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Old 02-22-2013, 05:46 PM
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Achieving maximum case life 201


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The next thing to be considered is neck turning. Turning necks on 308/7.62 brass in a SAAMI chamber will do little to improve the situation in that the necks will be even smaller and the chances of a bullet being tilted at an angle when the bullet takes the rifling is significantly enhanced.

If you are well equipped you will have several items in your reloading tooling: Feeler gage set, calipers w/ depth probe, micrometer (outside 0-1”) and a tubing micrometer for measuring thickness of case necks, MO Gages or RCBS Precision Mic, L.E. Wilson Case Gage and a case trimmer and neck turner and a good head loop. I prefer L.E. Wilson and have five of them with some pre set and tagged. (223.308,30.06). I also have collet type bullet pullers from L.E. Wilson and RCBS and neck turning tools. My favorite one is no longer in production which was a Marquart. The Marquart case holder in my opinion is the best ever made.

<OFor the mic case gages I prefer the MO Gage for several reasons. They come calibrated in 7.62/308 to zero at 1.630 which you can confirm by inserting a GO GAGE. Thus you can check the headspace on a new case, a FL sized case and a fired case and case length at the same time. As well Mo is a friend who I have shot with since 1973. You can also check your NO GO gages to see where they are and if you happen up on used headspace gages you can check them as well to determine if they are accurate.


OK so much for tooling and gaging and now on to neck turning. LC MATCH 7.62 brass has a neck wall tolerance of .005” per the case drawing which basically means the case neck wall can vary .005” measured at different places around the neck. Think of it this way which is one side of the neck is thicker than the other and when an expander is run it, the thinnest side logically will give way first and overwork that area where the thick side stays the same. Thus to have your case necks uniform thickness is another way to prolong case life.


Also thinking of it this way if the neck is .005” thicker on one side that means the bullet is set up to launch as much as .005” off center and it therefore follows the bullet is going to contact the throat much harder on one side than the other which will deform the bullet. Deformed bullets don’t do good things on the target for you.


Or it’s like trying to run full speed through a door with a narrow opening. One shoulder is very likely to hit a door jam very hard and the other side clear and the pain is going to be felt more by big guys than small guys and they will have clearance on both sides.
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<O</O
Many of you are already neck turning and I am sure have experienced that with the gap set wide you will only turn off the high (or thick) spots at first. I start off setting the neck turner to just contact the high spots and then just ease the gap closer to where more of the thick spot is removed. On my competition rifle cases used for rapid fire etc an examination will reveal between 1/3<SUP>rd</SUP> of the neck was reduced and upwards to ˝ the neck. Thus the offset of the bullet from the bore center line is significantly reduced and the neck wall variation places the bullet much closer to the bore center line.


On my 308 rifles used for slow fire long range the .337” neck dimension 308 reamer is used which requires the necks to be turned 360° to make sure the bullet is as close to dead center of the bore line as I can get it and maintain a safety margin.


Think of it this way, I cut a .337 neck and will be loading a .308 diameter bullet which means a uniform neck thickness is .029 which divided by two will leave me with .0145” thickness with neck touching. I want a little bit of expansion room so I take necks to .014” uniform thickness so .308 + .028= .336” neck thickness of loaded round going forward in a .337” neck.


In 101 I talked about the Humpy GO GAGE made with same reamer the rifle is chambered with for making sure there is no interference going into chamber. When I slide in my .336” diameter loaded round with the neck in the .337” neck the feel leaves no doubt the bullet is going to leave the case and take the rifling as close to dead center as I can make it with no yaw. I have been told the benchrest boys use as little as .0005” clearance but I have not tried this yet.

Cases fired in such necks generally only need to have primers replaced and new bullets will seat without running them through a die at all. Obviously the grip on the bullet is going to be minimal and this will not necessarily work for magazine feeding but should work just fine for long rifle single shot loading.


While you are getting Humpy GO GAGES made make one up with a SAAMI spec reamer and try the .336 loaded round necks in a .345” neck and you are realize immediately the potential for a bullet to mis-align before it moves much giving your bullet a bad case of the Yaw.


As indicated in 101 I run a .339 neck for LC Match ammo which works fine but cleaning up the high spots before reloading it gives loaded rounds that are closer to .337 so only .002” clearance.


Now picture this, you pull the trigger and the pressure starts to build on the base of the soft copper and lead bullet which means the bullet is going to want to expand a tad. Does it not follow that if the neck is large the shape of the bullet is going to change before it takes the rifling?


Ray Steele related to me a theory which he came up with to accurize the Secret Service Pistol Team REVOLVERS which fire 38 wadcutter in competition and he said he used as many bench rest shooter gun building techniques as he could apply. Let me see if I can put it in his words:


You pull trigger, pressure rises into hollow base of wadcutter and expands the bullet before it starts to move as the chambers in the cylinder are much larger than the loaded case diameter.

Before the bullet even moves the case expands to the diameter of the chamber as bullet base is hollow. (First expansion)


As the bullet moves out the front of cylinder it is squeezed back down by front of cylinder. (First compression)


As the bullet crosses the gap between the front of the cylinder and the forcing cone of the barrel it expands again.(2<SUP>nd</SUP> expansion).


Before the bullet hits the 13° forcing cone it is squeezed down yet again. (second compression).


Thus you have expanded and compressed the bullet twice before it takes the rifling.


So he figured if he could have a chamber set up to reduce the expansion/compressions better accuracy would be the result.


He ordered 221 fireball cylinders from S&W, had a chamber reamer made up with min dimensions of the chamber and the front of the cylinder matched to bullet diameter to keep the sides at the same dimension as it was in the loaded round before it made the jump from cylinder to forcing cone of the barrel. So he built the Secret Service Team guns and testing confirmed they gave much smaller dispersions than factory cylinders. The Secret Service Team won the matches that year.


