I recently acquired a custom-built rifle from another party and immediately found that a fired case, while it withdrew quite easily and smoothly from the chamber, would not rechamber (before doing anything to it), at least not without great difficulty. I mean, open the bolt, withdraw it to the rear, then attempt to reinsert the just-fired case in the chamber and you would find that it didn't want to go.

As you can see in the photo, I blackend a couple of fired cases in candle black and rechambered them. The longitudinal striations in the chamber are obvious when you do this. Is this the result of "reamer chatter"? Can it be cured by setting the barrel back and rechambering properly? Or is this barrel toast?

It's called reamer chatter. The only cure is to have the barrel set back and the chamber recut taking care to fix the reamer so it won't chatter again.

Why do anything? German G3 rifles have fluted chambers to function properly. It looks like yours is not deep enough to affect obturation.

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Originally posted by dpcd:
Why do anything? German G3 rifles have fluted chambers to function properly. It looks like yours is not deep enough to affect obturation.

"a fired case, while it withdrew quite easily and smoothly from the chamber, would not rechamber"

This forum is call "Accurate Reloading", hint, hint. I don't think that the German military intended to reload fireformed cases multiple times in their G3's for shooting prairie dogs. Additionally, this is a wildcat case (.20 Vartarg), so it would seem less than efficient to spend time and money reforming new, scarce .221 brass in order to fire them once then toss them.

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so it would seem less than efficient to spend time and money reforming new, scarce .221 brass in order to fire them once then toss them.

You can load them without any significant problem. I have a Browning 1885 .45-70 with the same issue. If you spin the case with one hand and grasp it between thumb and fore finger you can actually feel the chatter. I have fired hundreds and hundreds of rounds through my rifle. None of the cases ever showed any problems.
However if you plan to only neck size you may be SOL.

Wow. If this is un doctored then you have several issues

This load didn't seal the Chamber. Could be VERY low pressure or very over sized Chamber

Second the Chamber is fluted. Likely from mis handling the reamer

Call the guy and discuss

Jeffe,

OP said he blackened the cases so underpressure likely isn't an issue, just the longitudinal fluting he got for free, but doesn't want or need...

Thanks. Sometimes I just fail to read

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Originally posted by SR4759:

quote:

so it would seem less than efficient to spend time and money reforming new, scarce .221 brass in order to fire them once then toss them.

You can load them without any significant problem. I have a Browning 1885 .45-70 with the same issue. If you spin the case with one hand and grasp it between thumb and fore finger you can actually feel the chatter. I have fired hundreds and hundreds of rounds through my rifle. None of the cases ever showed any problems.
However if you plan to only neck size you may be SOL.

Resizing a straight-wall case to reduced the body diameter doesn't present the problem that this bottleneck case does. If I were to resize the cases enough to re-enter the chamber then the shoulder is pushed so far back that the cases would undoubtedly suffer a head separation in just a few firings.

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Originally posted by Stonecreek:

quote:

Originally posted by SR4759:

quote:

so it would seem less than efficient to spend time and money reforming new, scarce .221 brass in order to fire them once then toss them.

You can load them without any significant problem. I have a Browning 1885 .45-70 with the same issue. If you spin the case with one hand and grasp it between thumb and fore finger you can actually feel the chatter. I have fired hundreds and hundreds of rounds through my rifle. None of the cases ever showed any problems.
However if you plan to only neck size you may be SOL.

Resizing a straight-wall case to reduced the body diameter doesn't present the problem that this bottleneck case does. If I were to resize the cases enough to re-enter the chamber then the shoulder is pushed so far back that the cases would undoubtedly suffer a head separation in just a few firings.

I cannot see how it matters in the slightest unless your chamber is oversize. The chatter does not really make it significantly oversize. The chatter is probably less than .001. All you have to do is iron down the bumps.
You are theorizing about something you have not tried. You should try it and then comment.

A full length sizing die should solve the problem with the high spots on the brass. It's just that you must full length size every time and work the brass just a little more than you normally would. It really isn't that big of a deal to take it to a gunsmith and have it corrected unless you have something like a quarter rib or a fitted barrel channel either of which would complicate things. NORMALLY this can be cleared up by running the chamber about 1/16 inch deeper and setting the barrel back accordingly.

Yes, this potentially high-volume varmint rifle could be fired by full length resizing after each firing, but I don't know of any varmint or target shooters who would full length resize their brass and thus both shorten its life substantially and diminish the rifle's potential accuracy.

