ADI vs OSA brass .223

The Raven · Post by **The Raven** » Sun Jan 28, 2018 5:58 pm

Interesting observation.

I was prepping a mix of ADI and OSA brass today and despite being told they are exactly the same I did discover a minor difference.

Based on the brass I was prepping: ADI has a slightly smaller (or perhaps tapered) flash hole than OSA.

Not sure why this would be the case....as they are supposedly identical and from the same factory...but I could tell by feel when I was decapping the ADI.

No, I didn't try to measure the flash holes!

Anyone know if there is a practical reason for this or is it just a production deviation?

Camel · Post by **Camel** » Mon Jan 29, 2018 7:30 am

Dunno if it makes any difference or not, if it is it would only be very small, probably not worth worrying about unless you are interested in serious competition shooting. ADI 308 brass has a slightly smaller primer pocket as well, I just ran a drill bit through them the same size as the WW I was using and loaded them the same and found bugger all difference in accuracy.

Only did it because they were tight on the decapping pin.

The Raven · Post by **The Raven** » Mon Jan 29, 2018 6:04 pm

Heh! Same issue here, noticed while decapping and the difference wasn’t that much.

Don’t think I’ll be breaking out the drill....

Sent from my iPhone using Tapatalk

Camel · Post by **Camel** » Mon Jan 29, 2018 6:24 pm

The Raven wrote: ↑Mon Jan 29, 2018 6:04 pm Heh! Same issue here, noticed while decapping and the difference wasn’t that much.

Don’t think I’ll be breaking out the drill....

Sent from my iPhone using Tapatalk

You will wish you evened them up after you have bent/broken your last remaining decapping pin by not putting your cases into the shell holder exactly in the correct spot and spares take a couple of weeks to turn up.

The Raven · Post by **The Raven** » Mon Jan 29, 2018 6:30 pm

As soon as I felt the difference I got really cautious about breaking the pin.

Had I broke it I would have had a backup. Not that I want to resort to a backup.

I have some berdan cases if you want a challenge. A mix of steel and brass cases.

Sent from my iPhone using Tapatalk

Brad Y · Post by **Brad Y** » Tue Jan 30, 2018 7:27 pm

The OSA stuff I have is really hard to get to fit into the lee shell holder on the priming tool as well. ADI stuff no issue.

The Raven · Post by **The Raven** » Wed Jan 31, 2018 7:10 am

Brad Y wrote: ↑Tue Jan 30, 2018 7:27 pm The OSA stuff I have is really hard to get to fit into the lee shell holder on the priming tool as well. ADI stuff no issue.

I haven't noticed that with .223.

Had some trouble removing one or two pieces of brass from the shell holder, normally a burr from the ejector.

CORRECTION: I have noticed it with some cases, but never checked to see if it was brand related. Will check next time.

lee_enfield223 · Post by **lee_enfield223** » Mon Feb 05, 2018 7:46 pm

I noticed that the OSA seems to be softer and sometimes gets stuck in my sizing die where as winchester and ADI never get stuck ???? just adding my 5 cents worth, not sure if anyone else has had it happen to them, what lubes do you guys use? I use hornady in the white tub. but I tried RCBS one shot and still got stuck cases. and the lube was dripping off the brass.

The Raven · Post by **The Raven** » Mon Feb 05, 2018 10:27 pm

lee_enfield223 wrote: ↑Mon Feb 05, 2018 7:46 pm I noticed that the OSA seems to be softer and sometimes gets stuck in my sizing die where as winchester and ADI never get stuck ???? just adding my 5 cents worth, not sure if anyone else has had it happen to them, what lubes do you guys use? I use hornady in the white tub. but I tried RCBS one shot and still got stuck cases. and the lube was dripping off the brass.

I hadn't noticed any softness but then I'm generally neck sizing only.

I'm using the Lee lube because the it came with the press, and I haven't ran out yet. So expect a new thread by me asking what lube is best when I finally run out.

When FLS 270win in Hornady dies the first two cases can be really hard, but now I've learnt to put a lot of lube on them so it gets into the die proper.

Does anyone have access to the right gear to do a Rockwell C or Brinell hardness test? Could be interesting to compare the ADI and OSA and see if there is any difference.

Brad Y · Post by **Brad Y** » Tue Feb 06, 2018 12:00 am

Unless your annealing exactly the same method and repeatable each time your not going to know. Brass work hardens quickly. Would take precise measuring gear to measure springback and neck tension etc, but I’m 99 percent sure osa and adi brass comes from same factory. Difference in batches is entirely plausible.

The Raven · Post by **The Raven** » Tue Feb 06, 2018 6:42 am

Brad Y wrote: ↑Tue Feb 06, 2018 12:00 am Unless your annealing exactly the same method and repeatable each time your not going to know. Brass work hardens quickly. Would take precise measuring gear to measure springback and neck tension etc, but I’m 99 percent sure osa and adi brass comes from same factory. Difference in batches is entirely plausible.

I agree on the annealing or work hardening. It would probably be best to start with unfired or once fired brass to any measurements. Yep, could be batch differences (FWIW the brass this was discovered on was all once fired only).

A standard hardness test should do, springback and tension is getting more technical than I need.

Could there be a minor specification variation between the two? If most of the ADI production goes to ADF, there is a chance ADF may they have a slightly different spec (eg. Australianise a international military spec).

At the end of the day, I only noticed the flash holes were slightly different. Haven't noticed any difference out of the rifle or on the target.

Brad Y · Post by **Brad Y** » Wed Feb 07, 2018 11:59 pm

Honestly if it goes bang and something erupts into feathers or fur and pink mist, I’m not really bothered. I really think it’s just a batch difference thing. Go forth and smite ferals with it

The Raven · Post by **The Raven** » Thu Feb 08, 2018 5:49 am

Brad Y wrote: ↑Wed Feb 07, 2018 11:59 pm Honestly if it goes bang and something erupts into feathers or fur and pink mist, I’m not really bothered. I really think it’s just a batch difference thing. Go forth and smite ferals with it

Agreed. It was just something I 'discovered' and I have no plans on getting overly bothered with it.

Agree on the outcome. It doesn't seem to make a difference so I won't bother about it too much.

Just intrigued that there are minor differences between the two.

lee_enfield223 · Post by **lee_enfield223** » Thu Feb 08, 2018 6:09 pm

where I used to work I could have tested the brass with a rockwell hardness tester but it's all gone just like our automotive industry

and I used to work at a company called borg warner ,yes they made gearboxes and differentials, but it all went to Asia. where a can of Coke cost 25 cents and the same can cost $2.50 here,,,

The Raven · Post by **The Raven** » Fri Nov 23, 2018 7:33 pm

While picking out some brass for reloading I took another look at a mix of ADI and OSA brass.

Yep, the OSA definitely has a smaller flash hole. A quick check with some handy drill bits show the ADI .223 brass has 2mm(-ish) flash holes and the OSA below 2mm.

I know the internet suggests flash hole size has negligible impact on performance BUT wouldn't it be better if a 'batch' all had the same sized flash hole?

I don't really want to bother drilling them out BUT the alternative is a mixed batch of flash holes which will leave me wondering if I'm missing out on some consistency...

AusVarmint

ADI vs OSA brass .223

ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223

Re: ADI vs OSA brass .223