Straight wall chamber bore steel vs brass

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nicksterdemus
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Straight wall chamber bore steel vs brass

Post by nicksterdemus » January 15th, 2007, 2:05 pm

From what I've read the friction of the hulls helps slow the blowback action. That being the case would brass hulls expand more than steel helping the process, would steel being harder slow better, will steel wear out the bore faster or is it all just 6 of 1 n half a dozen of the other?
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Straight wall chamber bore steel vs brass

Post by nbender » January 15th, 2007, 3:36 pm

The Russians pride themselves on the soft steel in their cartridge cases and the guns were made to shoot their steel cases.

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Straight wall chamber bore steel vs brass

Post by kempin » January 15th, 2007, 9:28 pm

I don't think the expansion in a 9x18 would be enough to make a significant difference in slowing the blowback of the pistol, but I use all brass in mine on the theory that steel on steel will wear faster. Of course, it is probably not enough to notice a difference unless you shot thousands and thousands of cases, but that's my theory and I'm stickin' to it.

-Kempin

p.s. I don't worry so much about wear on the bore, but I would think that steel would wear the extractor quicker.

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Straight wall chamber bore steel vs brass

Post by steve98664 » January 16th, 2007, 12:12 am

I think the 2 factors for barrel wear are metal hardness and the coefficient of friction. I work in engineering and I'm often forced to look into material properties, but I'm not a materials expert. The numbers below should be somewhat accurate, but I only spent a few minutes getting the data for comparison.

I picked out some specs for friction and hardness. The info I found mentions lubrication but I think after a round or a few....you lose the lubrication in the barrel area although it remains in other parts of a pistol such as the trigger assembly, etc. Just an assumption to work with but I bet gun manufacturing engineers know more about this.

Anyhow, here is the coefficient of friction for steel on brass and steel on steel. You can see that the coefficient of friction is much lower for steel on brass. You can also see that other factors such as lube play in IF it is present. I don't think my barrels remain lubricated during firing.

http://www.carbidedepot.com/formulas-fr ... icient.htm

Secondly, I looked at metal hardness. I think we all know that steel is harder than brass, but here are the numbers.

http://www.arcraftplasma.com/welding/we ... tab7-2.gif

Next, I looked again at what brass is. It is a combination of Zinc and Copper.

http://www.hcrosscompany.com/metals/brass.htm

Finally, I looked at the materials that are used to coat the steel casings the russian manufacturers put out. I don't know the effect of a thin film of copper or zinc on a steel casing as compared to solid zinc/copper materials. I just assume the friction is for zinc on metal, or copper on metal without considering the underlying steel in a casing. You can see the first chart above to see the friction coefficients for those. Zinc and nickel have lower hardness numbers and lower coefficients of friction than steel on steel. Copper seems to have higher friction numbers to my surprise. Brass is still lower than these for hardness and coefficient of friction.

If the copper wash coating of some ammo has zinc in it, giving it more brass-like properties, the coefficient for friction is more likely lower than steel.

Bottom line, brass doesn't cause as much friction as steel or steel casings coated with other material. Also, brass is softer than these other materials. Logically, brass ammo should wear on your barrel less!

I still use steel cartidge ammo in my pistols though. I try to use brass when it is not overly expensive. Zinc and nickel are used to reduce the coefficient of friction, probably reducing the wear on a barrel compared to bare steel. Copper (assuming the copper stuff is not an alloy on Mesko or others) may actually cause more friction, even though it is a soft metal.

For all of the information above, I assume that the steel barrel of a pistol is not affected by the expansion of a casing during firing. Assuming you are using ammo with specifications for you pistol, the expansion should not be a factor and the barrel should easily handle outward expansion of brass or steel casings. The rubbing/friction of the casing as it moves in/out of the barrel should be the biggest factor. I ignored factors such as roughness, residue from firing, etc.
Last edited by steve98664 on January 16th, 2007, 12:42 am, edited 1 time in total.

