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New Brass Question

flyby71

Private
Minuteman
Aug 4, 2019
35
2
SE Texas
I broke in my Precision Firearms 6.5 Grendel barrel with factory Hornady ammo. I set up my full length resizing die to bump the shoulders back .003 when I resized all of the Hornady brass.

I just got my order of 300 pieces of Starline brass in the mail and am getting ready to load them. Should I run them all through my full length sizing die with the setting as is, or should I set it up in another way?
 
I broke in my Precision Firearms 6.5 Grendel barrel with factory Hornady ammo. I set up my full length resizing die to bump the shoulders back .003 when I resized all of the Hornady brass.

I just got my order of 300 pieces of Starline brass in the mail and am getting ready to load them. Should I run them all through my full length sizing die with the setting as is, or should I set it up in another way?

Your Hornady brass has thinner case wall thickness than Starline, which will produce different results. So, no! You're going to have to make some adjustments, like having a smaller expander ball that you might have in your sizing die.
 
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Your Hornady brass has thinner case wall thickness than Starline, which will produce different results. So, no! You're going to have to make some adjustments, like having a smaller expander ball that you might have in your sizing die.

Good to know!! I am using a Forster full length sizing die. I am still learning at this point, but I didn’t think that this particular die would allow for different size expander balls? If it does not, how should it be set up for new brass?
 
Good to know!! I am using a Forster full length sizing die. I am still learning at this point, but I didn’t think that this particular die would allow for different size expander balls? If it does not, how should it be set up for new brass?

You can get different size expander ball from Forster Products. Then you just put the new expander ball on your current spindle being sure it's in the right position. And be sure to have a way to easily distinguish one from another to help avoid any mistakes.

 
Also need to add that these loads will be shot out of an AR platform. Reading on the Oversize E-Z Out expander balls, it says to produce softer neck tension. I’m guess that probably isn’t good for a gas gun, or am I wrong?
 
Awesome, thank you. I can try to search and try to find this answer, but if you don’t mind me asking.....how does one know what size expander ball to use?

You can measure you're current expander ball and since you'll need a smaller want do to the thicker wall of Starline over the Hornady, you may want to go with one that's .001" smaller to get to do what you get with the Hornady brass. It's all kinda experimenting to see what give you the results you want due to the variables in the brass to include the amount of springback you get with either.

PS: Keep in mind what's taking place when the expander ball is being drawn through the neck. It's squeezing the brass between the ball and the inside surface of the die and as the ball moves from the neck area to the mouth, it's pulling brass upward (think as if it were clay and how it'd react). This makes the case neck longer and is why trimming is often necessary after sizing. Also, if the expander ball is too large relative to the neck thickness, it's trying to draw a lot of brass, which results in a hard time pulling the case out of the die (lube helps, of course). And I don't like expander balls in my dies as they tend to also induce runout on the neck, though for some people, that's not an issue.
 
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You can measure you're current expander ball and since you'll need a smaller want do to the thicker wall of Starline over the Hornady, you may want to go with one that's .001" smaller to get to do what you get with the Hornady brass. It's all kinda experimenting to see what give you the results you want due to the variables in the brass to include the amount of springback you get with either.

Man I have started reading on expander balls and the bushing dies and I feel like I am going down a rabbit hole! So much info out there it’s hard to know what the right thing to do is. I’ll measure what I have and see if Forster has one that is just slightly smaller.
 
I do not F/L size virgin brass, I feel it is not nesseasry to in my opinion. After firing the brass I will run it thru a my Redding Type S F/L sizing die with the nessary bushing. It varies what brass i am using at the time. So for example with my ADG brass I will use my .291 bushing, and run my mandrel thru it to get a .001 neck tension on my neck. Running the mandrel thru virgin brass helps with making the neck more uniformed, and also most virgin brass has super tight necks from the factory they were produced. Also i have multiple mandrels with diffrent diameters yo achieve .001 neck tension.
 
I do not F/L size virgin brass, I feel it is not nesseasry to in my opinion. After firing the brass I will run it thru a my Redding Type S F/L sizing die with the nessary bushing. It varies what brass i am using at the time. So for example with my ADG brass I will use my .291 bushing, and run my mandrel thru it to get a .001 neck tension on my neck. Running the mandrel thru virgin brass helps with making the neck more uniformed, and also most virgin brass has super tight necks from the factory they were produced. Also i have multiple mandrels with diffrent diameters yo achieve .001 neck tension.

