Ringing of the chamber

[lead chucker]

I have heard that you can ring your chamber with light loads and using dacron. I would like to load up some light to medium loads for my 308 using 2400 and unique with dacron to keep it in place but would rather not ring my chamber. I would like an expert opinion on this. Mabe this is a myth.

[Linstrum]

Hi, lead chucker. Ringing the chamber is real, but not all firearms are subject to it. Look up past articles using the search function here at Cast Boolits.

In the meantime I will try to find the post I wrote a few years ago about why some guns are susceptible but others are not, it has to do with the grade of steel used for the barrels.

Okay, here is the URL for the post here at Boolits:
http://castboolits.gunloads.com/showthread.php?t=1514&highlight=ringing+chamber

Here is the post I wrote back in 2004:

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Hey, there, jh45gun, how ya doin?

Thanks for the information on fast powders and the association with chamber ringing in large case capacity cartridges. I'm sure that it will help some folks out there who are new to the cast boolits and reloading game who don't know about some of these pitfalls that can cause unnecessary grief! I'd sure hate it if I got some 405 grain pills for a newly manufactured replica Trapdoor and then used loading data from an old Lyman 46th edition reloading book that says using 11 grains of Unique is okay when in fact it has the POTENTIAL to cause harm in even newly manufactured old design replica rifles that are ALSO made from low alloy steel that lacks the strength necessary to keep from getting ring damage to the chamber. There are booby traps like that out there, so thanks for taking the time to pass along their observations!

Last year I wrote up the following short article about the problems associated with ring damage in some rifles and why some get it and some don't. I hope that it is helpful as well as interesting.

From September 20, 2004:

I have read lots of threads on chamber ringing and when it happens it is usually a rather vague phenomenon that when it comes to explaining what did it no one can put an exact finger on it. It almost always involves a fast powder used in conjunction with card wads or sometimes fiber filler. Of course the small amounts of fast powder require the card wads and fiber filler to help with uniform ballistics from one shot to the next. So, which is it, fast powder or card wads and fiber filler? A horse and cart type thing. Maybe chicken and egg. But for sure it does happen and has caused lots of chamber damage. The part about chamber damage is undeniable.

What comes to mind is two guys comparing their cars. One guys says he can drive his car 80 mph all day for years and years, and the other guy says no way, if he drove his car 60 mph for a mile even one time the engine would be scrap metal. So who is right? Are cars unbelievably reliable? Or unbelievable pieces of junk? Same goes for rifles. The originals as well as far too many of the repro .45-70's are made from "steel" with around 65,000 psi yield strength. The "modern" rifles (starting with Winchester well over 100 years ago in about 1889) use iron alloys much more deserving of the name "steel" and yield strengths of the various alloys can run up as high as 265,000 psi yield strength for alloys like full heat-treated ASI 4340. The norm is more like 220,000 psi yield for the more commonly used steels in the class of steel centered around ASI 4130 and ASI 4140. So which of the alloys were the rifles made from that had chamber ringing? I hear .45-70 a lot (but never its over-grown brother the .458 Winmag), which is a good indicator right there of what is going on.

Buckshot holds part or even most of the answer here.

His high alloy modern steel .45-70 MAS 36 convert has ringing of the BRASS used in it! The yield strength of brass is not much AT ALL below the yield strength of the soft easily machined alloys used in original AND REPRO black powder rifles. The low carbon-low alloy steels used in far too many the European-made black powder repros is about the same as what was used originally 120-plus years ago, so when you buy a repro you are also getting a faithful reproduction of their low-strength as well! Today that class of alloy is typified by ASI 1005 or ASI 1010 low alloy steel, which is still stronger than the plain steels made by the old Bessemer converter process. If I had my way, those low strength steels would be outlawed for making firearms, except for maybe butt plates. The Italian and Spanish also go one further, which is they use free machining leaded steel (also called lead-blown steel), which cannot be heat treated to strengthen it. Even their so-called stainless steel they use for the old repro revolvers is similar to type ASI 303 stainless steel and about as strong as the free machining leaded steel. Those are the "steels" that are about as strong as cartridge brass.

You can do a very simple and easy test yourself to display the wide range of strengths encountered in commonly available steel alloys. Take a 3-inch long 3/8-inch NC carriage bolt and a 3-inch long 3/8-inch NC grade 8 bolt. Make sure your grade 8 bolt is not one of those counterfeits that are causing airliners to fall out of the sky. Pick one bolt and clamp the threaded part in your big bench vise then grab the head with a pipe wrench and start twisting. One will scare you how easily it twists off, the other will probably rip the sharp tips off of the teeth in your pipe wrench. One "steel" alloy is about the same as was used in old black powder rifles and modern repro rifles, and the other is the same or very close to what is used in all modern rifles. Which alloy do you want your reproduction rifle to be made from?

Fast powders often have extremely high initial peak pressures even though the powder is in very small quantities. The entire chamber is not subjected to the high pressure, just the area where the ringing occurs. It is probably caused by a combination of several factors working in concert to combine available energy as focused vector forces when a card wad or even just a compressed gas shock wave hits the bullet base, as was already mentioned. This creates Munro Effect conditions where the energy is focused onto a very small area, and after several repetitions the metal is displaced. Sort of like bubble cavitation that "eats"� high strength metal away where there are no obvious high pressures or strong forces that would normally explain such mysterious things taking place.

