New 6.5 Creedmoor brass headspace seems a little short

[kgunz11]

Virgin brass is always smaller than a go-gauge, for what that's worth. You shouldn't have anything to worry about with CHS on the new brass. Keep in mind that ADG brass is on the thicker side so reduce your load and work up to safe pressure.

 

[Starlite]

Thank you Starlight. I don't really trust the absolute values I'm getting from my caliper, but I think the differences between fired brass and the new brass are probably good. Do you have a difference between your fired brass and your unfired brass?

Here are some photos of my alpha brass (same lot). New, fired, resized and in the COAL gauge perhaps not in the right order as I'm posting and viewing from my iPhone. FiredNewgauge with fires brassfull length resize with 2 thou shoulder bumped back

 

[Starlite]

Forgot to mention. Not that it's super important as long as you're measuring from same POR but C.375 is the stated gauge for 6/6.5 (et al) creedmoor brass

 

[Carey Farmer]

Here are some photos of my alpha brass (same lot). New, fired, resized and in the COAL gauge perhaps not in the right order as I'm posting and viewing from my iPhone. View attachment 372355FiredView attachment 372354NewView attachment 372353gauge with fires brassView attachment 372352full length resize with 2 thou shoulder bumped back

Yep, looks like your new brass is 0.0055" shorter than your fired brass. That's pretty close to my 0.007".

 

[Carey Farmer]

Forgot to mention. Not that it's super important as long as you're measuring from same POR but C.375 is the stated gauge for 6/6.5 (et al) creedmoor brass

I got the .400 headspace reference diameter from SAAMI's website. Page 51 at this link: https://saami.org/wp-content/upload...99.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

 

[Lefty G-gear]

Prepping to load some practice rounds in my 6.5 Creedmoor target rifle with brand new brass. Checked brass length with a .400" comparator, and was surprised at how short the new brass is - about 0.007" shorter than fired brass from that same rifle. Checked my "go" gauge and the new brass is .005" shorter than a "go" gauge. Pulled a bullet from a Hornady factory round and the new brass is .006" shorter than the unfired Hornady case.

Should I be worried about this much extra chamber headspace compared to new brass length causing case - head separation?

Usually new, non-belted brass is at most a couple thousandths shorter than my fired brass.

6.5 Creedmoor case gauges

6.5 Creedmoor Rifle Gauges| Midsouth Shooters

www.midsouthshooterssupply.com

 

[XLR Industries]

Here is a 6-creed reamer print. Everything should be the same as 6.5 except the neck diameter. The datum line should be in the same location which is the headspace line. Check the internal diameter of your gauge also if you compare the numbers directly!

 

[Lefty G-gear]

Prepping to load some practice rounds in my 6.5 Creedmoor target rifle with brand new brass. Checked brass length with a .400" comparator, and was surprised at how short the new brass is - about 0.007" shorter than fired brass from that same rifle. Checked my "go" gauge and the new brass is .005" shorter than a "go" gauge. Pulled a bullet from a Hornady factory round and the new brass is .006" shorter than the unfired Hornady case.

Should I be worried about this much extra chamber headspace compared to new brass length causing case - head separation?

Usually new, non-belted brass is at most a couple thousandths shorter than my fired brass.

I'd be tempted to go ahead, load 5 or 15-rds. and shoot to see how they do.
Three 5-rd. groups, at 1/2 -grain increments, or so.

 

[Lefty G-gear]

Prepping to load some practice rounds in my 6.5 Creedmoor target rifle with brand new brass. Checked brass length with a .400" comparator, and was surprised at how short the new brass is - about 0.007" shorter than fired brass from that same rifle. Checked my "go" gauge and the new brass is .005" shorter than a "go" gauge. Pulled a bullet from a Hornady factory round and the new brass is .006" shorter than the unfired Hornady case.

Should I be worried about this much extra chamber headspace compared to new brass length causing case - head separation?

Usually new, non-belted brass is at most a couple thousandths shorter than my fired brass.

Oh. let us know if you sized the cases thru the die first, or not.
Some don't.
I'd size the new brass.
Measure EVERYTHING before n after with a caliper n case gauge.

 

[osok-1k]

I've been loading since'77, shot some benchrest back then and LE sniper work and still strive to be as precise as possible in my shooting / loading. A friend told me that he fireforms using a paper wad stuffed into the neck with whatever fast powder he has the most of and his results work for him. I have a 6.5-55 AI that I plan on trying his method. Still have to consume a primer and powder but no bullet. Just a possibility

 

[Carey Farmer]

Virgin brass is always smaller than a go-gauge, for what that's worth. You shouldn't have anything to worry about with CHS on the new brass. Keep in mind that ADG brass is on the thicker side so reduce your load and work up to safe pressure.

Good point kgunz, a go-gauge wouldn't be very useful if manufacturers made their brass longer than the go-gauge. Starting to sound like most folks with more experience hand loading don't think .005" shorter than a go-gauge is a problem. Sure appreciate everyone's comments.

Still trying to reach someone at ADG. I'll let everyone know what they say.

Oh. let us know if you sized the cases thru the die first, or not.
Some don't.
I'd size the new brass.
Measure EVERYTHING before n after with a caliper n case gauge.

Lefty, the dimensions I gave in the previous post were unsized cases right out of the box. I did subsequently full-length size them (to make sure the necks were straight and the bodies not oversize) but the die bottomed out against the shell holder before it hit the case shoulders.

 

[Carey Farmer]

I've been loading since'77, shot some benchrest back then and LE sniper work and still strive to be as precise as possible in my shooting / loading. A friend told me that he fireforms using a paper wad stuffed into the neck with whatever fast powder he has the most of and his results work for him. I have a 6.5-55 AI that I plan on trying his method. Still have to consume a primer and powder but no bullet. Just a possibility

Thanks osok. I guess I would have to neck up and then partially neck back down to create a false shoulder to make sure the case stayed snug against the bolt face? Hadn't really thought of going that route. But the fastest powder I have is the H4350 I bought for this chambering. I use H4831sc, H1000, or Retumbo in all of my other rifles.

 

[QuietTexan]

I guess I would have to neck up and then partially neck back down to create a false shoulder to make sure the case stayed snug against the bolt face? Hadn't really thought of going that route

I form cases with the false shoulder like you just described, but we're talking AI level of case movement there, not just the shoulders moving to fill the chamber. I shoot them, don't mess with COW. I shot a .300" group at 100 yards with fireforming loads, if it holds sub-MOA out to a reasonable distance there's no need to COW, the fireforming loads are more than accurate enough for me.

 

[Carey Farmer]

I form cases with the false shoulder like you just described, but we're talking AI level of case movement there, not just the shoulders moving to fill the chamber. I shoot them, don't mess with COW. I shot a .300" group at 100 yards with fireforming loads, if it holds sub-MOA out to a reasonable distance there's no need to COW, the fireforming loads are more than accurate enough for me.

Thanks QT. I'm thinking I'll probably load these cases with a slight jam into the lands, and just go about my business.