6.5 prc bushing

[Ezdoesit]

Good evening.

Short story
What size bushing should be used when reloading 6.5 prc with adg brass?

Long story
I purchase a 6.5 prc last year that came with brass and dies. I had sized and reloaded using Hornady match dies. I went to load today as this gun is primarily a hunting rifle and noticed there was no bushing in the die (obviously never had one).

I measured the neck of a dummy round and it measured .295 then I measured a fired case .295.
When I measured case thickness it was .020 so if my math is correct .264* (2x.020)= .304 to get .005 neck tension I should be using a .301 bushing.

I am lost. Should I load without touching the neck? Is my current neck tension .090?

 

[straightshooter1]

What did you use to measure the case thickness?

 

[Ezdoesit]

Calipers... I know that’s not the right tool for the job I have never needed anything else before so that’s all I had

 

[straightshooter1]

Calipers... I know that’s not the right tool for the job I have never needed anything else before so that’s all I had

OK, that's what I thought. That .020 is just WAY off. Depending on the brass I would expect the neck wall thickness to be around .011-.013

And for the purpose of getting decent or proper neck tension, calipers are jut not going to give you the resolution you need. You really need a ball micrometer, even a cheap one that's designed to give you accuracy down to +/- .0002 a would do better than a caliper. You might want to consider one like this:

Anytime Tools Tube Micrometer Dual Ball Anvil Round Carbide Tip Pipe Cylinder (Ball on Both anvils): Amazon.com: Industrial & Scientific

Anytime Tools Tube Micrometer Dual Ball Anvil Round Carbide Tip Pipe Cylinder (Ball on Both anvils): Amazon.com: Industrial & Scientific

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If the neck wall thickness is .012, then you have .264 + (2 x .012) = .288". Then you subtract the amount of neck tension you want (let's say that .005): .288 - .005 = .283 as your diameter of the neck you want after sizing.

So, you'll want a bushing ( and I assume with an appropriate sized expander ball in the die) that will give you this .283" (assuming you're after a .005 neck tension) from the fired dimension of .288.

Addendum: corrected the math above thanks to Jordanwickham

 

[Jordanwickham]

I've never used ADG brass for 6.5 but I have used Lapua, Alpha, and Hornady. They are all right around 13.5 untouched w/ ball micro. I'm not going to outright say 20k wall thickness is wrong but it would be obsurdly thick. It's kind of hard to give you a 100% this is the bushing size you want without you having either ball micro or a FL die that you could make a round with to measure the OD of the neck with a seated bullet. I would say that right around .287 should be real close that would be giving your neck wall thickness a generous .014. If you NWT is less than that you may be getting a couple bushings if you are dead set on the 5k neck tension.

Straightshooter1 I know you know your shit but that 2 am math is a little off. .264+.024=.288

 

[Jordanwickham]

OP you could either try to get a cheap FL die or pull the trigger on a ball micro to get you going. I feel like the biggest readily available 6.5 bushing is a .292. I could be way wrong on that but the .299" that was originally asked about seems huge.

 

[Ezdoesit]

Thank you so much for the help. I am obviously still learning and appreciate the responses. I will grab the ball micro and use the proper tools.
That being said I have been told to take a loaded round and subtract .020 to get close. (think every other caliber I have reloaded)
And just to be super clear I’m not saying look I’ve done it this way before and it works I’m asking if I have ever known neck tension.

 

[spife7980]

Thank you so much for the help. I am obviously still learning and appreciate the responses. I will grab the ball micro and use the proper tools.
That being said I have been told to take a loaded round and subtract .020 to get close. (think every other caliber I have reloaded)
And just to be super clear I’m not saying look I’ve done it this way before and it works I’m asking if I have ever known neck tension.

Take a loaded round and subtract .002

I would take a laoded round and subtract .004 and let the expander ball or mandrel open it back up to .002 under but it really doesnt matter but .020 is 10x too much.



You dont need a fucking ball mic to do this. A caliper is plenty adequate. Confirm your measurement though.
You say a loaded round measures .295? Get a bushing from .291-.293 and youll be fine.

Your case thickness math doesnt match up to what you literally measured so clearly youre wrong there.

 

[Ezdoesit]

You are correct 2 thousandth not 20 thousandth. I was trying to carry on a conversation with my wife about God knows what and mistyped.

I will measure again out of curiosity but I’ve ordered the .291-.293 bushings.

 

[Jordanwickham]

You are correct 2 thousandth not 20 thousandth. I was trying to carry on a conversation with my wife about God knows what and mistyped.

I will measure again out of curiosity but I’ve ordered the .291-.293 bushings.

OP let me know how this works out. Be careful with Spife he is all mouth no brain. He just talked you into buying a bushing based on a loaded neck dimension of .295" because he doesn't know the typical neck chamber dimension of a 6.5 is .295" and you said fired.
You don't have a baseline which is why we both suggested a ball micro. You can't order a bushing based off a caliper reading.

The way you get a bushing size is (caliber)+(2x neck wall thickness)-(desired neck tension)=bushing size

So even with Spifes example your bushing would be .290 since You want to have 5k neck tension. Which I can understand since you said it's a hunting rig not a 2k neck tension PRS rifle.

 

[Ezdoesit]

Multiple people have told me to order a ball micro so I am ordering that as well. With my other loads I have always measured a loaded round and subtracted the desired neck tension.

I figured for the extra few bucks buy the right tool for the job as well as multiple bushings.

There is no point spending money on a nice rig and cheaping out of a few reloading components.

Thank you all again for your advice.

 

[Jordanwickham]

Multiple people have told me to order a ball micro so I am ordering that as well. With my other loads I have always measured a loaded round and subtracted the desired neck tension.

I figured for the extra few bucks buy the right tool for the job as well as multiple bushings.

There is no point spending money on a nice rig and cheaping out of a few reloading components.

Thank you all again for your advice.

If I understood your first post you have no way to get to a loaded round correct? Since your only sizing die has no bushing? That method of measuring a loaded round is the easiest way and all you need is a caliper if you can get your round loaded up.

 

[straightshooter1]

If I understood your first post you have no way to get to a loaded round correct? Since your only sizing die has no bushing? That method of measuring a loaded round is the easiest way and all you need is a caliper if you can get your round loaded up.

The problem is one would need a caliper with higher resolution than .0005 to get decent accuracy.

 

[spife7980]

If I understood your first post you have no way to get to a loaded round correct? Since your only sizing die has no bushing? That method of measuring a loaded round is the easiest way and all you need is a caliper if you can get your round loaded up.

You didn’t. Because in his original post he said his dummy round measures .295 which is what my above posts were based on. The fired round just so happens to be the same from what we’ve been told. Which is why I said what I said before, not because I’m talking out of my ass but because that is the information that has been presented to us.

 

[Jordanwickham]

You didn’t. Because in his original post he said his dummy round measures .295 which is what my above posts were based on. The fired round just so happens to be the same from what we’ve been told. Which is why I said what I said before, not because I’m talking out of my ass but because that is the information that has been presented to us.

I got cha. There's alot of wtf in the original post. But there's no way a reloaded round and a fired round have the same neck dimension. He said he sized and reloaded with a die with no bushing. So I'm not sure how it could be possible to have the same number much less get a bullet to seat on an untouched neck. .295 is a standard chamber neck dimension if your loaded round is .295 you're going to have a bad day.
But at 20k neck wall thickness you would have to turn necks because it wouldn't fit in the gun.

 

[straightshooter1]

Straightshooter1 I know you know your shit but that 2 am math is a little off. .264+.024=.288

Yup . . . it was off indeed!!

Thanks for the head up.