Long Chamber Length & Brass Trim Length Rem 700 Bolt Action

[agbm]

Hello all, just say if my chambers length measures 2.020. I have been trimming my brass to 2.005 - 2.008. I was thinking if I trimmed the brass longer just say to 2.015 it would allow me to seat the bullet further out. My question is what are the advantages and disadvantages of doing this? Brass would be specific to this rifle chamber only!!!!

I will be using this to measure: http://www.sinclairintl.com/reload/...-gage-sinclair-chamber-length-gage30-cal.aspx

 

[jsthntn247]

The only advantage is to have more bullet in the case mouth. Just say you were shooting a bullet and only had .140 of the bearing surface in the mouth, allowing the brass to grow more would give more grip on the bullet. If your throat is eroding because you shoot allot, this can be beneficial and allow you to shoot that bullet a few hundred more rounds before you need to set the barrel back. A chamber cast is the only thing that will tell you exactly how long you can go, allow at least .005 clearance.

 

[Powermac]

You got it pretty well covered there, it will lessen throat erosion, and make the brass seal the chamber faster thereby lessen backflow and carbon rings if using slow burning powders.
In some cases it will lessen SD/ES to a small degree.
Stay safe and measure case growth though before going too close.

 

[427Cobra]

Chamber Length and Freebore are two different things, as for trim length 2.010 would be my choice.

 

[agbm]

I measured it and came up with 2.055. My understanding is Length of chamber is defined as distance from the bolt face of the bolt when closed to the end of the neck of the chamber. I shorten one of hornady's modified cases by .100 and inserted the Sinclair Chamber Length Gage into the case and installed hornady lock-n-load O.A.L. gauge and it measured 2.055 Rem 700p measured 2.055, Rem 700 AAC-SD measured 2.055 also. I looked at a 308 reamer print and those numbers fall close to other reamers. So now I see I could allow the case to grow a little bit, to allow me to load the bullets a little bit longer.

 

[agbm]

You got it pretty well covered there, it will lessen throat erosion, and make the brass seal the chamber faster thereby lessen backflow and carbon rings if using slow burning powders.
In some cases it will lessen SD/ES to a small degree.
Stay safe and measure case growth though before going too close.

My REM 700 I measured the chamber length and it came out to be 2.055 to neck (not freebore). I left the case long at 2.020 and loaded 45gr of 4895 , 175smk,lapua brass and cci br2 primer. All I can say is it shot great. I wanted to load the bullets longer and add a little room in the case so no more compressed loads. It saves on trimming brass and it will lessen throat erosion, and make the brass seal the chamber faster thereby lessen backflow and carbon rings if using slow burning powders.no more black ring. I will not let the brass be any longer than 2.020 trim length.