300 Winchester Magnum reloading question

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Here's What Makes Belted Calibers Different ....

Facts About Belted Magnum Handloads:​

1.) Factory loads ALWAYS headspace on the belt.

2.) Handloads MUST headspace on the shoulder.

3.) Shoulder clearance is often over .020" on factory loads.

4.) Belted cases ALWAYS stretch way to far on the very first firing.

5.) Excessive shoulder clearance causes cases to stretch when fired.

6.) Case stretching thins the brass considerably.

7.) Thin brass is weaker and it often bulges during the reloading process.

8.) Case bulges occur just above the belt.

9.) Bulged cases fit tight or will fail to chamber.

10.) Case width can easily be measured with calipers above the belt.

11.) Chamber clearance "at the shoulder" should ALWAYS be minimized.

12.) Obtaining minimum chamber clearance requires measuring.

13.) Accurate measuring requires finding the difference between your handloads and your particular chamber.

14.) Excessive chamber clearance causes headspace separations.

15.) Bulged cases can be saved by using the Belted Magnum Collet Resizing Die.

16.) The chamber clearance for YOUR handloads in YOUR particular chamber is easily measured with the Digital Headspace Gauge.

(It looks like this info will help a lot of shooters out there.)
 
I reload for 6 different belted cartridges and thus far have never had a cartridge fail to chamber because of a bulge above the belt.
 
I've spent 10 years (full time) working directly with thousands of shooters that reload belted magnum calibers, and the vast majority of them are very familiar with bulged cases.

Due to the cumulative effects from reloading cases again and again, this symptom never shows up until the third firing. That's one reason some shooters think everything is OK.
 
Small base dies are not the answer.

Small base dies are the reason I developed the Belted Magnum Collet Resizing Die. They are tighter on the case and often swage the brass rearward as well as inward. To reduce case diameter you need to force the case .100" into the SB die just to reduce diameter by .001" . . . . and when your case stops at the belt . . . . the last bit of case gets a build up of hardened brass above the belt.

Instead of just ironing out the case bulge, they reduce the whole body of the case, and depending on the size of your particular chamber, that usually lengthens the shoulder of your case. Talk about overworking the brass!

Think of it this way . . . .​

Imagine a roll of play dough shaped like a belted magnum shell casing. Now roll it to a much smaller diameter, and you'll see that the case shoulder has grown. You're overworking the brass, and in most cases you'll soon see headspace separations.

In 1998 I made several prototype small base dies, and the best was the one that used a collet to reduce case diameter, because it only reduces the case bulge. The top of this die is also a case width gauge to show when the "extra" resizing is needed, and this die isn't limited to do just one caliber.
 
Guess what - I am from Punxsutawney Pennsylvania!

I keep going round and round.

I measured EVERYTHING.

Compared the blueprint of the round to the reloaded round to the factory load and the only place I could find a difference was .001 in the extractor grove - which probably tells me that it was manufactured that way and that .001 one way or the other in the depth of the extractor grove is an allowable tolerance.

Clearfield PA is such a hick town that they have a Walmart Distribution center - not 5 miles away in Woodland PA 6023 and they have a Super Center Walmart that has a whole shelf full of reloading components - including dies for every make, model and caliber of rifle. You never seen so much stuff.

Grice Wholesale is such a large company - they provide a significant amount of Remington / Browning / Winchester firearms to the east coast of the USA.
I have seen 54' long trailers, packed top to bottom, front to back with Remington on the side and I have seen them unload the whole truck in the back door at one time.
If it is made - they usually have it on the shelf.
If you ask for it and they don't have it - they will get it for you.
If they open up their catalog and tell you - it isn't available - then it isn't a cataloged item.
At the very worst - they can't get it and if they did get it - they would be forced to take back the die's that they sold me and exchange them for the small base die's - which they would not like to do - since most gun shops works on profit and anytime they have to send something back - they loose money.

I can see a wipe mark on the brass where the die stopped - right above the belt.
But there is no bulge there.
The first set of die's I bought felt gritty and left small scratches in the brass and I sent them back.
The second set failed to resize properly and the third was no better.

Dad had two comments - first was that the .300 Winchester Magnum hogged up a lot more powder compared to a 30-06 - almost 50% more.
The second was that he said that case life was about 3 reloads before they would fail due to the fact that the brass was worked when you tried to reload it.

Most times with a 30-06, if the shells were all fired from the same rifle - you could full length resize the first time and trim to length and after that - you could just neck them and maybe get 6 to 8 reloads out of one shell, but not the .300 Winchester Magnum.

The purpose of small base dies' as others has said is to compensate for the lack of camming power that a bolt action rifle exerts on the shell and forces it into the chamber.
The pump action rifle - since there is no bolt handle - doesn't have the necessary amount of force needed to push the round the last couple of thousandths and make the round fit in the chamber..

