Been reading about which Hornady comparator bushing to use with 6 Creedmoor and I have a question.

[Xerothermic]

According to the forums either the C .375 or the D .400 will work. The majority (small sampling) think the D .400 over the C .375 without an explanation.

Anyone here have a definitive answer?

 

[209jones]

I know I've seen a Hornady destruction sheet for it somewhere, believe one closest to the center of the shoulder will work just fine. Main thing is, that it rests on a point of reference that you use consistently. That point may actually be just a hair different between fired and sized as well, due to mfgr tolerances on shoulder angle in the chamber, sizing die, but it is all you can do with it. Also, IE: for a while I had a Hornady one and a Forster one, I'd have two different measurements if I used the "other" one, even with the "same" sized hole. Never bothered actually measuring them. Sure you'd see the same between Hornady, SAC, Area 419, Derraco and Forster and others. And you are using a caliper, so, within +/-.001 is pretty good for an average across 10 rds or more.

 

[SKWERLZ]

According to the forums either the C .375 or the D .400 will work. The majority (small sampling) think the D .400 over the C .375 without an explanation.

Anyone here have a definitive answer?

 

[6ShotsOr5?]

Hornady.com doesn’t have a headspace bushing for 6 Creedmoor listed, but they do have the “C” bushing listed for the 6.5 Creedmoor, and that’s the one you should choose. The correct answer is bushing C. To get the correct shoulder angle, you stay within the same cartridge family.

 

[Xerothermic]

Hornady.com doesn’t have a headspace bushing for 6 Creedmoor listed, but they do have the “C” bushing listed for the 6.5 Creedmoor, and that’s the one you should choose. The correct answer is bushing C. To get the correct shoulder angle, you stay within the same cartridge family.

And that's why we ask these questions. Thank you, very much!

 

[Rocketvapor]

Why not ream the A 330 out to about 340?

 

[AICS308]

Based on the drawing dimensions above showing .400, would the D400 Hornady be the best choice?

 

[Edd]

Based on the drawing dimensions above showing .400, would the D400 Hornady be the best choice?

It is a tool used to compare lengths so it doesn't matter which one you use. I prefer using a .375 because it is closer to the center of the shoulder.

 

[LCazador]

If it's a custom barrel have a barrel stub made with end of your reamer.

 

[gunsandgunsmithing]

Based on the drawing dimensions above showing .400, would the D400 Hornady be the best choice?

Yessir! Per SAAMI specs, the proper datum diameter is .400. Thing is, it doesn't really matter as long as you use the same point always, for it. Before there was any such thing as a Hornady Case COMPARATOR, I used pistol cases turned upside down to check shoulder bump. As long as it's close to middle of the shoulder and you use the same tool as a COMPARATOR...it doesn't matter what you use. If you want the best solution, ask your smith for a bbl gizzy, made with your reamer and from your bbl. But even that is NOT a HS measuring tool. But it is the most consistent and easy to use way, IME.

 

[L.Sherm]

If it's a custom barrel have a barrel stub made with end of your reamer.

I've got some of these, I started using them before comparators

 

[L.Sherm]

You can find the lands on a brand spanking new chambered barrel also.