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Straight wall chamber bore steel vs brass

Post by nbender » January 16th, 2007, 1:03 am

Steve, as I wrote, the Russians use a soft steel for their casings. I don't see that accounted for on the pages you posted. Steel comes in a variety of compositions with a wide range of hardness; differing coefficients of elasticity and friction, etc. I don't know if the steel casings cause more wear - there is a lot written about that on different forums - but the Russians have produced these steel casings for their weapons for decades and that gives me some confidence in their suitability.

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Straight wall chamber bore steel vs brass

Post by bzinggg » January 16th, 2007, 2:21 am

Please, my good friends, could we consider referring to the "chamber" rather than the "bore" when discussing the friction of a case material and its' effect on the efficiency of the blowback action of a P-64 or other less consequential pistol. ;D

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Straight wall chamber bore steel vs brass

Post by nicksterdemus » January 16th, 2007, 8:08 am

You are correct. I should have used chamber instead of bore. I have a bad habit of tryin' 2 think while typin' n not proofreading. That combined w/advancing age, slowed motor skills n impaired cognitive function suppressing abstract thought. But if that ain't the consensus view, then hell, let's put it to a vote.


Okay... I'm with you fellas....................


Note 2 self: Ask Steve 4 techno info......................
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Straight wall chamber bore steel vs brass

Post by kempin » January 16th, 2007, 11:43 am

Wow. Great info, Steve.

Nbender, I don't mean to imply that the steel cases are not "suitable." They are certainly within specifications, and, as I said in my previous post, I'm sure you would have to use a great many to notice any difference at all. My approach is probably more superstitious than practical, but I hope to still be using my p-64 for many years to come.

As far as the hardness, cases are generally softened around the neck to allow for expansion under fire and to allow the case to worked when sizing or seating a bullet. The head, however, is usually hardened to prevent failure under pressure. Since the extractor is constantly jumping over the rim on the head of the casing--presumably hardened--I would think that this would cause it to wear a bit quicker than brass. As far as wear in the chamber, I doubt there would be any noticeable difference.

I may be nuts, of course, but that's my theory. It's not that I am afraid to shoot steel cases, but over the long run I am going to stick with brass.

God bless and straight shooting,

-Kempin

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Straight wall chamber bore steel vs brass

Post by nbender » January 16th, 2007, 2:04 pm

Well, I think maybe the subject approaches splitting hairs, but brass is probably, must be, somewhat softer than whatever type of steel the Russians use. I would suspect that the rails or other parts of the pistol may degrade faster than the chamber no matter which cartridge you choose.

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Straight wall chamber bore steel vs brass

Post by normsutton » January 16th, 2007, 6:54 pm

I don't like steel ammo because I can't reload it somebody else might be able to but I can't


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Straight wall chamber bore steel vs brass

Post by steve98664 » January 17th, 2007, 3:39 am

I use a lot of steel cased ammo as mentioned above.

I use the term barrel because the chamber is part of the barrel. However, I stand corrected, the chamber is what I was referring to.

I used to pay 5.50/50 steel cased zinc coated Russian rounds. I paid 8/50 for S&B brass. I mentioned this before in a post, but if you think about it over say 10,000 rounds, you pay $500 more for the brass rounds. That buys a lot of parts and gunsmith work if the steel cased rounds cause problems! However, for a P64, a Vanad or other pistols that parts are not available for, it might be smarter to be more careful. However, right now, you can get a whole new P64 for 139!

Nobody does know for sure how much wear steel casings add to a pistol. Maybe the trigger assy wears out before the other parts such as the barrel or extractor? Look at the steel casings after ejection from your pistols and note that the zinc or other coatings wear off around the rim and other areas where there is sharp/pointy contact. I think that extractors and metal casings see metal/metal wear.

If the casings of russian ammo do not cause feeding or wear problems why do the russians coat them with polymers, laquers, zinc, or nickel? I figured that was just an obvious conclusion....that the steel cased rounds are harder, rougher, or cause more wear. Why don't they just leave them bare like brass rounds?

Now I pay about 8 for steel cased (with shipping) and 10 for S&B brass. Still about a $400 difference over 10K rounds.

I am my own primary gunsmith. I would rather not have to fix a pistol. My Vanad will be hard to find parts for. I am not as worried about my Maks. Parts seem to be plentiful.

