I may need to measure the shoulder set back on my 300 Weatherby cases.

But how best to do it?

I have a Sinclair comparator set but they don't work right. A call to Sinclair / Brownells resulting in them saying it is a double radius shoulder and we don't have a comparator insert for or like that. Hmmmmmm ok. So how would I use the S die?

I hadn't loaded for my 300 Weatherby which is a Winchester Model 70. For years I always used Weatherby factory ammo in it. But I ordered a set of Redding dies, the competition micrometer seater, the S bushing dies and some new Weatherby brass cases to shoot it more.

I checked the new cases and fully prepped them. It was probably the easiest loading I have ever done. I loaded them with 7828 and Nosler Accubonds with Fed 215 primers and went out to the range. Eureka! They shot to about a half inch group and I was right away in the range of Weatherby factory velocities. Some Norma MRP loads were good too. I was kicking myself for not hand loading for this rifle years ago.

Afterwards I got to comparing the new case loading notes with the once fired brass. There is a lot of case growth in these cases. I set everything up and FL sized some of the now once fired brass with the carbide insert in the FL die and the run out was almost zero. Hey , I am on the way. I did try the once fired and now FL sized cases in the rifle and they feed and extract ok.

But I was bothered by the mid case dimensions growth of about +0.003 diameter or so and the growth of the case directly above the belt of 0.002 inch to about 0.512 which remained after the FL sizing. I have seen this before in magnums but I thought I'd see if I could size the case back in the range of the new unfired size. It appears that I can not size these that small. The neck od and id and shoulder od dimensions are spot on though.

I now set the FL die back up and ran the cases in the press another 1/8th. Then another 1/8th for a 1/4 of a turn then up to a 1/2 turn deeper with no measurable changes in the case. So I pulled the S die apart and just used it as a body die and again nothing. I grabbed the competition shell holder set and gave it a try to see if it changed things.

Somewhere in there I thought I would see what the shoulder set back is, before I got too far, but the comparator readings don't make much sense as they aren't made for the Weatherby cases.

One thing I did do was try the magnum collet die on the base above the belt. I have had the die in the cabinet at least 10 years and only tried it once before to no effect. Here it did work as the 0.512 above the belt measured cases wouldn't go into the dies case gauge. But putting the collet on the case, extra Imperial lube, and running them in the Ultra Mag press resulted in the cases being about 0.510 and going in the gauge.

Im not likely to use the reloads hunting, although the hand loads in the new cases are certainly an option. But Id like to get 2 more loadings from the Weatherby brass for just range and target use. So Id like to have a better idea about the shoulder bump to set everything up.

How do y'all do it? Thanks for your inputs.

It was all going too easy.

Then the Reloading Murphy stepped in for a visit.

I bet I had about 2 to 2.5 hours total in setting up and fully match prepping 40 new cases and loading them.

Then in 45 minutes of range time I had little holes in the center of the target and velocity differences of 1 - 5 fps shot to shot. I figured I had this one in the bag.

Now I have about 2 days of trying to get from once fired cases to resized once fired cases and ready to fire again cartridges.

The reload bench gives . . and it takes away.

You might be overthinking this, potentially overworking the brass thus shortening case life and making unnecessary work for yourself.
The case expansion you describe is probably just natural brass movement to fit chamber dimensions and therefore just fine at that. Case growth lengthways is restricted with the FL die to enable reloads to chamber easily.
I shoot a .300 Win Mag and started with new Norma brass. For the first couple of loads I FL sized only down to the base of the neck ( start with the die positioned high and look for a "ring" mark on the case neck. Keep turning the die down in 1/4 turns until the "ring" meets the neck base. Relube the case each time before running into the die again ). This will get you another one or two reloads until the case grows and the shoulder is hard against the end of the chamber. At that stage after firing the shot let the case cool then chamber the case again. If it feels tight you know the shoulder needs bumping back slightly. When next FL sizing cases have your rifle on the bench. Turn the die down 1/4 turn again, size a lubed case, clean the sized case and chamber in your rifle. If still tight turn the die down another 1/4 turn and repeat the process. When you can chamber the case with just a hint of, or no tightness, you have probably bumped the shoulder back all you need to. Tighten the die lock ring and you should be good to go for all future sizing.
This is the method I use. It works for me and my .300 Win Mag. Others may disagree or have their own take on the best approach. I use Redding dies too - they're the best I reckon. The competition micrometer seater is just the bees knees for minimal runout.
If I understand your post correctly it sounds like you have already nailed a fantastic load.

Seeing as though your rifle is a Model 70, what you should do is take the bolt apart, remove the firing pin assembly, then size a case and let the bolt handle fall, keep sizing by adjusting the die in 1/12th increments.
When the bolt almost falls closed, stop, this will be the amount of bump allowing good chambering and good brass life.