That makes sense. Thanks for the explanation.

Just to clarify, what mandrel/die set up do you use for the virgin brass?
 
Man I have started reading on expander balls and the bushing dies and I feel like I am going down a rabbit hole! So much info out there it’s hard to know what the right thing to do is. I’ll measure what I have and see if Forster has one that is just slightly smaller.
Sigh. Yeah, you're in a rabbit hole, all right. Since the bullets are ALL going to be 0.264 inches, just measure the diameter of a loaded round and use a neck bushing 0.002" smaller than that diameter. The idea is to minimize the amount you're working the brass. I use a 0.288" neck bushing for Hornady and 0.289" for Starline and Peterson.

While it isn't necessary to full-length size new brass, you definitely need to run a mandrel or expander ball through Starline and other bulk-packed brass because some of the case mouths are invariably dented.

Fwiw, my Sinclair carbide mandrel and the expander ball in my RCBS Gold Medal 6.5CM die are both 0.2630 inches.

Edit: Another branch of the rabbit hole is the question of how much "precision" makes sense in a 6.5 Grendel being run in an AR platform. I'm no gas gun expert, but the little understanding I do have is that brass intended for them needs to be sized "smaller" than one would do for a bolt gun, and small-base dies mush things pretty tight...
 
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Sigh. Yeah, you're in a rabbit hole, all right. Since the bullets are ALL going to be 0.264 inches, just measure the diameter of a loaded round and use a neck bushing 0.002" smaller than that diameter. The idea is to minimize the amount you're working the brass. I use a 0.288" neck bushing for Hornady and 0.289" for Starline and Peterson.

While it isn't necessary to full-length size new brass, you definitely need to run a mandrel or expander ball through Starline and other bulk-packed brass because some of the case mouths are invariably dented.

Fwiw, my Sinclair carbide mandrel and the expander ball in my RCBS Gold Medal 6.5CM die are both 0.2630 inches.

Yeah the rabbit hole can get quite extensive, and become a pain in the ass! Lol 😆
 
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I just FL size my new brass. Rum em through like they were fired. If you leave your current set up you know the shoulders won't be to long. Just be aware using 2 types of brass you are going to get different results in what ever load your loading and the first firing of the new brass will be different than after it's fired but it will be close.
 
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Sigh. Yeah, you're in a rabbit hole, all right. Since the bullets are ALL going to be 0.264 inches, just measure the diameter of a loaded round and use a neck bushing 0.002" smaller than that diameter. The idea is to minimize the amount you're working the brass. I use a 0.288" neck bushing for Hornady and 0.289" for Starline and Peterson.

While it isn't necessary to full-length size new brass, you definitely need to run a mandrel or expander ball through Starline and other bulk-packed brass because some of the case mouths are invariably dented.

Fwiw, my Sinclair carbide mandrel and the expander ball in my RCBS Gold Medal 6.5CM die are both 0.2630 inches.

Edit: Another branch of the rabbit hole is the question of how much "precision" makes sense in a 6.5 Grendel being run in an AR platform. I'm no gas gun expert, but the little understanding I do have is that brass intended for them needs to be sized "smaller" than one would do for a bolt gun, and small-base dies mush things pretty tight...

That last thought is very true, and exactly where I’m at. My barrel is a 24” Krieger made by Precision Firearms. The upper is a Seekins IRMT-3, and I bedded the barrel in it. I made every attempt that I could to build it for accuracy. You hit the nail on the head, I’m to the point of trying to make the most accurate loads that I can to see if the accurate “precision” loads make sense for this gun. Hopefully the answer is a lot of sense!!!!

My brain is jello after all the reading I’ve done tonight on this subject. I think where I am at the moment is to just use the Forster die as is and get the cases loaded and fire formed, or ordering a 21st Century or a Sinclair Gen 2 expander die and bushings to just expand the neck. I could add a Redding body sizing die and use a 2 step sizing method after the cases are fire formed.

God help the rabbit if I find it while I’m wondering around this damn hole.
 
That last thought is very true, and exactly where I’m at. My barrel is a 24” Krieger made by Precision Firearms. The upper is a Seekins IRMT-3, and I bedded the barrel in it. I made every attempt that I could to build it for accuracy. You hit the nail on the head, I’m to the point of trying to make the most accurate loads that I can to see if the accurate “precision” loads make sense for this gun. Hopefully the answer is a lot of sense!!!!

