Done Trimming Brass!

[Seabeeken]

I'm SOL on my AI chambers! I just got a 243 AI and noticed when I shot in 243AI mode, there was a lot more carbon built up in the throat!

My 243 AI was the same. The forming process caused necks to shorten and the cases never stretched enough to need trimming and a carbon ring was there. Ive only ever trimmed 1 AI case, a 257AI

 

[MagnumManiac]

I keep my comp rifle brass .005" off chamber end, all cases are run through the trimmer after a match and sized for the next match.
All of my chamber prints have it listed how much the chamber is longer than the max length of brass, most are .040-.050" longer, good to know on short neck cartridges like the 264WM & 300WM.
MY hunting rifles are kept at .020" from chamber end just because.

Cheers.

 

[Rimneck]

Took a peek with the scope.

Make and model of borescope, please.

 

[DoneNOut]

Make and model of borescope, please.

Teslong aluminum rod, plug to smart phone model. Got off Amazon

 

[ThrdKllr]

This is why I make a chamber length gauge for each of my rifles. It allows me to know what my trim length actually needs to be.

SINCLAIR INTERNATIONAL Sinclair Chamber Length Gage | Brownells

Check out the SINCLAIR INTERNATIONAL available Online at Brownells Today and many more Case Length Gauges products are available in our Reloading Department.

www.brownells.com

I do the same thing. Make them out of aluminum or brass so they don't scratch anything. My 300WM is about .020 longer than the spec'd trim length.

 

[nksmfamjp]

This is where trimming 10-20 on a setting, calculating Sd and then using 3 times Sd should get you the max length. Average length plus 3x Sd.

 

[Mikecr]

This is where trimming 10-20 on a setting, calculating Sd and then using 3 times Sd should get you the max length. Average length plus 3x Sd.

Interesting for sure.
Wish I was intelligent enough to understand it..

 

[AZShooter]

Learned about end of chamber gauges from Varmint Al thirty or so years ago. Had access to a lathe and made my own. Here is the link to the page where he shares the dimensions of the chamber plugs.

Varmint Al's Mini Lathe Page

 

[GimpyPaw]

I swear you guys are going to cost me money, again. I didn't know I needed a bore scope until this thread. Now a chamber length gage too?

Not to derail the tread, but can a bore scope also see when a bullet is touching the lands?

 

[Buckskinner]

Bore scope is very handy, more for actually, well inspecting the bore... I doubt you will be able to see if bullet is toughing the lands with one unless you cut off bullet ogive, but that's easy to measure other ways.

Chamber length guage is simple to make with a sacrificial piece of brass.

DIY Case Over All Length and Chamber Length Gauge

Here's a free tool that you can make to measure accurately your CBTO (Case Base to Ogive - Left Cartridge) and your max Chamber Length (To know your trim length - Right Cartridge). Why the Hornady Case Overall Length Gauge Sucks . . . Hornady does make some great tools, one which I recommend are...

www.dpgunworks.com

 

[QuietTexan]

Not to derail the tread, but can a bore scope also see when a bullet is touching the lands?

No, there's no way to visualize past the meplat, and even if there was the tolerances are so small you wouldn't be able to tell anything.