Please understand, the "fluting" of the chamber is so significant that a fired case will not willingly re-enter the chamber immediately after it has been fired. In forty-five years of reloading I've never come across a chamber in this condition. The chamber is not in any way "oversized" (in fact, it has a tight "target" neck which requires thinning the neck walls a bit). The chamber just ain't round; well, I suppose it is "round" like a cogged gear wheel is round.

There is no problem in reloading brass fired in the HK91s (G3) rifles. And this one is far less marked than the fluted chamber military ones are. As long as the chamber is within spec, and I seem to read that it is. You will have to full length resize. If you don't want to do that, have to pull and rechamber. Which isn't hard either.

Correct -- I don't normally full length size any of my brass for bolt action rifles, particularly not the high-volume ones like those used for colony varmints.

But even if I were to throw in the towel and FLS these cases, the chamber is actually on the tight side (normally a good thing to my way of thinking). The problem this causes is that in order to squeeze the case walls sufficiently to rechamber with my Hornady .20 VT FL die, I have to run the case all the way in, which sets the shoulders back by an unacceptable amount. Cases will neither last long nor provide the best accuracy if the shoulders are set back, thus creating excessive headspace.

If you'll notice in the photo of the lamp- blackened cases, the neck and shoulder of an unsized case don't even touch the chamber as they are held off by the fluted body. This is the only instance I've ever run across of a case "headspacing" on the body of the case. Come to think of it, I suppose the tapered 9mm Parabellum does, but I've never seen a rifle cartridge do it.

At any rate, I've started a search for a smith with the right reamer who can do the set-back and rechamber. If anyone has any suggestions of who to call on for this work I'd be pleased to have some names passed along.

No you don't want to set the shoulder back; and no case that I know of headspaces on the body; that would get stuck in the chamber. 9mm; no, it headspaces on the mouth; but it is tapered too. Whoever chambered your rifle needs help. Or the reamer maker and the die maker didn't talk to each other.

Well, being a wildcat cartridge with no SAMMI specs I can understand that it is a bit easier to get a mismatch. However, the die would work just fine for partial FLS or neck sizing if it weren't for the chamber "flutes". But the fact is, I've had worse die/chamber mismatches in cartridges with long-time accepted SAMMI specs with both components directly from the factory and not from a private shop.

And although I don't know exactly who put this rifle together, I am informed that the barrel is a name barrel from a manufacturer which does offer pre-chambered barrels in .20 VT, so it could actually be a chattered chamber from the barrel manufacturer -- or not, just don't know. But the seller has responded to my inquiry and is willing to stand for the cost of set back and rechamber. Just shows that most "gun guys" are honorable.

Hi all,

Just read this post and remembered a rifle a friend owned a couple of decades ago. It was a HK .308 and every fired round displayed an empty case with just those striations. Nothing unusual. Not all chambers are cut with a reamer causing the the supposed chatter. Many barrels are hammer forged with the chamber integral to the mandrel. Hence, no chatter. HK used this method for a reason. Perhaps a call to HK would clear the waters.

Luck,

Stephen

Bet I am wrong.

Let me know.

Stephen

Of course HK used the method for a reason. And there's also a reason the method is not used in sporting rifles.

Back to the original poster's problem, here is an example of a bad example, big time reamer chatter. The only remedy is to set the barrel back and re-chamber it. This is not for the faint-hearted, the chamber needs to be single point bored to the case taper and the neck area bored oversize enough to clean up the existing chatter there. There are probably a dozen tricks to eliminate chatter once it occurs but in this case, start over. You won't be happy until it is done. Reamer chatter is one of the hardest problems to overcome and a nightmare when it happens.

A friend comes out and shoots his HK 91/93 variant at my range and leaves brass like that behind. I always assumed it was a fluted chamber and the flutes acted as a "gas assist" to eject the spent shells. Makes sense to me for a battle rifle when overheating, dirt and fouling could be a problem and a stuck cartridge could end it all for you.

What rifle is the OP shooting that this brass is from?

Snellstrom, you are correct in that H&K 91/93s are made with fluted chambers to improve roller-action function and obviate problems that might arise with stuck cases in combat situations.

No one cares about case life in hand-loading (or picks up cases) on the battlefield!

Someone seems to have screwed up in chambering this rifle.