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Shoulder Bumping ???

What if you are loading for two different rifles? I have both a 6.5x47 Lapua and a .338 Lapua where brass fired in one rifle simply will not chamber in the other even using full length sizing dies.

One chamber is a bit more fat than the other, but headspace should be withing 0.003" from one chamber to any other (if it's headspaced correctly). So one would only need to bump the shoulder 0.003" to fit all chambers. A body die would be the other thing one would have to size the brass with, so the stuff fired in the fat chamber fits in the tight chamber (if the FL die doesn't size the body enough).
 
To the OP - let me ask you, just what do you hope to gain by sizing your cases UNDER SAAMI spec?

I can think of no good reason to do so, but numerous reasons NOT to do so.
 
I was thinking the same . . . .
I do have two .338's and 6.5x47's. I was hoping for an easy fix, but the idea of keeping two sets of ammo, one for each gun does make sense and it allows me to neck size only which keeps each different rifle happy although I'm not real happy about purchasing a bunch of new .338 brass. I thought that full length sizing would have brought the brass back to factory and it would work in either. I does fit in the Wilson case gauge. Too cold to shoot now anyway so I will play with things a bit later.
 
What if you are loading for two different rifles? I have both a 6.5x47 Lapua and a .338 Lapua where brass fired in one rifle simply will not chamber in the other even using full length sizing dies.


Your two rifles have different headspaces and your die is not set to bump the shoulder back far enough for the shorter one. (there are other possible explanations but this is the most likely).

Generally you should bump the shoulder back just a few .001" every sizing to get easy feeding and best accuracy. this means you need to have both rifles chambered to the same headspace. go and no-go gauges are .004" apart so your chambers could be .004" different and in a perfect world, you should change your shoulder bump for each chamber....now you can buy the PMA shoulder bump adjustment tool

https://www.brownells.com/reloading...ts-upgrades/micro-die-adjuster-prod77619.aspx

and record the 2 settings for the 2 chambers and adjust your die for each rifle. but then you have to keep separate ammunition for each rifle.

If the 2 rifles were mine, I would deepen the chamber in the shorter one so they were both within .001" and I didn't have to change my dies.

Another, simpler option, which traditional wisdom would recommend but might not result in perfect accuracy, would be to just adjust your die to bump the shoulder enough to accommodate the shorter chamber and don't worry about it in the longer one. Brass fired in the longer chamber will be worked more and might not be as accurate.

Jerry
 
Forgot that option. I think the shellholder set is available only for .473 base cases. Not sure. --Jerry
 
If you are worried about functioning in the field what's the problem with running each loaded round thru the rifle? How many cartridges do you need to kill a deer? Sounds like you are imagining a problem that doesn't exist. If you can extract a fired case easily and rechamber it you don't have a tight fit. Adjust your die using the closing the bolt without a firing pin in the bolt method and you will get the proper die adjustment. The case should be fired several times without any shoulder bump so the case fits the chamber.

I hunt more than deer, e.g. ghogs, predators. Between hunting and practicing I shoot approx a thousand rounds of centerfire rifle a year out of 14 different rifles. I wanted a sizing process that would produce reliable chambering; every time for every rifle.

I don't like the idea of chambering live rounds at the loading table, i.e. in the house to see if they chamber. Don't much like the idea of having to take the bolt apart every reloading cycle either. The idea of checking each round would be tiresome*. Instead I opted for adusting the die so the bolt will close just as you suggested which the .001 to .002" shoulder bump process accomplishes without having to check each round. This way I know without any doubt that all my reloads function without any problems but I also haven't oversized the case to create excessive headspace.

As far as imagining a problem that doesn't exist, well it happened to me more than once in the field when I was a 'neck sizer' and I can assure you I wasn't imagining it. It's the main reason I switched back to full length resizing but learned from a benchrest shooter how to do it right by measuring the amount shoulder bump from a fire case in the specific rifle that I'm reloading for. It works quite well so "I'm not worried about functioning in the field" any more.

