ADG Brass Not Growing After multiple firings, would you still bump the shoulder?

[kshea]

Hey Guys,

I'm trying to dial in a picky 7PRC build with a proof pre fit and after learning that Hornady Brass can be sub par, I bit the bullet (bad pun) and picked up some ADG brass to work off of. I'm on 3 firings with it now, and surprised that the ADG brass has not grown at all even having been fired 3 times. Using a hornady headspace comparator, the virgin brass measured 1.8905 - 1.8910. After three firings, its still measuring the same at 1.8910, and still seems to chamber without issue. Because of this, I've just been full length sizing the brass with the smallest redding comp shell holder for a .000 shoulder bump (i.e. no bump)

In comparison, Hornady brass after two firings seemed to grow as much as 1.8925 - 1.8930 (which I'm assuming is softer brass). It seems like at this point, it just starts to get tight in the chamber.

So, for all you experienced handloaders out there, does this seem normal? Does it make sense that premium brass wouldn't grow to chamber size after three firings? Also, does it seem strange that virgin ADG brass would only be like 1 -1.5 thou smaller than my chamber right out of the get go? Lastly, if this all seems normal, would you bump the shoulder back .002 or continue to not bump the shoulder until the fired brass doesn't chamber anymore.

Thanks for any insight!!

 

[VandelayIndustries]

Hey Guys,

I'm trying to dial in a picky 7PRC build with a proof pre fit and after learning that Hornady Brass can be sub par, I bit the bullet (bad pun) and picked up some ADG brass to work off of. I'm on 3 firings with it now, and surprised that the ADG brass has not grown at all even having been fired 3 times. Using a hornady headspace comparator, the virgin brass measured 1.8905 - 1.8910. After three firings, its still measuring the same at 1.8910, and still seems to chamber without issue. Because of this, I've just been full length sizing the brass with the smallest redding comp shell holder for a .000 shoulder bump (i.e. no bump)

In comparison, Hornady brass after two firings seemed to grow as much as 1.8925 - 1.8930 (which I'm assuming is softer brass). It seems like at this point, it just starts to get tight in the chamber.

So, for all you experienced handloaders out there, does this seem normal? Does it make sense that premium brass wouldn't grow to chamber size after three firings? Also, does it seem strange that virgin ADG brass would only be like 1 -1.5 thou smaller than my chamber right out of the get go? Lastly, if this all seems normal, would you bump the shoulder back .002 or continue to not bump the shoulder until the fired brass doesn't chamber anymore.

Thanks for any insight!!

I’m no expert here, but I’d guess your hornady brass with the 1.893” is a representation of your chamber. Did you pop the spent primers before taking measurements? If not that can really throw things off. As far as the other brass not growing I’ve never heard of something like that before. Dumb question, are you sure you have the correct “head” in your comparator gauge? Brass is clean, no debris on it? It’s weird if all that checks out you’re getting a tight bolt close on the adg. I’d bump it down .002 so the bolt will close easily on it. Hopefully someone more experienced will weigh in.

 

[DHDeal]

Not apples to apples, but my 223AI has never needed the shoulders bumped as they never grew and always drop right in after a little love on the base. Good thing for me as the Redding Comp bushing die won't go any further down in my Co-Ax.

If your cases chamber easily after running through your FL die, whether bumping the shoulder or not, what more do you need? If you are as anal as I, you can go to the trouble of pulling your firing pin and extractor and check if the bolt drops on a sized case with no or very very little effort. If this happens and no effort is needed, you should be golden.

The above paragraph is how I set up many of my FL dies. I'm older and lazier now and just bump .002" on boltguns. If factory ammo is available, I do my break in with it. I have found Lapua Brass usually needs a couple firings to get fireformed and the ADG brass maybe as hard.

 

[Holliday]

Hey Guys,

I'm trying to dial in a picky 7PRC build with a proof pre fit and after learning that Hornady Brass can be sub par, I bit the bullet (bad pun) and picked up some ADG brass to work off of. I'm on 3 firings with it now, and surprised that the ADG brass has not grown at all even having been fired 3 times. Using a hornady headspace comparator, the virgin brass measured 1.8905 - 1.8910. After three firings, its still measuring the same at 1.8910, and still seems to chamber without issue. Because of this, I've just been full length sizing the brass with the smallest redding comp shell holder for a .000 shoulder bump (i.e. no bump)

In comparison, Hornady brass after two firings seemed to grow as much as 1.8925 - 1.8930 (which I'm assuming is softer brass). It seems like at this point, it just starts to get tight in the chamber.

So, for all you experienced handloaders out there, does this seem normal? Does it make sense that premium brass wouldn't grow to chamber size after three firings? Also, does it seem strange that virgin ADG brass would only be like 1 -1.5 thou smaller than my chamber right out of the get go? Lastly, if this all seems normal, would you bump the shoulder back .002 or continue to not bump the shoulder until the fired brass doesn't chamber anymore.

Thanks for any insight!!

I run ADG in my 6.5 prc. No issues, on 9th firing.

What load are you running in the ADG? Are you sure it is powerful enough to blow the brass out completely to fire-form the chamber. ADG is a lot more stout than Hornady brass. Also is the chamber and brass squeaky clean so it grabs the chamber walls instead of just slamming back to the bolt face?

That’s all I can think of at the moment.

 

[Emerson0311]

My brass grows on a sliding scale depending on quality and how hard I’m pushing the pressure/velocity. Lapua with a gentle load will grow very little. Like a 600hp motor that never gets pushed past 400hp.

 

[RegionRat]

So, for all you experienced handloaders out there, does this seem normal?

It happens. Just depends on the fitment of the virgin brass compared to the chamber dimensions. However, 65 KSI has a way of making brass flow no matter what. Eventually, that brass and the chamber will mate up to the point where it will need some work to get it to chamber without effort on the bolt.

Does it make sense that premium brass wouldn't grow to chamber size after three firings? Also, does it seem strange that virgin ADG brass would only be like 1 -1.5 thou smaller than my chamber right out of the get go?

A slightly different view is... do we know how your chamber is cut? It is good to own the Go Gage to be able to anchor the comparator readings.

It is always good to detail inspect your virgin and cycled brass, but you will also want to know a few diameters to go along with the shoulder datum length. The neck, the body-shoulder junction, and the 0.200 line are a good place to start.

Lastly, if this all seems normal, would you bump the shoulder back .002 or continue to not bump the shoulder until the fired brass doesn't chamber anymore.

Keeping control of the reamer dimensions and getting chambers cut the way you want them is a graduate step in your shooting.

By having the bbls all cut to the same specs, you will not have to keep chasing changes in chamber dimensions and you can avoid having brass and die problems.

It is best to take a small sample of brass and load at the range to get the cycles up and establish your sizing process recipe.

For now, take a close inspection of all the lengths and diameters you can. Track the delta between the virgin, fired, and sized brass. Try to avoid bumping the brass unless it requires it for a few samples.

There is nothing wrong with a good tight fit between your brass and the chamber, but we don't want clickers and issues that loose the coordination between the brass, the chamber, and the dies. Watch the diameters too, not just the lengths. Good Luck and in for the range reports.