When Winchester introduced their Model 1894 rifle, its barrel was made from a steel radically different from all previous Winchester rifles, or all other rifles for that matter, except for a few of the newest German and Scandinavian Mausers. For a few years after the model 1894 and 1895 Winchester rifles came out, gunsmiths from all over the country complained and swore they would not work on them and carried on like it was the end of the world. But Winchester had seen the handwriting on the wall after observing the experiences that other rifle manufacturers had with smokeless powders and went ahead and developed a totally new grade of crucible steel to make their barrels from. Of course the old gunsmiths couldn't easily work with the new high strength steel because they couldn't machine it, drill it, tap it, or saw it with the old worn out plain carbon steel cutting tools they had and they did not like the idea of needing to buy new expensive high speed steel cutting tools to work with the new super tough alloys (cutting tool high speed steel was also just newly invented then to deal with the new super alloys). The steel that Winchester developed had nickel and manganese in it and even by today's standards is pretty tough stuff! Take a look at Roy Dunlap's book "Gunsmithing" for a description of the various problems associated with the older soft and weak steel in guns as well as his experiences working with high strength nickel steel barrels.

So, a Model T Ford and a 1959 Chevy are both cars. If you ran them hard for a very brief moment, which one do you think you would have trouble with the "rings" in it?

END POST

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I hope this helps
__________________
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There is no such thing as too many tools, especially when it comes to casting and reloading.
Howard Hughes said: "He who has the tools rules".

Safe casting and shooting!

Linstrum, All Outdoors.com survivor and Shooters.com alumnus.

rl 1048

[mpmarty]

There is really no need to use dacron or anything else with the two powders you mention. I never bother with the extra fuss of fillers.

[Linstrum]

Hi, mpmarty (and lead chucker again), I also don't use Dacron fillers or cards, instead I use the muzzle up first motion before firing. I know that won't cover all shooting positions, like shooting downhill at a steep angle, but I rarely have to worry about that because I don't hunt hardly at all anymore. Using Dacron filler and cardboard discs will improve accuracy and consistency often enough in some circumstances and that is why many shooters elect to use them in large volume cartridges that only contain a few grains of smokeless powder.

Speaking strictly for myself: Like a lot of things in shooting, there are no absolutes, and in the shooting I do I have not found the use of fillers and cards to be of any benefit. But your mileage may vary!


rl 1049

[lead chucker]

Thanks for clearing that up for me. The 308 doesnt have that large a case volume and im not useing real fast powder so im sure i will be fine. My rifle is a ruger compact. Ruger is known for making a strong firearm.

[Linstrum]

You got it! Rugers use tough modern steel. I shoot 45 grain 0.315" wheel weight round balls without any case filler in my .308 Win, .30-06, 7.62x54R, 7.5 Swiss, and 7.5x54 French pushed out the bore with 4 grains Unique, Bullseye, 700X, Red Dot, or Green Dot. I like Unique, 700X, and Red Dot the best. Those miniscule loads do fine without any filler. In the .308 Win I also shoot the Lee C309-113-F "soup can" using 10 grains Red Dot, and the Lee C309-180-R using 12 grains of Red Dot.

The Universal Load for all .30 and .31 caliber military cartridge high power rifles like the .308 Win, .30-06, 7.62x54R, 7.5 Swiss, etc., is 10 grains to a maximum of 13 grains Red Dot with boolits ranging in weight from 120 grains to 150 grains. No filler needed.

rl1050

[DLCTEX]

Dacron will not ring a chamber if it is not tamped down leaving a space between it and the boolit base.IMHO

[Linstrum]

Hey, DLCTEX, thanks for the info. I have never worked with Dacron filler (used Cream Of Wheat, though, for fire-forming brass) so I just plain don't have any hands-on experience with it. Good to know!

rl 1054

[Larry Gibson]

There is a distict difference betwen the use of a filler and a wad. Wads have been know to produce ringing under specific circustance. Appropriate fillers like dacron do not. As with many things, especially shooting and reloading, if done correctly they are perfectly safe, if done incorrectly they can become dangerous. Use the dacron as a filler and be safe.

BTW; Proper Unique loads in a .308W do not require or need a filler. The use of 2400 on the other hand can beifit, in a .308W, from a dacron filler depending on load and bullet weight used.

Larry Gibson

[swheeler]

There is a distict difference betwen the use of a filler and a wad. Wads have been know to produce ringing under specific circustance. Appropriate fillers like dacron do not. As with many things, especially shooting and reloading, if done correctly they are perfectly safe, if done incorrectly they can become dangerous. Use the dacron as a filler and be safe.

BTW; Proper Unique loads in a .308W do not require or need a filler. The use of 2400 on the other hand can beifit, in a .308W, from a dacron filler depending on load and bullet weight used.

Larry Gibson

Bingo! I think we have a winner.:bigsmyl2: