Cartridge length

[COLT45SA]

The maker of my 6mm PPC gave me 40 loaded cartridges measuring 1.510" in length. Several sites and loading manuals show that the length should be over 1.500. Should I assume that the chamber of my rifle is deeper than the manuals and the one shown on Accurate Shooter~? And how badly will my accuracy suffer if I use cartridges as short as 1.490~?

 

[Bill Norris]

The maker of my 6mm PPC gave me 40 loaded cartridges measuring 1.510" in length. Several sites and loading manuals show that the length should be over 1.500. Should I assume that the chamber of my rifle is deeper than the manuals and the one shown on Accurate Shooter~? And how badly will my accuracy suffer if I use cartridges as short as 1.490~?

I trim to 1.495 for 1.510 suggested trim length. Shooting in the zeros and ones.

 

[COLT45SA]

I trim to 1.495 for 1.510 suggested trim length. Shooting in the zeros and ones.

Thanks for that. I was concerned that the shorter cartridges would cause some kind of a problem. Zeros and ones sound great to me. I'll now separate them into batches so 20 to 50 in sizes 1.495+/-.005, 1.500+/- .005 and work from there.

 

[David Christian]

I would suggest you measure your chamber. At a minimum, borrow a Teslong and insert it from the muzzle while a sized piece of brass is chambered and look at how close the brass is in relation.

 

[K22]

You can purchase a Sinclair Chamber Length gauge, very inexpensive, and measure the chamber length. It will remove the guess work.

 

[divingin]

If you have the Hornady OAL gauge and the requisite modified case, you can use a .22Magnum fired case as a chamber gauge for 6mm. Chuck the 22Mag case in a drill and file the rim down to about .272" (or whatever your chamber neck is supposed to be.) Hit the base of it to make sure it's flat. Slip the 22Mag into the modified case neck, insert in the chamber, and run the tool's rod out until it stops and lock it in place. Extract everything and the modified case base to the 22 mag head is the length of your chamber (at least pretty close - as close as the tools case base to shoulder relates to your chamber measurement.)

 

[gunsandgunsmithing]

You can purchase a Sinclair Chamber Length gauge, very inexpensive, and measure the chamber length. It will remove the guess work.

Yes...this is what ya need. Pay attention to neck diameter vs the tool. They have what they are now calling a "tight neck" model. I would only assume maybe that means a .262 neck. Verify or it's super easy to make these from brass or aluminum. I'd make it about .002 smaller than the chamber neck diameter and don't bevel the end much if at all. Just enough to remove any burrs.
There are different length ppc's out there. This will tell you what ya have for sure. I'd make my max length about .010 under what the tool measures.

SINCLAIR INTERNATIONAL Chamber Length Gauge, Tight Neck, 6mm SKU: 749000751

Check out SINCLAIR INTERNATIONAL Chamber Length Gauge, Tight Neck, 6mm SKU: 749000751 available Online at Brownells Today and many more Case Length Gauges products are available in our Reloading Department.

www.brownells.com

 

[COLT45SA]

Yes...this is what ya need. Pay attention to neck diameter vs the tool. They have what they are now calling a "tight neck" model. I would only assume maybe that means a .262 neck. Verify or it's super easy to make these from brass or aluminum. I'd make it about .002 smaller than the chamber neck diameter and don't bevel the end much if at all. Just enough to remove any burrs.
There are different length ppc's out there. This will tell you what ya have for sure. I'd make my max length about .010 under what the tool measures.

SINCLAIR INTERNATIONAL Chamber Length Gauge, Tight Neck, 6mm SKU: 749000751

Check out SINCLAIR INTERNATIONAL Chamber Length Gauge, Tight Neck, 6mm SKU: 749000751 available Online at Brownells Today and many more Case Length Gauges products are available in our Reloading Department.

www.brownells.com

Just ordered one from Brownell's. The shipping cost was outrageous at $9.99~!

 

[fkimble@charter.net]

Chamber specs must always be = to or bigger than the brass case. Otherwise we would have all sorts of problems!

Frank

 

[TTE]

Just ordered one from Brownell's. The shipping cost was outrageous at $9.99~!

Shouldda called .... I have both sizes of chamber gauges