Bad 22lr chamber finish help

Hbjj · Jul 18, 2020

Ptg 52d reamer
Green mountain 416ss barrel
Ridgid dark thread cutting oil (its very old I'm guessing 20 years)
I'm holding the reamer with a tap handle and a center finder in a drill chuck
Running at 85 rpm (slow as my lathe will go)
Cleaning chips every .100ish
What am I doing wrong?

Also how do you guys finish your chambers after reaming

wesg · Jul 18, 2020

Curious what you took the picture with. Some strange artifacts there that had me baffled for a bit.

Assuming the nicks in the leade are the issue, they'll probably go away with a shallower pass. Try a couple at. 015 and see how it looks. Nothing wrong with starting at .100, just less as you reach finished depth. I usually back off on the feed rate as I approach depth and dwell for a second before retracting.

Higher RPM would probably help too. 150 or even more would be fine.

I finish rimfires with JB on a tight patch. Just trying to knock off any burrs on the lands and leade. The chamber body gets what it gets in the process. IOW, I dont bother trying to polish it with emery or whatever.

gappmast · Jul 18, 2020

Is it a new reamer? You may want to measure the back of the chamber to see if it cut oversize.

Hbjj · Jul 18, 2020

Its is a basically new reamer 1 chamber about 10 years ago
But the finish on it is very poor under magnification

Chamber is .2275 reamer is about. 227
The bore scope I'm using

What cutting oil are you using?

gappmast · Jul 18, 2020

I use a high surfer oil with animal fats and chlorine. Call Grizzly and get a bottle of Viper's Venom a lot of people use are using it for chambers.

wesg · Jul 18, 2020

Thats the reamer? Ouch. What kind of barrel did you chamber with it 10 years ago? I've got one that got trashed by a takeoff Remington 541 barrel, that seems to have been induction hardened at the breech. My best guess anyway. It's just fine a few inches up.

As for the tap wrench you're using, a t-handle type and spring loaded tap guide? If so, you'd be better off with a dead center and a crescent wrench. And I think there's so little material coming out of a rimfire chamber that the cutting oil type isnt so critical. Rigid dark is just fine.

Hbjj · Jul 19, 2020

The first barrel I cut with it was also a green mountain but 4140

The reamer setup

But after seeing how bad this reamer is I'm not going to use it anymore

Im getting set up to chamber one of these

I have high hopes that it will out shoot the green mountain stuff

It slugs a bit better
I going to try boring a chamber next

wesg · Jul 19, 2020

Ah, using the pointy end of an edge finder (the one I've never figured out how to use) as a floating pusher.

I'm curious as to whether you found any choke in the Anschutz barrel.

Since you're using a 52d reamer, I'm guessing this is a bolt gun? Another good choice is the Calfee chamber, .225 dia and a 2° leade. also known as an Eley, or EPS. I bought one as a throater, which was a bit cheaper I think, but it's pretty long too.

As for boring, I'd be concerned about getting a good enough finish on the leade. But at least it'd be one compound setting with a straight chamber. Finish is important, as these won't eventually burn the tool marks off like a CF.

I bought a GM blank years ago for an AR conversion, and didn't like how it felt slugging it. And I found out it needed to be mounted 'backwards'. It got tossed aside and I ordered a Lilja. Decided to try it out on a Kidd receiver recently. It felt pretty decent this time. Either my standards have gone down, or my slugging technique has improved (not likely), or maybe it got stress relieved a bit being thrown in a fiber drum for 10-15 years with a drill press casting set. Who knows. I tapered it, but left a larger straight section at the muzzle. Not sure it doesn't shoot every bit as well as the lapped match barrels I have on other rifles.

iwananew10K · Jul 19, 2020

hand holding will exasperate the tendency to chatter.
agree with the suggestion to ridgidly hold it.

Hbjj · Jul 19, 2020

I'm messing with the cheap gm barrel and they are basically wine barrel shaped inside
Tight ends loose middle with one tighter spot about 8"in from a end
They also usually have one grove that is a bit deeper than the rest
What more can I expect for 50$
Even with all that I'm getting them to consistently out shoot my stock ruger barrel
The anshultz is much more accurate in the grove/land. no measurable difference with a .0001 indicator
It slugs a bit better but still barrel shaped with less choke on one end

the end with the mark is the small end...

