Cartridge weights are inconsistent

[clunker]

I went to the range today with my new scope, and was a little disappointed at my earlier groups. After getting everything dialed in, I shot a .295" at 100 yds. But then I got curious why my earlier groups were not as consistent. I decided to weigh the rest of the live factory rounds and found they ranged from 11.73g to 11.89g. Doesn't that seem like a big difference in weight? Then I decided to weigh the spent brass and found they were also not identical, but to a lesser degree. Admittedly, there still could be some residue in the cases. I haven't started reloading yet, but I know that reloaders are meticulous about weights of cases, powder, and bullets.

Is it possible that my earlier groups were spread vertically because of varying powder amounts or bullet weights? The ammo was on clearance, and maybe there was a reason for that. Would it make sense to select cartridges with the same weights and see if groups tighten up?

Nosler Match ballistic tip BT 60gr in .223

 

[Dusty Stevens]

Varying weights in factory ammo?

 

[clunker]

Varying weights in factory ammo?

I know, I know! I just thought Nosler was a little better at quality control. Their bullets are highly respected, so do you think it could possibly have been differences in powder charges?

 

[Dusty Stevens]

I know, I know! I just thought Nosler was a little better at quality control. Their bullets are highly respected, so do you think it could possibly have been differences in powder charges?

I would imagine the biggest difference is the case weights

 

[Ned Ludd]

Try measuring seating depth with commercial ammunition preps if you think the the overall weight spread is poor .

In your case, the bullet weight may be almost as much of the total as the case weight. Add in the powder weight, and it's likely there is far more weight variance in any or all of them than if you developed your own handloads and were able to sort components prior to assembling loaded rounds. You can easily pull a few rounds and weigh all the components. If the total weight variance turns out to be fairly evenly distributed among all the components, sorting loaded rounds by weight will accomplish very little. If it turns out that case weight is responsible for the lion's share of the cartridge weight variance, then weight sorting may be of some benefit.

 

[corning]

I don't know how grams and grains are related.

Case weights will have a significant impact on vertical dispersion. About 15 years ago, when I was doing more shooting, I was using Federal brass. I never paid much attention to case weights. I was shooting a match at 1000 yards. One shot kicked my butt, and was an 8, or about 20 or more inches high. I set that case aside, and weighted it when I got home. It was 20 grains heavier than any of the other cases I had used that day. Believe me, I have weighed my cases since then, the only exception being Lapua brass. I spot weighted the Lapua I use and my samples it all within 1 grain of each other.

Lessons learned:

1) weigh brass, or at least do some sample weights
2) don't mix lots
3) sample weigh loaded rounds to insure consistency.

John

 

[Dusty Stevens]

I don't know how grams and grains are related.

Case weights will have a significant impact on vertical dispersion. About 15 years ago, when I was doing more shooting, I was using Federal brass. I never paid much attention to case weights. I was shooting a match at 1000 yards. One shot kicked my butt, and was an 8, or about 20 or more inches high. I set that case aside, and weighted it when I got home. It was 20 grains heavier than any of the other cases I had used that day. Believe me, I have weighed my cases since then, the only exception being Lapua brass. I spot weighted the Lapua I use and my samples it all within 1 grain of each other.

Lessons learned:

1) weigh brass, or at least do some sample weights
2) don't mix lots
3) sample weigh loaded rounds to insure consistency.

John

Man 20gr heavier has to be a record or a cull. Usually lapua is within a grain

 

[270WinDude]

I generally find 1.5 gr variance between Hornady, Norma and win. The difference being which has the most in the middle. Win is all over the place in more ways then one but I’m currently needing more range time as I suspect once culled and sorted it’s more accurate then my Hornady brass but so far just theory. With the heavier brass mentioned above, I’m assuming 2 grains, and that’s what we we were talking about on another thread... that tighter space with same charge would be a higher pressure with different poi especially at 1k....... edit.. also op, you are shooting phenomenally imo with factory Nosler ammo. May I ask what barrel specs are or gun?

 

[corning]

Man 20gr heavier has to be a record or a cull. Usually lapua is within a grain

No, it was Federal brass that was inconsistent. I, more than likely mixed lots on it too, not realizing that it would be an issue.

Lapua is very consistent. When I sampled the Lapua, it was less than +/- 1 grain

 

[Dusty Stevens]

No, it was Federal brass that was inconsistent. I, more than likely mixed lots on it too, not realizing that it would be an issue.

Lapua is very consistent. When I sampled the Lapua, it was less than +/- 1 grain

Thats still way off even for a 20yr difference. I cant see how it made it thru the machines being that far off thats amazing

 

[270WinDude]

No, it was Federal brass that was inconsistent. I, more than likely mixed lots on it too, not realizing that it would be an issue.

