Shoulder bumping technique

[338 dude]

it is confusing , I have just about ordered the wrong ones a couple of times . I just looked , I get the type S bushing ,competition sets . this set has two dies with micrometer tops , and a body die .

 

[Scott E Ames]

Thanks to everyone for sharing your knowledge. Looks like I have a few more dies to order.

 

[SCSCHNUR]

To add to the above post. Pull your firing pin or if a shroud mounted safety ie winchester put on safe. Also remove the ejector plunger and spring for a case only feel and not that spring induced feel from the above parts.
The best video I know of explaining the above process

This is exactly what I do.

 

[fguffey]

The best video I know of explaining the above process

I could determine the amount of bump if Redding would publish the amount of cam over for the Redding turret press. I can measure bump on all of my Herter presses because my Herter presses are cam over presses. My cases do not have head space; my cases have 'length' from the datum to the case head.

Before the Redding Competition shell holder a reloader could have used a feeler gage to set the die up; problem, it was impossible to convince a reloader it was possible. And then there was Skip's shims and grinding on the bottom of the die and top of the shell holder to compensate for reloaders did not understand.

F. Guffey

 

[Svashtar]

To add to the above post. Pull your firing pin or if a shroud mounted safety ie winchester put on safe. Also remove the ejector plunger and spring for a case only feel and not that spring induced feel from the above parts.
The best video I know of explaining the above process

Great info in the video, and looks very repeatable, but he doesn't say if he's using a standard FL sizing die, or a body die? I have the first of course, but don't know anything about the second. I guess this technique would work with either, with the difference being the FL die will also resize the neck...? So, is one preferable over the other?

 

[Mram10us]

"What is wrong with this idea?"

Everything...

But mostly, fired cases are never the length of a sizing die, so cutting 2 thou off of a die does NOT get you a case that is 2 thou shorter than your fired cases - they don't even match each other from the same rifle, so modifing a die gets you no where fast, and now you have a die that is too short.

I am confused why say this idea doesn't work. Trim the top of the shell holder or bottom of the die, either way it allows the case to be more compressed, assuming they are touching in the beginning. What am I missing?

 

[Capt RB]

Great info in the video, and looks very repeatable, but he doesn't say if he's using a standard FL sizing die, or a body die? I have the first of course, but don't know anything about the second. I guess this technique would work with either, with the difference being the FL die will also resize the neck...? So, is one preferable over the other?

The die doesn't have a stem so it is a body die. He said this in a 1,3 word sentence. If you're like me if the first or second word isn't tuna, marlin, striped bass or eels I'll miss it lol.

 

[jimirwin]

I'm new to reloading and would like some advice on shoulder bumping. What I'm noticing is that on the first pass through my FL sizing die the case lengthens of course, and after a couple more strokes the shoulder is back about a half of a thousandth (or not at all), and sometimes further passes will get me about 0.0015 or maybe 0.002, which is what I'm trying to obtain. Adjusting the die less than a tenth of a turn deeper gets me too far, sometimes 0.0035 or more. I can't seem to find the middle ground that gets me 1.2-2 thousandths on the first pass. First time the ram comes down (full stroke) there is a gap between the die and shell holder about the size of a sheet of paper, and second or third the die touches. With no case, the die touches. Appropriate "cam-over" at the end of the stroke. I attribute what I'm seeing to some slop in the press, not sure if I should change anything.

What would you do? Does it sound like I need to work on getting better adjustment or is this acceptable technique?

Equipment:
RCBS Summit press, bolted solidly
RCBS FL sizing dies & shellholder
Measuring shoulder with Larry Willis digital headspace gauge (confirmed my technique with them, measurements are consistent and repeatable)
Norma 6.5 Creedmoor brass, once fired, deprimed and cleaned, lubed

I have some possibly heretical thoughts on these matters.
1. Why are you FL sizing fired brass? It will never fit your chamber better than after it is fired with a normal load. New brass comes typically at or about SAAMI spec dimensions, so should feed into any normal SAAMI spec chamber. This means it will be undersize for your chamber, unless distorted thru handling damage.
2. In my specialized accuracy and precision quests, I've found that using as fired brass is best, followed by neck sizing only. Then sizing only about 2/3 of the neck length.
3. I hypothesize that a best condition for accuracy and precision is to have all sizing take place upon loading the round. All snug and stationary for the shot. We are talking best case for long range shooting, yes? Not for tactical or rapid fire run & gun.
4. So a bit of force required at receiver lock-up seems :best: eh?

Jim Irwin

 

[30BR]

I'm new to reloading and would like some advice on shoulder bumping.

Take the worlds biggest shortcut and watch these videos.

Videos | wheeleraccuracy

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They will save you years of tinkering.

 

[CatShooter]

I am confused why say this idea doesn't work. Trim the top of the shell holder or bottom of the die, either way it allows the case to be more compressed, assuming they are touching in the beginning. What am I missing?

Why are you grinding 2 thou from the bottom of the die - what do you expect to accomplish with that?

 

[Capt RB]

I could determine the amount of bump if Redding would publish the amount of cam over for the Redding turret press. I can measure bump on all of my Herter presses because my Herter presses are cam over presses. My cases do not have head space; my cases have 'length' from the datum to the case head.

Before the Redding Competition shell holder a reloader could have used a feeler gage to set the die up; problem, it was impossible to convince a reloader it was possible. And then there was Skip's shims and grinding on the bottom of the die and top of the shell holder to compensate for reloaders did not understand.

F. Guffey

My grandfather made the dies I use in 222 30/06 and 22-250(still a wildcat back then) The 2 03a3s have Douglas barrels that were cut with his reamer. I couldn't tell you how much they move the brass. All 4 rifles are at my dad's. I can shoot anyone of them as well or better than just about everything I have ever shot outside the ppc. The common thing is that they make very straight ammo and all need to be neck turned to use properly something I'm trying (unsuccessfully) to reduce.
If you cerrosafe your die you will have within .0015 of the dimesion. You are better off getting a body die vs trying to use a Fl die or getting a custom die from Forstner on a budget or Warner if you want top shelf

 

[jimbires]

Great info in the video, and looks very repeatable, but he doesn't say if he's using a standard FL sizing die, or a body die? I have the first of course, but don't know anything about the second. I guess this technique would work with either, with the difference being the FL die will also resize the neck...? So, is one preferable over the other?

using the competition shellholder set , it doesn't matter if it's a full length , or body die . the shellholder will make firm contact with the die . then you choose the correct shellholder for the bump , or shoulder set back , or whatever you want to call it . yes , this is a very repeatable way to size your brass .

 

[SCSCHNUR]

Great info in the video, and looks very repeatable, but he doesn't say if he's using a standard FL sizing die, or a body die? I have the first of course, but don't know anything about the second. I guess this technique would work with either, with the difference being the FL die will also resize the neck...? So, is one preferable over the other?

When you resize you must use redding shell holder and place that in you competition shell holder case as each companies shell holders have different thicknesses at the base that way you get the repeatable settings.

 

[CatShooter]

When you resize you must use redding shell holder and place that in you competition shell holder case as each companies shell holders have different thicknesses at the base that way you get the repeatable settings.

ALL companies make their shell holders to the accepted standard of 0.125"... if you have one that is not, return it to the maker for a replacement.