Finish reaming K22s, or, How To Solve Difficult Extraction In .22lr S&Ws

Got tired of the ridiculously tight chambers which were essentially non-functional on my K22. After one cylinder required a hammer or a bloody hand. See my other threads on chamber measurement.

So, I purchased a finish reamer from Brownells and went to work.

EXTREMELY PLEASED with the results!

Observations.
1. This is EASY and CHEAP to do.
2. This completely fixes the ejection problem these guns are known for.
3. There will still be a significant "tight" area ahead of the base of the chamber after reaming. See pic below.
4. Leave the extractor in while reaming. Mine certainly benefited from the chamber reamer as several charging hole cuts were off, and several weren't actually flush with the cylinder recess. Primer strikes are better than they were, now, as all cartridge rims are actually sitting flush with extractor and cylinder recess.

Pics.
You can see here where the reamer finished in the bottom left chamber. The tighter area ahead of the now correctly-sized chamber will swage down the bullet to the same diameter as the original S&W chambering, before it leaves the cylinder... and the shells will now actually eject and don't require a hammer. Oh, and fired casings from the pre-reamer shooting sessions (which drew blood) drop in perfectly, with no wiggle... before I couldn't even get fired shells to seat in the chamber...



Really tight chambers... perhaps the final finishing method they used on centerfire revolver chamberings was carried over to rimfire, but with unintended consequences. Unknown if the super tight chambering was fine in olden days, but it doesn't work with today's ammo, match, CCI, or otherwise. I had a 60s vintage M41 that had exactly the same problem. Made the gun unusable and I sold it. Anyways, this is the metal removed after 3 chambers were done.



And after all were done... this doesn't show the full amount of metal actually, as some ended up on towels I used to wipe the reamer off...



All in all, I'm tickled pink. And, now I have an extra original, unmodified complete M17 cylinder assembly that I'm considering selling or having fitted to the gun and reamed to WMR or other caliber...

Nice post and just want to mention to guys thinking of doing this that it is important to use proper cutting fluid while reaming and keep the reamer as clean as possible between cylinder charge holes. I not only wipe it off with a rag, but I use an air gun and compressor to make sure there are no stray chips stick in the reamer. Keep Cyinder chip free as possible too.If you do not have a compressor handy, use an old toothbrush or similar. Don't be stingy with the cutting fluid either - and go slow and steady.... no jerky motions. Usually a simple job with positive results..........

Precisely what Chief said. I used lots of high sulfur cutting oil (as you can see), only turned clockwise with the bit, went slow and removed as many chips as possible every 3-4 full turns of the reamer.

A few more words.

Make sure to have a good way to clamp the cylinder without marring it. I used poly inserts on my vice and they worked well.

Make sure you get a GOOD handle for the reamer. Buy once, cry once. I recommend the Brownells handle you see in the pics.

Make sure you use dykem around the charging holes to see when your reamer touches down on the chamber recess. Cleans up with acetone.

A few pics to see the finished product...

PzKfW5, I have a Model 17-4 and it has the same problem with hard extractions. I notice in the pictures you furnished that you did not ream all the way through the cylinder. Is there a reason for that?
I'm trying to clean my cylinders with a stainless steel cleaning brush and some J-B from Brownells. If that does not work I was going to look into getting a finish reamer. Any information would be appreciated.

The reamer simply does not cut to the end of the cylinder. This is a good thing in my opinion, as the bullet will leave the cylinder in the same diameter as the original tight s&w chambering, which is 0.224" by my pin gage measurement. Thus it will be just as equivalently centered in the forcing cone as the original "tight" s&w chambering provided - which is the whole point of having "tight chambers" in the first place... IE decreased bullet deflection from bore centerline and increased accuracy. Also note that the bullet will still be plenty big enough to get full advantage of swaging into the lands and grooves (0.217" and 0.222", respectively) so it will be biting as well as possible for good accuracy there, too. I ran a metal probe over the "transition area" you can see in the chamber, and it is NOT a sharp shoulder at all. It is imperceptible via the probe. The reamer seems to use a gradual slope for this area, it just appears to be a sharp transition in the photos because of the light.

There have been a few anecdotal stories of how excessively tight .22lr chambers may actually hurt accuracy, due to excessive leading/lube buildup. Here is another post on the subject. It deals with bolt guns, but I think you can extrapolate the principles to .22lr revolvers easily enough. Personally I think by chambering the gun in SAAMI standard, you get the best of both worlds, accuracy AND function. This is borne out by anecdotal evidence from those who have reamed their K22/Mx17...

"A competitive bolt gun in 22LR uses a very tight chamber. I learned about all this working for Neal Johnson and Anschutz as a gunsmith on Olympic Target Rifles for resident athletes at the Olympic Training Center in Colorado Springs.

The throats on the chambers are short and they are tight. Match grade barrels typically run the minor bore dimension a couple thousanths tighter than what the SAAMI tolerance is.

This "chokes" the bullet and helps insure that it is running concentric to the bore's centerline.

Well, that's great on a bolt gun where you have a powerful camming action when going into battery.

Blow back operated semi autos won't put up with this, so it's modified to what is commonly called the "Benz" chamber. It's a compromise between the two.

The throat region is kept "almost" as tight while the back half of the chamber, the part that supports the case, is loosened up a bit to facilitate operation. (Feeding, chambering, and extraction)

The bullet gets the support it wants and the chamber will let the gun "run" right."