Lapua is very consistent. When I sampled the Lapua, it was less than +/- 1 grain

What cartridge? Did i miss that part..

 

[corning]

What cartridge? Did i miss that part..

My Federal brass experience was with a .308

 

[clunker]

edit.. also op, you are shooting phenomenally imo with factory Nosler ammo. May I ask what barrel specs are or gun?

It is a factory Tikka T3 Lite in .223 with a 1/10" twist that I bought on clearance about 6 months ago (my first rifle, even though I'm 46). Thanks to the phenomenal experience and support from this forum, I have turned a fun little plinker into a hobby. Next step is to start investing in reloading. Shots were taken off a bipod from prone position on bare ground at 100 yds. After getting advice on bore cleaning, scope and ring selection, shooting form, and many other variables; I am now addicted to the sport, and my groups keep getting smaller. The rifle has always liked Nosler and Sako ammo. I think I can do better with Nosler bullets, quality brass, and the right custom load.

 

[Rust]

Back about 25 years ago I decided to build my first from scratch fully custom competition rifle, no factory anything. Learned a hard lesson (as in money and time wasted). Brass other than Lapua or RWS (if you can find it) sucks. Now the only chamberings I'll use in a new build are those that have Lapua brass available. Before anyone says anything about Norma, I got burned hard buying 500 pieces of Norma 6.5 X 284. About 95 decent pieces out of 500. Neck thickness variances were horrible, up to .008" and that is way too much for a no turn chamber. Last few Lapua purchases (including .308 and .223) typically ran less than .0015 at most and the majority were much better.

 

[clunker]

Back about 25 years ago I decided to build my first from scratch fully custom competition rifle, no factory anything. Learned a hard lesson (as in money and time wasted). Brass other than Lapua or RWS (if you can find it) sucks. Now the only chamberings I'll use in a new build are those that have Lapua brass available. Before anyone says anything about Norma, I got burned hard buying 500 pieces of Norma 6.5 X 284. About 95 decent pieces out of 500. Neck thickness variances were horrible, up to .008" and that is way too much for a no turn chamber. Last few Lapua purchases (including .308 and .223) typically ran less than .0015 at most and the majority were much better.

I have heard positive reviews of all types of brass, but the only brand where I can't remember a single negative review is Lapua. However, my first practice reloads for the .223 will probably be with Nosler brass because I have lots of it, and I don't want to waste the good stuff until I have some experience. Hopefully, Lapua is as good as everyone reports because I have started ordering Berger factory ammo with Lapua brass for my Creedmoor, in anticipation of reloading for that as well.

 

[Uncle Ed]

Your cases can't weigh 11.73 to 11.89 "grains"?????????

Weigh your cases in grains on a reloading scale and compare below to extreme spread.

 

[Dave Berg]

I decided to weigh the rest of the live factory rounds and found they ranged from 11.73g to 11.89g.

That's 181.02 to 183.49 grains Uncle Ed. Pretty consistent for loaded factory ammo. Less variance than just the brass for most of the brands tested here many moons ago.

Get some Lapua brass and custom bullets or you'll drive yourself nuts. While you're getting set up to reload find some Black Hills blue box 52 grain hollow points. They shoot as well as most guys handloads.

And despite their claims Nosler and accuracy don't often show up in the same sentence.

Lapua is good but not always great. We waited a very long time for them to produce .221 Fireball brass and the first lot I got varied by +/- 2 grains. A four grain spread for a 95 grain case.

 

[Uncle Ed]

That's 181.02 to 183.49 grains Uncle Ed. Pretty consistent for loaded factory ammo. Less variance than just the brass for most of the brands tested here many moons ago.

You are correct about the weight, my brain would not accept the fact that anyone would buy factory loaded ammunition and weigh the entire cartridge. And then complain about weight variations in loaded factory ammunition in the Reloading Forum (All Calibers).

I will mark this down as half a brain fart on my part.

 

[mikeinct]

When the shooting is serious or just being safe..weigh the brass & sort into lots...I had one batch of Lapua 223 2 grains or better over my recordered normal average...be careful...mike in ct

 

[Dave Berg]

When the shooting is serious or just being safe..weigh the brass & sort into lots...I had one batch of Lapua 223 2 grains or better over my recordered normal average...be careful...mike in ct

You're right Mike. I have some perfectly normal looking Lapua 223 brass around here that weighs 103-104 grains vs the 93-94 I normally see. Probably 15 years old. It doesn't have "Match" on the headstamp but it looks just like the new stuff.