My dad assured me that they were all trimmed to length, polished before they were decapped, he took the ram right down to the shell holder and couldn't get the die to resize the entire shell. I don't think that the belt is the problem - because I chucked one up in a lathe and removed a couple of thousandths off one and it did not make any difference when I went to chamber it. Plus the die can't resize the belt - it would be nearly impossible to do.
There is no dents in the shoulder - which would indicate too much case lube.
We tried using graphite inside of the neck to reduce drag when the resizing die traveled over the brass - didn't make any difference.
We tried polishing the brass - didn't make any difference.
We tried different over all length for the shell - bullet placement in the shell - didn't make any difference.

Its got to be that last little bit of brass that the die can't reach - just before the belt.
Thanks
 
You're getting closer ....

Daniel .......

You're right that the belt is clearly not the problem. Your problem is excessive case diameter about .060" above the belt. New belted case measure .507" in this area. You can measure this with the wide part of the blade of an ordinary set of calipers. What do your problem cases measure there?
 
Daniel B:

I'm running 9 reloads on a current batch of WW 300 WinMag brass so far using only "standard" FL-sizing dies. Now I'm not eeking out the last centilla of pressure, to be sure, and the neck does tend to work-harden in that cartridge so I did aneal the neck/shoulders at #6, ...but that was it.

You mentioned that the resized shells did seem to fall into the chamber cleanly ('sewer pipe' I think you said) but had problems in getting the bolt/extractor to go home against/over the rim. Any chance in seeing how things will lock up without the extractor installed?

Any chance to get a measurement 'just' above the belt to see if it's really grown there?


POST SCRIPT: What brand brass are you running?
 
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Saying that belted brass will only last 3 reloads is poppycock. I load for a .300 WM and two .338 WM Ruger 77's. When I first started, I used the traditional method of die adjustment and yes....had head separations within 4 firings. I then learned to set my dies so the case headspaces on the shoulder, and now get 10 to 15 loadings from each case.

Since you are a machinist, you can modify a cheap shell holder by facing off a few thousandths and find out if your dies are not sizing enough.........but I doubt that is the problem.
 
454PB .........

Your belted cases can get bulged in as little as 3 firings. It depends on the size of your particular chamber vs. the size of your particular die and how you set it.

However, shaving the top off your shell holder is definitely no solution! That will just push the case shoulder back even farther, ensuring that your case will stretch even more when it's fired. That stretches your cases (at each firing) until the brass is paper thin. You'll soon be getting more headspace separations.

Setting your die height accurately requires "measuring" the right things . . . . and using the right equipment. For that I recommend the Digital Headspace Gauge.

At the very least, measure your case width .060" above the belt, and stop guessing where the problem is.
 
Flex of a Lee Press During Full Length Resizing- Die Adjustment Needed.

The problem I believe is that the shoulder has moved forward.We were using a Lee reloading press,
Click to expand...
Full Length die adjustment

When using our full length sizing dies (RCBS or LEE, no difference) for rifle cartridges, the die should be turned in to touch the shell holder and then enough more that there is no daylight between the top of the shell holder and the bottom of the die during the sizing process. This is the preferred method because the act of sizing sometimes results in flex that prevents the shell holder from touching the bottom of the die.
Click to expand...
 
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You missed the point!

I am not saying a small base die is the answer. I am simply stating they are made. Don't like seeing false information that some people may believe.
 
Daniel,

This trouble is usually caused by a full length sizing die not being screwed down deep enough in the press. When a case is sized the body of the case is sized to a smaller diameter causing the shoulder to move forward far enough the cause the case to become longer than the chamber. This causes the case not being able to chamber and the bolt to close. The die should be screwed deeper in the press 1/4 of a turn and the sized cased tried in the rifle. I suggest this be done until the bolt almost closes without effort and will close with just a little feel. Your cases life will be reduced with full length sizing. I'm a strong believer in the use of neck sizing a case. RCBS makes a neck sizing die for the .300 Win. Mag. The life span of your cases will be much longer if you neck size your cases.
 
Measure case diameter above the belt ....

When reloading belted magnum calibers, if you don't know how to set your die height accurately, then neck sizing is better.

However, if you FL resize accurately, you'll never need to guess about chamber clearance or case life.
 
Theoretically, a FL belted magnum sizing die will limit brass travel into the die by touching the machined recess for the belt, or the shell holder will prevent further sizing. If you have a defective (too long) die, nothing you do will size the cases enough to fit YOUR chamber. We know your chamber is not the culprit because factory loads chamber fine.

My suggestion to face off a shell holder will test the sizing die and tell you if you have a defective die. Once you know, if the die is NOT the problem, throw away the shell holder.....they are a lot cheaper than the FL sizing die or a small base die.

For the cost of a $6 shell holder, you can eliminate a lot of conjecture and questions.
 
Bob - you are absolutely right - but in this case - we tried all of that.

The diameter of the body of the shell is .511 back by the belt and .5175 up next to the shoulder..

My brother stopped at Cabela's a couple of months ago and bought me a brand new Sierra Rifle and Handgun reloading data book and a brand new Precisioneered Handloading DVD...

The book says the body of the shell should be .513

You just don't walk into the door of the Cabela's and ask for a set of small base 300 Winchester Magnum die's.

The other thing is - Calipers are only used in a machine shop for comparison - inspection and not for actual measuring. Although my Mitutoyo and Starrett calipers - digital with SPC are pretty accurate - they are not accurate enough to rely on solely for measurements for final inspection.