My brain is jello after all the reading I’ve done tonight on this subject. I think where I am at the moment is to just use the Forster die as is and get the cases loaded and fire formed, or ordering a 21st Century or a Sinclair Gen 2 expander die and bushings to just expand the neck. I could add a Redding body sizing die and use a 2 step sizing method after the cases are fire formed.

God help the rabbit if I find it while I’m wondering around this damn hole.
Don't overthink it, just run the brass through whatever die you plan on using and then neck up with the mandrel (I like .262 for 6.5G). New brass is pretty inconsistent and benefits from getting sized down a little too much and then expanded back up.
 
I just measured several of the Hornady brass cases that I resized with the Forster FL Die and the inside neck diameter of them was .259, which seems too small for .264 bullets. I forgot to add that I will be finishing the loads with a Lee Factory Crimp Die due to the gun being an auto loader.

So with this info, would y’all recommend keeping things as they are with the Forster or getting a Redding Body Sizing Die and a Sinclair/Century 21 Expander Die and the appropriate size expander mandrels?
 
How did you measure ?

If it were me I would use what you got. Do a proper load work up starting low and increase the charge. Only way your gonna know is to shoot. If i couldn't make accurate ammo with what i have then I may look into other options.
 
How did you measure ?

If it were me I would use what you got. Do a proper load work up starting low and increase the charge. Only way your gonna know is to shoot. If i couldn't make accurate ammo with what i have then I may look into other options.

I used the flat sides of my caliper to measure the inside of the case neck. Would .259 inside diameter cause part of the bullet to shave off when seating, or is that an appropriate inside diameter for seating?
 
I just measured several of the Hornady brass cases that I resized with the Forster FL Die and the inside neck diameter of them was .259, which seems too small for .264 bullets. I forgot to add that I will be finishing the loads with a Lee Factory Crimp Die due to the gun being an auto loader.

So with this info, would y’all recommend keeping things as they are with the Forster or getting a Redding Body Sizing Die and a Sinclair/Century 21 Expander Die and the appropriate size expander mandrels?

If you're going to use a Lee FCD you may as well load the cases with a powder scooper and seat the bullets with rock. .003" of neck interference is more than enough for a gas gun alone.
 
If you're going to use a Lee FCD you may as well load the cases with a powder scooper and seat the bullets with rock. .003" of neck interference is more than enough for a gas gun alone.

Point taken. I’m here for the advise! Still learning as I go. If .003” is more than enough for a gas gun, what is the optimal neck interference measurement for a gas gun ( NOT using the Lee FCD)?
 
I just measured several of the Hornady brass cases that I resized with the Forster FL Die and the inside neck diameter of them was .259, which seems too small for .264 bullets. I forgot to add that I will be finishing the loads with a Lee Factory Crimp Die due to the gun being an auto loader.

So with this info, would y’all recommend keeping things as they are with the Forster or getting a Redding Body Sizing Die and a Sinclair/Century 21 Expander Die and the appropriate size expander mandrels?
Was this measurement before or after you ran an expander ball or mandrel through the neck?

As I noted, my mandrel and expander button both measured 0.263 inches. I find a 0.262" neck after neck expansion.

Keep in mind that 0.004" is the thickness of a piece of printer paper.

Looking at it another way, if you weren't wandering around in Wonderland, would you even know what the exact post-resize neck diameter is, or would you just load & go? And, for all that, if you have a tight neck, you don't have to mess with crimping....
 
Point taken. I’m here for the advise! Still learning as I go. If .003” is more than enough for a gas gun, what is the optimal neck interference measurement for a gas gun ( NOT using the Lee FCD)?

Anywhere between .003 and .005 is fine. I size my 6.5G brass to .261 ID. I size down to .260 and then run a .262 mandrel through the necks.
 
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Was this measurement before or after you ran an expander ball or mandrel through the neck?

As I noted, my mandrel and expander button both measured 0.263 inches. I find a 0.262" neck after neck expansion.

Keep in mind that 0.004" is the thickness of a piece of printer paper.

Looking at it another way, if you weren't wandering around in Wonderland, would you even know what the exact post-resize neck diameter is, or would you just load & go? And, for all that, if you have a tight neck, you don't have to mess with crimping....
That measurement was after running the expander ball (Forster FL Die) on the Hornady brass.

That’s a good point, if I never would have dove down the hole, I would be none the wiser.