Shoulder bump question 30 Nosler

[rharfo]

I've just bought a Nosler 30 Nosler rifle. Literature from Nosler says to "slightly bump the shoulder back between firings for longer case life". Please explain bump it slightly. I have reloaded for a long time and I've either full length or neck sized the case per the die instructions. Thanks for the help.

 

[Predator 22]

I bump the shoulder 2-3 thousands on most of my cases, do not use the old set the die to get the cam over feel unless that is where you get your 2-3 thousands bump. A hornady head space gauge or the likes is a must. Hope this helps.

 

[maninthemaze]

Like Predator said, a head space gauge is a must to accurately measure shoulder bump. Basically, measure from base to shoulder on a couple of fired cases to get an average. Then set the FL sizing die to push the shoulder back a few thousandths.

 

[bigngreen]

First you need to fire a case and get one blown out and tight to the shoulder, sometimes it take a couple firings, then measure with a gauge and set the die to bump the shoulder .0015-.002 no more!

 

[FEENIX]

These guys IMHO did a very good job explaining it in the video ...

[ame]https://youtu.be/V2Wt8-VqeAE?t=748[/ame]


[ame]https://youtu.be/iwpqvE_r7Oc?t=136[/ame]

 

[rharfo]

Thanks!

 

[J E Custom]

With brass being so hard to come buy these days, I avoid shoulder bumping as long as I can. (Less working of the brass, means longer life).

I have all of the gauges to measure the case length and use them, but I prefer to let the chamber tell me what needs to be done.

Minimum sizing to be done is to Neck size only. This works on precision chambers and extends brass life to its max.

Bumping the shoulder is only required when the loaded cartridge is difficult to chamber. I bump only enough to make chambering possible without forcing the bolt down (I want to feel the round and be able to close the bolt with no slack/head space between the bolt and the round. A full length die can be used for this if set shallow and get you just enough bump to work.

Dies that are made to adjust from zero sizing to small base sizing Like Hornady New Dimension dies
work well because they can be adjuster to get any fit you want (Normally sizes more than full length for tight chamber or gas guns where cases are sized below normal to aid in feeding)

I never bump my cases more than necessary (Normally .0005 to .001) because every time you fire the case it expands back to the chamber size and the process starts over again. All chambers are slightly different and require different sizing amounts, so adjust according to your chamber needs
and not some number below the SAMME dimensions.

Even if you don't have a set of dies that adjust over the standard full length sizing, you can use shims between the shell holder and the case head to get exactly what you want in case fit in your chamber. During the loading process I regularly remove the firing pin and test the first die setting.
If it feels tight, I add a .0005 shim under the case head and size another case if it needs more I change to a .001 shim and if it feels good I leave it and finish sizing all the rest of by brass.

In my opinion this is another example of over doing/thinking a process. Accuracy is based on many things including your ammo quality. the better the ammo fits your chamber the better the accuracy
can be.

My opinion is -Don't bump unless it is necessary and only enough to aid in chambering.

J E CUSTOM

 

[rharfo]

With brass being so hard to come buy these days, I avoid shoulder bumping as long as I can. (Less working of the brass, means longer life).

I have all of the gauges to measure the case length and use them, but I prefer to let the chamber tell me what needs to be done.

Minimum sizing to be done is to Neck size only. This works on precision chambers and extends brass life to its max.

Bumping the shoulder is only required when the loaded cartridge is difficult to chamber. I bump only enough to make chambering possible without forcing the bolt down (I want to feel the round and be able to close the bolt with no slack/head space between the bolt and the round. A full length die can be used for this if set shallow and get you just enough bump to work.

Dies that are made to adjust from zero sizing to small base sizing Like Hornady New Dimension dies
work well because they can be adjuster to get any fit you want (Normally sizes more than full length for tight chamber or gas guns where cases are sized below normal to aid in feeding)

I never bump my cases more than necessary (Normally .0005 to .001) because every time you fire the case it expands back to the chamber size and the process starts over again. All chambers are slightly different and require different sizing amounts, so adjust according to your chamber needs
and not some number below the SAMME dimensions.

Even if you don't have a set of dies that adjust over the standard full length sizing, you can use shims between the shell holder and the case head to get exactly what you want in case fit in your chamber. During the loading process I regularly remove the firing pin and test the first die setting.
If it feels tight, I add a .0005 shim under the case head and size another case if it needs more I change to a .001 shim and if it feels good I leave it and finish sizing all the rest of by brass.

In my opinion this is another example of over doing/thinking a process. Accuracy is based on many things including your ammo quality. the better the ammo fits your chamber the better the accuracy
can be.

My opinion is -Don't bump unless it is necessary and only enough to aid in chambering.

J E CUSTOM

I was concerned since I read this in Nosler literature but your explanation indicates I shouldn't worry about unless it becomes a issue. Thanks

 

[J E Custom]

I was concerned since I read this in Nosler literature but your explanation indicates I shouldn't worry about unless it becomes a issue. Thanks

Correct !!

The only reason to bump a shoulder is that the cartridge is to long for the chamber and is difficult to chamber.

Before Bumping became an obsession/the new thing, the use of full length dies did the same thing
without moving the shoulder back (Altering head space).

loaders either shortened the die to over size or ground the shell holder to allow the dies to size a
little more. I preferred not to grind or change either one and just added a shim the shell holder. when die makers started making new/full dimension dies, (Dies that will adjust beyond SAMME chamber dimensions, I started to slowly replace the old style dies with these to get the best fit.

Bumping has its place if the chamber is short or tight and feeding is a problem, The purpose/intent
is to move the shoulder back without reducing case body dimensions. But there is almost no body sizing when the case is properly sized and if the shoulder is moved back a few thousandths, For best head space on a shouldered case, the shoulder needs to be as long/far from the case head as possible without hindering feeding. Proper sizing can be done to make feeding easy without bumping the shoulder in many cases and shortening brass life. (The less you work your brass, the longer it will last).

Remember, best chamber fit, best accuracy and best brass life will normally occur with the least sizing possible/necessary.

Just my opinion

J E CUSTOM

 

[stinkyduck13]

I have been reading pages here for many years, just never signed in or remembered my pass word. MAN DO I EVER MISS J.E.CUSTOMS.