I've had an M1A Squad Scout for a while now. It does very well with several of my handloads. Very well meaning consistant four round groups running 1.3-1.5 MOA.
But I've never seen brass make much of a difference. In the .308, some brass like Hornady or Winchester is much lighter than say Prvi Partizan or Federal. But that has always meant that I needed to raise or lower the powder charge a grain or so to get the same level of accuracy.
So, I bought some Lake City, 7.62 Nato brass made my Federal under their American Eagle brand because it was alot cheaper than anything else.
Never could find a load that shot much under 4 MOA. Tried different charges of both TAC and H4895 and still 4 MOA plus.
So, I loaded up some of the same load that works well with Prvi brass and the 150 gr. Barnes TTSX, 44 grs. of TAC.
I used both Sierra's 150 gr. FMJ/BT's and Sierra's 150 gr. Game Kings.
The results were amazing. The Lake City/Federal brass ran groups that were 4-4.2 inches @ 100 yds. for four rounds.
The Privi brass ran groups that were 2.0 with the FMJ bullets and 1.6 inches for four rounds with the Game Kings.
Never have I seen results like this. Both makes of brass are very close in weight, so that's not why.
The only thing I can think of is that the LC brass was annealed too much creating inconsistant neck tension. It's not the neck thickness. I measured both brands.
Thoughts, or comments ? E

I think the American Eagle brass is sold as either 308 brass with Federal cases or 7.62 NATO with Lake City cases. Is the headstamp LC or FC? I picked up two bags of American Eagle brass at Cabelas a few weeks ago and noticed one bag said .223 and one said 5.56. After I looked, the .223 was FC brass and the 5.56 was lake city. I swapped one for another 5.56 bag before I checked out as they were the same price. In my experience, FC .223 brass is a one time thing.

Did you resize the cases before loading or just load them straight out of the bag?

Brass can make a big difference.

Or none, depending...

if it works, I go with it, if it won't, I try something else..

I don't think it can be annealing, as I anneal my own stuff and am not real scientific about it.

Play the neck tension game and it should work. IE keep adding and see if something changes.

I've shot LC and FC 308 years ago, and never had an issue with either, both were sub MOA in our M1As.

I loaded them w/o resizing them, but I did chafer the the rough edges off of the case mouths. After shooting, full lenth resized them and tried them again. Later, I tried different powders and charge weights. Nothing worked.
I've had good groups with other lots of both Lake City, and LC Match brass in other rifles, BTW. E

Weigh the brass? Wild fluctutaions?

I didn't find much weird fluctuations but IIRC in 223 a certain lot of 92 and 93 brass was not desirable accuracy wise at all...

Can you check neck concentricity? That can definitely make a difference. If your chamber is at max sammi and your die is resizing to minimum that can make a big difference also. Might try minimal resizing brass that has been fired in your chamber just to see if that makes a difference.

Check it Gen Zediker's article: http://www.zediker.com/downloads/m14.html
I consider the m1a to be 1 of the most finicky rifles to reload for. Once you find the right combo, great shooter.

I did check the necks of several of each for consistancy, both were good.
They weigh within a few grains of each other. I did not check either for weight consistancy, but I have done that with other brands of brass. It's common for them to vary up to three grains either way and still shoot well/ well enough.
I've found I must fully resize my brass otherwise the bolt will not close.
I have not found my M1A Scout to be at all fussy to load for. After reloading for lots of different rifles since 1958, I know what a fussy rifle can be like. This one simply is not one. E

M1A experience says opposite of AR15 experiences, sometimes sizing with small base on the M1A helps accuracy a LOT.

Brass can vary a LOT more than 3 grains in 308 brass...

And finally I"ve had brass that seems fine and simply won't shoot... it is what it is.

here is a list of brass from 1 to 5 Lapua Hornady Federal Lake City WCC At below 5 was Rem Win

Sounds interesting, but I can see no list.

Could you post it again please?

John

Lists don't count, unless they are very recent.... Some of the better I"ve seen over the years, have been Rem and Win... and some of the worst the same.

I shoot to much volume to consider Lapua... or at least we did in years past...

check your flash holes. some leave a lot of material inside the head when punched. this can cause erratic ignition.

Flash holes are fine, open and round. No problems there.
I agree with Rost. Unfortunately brass lots can vary over time. But why the Privi Part. brass shoots the same loads so much better than the federal made Lake City brass is a complete mystery to me.
I've had really good performance from Federal brass in the past. I've used a fair amount of it in both the .308, and the 30'06. So good in fact, that I've never had to retire any of it in spite of alot of full lenth resizing for my 760 Remington.
I've been very disapointed in the Hornady '06 brass that I've bought. It doesn't last long before I get cracks near the pressure ring area of the case heads. Even with loads well below the book maximums. I've never had that problem with Winchester brass in the same rifle with the same loads. In the .308, it does well w/o such problems. While it won't last as long full lenth resizing it for my M1A as does the Privi stuff, I'm not unhappy with it.
As to Remington and Winchester being the worst, I haven't seen it. Winchester's shoots as well as any of the above. I just shot a group at 200 yds. with old Remington .280 brass on it's 7th loading that put four into 1.1 inches..... That's alot better than I can ever use in the field.
BTW, I used Mule Deer's annealing process with a candle to redo the case necks. Thanks, MD. Worked like a charm. E