help with full length sizing/shoulder bump

[1KPerDay]

I'm trying to get the proper setting on my lee FL sizing die where I'm not working the brass too much, or allowing for too much headspace, while still getting proper fit. I'm sizing HXP and some 50's era M2 U.S. surplus brass for garands as well as 1903s; I know to maximize case life I should ideally keep the brass separate for the bolt guns and maybe just neck size them until they need a shoulder bump, but for the sake of my sanity for now I'm just processing them all together and loading for the common denominator (the Garands).

So here's my question: Using the Wilson case length/headspace gauge as the measurement for the "correct" amount of shoulder bump, I've had to back the die off of the shell plate and it's still setting back the shoulder to the "deep"/minimum shelf of the case gauge, or maybe a couple thousandths too much.

The Lee instructions say to turn in the die to shellplate contact, then another 1/4 to 1/3 turn. Doing this results in bumping the shoulder back too far.

Is there any danger with me backing the sizing die out so it's not even contacting the shell plate? Assuming the brass then gauges properly?

Just wanted to check.

 

[dmazur]

There are some assumptions involved. You'd like to find that both the 1903s and Garands have "normal" chamber headspace, which is what you're trying to resize for, and that some point between the Wilson gauge steps is the target resized length that will be an acceptable compromise for use in any rifle.

Many Garand shooters recommend resizing to SAAMI minimum, which is the bottom step on the Wilson gauge. This may result is slightly less brass life, but makes reliable chambering more certain, which is what is wanted when reloading for semi-auto gas rifles.

However, a check of resized vs. fired case dimension to datum with a gauge will help verify that you are not over-resizing. I believe 0.006" is a good number to use. If the difference is much larger than that, you could possibly experience case head separations. If the difference is much smaller, you can have chambering problems including OOB firing.

While it is possible to use the tail end of a caliper to measure differences in the dimension to datum on a Wilson cartridge headspace gauge, there are better tools available to do this (like the Hornady pattern.)

One of the Garands may be 0.006" less than chamber headspace when the case is resized to the top step of the Wilson gauge...

Another thing that can be done is to borrow a GO/NOGO gauge pair from someone at a Garand match and verify that your Garands have chamber headspace that is within SAAMI spec. In other words, the stripped bolt should close on a GO gauge, but not close on a NOGO gauge. I believe these two gauges usually differ by 0.006".

Then there is the 1903s' headspace dimensions, which may not agree with the Garands'. The difference may affect your decision to use the same reloaded ammunition in either type of rifle. For example, a particular 1903 could have headspace a few thousandth's larger than a Garand, which might be at SAAMI maximum already. Then you're looking at 0.009" difference for cases resized to the bottom step of the Wilson gauge, and that's a little bit more than desired. Case life will be short and case head separations more likely.

As far as the die setup goes, 1/4 turn is 0.018" and is generally considered a guideline to handle press flex. Fine adjustments much smaller than 1/4 turn are necessary when chasing GO/NOGO dimensions that differ by only 0.006".

Finally, while this problem can be discussed in general terms, I'm not sure if the "is it safe" question can be answered without knowing the headspace of each rifle.

From my own experience, I had 4 rifles (all in .30-06) that I wanted to be able to shoot the same reloaded ammunition. Three rifles were within SAAMI spec and cooperated, but the fourth had excessive headspace. I had to segregate my brass until I finally solved the problem by having the rifle rebuilt. Now the headspace measurements of all four agree within 0.002" so I feel more comfortable with using my .30-06 reloads in any.

With military surplus rifles of uncertain history, I wouldn't go very far down the road of assuming they have similar headspace...

 

[hvychev77]

at one time i was curious about the same issue here. what i did was found some of my brass that had been once or twice fired that wouldn't chamber in my bolt action. What i did was back the die out until there was a significant gap between die and shell plate. then i started to full length size and then try it in my gun, if it didn't fit i turned the die in a quarter of a turn or maybe a little less. I did this until the brass chambered. I had several pieces of brass that wouldn't chamber and once i got the die set correctly, all of them chambered. I want to say that mine is just kissin' the shell plate. I'm not going to say that is the correct way, but, someone on here i think recommended it to me and it worked and i know it's not overworking my brass.....

