Sizing for Revolver Accuracy

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  • Last Post 20 January 2017
Eutectic posted this 13 January 2017

 

Shooters seeking small groups have known for decades neck sizing cartridges gives both an accuracy advantage and increased case life. Unfortunately revolver shooters have been mostly unable to benefit from this knowledge. Unless you restrict your loads to one revolver and that revolver has perfectly matched chambers which are perfectly round, neck sizing will not work. Usually you are forced to full length size in a standard die which both overworks the brass case and leaves it loose in the chamber compromising accuracy.

 

Redding has come up with a solution which they claim improves accuracy. It is a dual ring carbide sizing die, in which the lower ring sizes the whole case to maximum dimension and the upper ring sizes the upper case to hold the bullet. This is not quite the same as fire formed, but it does guarantee fit in all chambers and in different guns without excessively sizing the entire case.

 

I have not verified Redding’s claim of improved accuracy, but I see no reason why this should not be true. It may not be a perfect chamber fit, but it is certainly an improvement. Increased case life? Most of my revolver cases fail from mouth cracks, so maybe. The cost for this improvement is around a hundred dollars for the die alone, sets are more. If I were buying a new die set it would be tempting.

 

Unfortunately carbide dies last a looooong time, which at my age is a lifetime. Fortunately there may be a way available and I have it have on the shelf! I use the LEE Factory Crimp die without the crimper as a last step in loading. The Lee Factory Crimp die sizes the case to maximum SAMMI dimension. Can I use it to full length size the case before loadng?

 

The test:

 

I wanted a tough test so I went to the range and picked up some “free range” brass. I quickly had 25 assorted 38 Special cases which would not fit in my S&W M66. Some were swelled 0.012 oversize, and had a prominent bulge at the base. There are some very poorly made revolvers out there!

 

After sizing in the factory crimp die all of the cases chambered easily in the M66. Seating 0.358 wadcutters in the cases required minimal force, and 0.357 jacketed bullets were a slip fit in most cases. Several with thicker walls would have been OK with the jacketed bullets. 

 

This may be the answer to interchangeable ammunition and extended case life Some cases are not sized enough to hold a 0.357 jacketed bullet, so  mouth sizing is required if you size your bullets 0.357 or want to load jacketed bullets. The dimensions are close, so it depends on the make of cases. Another reason to use single head stamp cases. If you have enough places on your progressive loader you can put both the Lee die and a regular die in the tool.

Let us know how this works for you.

 

Steve Hurst

 

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45 2.1 posted this 13 January 2017

You can size the case to slip fit specs with a 38 S&W or 38 Super sizer also, then size for your bullet if your chosen diameter is 0.3585” or less..... otherwise it works fine with 0.360” bullets.

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David Reiss posted this 13 January 2017

The first thing that came to mind when reading Steve's discussion is cost. I know that everyone does not have a range they share with other shooters, but range brass is available for free on nearly every public or private club range I have ever been on. So the natural conclusion is there is a lot of free brass out there. But I also think about the cost of common handgun caliber brass, .380, .38sp, .357mag, 9mm, .40S&W, .45acp and they are also very cheap if buying once fired brass. Also my experience in firing and reloading handgun calibers is probably much more than the average shooter / handloader. I have found that the percentage of failed cartridge brass to be very small. I have nickel cases with most of the nickel plating worn away and are still reloadable. Except for a few wildcat calibers or single shot handguns, I do not keep brass segregated to one specific gun. I do try and keep the same headstamp and lot of 50 or 100 cases together. However I also have large lots of unsorted brass keep together for loading of 500 to 1000 rounds of practice or plinking rounds. I can say in all honesty that I have never notice a greater % of failures for those rounds as compared to segregated brass.

In conclusion I think that spending a $100 or more for a special sizing die to be a waste of money for me. That $100 would buy many years of brass and would basically serve the same purpose. But to me that same $100+ could be better used on powder & primers. I just can't justify buying just such a die when there is so much free brass, even when ammunition costs have went up, shooters just leave those nickels, dimes & quarters lying on the ground or thrown into the garbage can, sometimes placed safely back into their box.