Gun is a ruger precision rimfire

I've been messing with a D reamer and boring chambers so far but I really wanted to do a proper reamer cut chamber but I think this reamer is dead

Ps I found the viper venom it's 20$ a pint!

wesg · Jul 19, 2020

I think PTG has it cheaper than I've seen elsewhere, 15 maybe. Dave pointed me in the direction of dark cutting oil, which is a bit harder to find in CA these days. But I found a reference to Oatey on PM, that its the only one left that's still chlorinated. Got a couple pints at HD. 8 bucks? Seems to be a bit thin, but got the job done.

A D reamer should work well. Classic screw machine solution for deep bores. A friend pulled a liner out of an old barrel, and the thing looked like a snake inside. I bored it true on one end, and made a drill with a v groove from A2. Overall, it was a failure to straighten it out, but the finish was nice.

I was too poor to buy one:

541-X from CMP. Threaded the receiver, put an 18 twist Lilja on it, Calfee chamber. Gutted the trigger and started over. I had access to wire EDM back then.

Shot a couple smallbore matches with it in a Ross Precision barrel bedded stock, and then it sat gathering dust for quite a few years. Then I got the idea to make a junior sized tube gun out of it. Cut the barrel back to 22" for balance and made a few small piles of aluminum chips. The only CNC work is the trigger guard/grip mount, and the buttplate and rocker. Dialed out all those slots in the forearm with an indexer, rough, finish, and chamfer.

Couple weeks ago, prone with sling and irons. Aquila SE (meh). 200 yards. I know it will do a lot better with good ammo, and a kid with good eyes and steady hands.

Hbjj · Jul 20, 2020

541x you say
I'm going to look that up
I'm not sure the ruger can ever shoot 1 moa constantly (that is my goal)
I'm interested in shooting NRL22 matches and the smallest target I've seen there is 1 inch at 100 yards
My best so far is about 1.4" average with green tag at 100
The ruger barrel was about 1.8"

Over on rimfire central forum there is a thread 50 at 200
That inspired me to try it and

my results
those groups are about 5x6 inches

BSCustoms · Jul 20, 2020

I used to shoot a local match with a Mossberg plinkster that I rebarreled with a blank from green mountain and a calfee spec reamer. Went from 4MOA to sub 1 out to 200. I eventually retired it for a sears model 1 that I put some time into.

I like that tube gun! Ive always wanted to chop up my old Anschutz like that. But the local matches dried up and I lost steam.

akajun · Jul 20, 2020

Try making an actual gloating pusher instead of using the dead center. If you tailstock is off even a tad, the center will not only cut a misaligned chamber, but will cause chatter as your cutting sideways on the body of the reamer against the lands giving a bouncing/spring effect.
Green mountain does in fact make really accurate 22lr barrels, I put one chambered one with a Bentz on a space gun upper and it shoots sub MOA at 100 with Wolf Match Target. As was stated above, the tight end was backwards so do your slugging before you cut it and make sure what you find translates to the point in the blank you want the muzzle to be. They are not hand lapped at all.

akajun · Jul 20, 2020

wesg said:
I think PTG has it cheaper than I've seen elsewhere, 15 maybe. Dave pointed me in the direction of dark cutting oil, which is a bit harder to find in CA these days. But I found a reference to Oatey on PM, that its the only one left that's still chlorinated. Got a couple pints at HD. 8 bucks? Seems to be a bit thin, but got the job done.

A D reamer should work well. Classic screw machine solution for deep bores. A friend pulled a liner out of an old barrel, and the thing looked like a snake inside. I bored it true on one end, and made a drill with a v groove from A2. Overall, it was a failure to straighten it out, but the finish was nice.

I was too poor to buy one:

View attachment 294452

541-X from CMP. Threaded the receiver, put an 18 twist Lilja on it, Calfee chamber. Gutted the trigger and started over. I had access to wire EDM back then.

Shot a couple smallbore matches with it in a Ross Precision barrel bedded stock, and then it sat gathering dust for quite a few years. Then I got the idea to make a junior sized tube gun out of it. Cut the barrel back to 22" for balance and made a few small piles of aluminum chips. The only CNC work is the trigger guard/grip mount, and the buttplate and rocker. Dialed out all those slots in the forearm with an indexer, rough, finish, and chamfer.

Couple weeks ago, prone with sling and irons. Aquila SE (meh). 200 yards. I know it will do a lot better with good ammo, and a kid with good eyes and steady hands.

View attachment 294453

Nice work on that tube gun

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