 

[Walkalong]

The Lee instructions say to turn in the die to shellplate contact, then another 1/4 to 1/3 turn. Doing this results in bumping the shoulder back too far.

Is there any danger with me backing the sizing die out so it's not even contacting the shell plate? Assuming the brass then gauges properly?

No danger at all, but as dmazur posted, if you want to size the minimum for your gun, you need to know where the shoulder is when fired in the guns. When sizing to fit a case gauge you are ensuring the brass is safe with any properly headspaced rifle, but it could still be sizing more than needed.

Since you are sizing to fit multiple rifles you need to size to fit all of them. That might mean that for on gun the shoulder is being pushed back .001/.002, while for another it is .002/.003 and yet another .003/.004.

.006 is the max you want to go. Hopefully this will not be a problem. If it is, you have one really tight chamber (headspace wise, not necessarily diameter wise) or one really big chamber, again, headspace wise.

You need brass fired with full loads from each gun so you can measure where the shoulder is with whatever device you choose to use.

This thread may give you some ideas on that.

If your chamber vary widely, you may be forced to separate brass, or size a little more than you really wanted, but in the end that is not a real big deal.

Personally, I would be inclined to size to fit the gauge for the auto's, and size minimally for the bolt guns. Only two batches that way as well.

 

[fguffey]

oneKperday, bad habits are int easy to overcome, the threads on a die is 14 per inch, if a reloader could make a wild guesstimate of a turn of 1/4 turn without an index the gap would be .017 plus a little, if the reloaser could make a wild guesstimate of a turn of 1/8 turn the gap would be .0088plus a little, back to bad habits and hard headed, why make the wild guesstimate of a turn if he/she can confirm the adjustment with the feeler gage? Why not go straight to the feeler gage and skip the wild guess?

rational? If the wild guess does little or nothing to solve the sizing problem, where does the reloader go from there, do they make another wild guess, and that is the part about being hard headed, skip the wild guessing and use a feeler gage, the companion tool to the press, the feeler gage, it is a transfer, a standard and a tool that can be used to verify adjustments, or?

1/4 turn = .017 thousands when backing the die off the shell holder, on a 30/06 that is equal to a field (reject) length chamber +.004, backing the die off 1/8 turn is equal to a chamber that is no-go gage length lacking .0002 thousands, again, I form/size cases from .017 thousands shorter than a go-gage length chamber (short chamber) to infinity, (a very long chamber) or a more practical .016 thousands longer than a minimum length/full length sized chamber with nothing more than a good press, RCBS shell holder, die and feeler gage, I am not a fan of head space gages, they do not fit my chambers, the head space gage always chambers and fits like my shirt, only where it touches, I check head space in thousands, I transfer the measurement from the chamber to the press, die and shell holder, I form first then fire. Others fire first then try to make sense of what happened, and then it gets expensive, they surround them self with tools, expensive tools, tools are nice, but? not always necessary.

My press has threads, my dies have threads, that makes my press, when sizing adjustable, I could make wild guesses, I choose to use the feeler gage, again, I have one rifle with .016 thousands head space, the rifle is 93 years old, it was made that way, it was/is not the only one.

F. Guffey

 

[1KPerDay]

I don't think I'm smart enough to understand any of this.

Basically...

1. if I size to the "long" end of the gauge range, I'm theoretically working the brass less but it may cause chambering problems in one or more rifles, particularly the Garands...
2. If I size to the "sort"/min end of the gauge range, I have a theoretically better chance of having reliable brass in all rifles but may shorten case life/cause case head seps if not carefully watched, right?

I suppose what makes sense is to (from now on) keep brass separate for all rifles.

Unless the rifles all happen to have similar headspace which is highly unlikely.

Maybe I should just stick with reloading for handguns....

 

[murf]

no, you should make a decision to either fully size all your brass, or have separate lots of brass for each rifle that are sized for each rifle (never confuse the two. always keep them separate).

we don't want you to stop reloading for your rifles. we all enjoy this reloading thing. it is not easy and not for everyone. seems like it is for you, though.

don't give up. we are all here to answer your questions. just be patient.

murf

 

[Walkalong]

I don't think I'm smart enough to understand any of this.