Click to expand...

I would go with a reamer before I polished. Why? Several reasons. One, well, because the chambers are already well polished from the factory. So what you're doing with the polisher to gain function is actually removing material. What that means is that you're doing the same job as a reamer but in an uncontrolled fashion. You might off-center the chamber, or eggshell it, etc. Yes it is tough to remove a lot of material by polishing but that is what you're doing in principle. I would save time, effort, and do it right with a reamer. If you wanted to have less clearance in the chamber you could call up Dave Manson of Manson's reamers and have him custom make you a slightly tighter spec reamer to use. Two, because highly polished chambers aren't actually necessary or desirable to begin with - unless you have a chamber that is so tight the brass will force itself into every microscopic nook and cranny upon firing, necessitating a highly polished chamber for shell extraction. In bolt rifle terms (or in S&W .22jet terms) the cartridge brass upon firing will grip the chamber less if it is polished, and will exert more force on the bolt (or recoil shield). This will result in much larger bolt stress (in a rifle) and/or inconsistency (in a revolver). So polishing is good for the bullet, but not so good for the chamber, unless absolutely needed because of a ridiculously tight chamber.

Thanks for the helpful report. Can you say about how long it took to accomplish? Obviously there are instructions to read, some setup time, and time to get up the required nerve to begin.

About 1.5hrs for the whole cylinder.

I may try that I have 2 Really Nice Revolvers That Just sit in The Safe due to difficult extraction (a S&W 17-4 & a 6" Colt Diamondback)

What is the product number and price of the reamer if you don't mind
please?

Just be sure to use plenty of cutting oil, and "never" turn the cutter in a reverse direction. I recommend removing the cutter frequently and wiping clean several times for each chamber. When using any cutter, cleanliness is paramount. I've done 7 or 8 now and all have marked improvement.

Brownells Manson Reamer 513-051-220WB $45

Brownells Starrett #174 straight tap wrench $33

Brownells Cutting Oil $8

I have four S&W .22 cal revolvers, a pre 34, a 34-1, a pre 17 and an
18-4. The 18 is by far the worst of the four and it just sits in the gun
safe buried under other guns. It's in like new condition and I love the
gun but it's such a hassle to shoot it that takes any enjoyment out of
it. I've seriously thought about selling it just to get rid of it but if I
did I would probably never get another one. It would be great to use
it without a struggle so I'm going to give it a try.

Good job, I've done four of my k 22s and it's done wonders for them

Chamber reaming on the S&W 22 LR revolvers is one of the best things you can do. The Manson reamer is SAAMI spec so there's no "hogging it out" involved. You're just ending up with chambers sized like they should have come from S&W.

Not to hijack but am curious from those that might know, of the 2 brands of cutting oil carried by Brownells (Do-Drill and Viper Venom) does one perform better than the other? The Viper Venom is priced less per ounce and has a squeeze bottle to dispense from while the Do-Drill carries the Brownell name and is maybe better???

I used the Viper cutting oil and it worked great. The squeeze bottle is perfect for this task. High sulfur content is what you want and the Viper oil's got it (as you will smell). I'm glad people are going to try this, that was my motivation for posting.

tomcatt51 said:

Chamber reaming on the S&W 22 LR revolvers is one of the best things you can do. The Manson reamer is SAAMI spec so there's no "hogging it out" involved. You're just ending up with chambers sized like they should have come from S&W.

Click to expand...

My thought is that the chambers may have been undersized on purpose. If you think about it, this gives the buyer of the revolver the option to size the chambers to their needs, while retaining the tight freebore in the cylinder ahead of the chamber. If the factory's logic was that these were designed as competition guns, where some gunsmith work would be done as a matter of course, then that assumption makes sense. Anyways as I wrote earlier the post-reaming "dual size" of the cylinder I believe will give the best of both worlds, accuracy and function. Of course in a perfect world, reaming the chamber to SAAMI sporting spec, rather than dealing with bolt-gun territory SAAMI match chambers in a hand-ejected revolver, would not be necessary, and the factory would have found a way to use the extra length of the cylinder in front of the chamber as an accuracy aid without impinging on function.

I've been using Brownells' Do-Drill. I apply it with an acid brush. It's the brown nasty hi-sulfur stuff. I've seen no reason to change.

Can't say if it's better or worse than the Viper Venom but NOT being in a squeeze bottle probably means I waste less by not over applying.

PzKfW5 said:

Of course in a perfect world, reaming the chamber to SAAMI sporting spec, rather than dealing with bolt-gun territory SAAMI match chambers in a hand-ejected revolver, would not be necessary, and the factory would have found a way to use the extra length of the cylinder in front of the chamber as an accuracy aid without impinging on function.

Click to expand...

??? Am I missing something? I have the Manson revolver specific reamer. It pilots off the throat and does NOT cut the throat. It does cut the chamber and tapers that cut into the existing throat diameter. I've polished down the pilot diameter on a mine a couple .0001's to accommodate the smallest throat I've encountered. Reamed chambers retain pre-reamed throat diameters.

I had a nice Model 18 that I got so tired of I sold it and purchased the M&P .22C, problem solved and I'm having fun plinking again. Interestingly enough I just bought a '97 vintage Model 317 that did not have the tight chamber problem, who knows why.