My Brown and Sharpe micrometers are set using a standard - which is very precision.
Calipers are like bore sighting - good enough to get you on the paper - but not really the final word when it comes to a measuring device. Even the way you hold it or the way you close it or how you handle it or how you store it has a direct bearing as to how it measures.
 
With RCBS - you can take back any component for any reason and they will replace it free of charge - no questions asked.
Even abuse isn't a good enough reason for them to refuse to replace anything they make for reloading.
 
Daniel ......

If your measurements are accurate, most of us could see that problem from 6 feet away - no calipers needed.

You need to be able to read (and believe) what your calipers are showing.

.
 
chamber is oval shaped or the bolt face is not square?

If u try to put a fired factory round back in after u shoot and eject the case is it hard to close the bolt and the round won't eject again?
If so, the chamber is oval shaped or the bolt face is not square to the chamber. Put a mark (index mark) on the case head of a factory round, fire it, extract, try to put back into chamber with the index mark at the same position. What happens? :confused:
 
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so right now, I only have a Lee FL sizer die, and I need to order a Neck only sizing die. I only use 300 Win Mag for my R700 XCR Long Range Tactical rifle 26". I use a Lee Turret Classic press, which neck/Collet sizer die should order?
 
Just ahead of the shoulder - the spot on your print where it says R102 [R2.59
The diameter of the shell is .5175

On the other end where the belt is - the micrometer reads .511

The middle of the body of the case reads .513

The contricity is less then .0005 (90*) (180*) (270*)

The contricity of the thickness of the brass at the neck is less then .0005 (360*)

The shell is not oval.

If you look at the picture I took - you will see a rub mark slightly ahead of the belt that goes about 1/2 inch up the case on one side only - about the thickness of a marker.

After putting the shell in - with the marker on the case and jacking the shell in and out a couple of times - it will go in and chamber and eject.

Since the print only shows one diameter from front to back - that leads me to believe that the diameter is wrong at the front of the case and is a little shy in the back.

So that must all go back to the people who said that when you shoot a brand new factory round that the brass expands and pulls away from the rear and is shoved towards the front and that is the reason why the case separates from the area just above the belt and also the reason why the brass gets weak there and bulges at that point.

So the question is - since the brass really can't expand past the limits of the chamber and the die should resize it back to the same as it is near the belt - why is the front of the case expanding and why isn't the die resizing it back to OEM.

Like I said - this is the 3rd set of dies.
The first two being brand new and the third set being used - a trade in at the local gun shop.
I didn't even know that they were used until I got them home and found that someone had used a pair of pliers on the locking nut and had messed up the knurl on the nut and thumb adjustment.
But in theory - if they worked for someone else - then they should have worked for me too.
But if they did not work for someone else - then that is the reason why they did not work for me.
I never knew RCBS to make junk and their quality control is quite high in my opinion.

I'm just real frustrated - because it doesn't make much sense to reload shells if they don't fit and give me problems.
The other thing is - if there was something wrong with my dies, then why does the reloaded shells that I bought have the same dimensions and fit the same way as my reloaded shells and not feed or chamber in the rifle.

By chamber - I mean that if the slide does not travel completely until it locks up the bolt - then the trigger will not pull.
A bolt action rifle - if the bolt closes the trigger will always pull - right?
 
Just ahead of the shoulder - the spot on your print where it says R102 [R2.59
The diameter of the shell is .5175
Click to expand...

Something's not quite right here. the Diameter at the shoulder/"R102" point has to be ~0.489" (The case is tapered from the base measurement starting at 0.513" ahead of belt.) The middle of the case should therefore have a diameter about midway between 0.513" and 0.489" (say, ~0.500")

...see a rub mark slightly ahead of the belt that goes about 1/2 inch up the case on one side...
Click to expand...
That doesn't surprise me as that's where the case rides on the bottom edge of the chamber entrance.
 
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I've spent 10 years (full time) working directly with thousands of shooters that reload belted magnum calibers, and the vast majority of them are very familiar with bulged cases.

Due to the cumulative effects from reloading cases again and again, this symptom never shows up until the third firing. That's one reason some shooters think everything is OK.
Click to expand...

Are we throwing credentials around? I've been reloading for going on 50 years, designed cartridges and copper jacketed bonded core bullets, selling both, my cartridges/bullets as components and new factory ammo.

I not only sold my new ammo, but i also sold well over 100,000 reloads, many of them belted magnums... (i could go on, but i think you get the picture)

AND, although i may be familiar with bulged cases, that doesn't mean it's been a big problem, because it hasn't been.

When i custom loaded ammo for someone, i asked that they brought their gun by, and i checked it over, including the sized cases for fit to that firearms chamber. That's why the something over 100 thou number is so low, i didn't try to mass produce "reloaded" rifle ammo.

I agree with most of your list, just not all of it.

DM

BTW, i started loading belted magnums in the 60's, and it was a 300 Win. Mag....
 
I'm not trying to ruffle any feathers here . . . .

. . . . just trying to help out a fellow shooter.

Send me one of your bad cases, and one of your fired cases, and I'll email you a detailed report.
 
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