When to trim?

[MattE93]

Here is the scenario. I am loading up 6.5 carcano brass. Prior to sizing they measure 2.067” in length as they should. However, the case mouth is .264” when it should be .268”. No problem, I have .268 expanded in my die set. The problem is the brass being pushed out the way has to go somewhere, and the only place it can go is up. This makes my sizes cases 2.072” or about 5 thou over nominal. These rounds with a longer case still chamber so I am assuming they are good to go but wanted to make sure it was safe to use longer cases. I know some manuals list a maximum case length but I am guessing this is some standard to ensure they chamber in all rifles

 

[cosmic]

Well - Chambering an empty brass is the definitive test.

 

[Paul_T]

For fired brass I use the Case Trim Length in the reloading books

Hornady X for eg has 6.5x52 Carcano Trim Length 2.055 so anything over that (after sizing) would be trimmed to 2.055"

2.067 is SAAMI max case length

 

[Potashminer]

Cases to be trimmed after sizing, not before... Might be of interest to take your rifle to someone with a bore scope and inspect your neck area in your chamber - maybe eroded which is allowing over length cases to chamber?? Or do a casting to see what dimensions your chamber is actually at? Too much case neck length for the chamber neck will crimp the neck to the bullet upon chambering, which should elevate pressure, but you likely knew that...

 

[MattE93]

Okay looks like I’ll order the case length gauge for 6.5 carcano. I am using lead bullets do it is possible the chamber is crimping the brass

 

[snooker]

Matt, my hornady book lists your brass at 2.067" this will be your max length. (for the brass).
You can safely trim 10 thousands shorter. This will be your min. & max lengths. I know you are
crimping, so trim all your cases to 10 under the max and adjust your crimp accordingly. Depending on how hot your loads are, (I suspect fairly lite using lead bullets, you should only have to trim every 5 to 7 times they're loaded.

 

[MattE93]

Cheers for that info. My Lee book has the SAAMI drawing which shows a case length of 2.067” but curiously didn’t have any trim to lengths or max lengths listed, and my Lyman edition has nothing on this caliber.

One more headache to add to loading this caliber, components are harder to come by with the non-standard .268 bore diameter versus .264” for standard 6.5 ammo, I had to order a special shell holder as the Lee #2 ripped the thin rim of the carcano rounds off, and now I have to order special trimmer gauges too.

So much for loading some rounds up this weekend and shooting next week...