As far as how many cartridges I need to kill a deer, only one if I place the shot correctly. For ghogs and predators it depends on how many I see and get shots at. Also would hate to drive 15 miles to the range to practice and find out that some of my reloads won't chamber. It would upset my digestion.

* Being kind here, actually it would be stupid for the amount of rounds and number of rifles I shoot. :)
 
I hunt more than deer, e.g. ghogs, predators. Between hunting and practicing I shoot approx a thousand rounds of centerfire rifle a year out of 14 different rifles. I wanted a sizing process that would produce reliable chambering; every time for every rifle.

I don't like the idea of chambering live rounds at the loading table, i.e. in the house to see if they chamber. Don't much like the idea of having to take the bolt apart every reloading cycle either. The idea of checking each round would be tiresome*. Instead I opted for adusting the die so the bolt will close just as you suggested which the .001 to .002" shoulder bump process accomplishes without having to check each round. This way I know without any doubt that all my reloads function without any problems but I also haven't oversized the case to create excessive headspace.

As far as imagining a problem that doesn't exist, well it happened to me more than once in the field when I was a 'neck sizer' and I can assure you I wasn't imagining it. It's the main reason I switched back to full length resizing but learned from a benchrest shooter how to do it right by measuring the amount shoulder bump from a fire case in the specific rifle that I'm reloading for. It works quite well so "I'm not worried about functioning in the field" any more.

As far as how many cartridges I need to kill a deer, only one if I place the shot correctly. For ghogs and predators it depends on how many I see and get shots at. Also would hate to drive 15 miles to the range to practice and find out that some of my reloads won't chamber. It would upset my digestion.

* Being kind here, actually it would be stupid for the amount of rounds and number of rifles I shoot. :)

Don't mean to be rude but I never had a problem in 45 years of reloading.
 
I have two .308s, there's a .002" difference between the two chamber's fired shoulder. I don't like to touch my dies once locked down, I just use the Redding Competition Shell Holders. .006 for one rifle and .004 for the other.
You will still have to identify both pieces of brass as to which was sized .006" and which was sized .008". Use different brands of brass or mark each case or segregate into marked lots. The idea I presented was to keep both lots separate in some way shape or form,:confused:!! This is not rocket science, ohh sorry Mr. Rocket Man,:oops:!!
 
Don't mean to be rude but I never had a problem in 45 years of reloading.
Which part of K22s post are you addressing? 1/ the stripping of the bolt/ 2/ the unwillingness to cycle rounds in the house ;) just kidding on this one or 3/ his changing from neck sizing to FLS?
 
I gave my son my second 308 but before that I would load different bullets for each rifle. SMK for one A-max for the other. Nosler BT for Hunting for each head spaced the same.
 
Which part of K22s post are you addressing? 1/ the stripping of the bolt/ 2/ the unwillingness to cycle rounds in the house ;) just kidding on this one or 3/ his changing from neck sizing to FLS?

Sorry the replies covered several areas.
1. Cases will chamber no matter how long the necks grow.
2. Reliable chambering in the field related to bumping.
 
Don't mean to be rude but I never had a problem in 45 years of reloading.
My problem was that I was using neck sizing exclusively which eventually caused chambering probelms. I believed neck sizing created more accurate reloads and longer case life which I learn subsequently that niether is true.

I was still learning about precision rifle reloading. I've been reloading about as long as you but I never had the benefit of learning from someone really experienced. I had to learn by trial and error until I met a benchrest shooter who taught me how to properly full size cases.
 
My problem was that I was using neck sizing exclusively which eventually caused chambering probelms. I believed neck sizing created more accurate reloads and longer case life which I learn subsequently that niether is true.

I was still learning about precision rifle reloading. I've been reloading about as long as you but I never had the benefit of learning from someone really experienced. I had to learn by trial and error until I met a benchrest shooter who taught me how to properly full size cases.
I hope everyone remembers to remove the fired primers, or reseat them before starting any case bumping measurements.
 

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