I used my comparator on Weatherby cases, you need the .420 insert on Weatherby’s, it just kisses below the upper radius, which is just enough to tell you how much you’re moving the shoulder.

Cheers.

1. The diameter of the fired case at any point above the web is a reflection of the size of your chamber, minus brass springback.

2. Why would you want to resize the body of your brass significantly smaller than the size of your chamber?

3. As 416Rigby indicates, bump the shoulder back only enough to allow easy chambering. Any more simply represents additional and unnecessary work-hardening of the brass.

4. Why wouldn't you hunt with reloaded ammunition? If you are that unsure of your reloading skills then why reload at all?

5. If you don't get more than two reloadings from a case then your pressures are significantly too high. Sustainable pressures should allow you to get many more uses of a single case than just two or three.

Yes you are definitely overthinking this; two or 3 thousandths is nothing in chamber/brass/ammo tolerances.
Do what 416 said; use your rifle as the gauge; there is no other substitute as no gauge will ever have your exact chamber shape or dimensions.
Just make the bolt close with a slight "feel", and there you are. Ignore any OD measurements, unless the brass won't chamber then you have another problem. It is amazing that our dies and rifles work at all because the tolerances are huge. Relatively. Several times .002; you get the picture.

what they are saying is stop killing your cases with the size dies.
get them to fit your rifle and chamber smoothly that's all the sizing they need.
[sizing them more makes them longer and weaker, and then you have to trim the cases]

just sizing the neck is plenty for the second firing.

Thanks guys. I have loaded a lot of magnums - just not for the Weatherby calibers or Weatherby cases.

From what I can tell I probably set that shoulder back 0.005 or so. I scratched around and found a comparator that would semi fit the case, a 416 that I had after it was recommended.

Yes the load is right on really for this rifle. I wasn't trying too hard and just broke the shots to get velocity data, and was concentrating on that more than ultimate accuracy, and they were shooting tight. As I said some of the shot to shot velocities were 1 fps and they cut the previous shots entry hole. Can't ask for more at full house Weatherby velocities.

One reason I was chasing it some on the case sizing, was that the rifle shot so good with the new brass case sizing. That was FL sized as new of course too prior to loading. So why not see if I can't approach that again. As it is, the fired and FL sized brass chambers and ejects ok.

Since I have had the Redding S bushing dies, I have used those in conjunction with the Competition seater with very good results with fired cases. The ammo for most of them shoots about as good as I do. Some days are better than others. With the S die I needed a way to check the bump too.

I have not had good success with neck dies except in target style rifles with more precision chambers. And again, while it is personal preference, I only trim brass twice. I havent had any case separations that way.

I wasn't too concerned about the case belt area. Ive seen it before. But I had never actually tried the collet die other than just curiosity. Its ok. I might use it at a later time. Or not.

Beings that my hand loaded velocity spreads were better and more consistent than the Weatherby factory ammo, I am liking that for the actual hunting rounds. But FWIW all of the hunting rounds I make up for any of my rifles are in new brass every time. Whether that is in 223 or 416, and for use 15 miles away or 15,000 miles away. It is personal preference and it works. Also, since I am running these Weatherby loads up in the velocity range, I don't expect all that long of case life and I hate annealing brass.

I am going to try some both FL sized, and some resized with the S die, and see if there is a difference.

Now - - - where did I put those once fired brass from the Weatherby factory loads shot in this rifle?

Thanks again for all the help and inputs guys.

I agree with the method most have said here, turning the resizing die down in small increments until the case chambers with a slight snug feel to the bolt i.e. headspacing on the shoulder and not the belt, as perfect a fit to the chamber as you can get with your particular die.
I used this process for years when reloading for my 7x61S&H, a belted case not truly double radiused like the Weatherbys but visually difficult to say it wasn't double radiused. The only thing I would add is that I found that when adjusting the FL die down in small increments it was better to use a different unsized case for each increment adjustment as if just using the same case the spring of the press and leverage system was not accounted for and once it seemed all was good and the die locked, the next unsized case that was sized was still a bit tight to chamber i.e. sizing in increments is easier on the press than sizing in one pass.
This may depend on the reloading press of course as to the degree of spring in the frame and the leverage system, mine is a Pacific C press but I did learn a valuable lesson.

Very annoying if you go ahead and resize and load a batch of cartridges only to find after all your careful incremental die adjustments the damn cartridges that are sized in one pass are a little tight to chamber

Thanks eagle.

And yes, I have had that happen before that it was just a wee bit large. Uggggh. Using that Redding Ultra Mag press it is enough leverage to lean it on it some.

It is due to the fact that brass is a very ductile, but also has some spring to it, and it varies case to case, lot to lot, brand to brand, age to age, you get the point. Not from your press.
Just make sure it all fits your chamber. Chasing the last .001 is futile.