David Reiss - NRA Life Member & PSC Range Member Retired Police Firearms Instructor/Armorer
-Services: Wars Fought, Uprisings Quelled, Bars Emptied, Revolutions Started, Tigers Tamed, Assassinations Plotted, Women Seduced, Governments Run, Gun Appraisals, Lost Treasure Found.
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JeffinNZ posted this 13 January 2017

I'm with David on this.  Whilst I always enjoy seeing innovation in technique and design of tools there is no shortage of free brass.  Interesting none the less however. 

Cheers from New Zealand

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R. Dupraz posted this 13 January 2017

After having bought my first handgun,a nickel S&W 6” m-19 .357  in the early sixties, quite a few revolvers have come and gone since then. As well as a round or two of handloaded ammo. In my opinion, this tool sounds like an expensive solution in need of a problem. 

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Eutectic posted this 16 January 2017

Let us not get off track, I should have focused more on accuracy benefits. If I load wadcutters into cases sized in a normal die and expanded normally they are less accurate. If the cases are +P which are harder brass, the effect is very bad. Very bad means a load I expect to do 2” at 50 yards will go over 6". I think the reason for this is the bullet is sized down by the greatly undersized case. If I pull the bullet, the base band can be 2 to 3 thousandths undersized, often the band above is also undersized. Since I do not have the advantage of a hollow base to assist obturation, I am firing a undersized bullet.

The larger case diameter will help center the case. This probably produced the accuracy gain Redding saw with jacketed loads. The bigger advantage is for cast bullet users, minimally sized cases give less bullet deformation and better accuracy.

Steve

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45 2.1 posted this 16 January 2017

A lot of people neck size revolver cases to get superior accuracy. It's nothing new. In fact, if you have some of the old steel RCBS dies from before '70 you will probably find they sized a two diameter case as Steve is talking about here, I know the 45 Colt was like that.

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R. Dupraz posted this 16 January 2017

"Shooters seeking small groups have known for decades neck sizing cartridges gives both an accuracy advantage....."

 

This is not  universally true. There is and has been an ongoing discussion among-st the jacketed benchrest crowd regarding neck sizing as opposed to FL sizing. And in my own experience with my 30's and cast, some of the smallest groups and best match scores I have  fired have been with full length sized brass. I used to neck size only, but any more, it's full length for everything. In rifles of course. I have yet to lose a case because of a failure. But I do anneal every so often. 

But to the point of your last post.

All being theory at this point, it seems to me that for about 20 bucks or so, this could be proved one way or the other by getting a Lee universal neck expanding die and then replacing the Lee expander button with  an NOE pistol expander button. These come in .001” diameter increments. And then mount the revolver in a Ransom rest attached to a solid base.

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onondaga posted this 17 January 2017

R. Dupraz, you said,

".... by getting a Lee universal neck sizing die"

 

Is that a joke? Lee makes no such tool. Lee Collet Neck Sizing Dies are in specific calibers and have custom mandrels available for non standard chambers, but there is no universal neck sizing anything from Lee. Tell me the Lee name and Lee item number that you say is a universal neck sizing die.

 

 

 

Gary

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R. Dupraz posted this 17 January 2017

Thanks for the correction, What I meant was the Lee universal neck expanding die.

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45 2.1 posted this 17 January 2017

Note that this thread is about revolver accuracy. It does have parallels with straight cased rifle rounds though.

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R. Dupraz posted this 17 January 2017

45 2.1

If there is some misunderstanding about my initial reply. those are pistol neck expanding plugs that NOE makes in various diameters to fit the Lee universal neck expanding die.

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45 2.1 posted this 17 January 2017

No misunderstanding at all. This is what I was responding to:

This is not  universally true. There is and has been an ongoing discussion among-st the jacketed benchrest crowd regarding neck sizing as opposed to FL sizing. And in my own experience with my 30's and cast, some of the smallest groups and best match scores I have  fired have been with full length sized brass. I used to neck size only, but any more, it's full length for everything. In rifles of course. I have yet to lose a case because of a failure. But I do anneal every so often. 

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R. Dupraz posted this 18 January 2017

"Note that this thread is about revolver accuracy. It does have parallels with straight cased rifle rounds though"

 

Simply replying to what Eutectic wrote!.

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dan l posted this 20 January 2017

I wouldn't waste good money on that die for revolvers. Bullet fit is king good reloading practices loads and such. Pistol brass will last along time. Some of my brass has been loaded more times then not.

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