A question about bumping the shoulder?

[WildBillG]

As my title says I need to know what is meant and where to measure this bump. I believe I know where the shoulder of the case is but I could be wrong. Any help here would be great thanks in advance.

 

[Remmy700]

It is just like it sounds brother u are using a bump die or F/L sizer to just push shoulder back enough for chambering. This is with fully fire formed brass. If u set dies up according to instructions with most die sets u are going to push shoulder back way more than needed working brass for no reason. Sinclair and hornady both have headspace Gauge sets that measure on a datum line between body shoulder junction and shoulder neck junction. U measure fired brass and record that number and the. Adjust die downward until u achieve that .002 bump.

 

[Remmy700]

Here is an example. This is whidden model that comes in their die sets.

 

[Remmy700]

Here is the hornady set it's like 40 bucks.

 

[WildBillG]

Well great Remmy700 now I need another tool. Seriously thank you for the help that little tool will be handy.

 

[Remmy700]

Yes sir it is very handy. If u don't have the hornady set for measuring seating depth get that one also. Both are money well spent and imho they are not optional if u are serious about reloading. Best of luck brother.

 

[ShtrRdy]

I use a .40 S&W case with the primer knocked out for a gauge. You place the mouth of the .40 case over the neck of the rifle case and it will rest on the shoulder.

 

[MagnumManiac]

All info is spot on, BUT, the measurement is taken at a certain radius point on the shoulder, referred to as the Datum.
For example, the 30-06 Is measured at the point on the shoulder measuring .375", the 300WM is measured at the .420" point.

This 'datum' is important so that ALL measurements have a baseline.

Cheers.

 

[aushunter1]

Well great Remmy700 now I need another tool. Seriously thank you for the help that little tool will be handy.

Welcome to the world of reloading.
I have the Hornady set of headspace gauges plus the comparitors & both the straight & curved OAL gauges.
They were in the same delivery as my first ever set of dies.
They are tools that if you want to do the job properly & know where everything is to a thousand of an inch then they are irreplaceable.
They pay for themselves in the long run.

 

[elf]

I have the Hornady guage to measure bump,but do not use it because I favor the Redding Instant Indicator.

https://www.midwayusa.com/product/1016220899

 

[nicholasjohn]

I use a .40 S&W case with the primer knocked out for a gauge. You place the mouth of the .40 case over the neck of the rifle case and it will rest on the shoulder.

You are a clever fellow. I'm feeling a bit like a doofus for not thinking of this nifty trick myself. Have you devised a means to attach it to you caliper blade, or do you just hold it in places with your fingers while taking a measurement ?

 

[entoptics]

All info is spot on, BUT, the measurement is taken at a certain radius point on the shoulder, referred to as the Datum.
For example, the 30-06 Is measured at the point on the shoulder measuring .375", the 300WM is measured at the .420" point.

This 'datum' is important so that ALL measurements have a baseline...

This is only important when comparing measurements from other folks. As long as you're internally consistent, and are somewhere near the middle of the shoulder, you can compare fired and sized brass with a variety of methods. The only important measurement is the difference in length from the cartridge base to the midpoint of the shoulder of a fired brass, before and after sizing. This is why the "pistol brass trick" mentioned above is viable. I have the Hornady bullet comparator set, and just use whichever insert is appropriate for the caliber I'm measuring

 

[Orange Dust]

This is only important when comparing measurements from other folks. As long as you're internally consistent, and are somewhere near the middle of the shoulder, you can compare fired and sized brass with a variety of methods. The only important measurement is the difference in length from the cartridge base to the midpoint of the shoulder of a fired brass, before and after sizing. This is why the "pistol brass trick" mentioned above is viable. I have the Hornady bullet comparator set, and just use whichever insert is appropriate for the caliber I'm measuring

Before I got one I used to use sockets from my socket set. Easy to find one that fits. The hornady gauge is much easier to use. The good news: It doesn't cost much, and works really well.

 

[nicholasjohn]

Before I got one I used to use sockets from my socket set. Easy to find one that fits. The hornady gauge is much easier to use. The good news: It doesn't cost much, and works really well.

I think that you can buy the measuring tools for the various cartridges without buying the whole tool. It will work with the same fitting that clamps to the caliper blade on the tool that measures bullet seating depth. So, if a guy already has that tool, he just needs to get the sleeves that measure the shoulder height of the cartridge case. There are also videos on YouTube that show the operation of this tool. The 6.5 Guys made a good one, which shows a few of the nuances of getting an accurate measurement.