New virgin brass vs new factory ammo vs 1x fired brass

stello1001 said:

Hey all,

I'm starting this discussion to see if I can spark some conversation and maybe gather input from those who have been reloading for longer.

Why is virgin brass tougher (in general when compared against fireformed or 1x brass) to get grouping small vs brass that's been shot already and you are reloading?

I've been loading 1x fired brass for my creedmoor and almost any load I throw at it does pretty well. I've been loading virgin brass on my grendel and can't seem to get consistently good ammo. It could also mean my grendel barrels just aren't accurate or my creedmoor components are much higher quality so naturally they'll group better.

However, in general, we always hear that virgin brass should not be used to do full on load development as it will not give the best results like fireformed brass.

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When I take measurements of virgin brass, there tends to be substantial variations in their head space, case length and even with the thickness of the case walls. . . particularly from one lot to another. You have cases that are mass produced to within a range of tolerances to fit a range of factory chambers that are constructed to within the SAAMI range of tolerances. In addition to that, I find virgin cases are often just trimmed to length with a square cut (no chamfering or deburring), which certainly has effects on a bullets bearing surface and affecting performance. If one is one is not addressing these issues of virgin brass, one can expect to not have as good performance as one can get with well prepped reloaded brass.

High quality brass, like Lapua, will pretty uniform compared to some other brands, having less of these issues, but still there issues like a case headspace that just doesn't fit well in a particular chamber. I happened to try some virgin Alpha brass for the first time in my .308. Measuring the various dimensions, they were very very consistent, but the case mouths were cut square so I chamfered and deburred them. Upon loading them up to fireform using my favorite precision load, it performed outstanding where the whole batch was chronoed and I got an SD of 6.2 with an ES of 29 and the result on target was great too (like 5 shot groups between .350 and .500). That's as good as I do with my Lapua brass that has been fully fire formed and processed.

I've always been of the school that one can do "some" load development with virgin brass. But they're not fully ready until fire formed and fully prepped to include annealing so that the cases are as uniform from case to case as possible. Along with all this, it's also very important to have very accurate powder weights in these cases for consistencies sake.

stello1001 said:

This brings me to my next topic. Why is factory new ammo very tight shooting if it is using virgin brass. Obviously not all factory ammo shoots very tight but many offerings are shooting sub moa consistently.

A few examples include:
-Fgmm for 308
-Hornady match in 140s & 147s for CM
-Berger ammo for 6 or 6.5 CM
-The old prime ammo across various platforms
-sig ammo

And the list could go on.

It will be interesting to hear what the hide has to say. One more thing to note. I believe my grendel loads on virgin brass are giving me trouble when the bullet is released due to no carbon build up in the ID of the case necks. This is all speculation on my part though. The brass is also about 8 to 12 thousands short in the headspace department.

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Factory cartridges shooting sub MOA consistently isn't really that hard to get if one has a quality barrel. And it can be harder to achieve with factory ammo with a pencil barrel compared to good sporter barrel. So, there are various factors involved.

On more than one occasion I've taken factory ammo (like Federal Premium match grade, as they call it) and taken half a box of the cartridges apart, measured them (like seating depths) and the powder weights. On each occasion the factory cartridges has substantial variances that not only showed up on the targets, but also on the chronograph. Having taken half of them apart and reloading them using the same bullet and powder (weighed the total weight and divided the weight by the number of cartridges to make each cartridge have the same powder weight). Before doing the total weight, I recorded the powder weight of each cartridge and yup, there was what I'd call significant differences. When I reseated the bullets, I also seated them to the same seating depth as the average of the from the factory seated cartridges. The last time I did this was March of this year with Fed Premium 175 SMK's. The factory cartridges produced an SD of 13.3 and an ES of 43 with a group of .655 MOA and the reloaded cartridges produced an SD of 8.6 and an ES of 25 with a group of .491 MOA (this is from an RPR with a 26" Krieger heavy barrel). Average velocity was only 4 fps difference. Though these were only 10 shot of factory ammo and 10 of the redone cartridges, on other earlier occasions I saw the same kind of thing.

I think the biggest factor one is going to find with factory ammo is the particular company's quality control. And along with that, like when evaluating when one's load development, one can get lucky and happen to get a real good results from a small number of rounds fired, but firing more becomes hard to reproduce the results.

.008 to .012 short on headspace is a lot and may take several firings to get them fully fire formed . . . especially if they're not annealed properly. In my limited experience, that amount and variance would certainly produce poor results.

stello1001 said:

Hey all,

I'm starting this discussion to see if I can spark some conversation and maybe gather input from those who have been reloading for longer.

Why is virgin brass tougher (in general when compared against fireformed or 1x brass) to get grouping small vs brass that's been shot already and you are reloading?

I've been loading 1x fired brass for my creedmoor and almost any load I throw at it does pretty well. I've been loading virgin brass on my grendel and can't seem to get consistently good ammo. It could also mean my grendel barrels just aren't accurate or my creedmoor components are much higher quality so naturally they'll group better.

However, in general, we always hear that virgin brass should not be used to do full on load development as it will not give the best results like fireformed brass.

This brings me to my next topic. Why is factory new ammo very tight shooting if it is using virgin brass. Obviously not all factory ammo shoots very tight but many offerings are shooting sub moa consistently.

A few examples include:
-Fgmm for 308
-Hornady match in 140s & 147s for CM
-Berger ammo for 6 or 6.5 CM
-The old prime ammo across various platforms
-sig ammo

And the list could go on.

It will be interesting to hear what the hide has to say. One more thing to note. I believe my grendel loads on virgin brass are giving me trouble when the bullet is released due to no carbon build up in the ID of the case necks. This is all speculation on my part though. The brass is also about 8 to 12 thousands short in the headspace department.

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I would argue new brass is less consistent, not necessarily less accurate on target. My Grendel load with brand new Hornady brass shot exceptionally well across 1000 rounds. Brand new Starline 223Rem brass, not so much.

I will have to disagree with the idea that virgin brass is necessarily inaccurate.

I know several folks who compete at high levels of Highpower (XTC, sling, F-Class) and PRS, that run only virgin brass.

I have been beaten by guys (and gals) who were doing their fire-forming during club matches.

These friends went to High Master and Distinguished running only virgin cases. One of these guys is also high level PRS shooter and only runs virgin Alpha Dasher brass.

Their chambers are set up for this which solves the ignition problem that can give erratic ES/SD.

Further, I can personally vouch for the virgin runs of my own varmint wildcats being sub 0.4 MOA in several barrels, and I'm not talking about small samples either.

After all, before there was factory brass for examples like Dasher, we had to fireform to make them and there were many folks who ran that cycle during a match and won. YMMV

Merry Christmas and Happy New Year!!!

stello1001 said:

A few examples include:
-Fgmm for 308
-Hornady match in 140s & 147s for CM
-Berger ammo for 6 or 6.5 CM
-The old prime ammo across various platforms
-sig ammo

Click to expand...

The 308 FGMM that you mention is a very well known round and is the standard for testing a rifle chambered in that cartridge. It is accurate because care is taken in selection of bullet (SMK) and in selection of cases and powder. I have some of the IMR 4064 flavor and it has uniform datum dimensions and none of the cartridges varies in weight by more than 1 grain. Quality components, consistent loading, and consistent brass…. Are you getting the vibe here?