierra offered seating info: not a way to mimic the results of the newer style projectile.
 
GcG166 said:
The bullets DE definitely have a different shape. The projectiles were measured and have different overall lengths. I emailed Sierra and they told me to just seat so the jump to the rifling is the same. Which I did
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what a suprise? You changed a major component and are wondering why you are having different results? Get another load made up and do it again, I'd suggest getting the biggest packs of bullets so you dont have to worry about lot changes.
 
bsand said:
what a suprise? You changed a major component and are wondering why you are having different results? Get another load made up and do it again, I'd suggest getting the biggest packs of bullets so you dont have to worry about lot changes.
Click to expand...

I asked about this when I first realized and was told the load should shoot around the same in the rifle with the same distance to the rifling with maybe a poi change. So I tried it out to see. Like I said I'm new to this so I wanted some opinions from experiencedifferent reloaders instead of wasting more ammo.

I guess Ill just have to load up another ladder test.
 
rral22 said:
Yup. Change a component and you change the load. Unless, of course, it doesn't change anything you can see (which can also happen, but rarely).
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That's very annoying since I thought I thought all the smk bullets were the same and had a good load. I guess that's just how it goes. This is why I'm using the .223 to learn to load for a precision rifle��
 
Id start over with the newer bullets and get your load where u want it. if you can find more with the same lot number stock up. if you can't get the same lot number stock up anyway and a few tweaks should get u back to where u want to be.
 
With a different bullet and jamming into the lands, why would he expect them to group the same? Seating depth can make a big difference sometimes.
 
Try the brass again once you fire form and neck size , you might find it does make more diff than you think .
Let us know
Good luck and keep shooting
 
The bullet making dies last about 100,000 bullets. So each different lot number is "similar" but not exactly the same.

If you are going to use the Sierra 69 gr, buy several of the 500 round boxes, making sure they are all the same lot number. Same for the powder, buy a couple 8 pounders of the same lot number. Same for the primers, buy a case or 2 of the same lot #.

Then your only variable is slow throat erosion, and you load your ammo 5 or 10 thou longer each year.

In this particular case, there was a bigger than usual difference between lot numbers.
 
I wish buying in bulk was an option but as I am a college student at the moment it won't be an option as I have limited funds.

I didn't realize that the same bullet would be different from different lots. It's gonna take me a few stupid questions and wasted round's to get good at this
 
GcG166 said:
I wish buying in bulk was an option but as I am a college student at the moment it won't be an option as I have limited funds.

I didn't realize that the same bullet would be different from different lots. It's gonna take me a few stupid questions and wasted round's to get good at this
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OK. limited funds we all understand.

Loading ammo with the bullets touching the rifling is tricky. The slightest variations can cause accuracy issues.

You want a load that gets a good result - every time, even if the bullet or powder changes.

The solution is to jump the bullets about 20 thou to the rifling. This tends to negate the minor variation in bullet shape, neck tension, etc. and you get a repeatable result.

When developing a load for a match bullet I always try hard into the rifling, kissing the rifling and 20 thou off. In 9 out of 10 cases, the 20 thou off works best.

So take your pet load, seat the bullets a quarter turn deeper, and try the same powder charge and 0.3 gr more, and see how it goes.
 
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