30BR

[North Fork]

What case length are you trimming your case's to on the 30BR The gun has a 330 neck Randy reamer.

 

[madmixerman]

I trim mine to 1.500 " .

 

[GSPV]

Depends on the reamer. Do you have access to the print?

 

[jbarnwell]

Get a Sinclair gage, follow the instructions, and you will know what your exact chamber length is. You can then make an informed decision on your correct trim length. I hope this helps.

Jarvis

 

[AlNyhus]

Northfork:

The standard 'Robinett' 30BR chamber is 1.520 long. Most with this chamber trim to 1.515 for f-forming, then 1.500 after f-forming and stay there. Reamer mfgs. work to +/- tolerances, so there's always the chance that the actual 'as cut' chamber will vary a bit from the print. Also, some will order a reamer with a neck a bit longer/shorter than the 'standard' Robinett reamer.

An easy way to check this is to neck up a case to 30, turn the neck to .328, but don't trim the neck length..most Lapua cases will be around 1.535-ish long after being necked up from 6BR. Anyway, with the f-p assy removed from the bolt, try to chamber the case. Then, trim off a few thou. (.002-.005) at a time until the bolt closes. You've just found your max. chamber length and now know exactly what to trom your cases to. I like 'em about .020 short (1.500 case in an 1.520 chamber).

Takes less time to do this than to type it....... -Al

 

[RGRobinett]

Northfork:

The standard 'Robinett' 30BR chamber is 1.520 long. Most with this chamber trim to 1.515 for f-forming, then 1.500 after f-forming and stay there. Reamer mfgs. work to +/- tolerances, so there's always the chance that the actual 'as cut' chamber will vary a bit from the print. Also, some will order a reamer with a neck a bit longer/shorter than the 'standard' Robinett reamer.

An easy way to check this is to neck up a case to 30, turn the neck to .328, but don't trim the neck length..most Lapua cases will be around 1.535-ish long after being necked up from 6BR. Anyway, with the f-p assy removed from the bolt, try to chamber the case. Then, trim off a few thou. (.002-.005) at a time until the bolt closes. You've just found your max. chamber length and now know exactly what to trom your cases to. I like 'em about .020 short (1.500 case in an 1.520 chamber).

Takes less time to do this than to type it....... -Al

Al, the [so called] 'Robinett' reamer calls fo a maximum OAL of 1.510"; following FF, at 1.510", I trim to 1.500". Necking-up, using my OLD tooling, dictated this OAL: my tooling/procedure never produces a case over 1.515". As determined per your description - for so determining - my original reamer is very close to the print OAL, of 1.510".

Therefore, once my case-forming operation was set (the Original, or, Ronnie Long chamber was/is/ 1.520" - Ronnie chambered my first [30BR] barrel), I ordered the 1.510" reamer, which has come to be called the 'Robinett' reamer . . . the problem, as you point out, is that there are a variety of lengths - many still labeled, 'Robinett' reamer.

I did not like the 'gap' resulting form the 1.520 chamber and my necking-up process/tools: prior to neck-turning, to assure a uniform cut into the shoulder-wall, I 'square' the case-mouths, which dictated to 1.510" length" I prefer no more that 0.010" of clearance between the case mouth and the 'end' of the chamber-neck.

Knowing the Max. chamber OAL, I FF at that length, the brass 'shrinks' a couple of 1/1,000Ths, it's fired again, then trimmed to 1.500" and trimmed if/as soon as a case reaches 1.505". As you point out, for any nonstandard cartridge (Wildcat) it is important to KNOW (measure) the length of any particular chamber/reamer . . . Many tools/methods - including FF using various formulas - result in the potential for LONGER chamber/case OAL, which while OK, produce no real performance enhancement: again, the key is knowing what we've got. RG

 

[skeetlee]

to much of a gap will collect carbon. make sure you keep an eye out for this. lee

 

[4xforfun]

Dumb, semi off the topic question. Can you actually buy 30 BR brass, or are you guys taking them up from 6mm?

 

[josh shrum]

form them from Lapua 6BR

 

[snowpro440]

Or buy them to fit from Ron Hoehn
http://www.benchrest.com/hoehn/

 

[fm1947]

North Fork, you got your answer from the guy who's reamer your barrel was done in Randy Robinette, just do what he says

 

[Batraven]

Northfork:

The standard 'Robinett' 30BR chamber is 1.520 long. Most with this chamber trim to 1.515 for f-forming, then 1.500 after f-forming and stay there. Reamer mfgs. work to +/- tolerances, so there's always the chance that the actual 'as cut' chamber will vary a bit from the print. Also, some will order a reamer with a neck a bit longer/shorter than the 'standard' Robinett reamer.

An easy way to check this is to neck up a case to 30, turn the neck to .328, but don't trim the neck length..most Lapua cases will be around 1.535-ish long after being necked up from 6BR. Anyway, with the f-p assy removed from the bolt, try to chamber the case. Then, trim off a few thou. (.002-.005) at a time until the bolt closes. You've just found your max. chamber length and now know exactly what to trom your cases to. I like 'em about .020 short (1.500 case in an 1.520 chamber).

Takes less time to do this than to type it....... -Al

Hi All,

Is it normal the new cases do not have to be full lenght sized before the first firing?
My newly made cases fits without doing this and the bolt closes without any ressistands.
My other 30br needed some full lenght sizing before the first firing so thats why i ask a expert

 

[savagedasher]

The barrel I got is marked with that information. But you must remove the stock to see it . Larry