Really, reloading is probably the way to go and that forces the use of brass. Anybody know where to get a reasonably priced progressive setup?

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Straight wall chamber bore steel vs brass

Post by kempin » January 17th, 2007, 9:43 am

Steve,

I was about to say something along the same lines, though perhaps it should be the beginning of a new post. I prefer brass over steel but, like nbender said, it is probably splitting hairs.

A much larger factor for the pistol's longevity is, in my opinion, the load used. I have been loading my own for the past year or two, and the slightly reduced load that I have settled on for the p-64 have been extremely satisfying. Function and grouping are both outstanding. In fact, I would even subscribe to the theory that the p-64 may have been designed for a lighter load than what has become the standard 9x18.

An interesting, semi-scientific, anecdote may back me up:

Just the other day, I was doing a quick cleaning of firearms. I am not always the best example of prompt cleaning, and so I had a little pile of weaponry. I cleaned my 2nd p-64--the one I have only used with my hand rolled, reduced loads--and I cleaned my 1st p-64--the one I shot several hundred factory loads through before I started loading. Because I now use my 1st pistol for carry, I mostly use the second at that range. Well, the bottom line is that they are approximately the same in terms of overall rounds fired.

I did notice, however, when I had them side by side, that the p-64 that had not shot factory loads seemed to be broken in uniformly. The portion of the slide that impacts the trigger guard on recoil was marked, but the bluing was still intact and everything was smooth.

The same place on the first pistol looked like it had been pounded with a hammer. The bluing was becoming obscured, and you could feel a slight "notch" beginning to develop. It was a noticeable difference.

I am more convinced than ever that a steady diet of "hot" factory ammo will shorten the life of a p-64.

Am I saying that it will fall apart after 100 rounds? Of course not. It will last a good long time, and if you think that it is not worth the effort to preserve a $140 pistol, I have no problem with that either. I'm just sayin'

For what is's worth,

-Kempin

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Straight wall chamber bore steel vs brass

Post by nicksterdemus » January 17th, 2007, 11:13 am

"same place on the first pistol looked like it had been pounded with a hammer"

Could this have been prevented w/recoil spring of adaquate stiffness 4 said ammo?

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Straight wall chamber bore steel vs brass

Post by bzinggg » January 17th, 2007, 2:19 pm

Steve and Kempin,

Good and thoughtful posts, thank you. I'm just adding a small note on one point, and that is about the coatings on the steel cases. Steel corrodes quickly without them, and preservation of the ammo until use is the primary need for these coatings. Lubricity figures in, as well as cost of a particular material and its' application when choices are made at the factory in this regard, and I have heard discussions on the rate of expansion varying with different coatings and base case metal (brass vs steel). However, corrosion is the main issue, and the rims of mouth cases and primer pockets being where a coating would fail first, often got an extra seal (sealed primers and case mouths having that little red stripe as evidence). I believe the best and most dependable steel cased ammunition was the nickle-plated. It always had both the mouth and primer sealed, and the packaging was even better quality, having the plastic cartridge racks inserted into the box instead of the paper dividers. Of course, these extensions of quality are more expensive to produce, therefore, we see zinc and paper now and the true nickle-plated has disappeared from the market, as the Russian and other Eastern European producers become acquainted with capitalism and the advantages of making a profit.

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Straight wall chamber bore steel vs brass

Post by steve98664 » January 18th, 2007, 12:35 am

Thanks for the info guys! I think that if I can find a used progressive rig, that is the way to go. I'm gonna look harder at the next gun show here. Can factory brass like S&B or MFS be reloaded easily? I may start collecting my brass now.

What are the hotter factory loads that you believe caused the indentations? I use silver bear, the new stuff, S&B, Mesko, and I might pick up some of the steel cased S&B that NB mentioned before. MFS is still around too.

I hadn't considered the other reasons for the coatings. I liked the old silver bear, but I read that some people felt the loads were unreliable (squibs and hot loads both). I didn't shoot that much of it, but didn't have any issues. It is gone for good though.

I think a lot of engineering goes into cartridge design. Ever since I read about unsupported chamber issues, I realized there is lot more to the design than I realize.

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