Model 43 Airweight Tight Chambers

[Rodfac]

A friend has brought his M-43 Airweight over looking for a cure for its overly tight chambers. It's an ejection problem which worsens after as little as 12 shots. To be precise, the gun is an aluminum framed M-43 with an aluminum cylinder.

I do have a Brownell's reamer which worked wonders with my own Model 18 & cured the same stiff ejection problems. We've tried polishing the chambers, and did a thorough cleaning to no avail. I'm inclined to the reaming solution and confident I can do it well, assuming that's possible.

It has an aluminum cylinder, verified using a magnet. Did S&W use a steel insert in those aluminum cylinders, and if so, is it possible to ream them as I have done with my Model 18?

The M-18 ream job was no problem and took about 40 minutes to complete. I used an excessive amount of honing oil and cleared all chimp 4-5 times per chamber, and had no problem doing the job. After finishing up, I put 70+ rounds through it, using a variety of brands of .22's. Accuracy was not effected...CCI Standard Velocity, for instance, is still averaging ~1.5" at 25 yds from rest...about the limit of my vision, in other words.

So, back to my friend's M-43 (serial number 846xx, with a 3.5" bbl. and a flat cylinder release latch). Are the cylinders steel lined or not? And can I ream the chambers if lined or if aluminum?

Thanks in advance. Best regards, Rod

 

[Truckman]

If it has steel liners, a magnet will show it...Your other questions I'll leave to someone else......Ben

 

[Alk8944]

The cylinder should be steel in nearly all S&W models, regardless of caliber.
The .22 caliber S&W revolver chambers are not tight, they are straight. If they were tight it would cause loading problems. Reaming introduces a slight taper into the chambers thereby relieving the extraction issue.

 

[Bill Lear]

The cylinder is 100% aluminum with a stainless steel extractor.
The surface both inside the chambers and out is anodized black which imparts a glass-hard surface treatment that resists scratches and deformation - kind of like case-hardening on mild steel.
Because an anodized surface is composed of hard particles of aluminum-oxide I would not think it easy to ream without damaging the reamer. Same goes for trying to polish the chambers - their surface is harder than the polishing compound!

I would consider trying a variety of different .22LR ammo, and maybe carefully examine the extractor star as a possible point of binding that can be corrected.

Me, being me, I would also consider buying a replacement cylinder - usually under $80 mail order and just swap the entire thing out, or send it back to S&W and see what they say.

 

[Retired W4]

You might find your answer posting in the Smithing section. There are some highly experienced gun smiths that hang out there that are more than willing to share their knowledge.

 

[SLCDW]

I second Bill Lear's suggestion to first try different ammo brands. I use my 43c extensively as a trainer for my center fire airweights. The cylinder is aluminum. I bought it new and when I first started shooting it, I noticed that many ammo brands wouldn't load, including my favorite, Aguila plated Super Extra. However, it had no issue with Federal HV match, so I shot a lot of it. Even with the HV Match, it had extraction issues after a few cylinders. I routinely brushed it out between cylinders to keep it running. After about 1000 rounds, I tried Aguila and it chambered and extracted with no issues. I then gradually began trying other ammo with no issues. My conclusion is that the aluminum cylinder broke in. How may rounds does your friend have through his 43c?

 

[Rodfac]

I had no idea that those cylinders were anodized inside and out; but the comments regarding reaming which would break the anodized finish inside the chamber makes sense...I'm inclined not to ream at this point for that reason alone.

No idea on the total number of rounds through it, nor where he acquired it.

Thanks for the tips on ammunition selection vs. reaming.

And I'll check the Smithing forum for suggestions, as well.

Thanx to all for responding. Rod