Ray and Bob Lutz had got into bullet swaging experiments for the Secret Service Rifle Team and since they came from Frankford Arsenal they knew all the dos, don’ts and what ifs of the bullet making art.


For instance he said if you took 173 grain match bullets which are around .3084 diameter (they can be upwards of .3089 per the drawing) and attempted to squeeze them down to make them all .3080 diameter the accuracy would be poor because the copper jacket would pop away from the lead core and which would be “loose” inside the jacket making for a disaster upon leaving the muzzle.


Thusly I had an idea of getting a Corbin bullet swage made to the 173 bullet drawing and expanding them all to .309”. I ran this by the Dean of the gov’t ordnance program Bill Davis as he was on the team that designed the 173 grain Match bullets and he thought that would work great and wanted me to keep him posted how it turned out.


I never got around to getting to this project and Bill has now passed. For those of you that watch the History Channel he is the old guy with white hair and flat top haircut who was interviewed about the M16 program.


Next thing on case sizing is I DON’T USE EXPANDERS in my FL dies. I FL size most of my ammo or if I neck size I size the full neck but don’t use the expanders the dies come with. Why? If you have a good caliper FL size a case as you normally would and measure the inside diameter of the case mouth.


Next FL size another case without the expander and measure that. Chances are the neck will be about .005” smaller on the second case.


If you have a normal expander when you lower the case you are using the expander to open the case back up to where it can be loaded and this will put lots of stress on your case neck and you are pulling the brass in the neck towards the muzzle stretching it so you will wind up trimming case neck even though the shoulder/base is not moving. This will thin the necks.


Now if you have a expander that opens the neck from the top going down you don’t stretch the neck and the brass does not work harden as quickly. This is done several ways, one is to get an expander mandrel set up from Sinclair international with a expander to a dimension you want. For 30 cal I would use a .306 expander for rapid fire ammo and a .308 for slow fire ammo in bolt guns.


Another thing is to make a Humpy button. For 30 cal I have sections of oil hardening drill rod .311 diameter and I cut them in 1” or slightly longer sections and turn one half of it down to lets say .308” tapering the end so it will enter FL size case mouth easily. I have a lathe and I make mine in all kinds of configurations from .3060 to .3090".


The other end I leave at .311 and place that end in a RCBS collet type bullet puller and clamp it in place. I grease the other end sticking out and run FL sized case necks expanding them right where I want to have it.


After I turn the Humpy button to the dimension I want I heat the button to bright red and oil quench the button and polish it. Once I arrive at the diameters I want I place them in die box. You can do unique things like expanding necks to dual dimensions. For instance you can leave the bottom of the neck internal dimensions at .3085 and the top of the neck at .3095.


For smaller calibers I leave one end .311 and just turn the other end down smaller. Thus I can adjust the bullet pull to hold the bullet more uniformly.


Some folks like the dies with the changeable bushings. I see no reason why they would not accomplish the same thing but from the ones I have seen they are pricey.


As well many of you have read about the “Dreaded DO NUT” that can be present inside the case neck at the bottom of neck at the shoulder junction and many make a determined effort to ream them out etc to avoid the bullet being wedged into the tight section at the base. The Humpy button expands that right out and thus the DO NUT is not a factor.


Now we arrive at the best of all worlds in my opinion is to have a L E Wilson FL die with neck opened up with a pin grinder so you FL size the full body, set shoulder back but only take case down to where you want it. If you look at factory Wilson dies the necks come out very small and I asked one of the Wilson brothers about this a few years back and he said most folks that buy L E Wilson FL dies grind out the necks to size to the dimension they want without overworking the brass.


Thusly when I cruise the gun shows I am on the lookout for L E Wilson FL dies regardless of caliber and have several for 308 and 30.06 ground out to fit the outside of my turned case necks to give me only about .002” reduction. Then I expand them to exactly where I want with Humpy Buttons. As indicated previously don't move anything over .002" for maximum case life.


If you ever get a chance to get a metal lathe jump on it as you can do lots of neat things with your loading set ups and make life easier for your brass by not overworking it.
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Old 02-22-2013, 06:07 PM
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Well done. I have always enjoyed making my own neck expanders and felt like that helped me learn quite a bit.
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Old 02-22-2013, 06:29 PM
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Always glad to help out other shooters.
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  #4  
Old 08-24-2013, 12:13 PM
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I have some Remington 45/70 brass that I have loaded dozens of times since 1978 whenever I bought it. Thats 35 years! But I have always loaded those cases with either Black Powder or light loads of IMR 3031. I neck size only, I do not full length size the 45/70 at all. All of my other brass gets automatically trimmed 0.05 inch whenever I first get it so that additional trimming is seldom necessary. But the 7mm Remington Magnum is a royal pain if it is not F L resized, and its case life is quite short anyway. So I can't win them all can I?
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Old 10-18-2013, 04:35 AM
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Swampdoc, Sorry I missed your response until now. I got rearended on June 16, knocked me cold and I have been dealing with post concussion issues for a while but now I am about right though I am still in physical therapy twice a week since and looks like maybe three more weeks may have my shoulder straightened out.

I have seen several messed up magnum chambers over the years and a lot of messed up dies.

You might size your cases in someone else's dies that has not has similar problems and see if that changes things for you.

Had a friend buy three sets of 300 Win Mag dies and could not chamber a round he sized with any of them.

I told him to bring his rifle and ammo down and ran his brass through my dies and still would not chamber though new unfired cases went in and fired just fine.

I cut off about three threads (set barrel back) and rechambered his rifle now all his dies size just fine.
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Last edited by Humpy; 10-18-2013 at 04:44 AM.
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