Yes you are, it just seems confusing at first.

1. if I size to the "long" end of the gauge range, I'm theoretically working the brass less but it may cause chambering problems in one or more rifles, particularly the Garands...
2. If I size to the "sort"/min end of the gauge range, I have a theoretically better chance of having reliable brass in all rifles but may shorten case life/cause case head seps if not carefully watched, right?

Basically yes.

I suppose what makes sense is to (from now on) keep brass separate for all rifles.

I suggested sizing to fit the gauge (Not long, not short) for your Garands, and FL sizing minimally to fit your bolt guns. That would keep it to two batches of brass. It would be reliable for the Garands, and still help case life for the bolt guns. I do not have more than one rifle in any caliber (Unlike pistols), but if I did, I would probably size to fit the smaller chamber and call it good if it was a hunting or general plinking rifle. Target grade stuff is a whole nother thing.

 

[Waywatcher]

Hey 1KPerDay,

The fact that you are asking questions is a good sign. I was also intimidated moving from handgun reloading into rifle.

The best solution I found for myself uses the RCBS Precision Mic. My fired brass measures +0.002 in that gauge, and when I resize it, I aim for between -0.001 to -0.002. So I'm bumping the shoulder 0.003 to 0.004 back. This is for my AR. To check my work, I measured some factory new brass and loaded ammo and found that they measured anywhere between 0.000 to -0.002 on my Precision Mic. Being able to quantify the shoulder bump helped me feel confident in my results.

I haven't had any problems, and don't expect any.

 

[bigedp51]

Nothing is written in stone with rifle head space, cartridge head space and reloading die accuracy.

Below is an extreme example but it is a fired .303 British case resting on its shoulder in a Wilson case gauge. You can clearly see the British "military" chamber is much longer than SAAMI standards.



To complicate matters Military 30-06 head space is not measured the same as SAAMI standards and the datum line is different.
Lap is the datum line for the military and the blue line is SAAMI below.

30-06 military head space
1.942 GO
1.944 NO-GO
1.950 Field



On top of this SAAMI listed head space is different than Forster 30-06 head space standards.

SAAMI 30-06 standards
2.0487 Go
2.0587 NO-GO

Forster 30-06 standards
2.049 GO
2.055 NO-GO
2.058 Field.



There is a reason they make different size shell holders and reloading die shims to compensate for the variations in the "variations" of all the reloading variables. As stated above you only need the case to be .001 to .002 smaller than the actual chamber size. Anything larger and you overwork the brass and and increase the chance of case head separations.








I use my die shims on most of the rifles I reload for and I load-shim for each individual rifle.



On some surplus rifles you forget the shims and use thick washers under the lock ring.



And on some rifles you lap the shell holder just to get the cases in the chamber.

 

[ssyoumans]

And on some rifles you lap the shell holder just to get the cases in the chamber.

This is what I had to do for my Marlin XS7 in 243 Win. The bottom of my Lee sizer die was hitting the shell holder before bumping the neck back. I use the Hornady Headspace measuring set and set the reference to be a Once Fired Factory load. My rifle will chamber up to +.0015 compared to it, but I was wanting -.001 relative to it. Had to shave .005 of of my shell holder. As was, I couldn't bump back some once fired brass from a friend's rifle which measured +.0045 to my reference. Guess the Marlin has a tighter chamber? I like the Hornady headspace gauge since it can work for multiple calibers. Seems very repeatable with it's measurements and is much less than buying multiple RCBS headspace precision mics, although I'm sure the RCBS is nice.

 

[Walkalong]

Just remember to keep that shell holder segregated for use with that die. I would mark it -.005 as well. If you remove material from the die, you don't have to worry about that.

 

[USSR]

...found some of my brass that had been once or twice fired that wouldn't chamber in my bolt action. What i did was back the die out until there was a significant gap between die and shell plate. then i started to full length size and then try it in my gun, if it didn't fit i turned the die in a quarter of a turn or maybe a little less. I did this until the brass chambered.

This is a good way to handle it, if you have both a boltgun and an autoloader for the same cartridge and want to be able to share cartridges, as long as the autoloader doesn't have a tight chamber. Otherwise, set up your FL resizer for use in an autoloader by using the RCBS Precision Mic or some other similar tool.

Don

 

[ssyoumans]

Just remember to keep that shell holder segregated for use with that die. I would mark it -.005 as well. If you remove material from the die, you don't have to worry about that.

Yeah, I thought about removing material from the die, but with the limited tools on hand, I felt it would be easier and more consistent to remove from shell holder. I marked it in red, but will go back with -.005 too.

I have another shell holder still, since the size is common with my 45acp.

 

[1KPerDay]

I suggested sizing to fit the gauge (Not long, not short) for your Garands, and FL sizing minimally to fit your bolt guns. That would keep it to two batches of brass.

I neglected to thank you personally and mention that I thought that was a good solution... when you say FL sizing minimally for bolt guns, do you mean FL sizing only when necessary (when the case has grown too long) and primarily neck sizing only for the bolt guns? I have a collet neck sizing die also.

For now I've been resizing to the longish range of the case gauge, and if I get chambering problems in my garands I'll use this batch for the bolt guns only. Does that make sense?

 

[ranger335v]

"The Lee instructions say to turn in the die to shellplate contact, then another 1/4 to 1/3 turn. Doing this results in bumping the shoulder back too far."

Basic die instructions are not precision guides, it's only to make sure noobs can make ammo that will chamber and go 'bang.'


"Is there any danger with me backing the sizing die out so it's not even contacting the shell plate? "

No. If you go too far up you may not be able to chamber the ammo but if you can close the action on it there is no safety issue. TRY the sized cases in your rifle before you complete the loading.


"Assuming the brass then gauges properly?"

A chamber type cartridge gage is virtually meaningless if you're loading for a single rifle because it's not the gage you need to make it fit. You're going to fire it in your rifle so make your ammo fit it.

 

[Walkalong]

when you say FL sizing minimally for bolt guns, do you mean FL sizing only when necessary

No, size to fit the chamber.

Measure where the shoulder is on a fired case (full load, and twice fired is better) with your choice of measuring tool, and bump the shoulder .001 to .003. In reality, as long as you keep the shoulder right where it is you will be OK, since the case will chamber easily at that point.

One thing to consider when trying to size that finely is that dead soft brass will size further than work hardened brass using the same exact sizer position. As your set of cases get work hardened from multiple firings, you will find that the sizer will have to be turned down lower a hair to get the shoulder to the same place if you are really getting a good tight fit to start.

Most folks don't see this because they are not sizing that finely, nor that tight in the chamber.

 

[1KPerDay]

Interesting. I actually wondered about that and if "re-sizing" the same case again before loading/firing would result in a different measurement.

When you say

In reality, as long as you keep the shoulder right where it is you will be OK, since the case will chamber easily at that point.

is there any reason I should set the shoulder back any, in that situation (loading for a bolt gun)? As long as it chambers easily?

 

[Walkalong]

Not really, except for that little margin of error and to be a little more reliable chambering. Cutting it too close can bite you once in a while with a round that is tough to chamber. No good in a match or on a green field.

The first firing doesn't really get the brass to chamber size. Subsequent firings get it really close. If you load and fire one piece of brass and get a measurement, then load it again and shoot it, you will often see the shoulder farther forward this time. Pressure makes a difference as well. More pressure hammers the case against the chamber harder leaving the shoulder farther forward.

I recently fired the same .35 Remington case eight times. I measured where the shoulder was after each firing and after each sizing using my home made tool. It is interesting how the measurements can vary according to the pressure. Not all loads were max as I was working up with different powders.

 

[gamestalker]

No danger what so ever, the worst that can happen is the shoulder won't get bumped back enough and you'll experience chambering issues. However, if the FL die isn't getting enough sizing contact, it is possible that the neck won't get sized far enough down to effect adequate neck tension. If your really wanting to increase case life and don't want to deal with the FL die every time you load, go to neck sizing and then when necessary use the FL die to bump the shoulders back a little.
I use neck dies for all my bolt action bottle neck applications and then bump when necessary with the FL dies. I don't use a case length guage though but rather just bump until the brass will chamber without any resistence.