OP
Two month update - Ejection issues solved
Evenin' Gents,
A couple months back I mentioned having occasional ejection faults. It didn't seem to matter what ammo I was using, I kept seeing the same problems with fired cases failing to leave and tying up the gun.
This kinda bovine excrement is bad for my blood pressure
Over the past few weeks I had tried correcting this fault by addressing a number of things.
Today, I went to the range and burned through 100 rounds of 165gr Speer FMJs in Underwood's loading (perfect training companion to Underwoods 165gr GDHP loading BTW. Thanks to 6actual for bringing that to my attention
). Anyway, The gun ran perfectly, not a single hiccup so I thought to share the things it took to get it running right.
Initially, I suspected the recoil spring weight might be at issue. I was thinking perhaps the spring was too heavy and either preventing full travel of the slide or closing the slide faster than the brass can leave. I tried progressively reducing the weight of the recoil spring from the original 30 coils to 28, 26, 24 and the 20 coil Wilson spring. This tack was a dead end. None of this meddling had any effect of the ejection problems. In fact the lighter I went in spring weight the further I had the chase brass and I started to see signs of early extraction in the cases.
Clearly messing with recoil springs wasn't the answer so the problem or problems must lie elsewhere. I closely examined the breechface area under the loupe, Right away I noticed the area opposite the extractor was very rough with a significant burr overhanging the breechface.
This is the the spot right here already smoothed out but still dirty after today's range session.
That overhanging burr acted somewhat like another extractor. With the slide off I could slip a case up the breechface under the extractor and as I tipped the casemouth towards the ejection port the rim would catch firmly on that burr.
So, how to fix that... No way to get at that with a file and I certainly didn't feel good about going in there grinding with a mounted stone. What I did was turn down a piece of mild steel hex bar to about the diameter of a 10mm case, chucked that in my lathe and with a little dab of 400 grit lapping compound on the end I carefully ran the slide up over the spinning bar and lapped the roughness and burrs away.
Here's a closer look. It's that shallow radius cut right above the ejector. Nice and smooth now.
I wish I had taken a picture of that area before I cleaned it up, it was truly nasty. Of course everything looks worse under magnification but that cut looked like it was gouged out with a broken hacksaw blade.
Waited for another Saturday to come by and back to the range for testing. Once again I'm back to a full length 30 coil 22# spring installed in the gun. Ejection faults were much less frequent but I was still seeing problems so I turned my attention towards the extractor.
I didn't note any binding and the extractor pivoted freely. Checked the weight at deflection and it was just a hair over 5#. I pulled the extractor for a closer examination. Nothing out of the ordinary. Everything is clean & corrosion free, red spring installed (heavy), only thing I noted was whomever fitted this extractor did not know how to keep a file level & true when cutting on a part. The adjustment pad on the extractor was rolled on the edges with file marks going every which way. Hmm says I, methinks I be needin' a bar gage. For those who don't know, the bar gage is a tool for setting how far the extractor hook reaches across the breechface.
Anyway I eventually got around to calling S&W on the remote possibility I might be able to order a bar gage. No such luck, not even available. But was lucky enough to get a knowledgeable fellow on the phone and not some beancounter. While I didn't get a bar gage I did get the critical dimensions so I can machine one. In discussing my problem It was mentioned that during production, they were looking for at least 8# at deflection for the extractor weight on the 10mm guns and if a one didn't gage there even with the heavy spring they'd shim up the spring to make weight (lightbulb moment).
After thanking the gentleman I navigated right over to McMaster-Carr and added some 316 stainless miniature shaft shims to my running order.
In the meantime while waiting for that stuff to show up and knowing the specs for the GO and NOGO on the bar gage I was able to sort of halfassed gage the extractor with a caliper. Not exactly precise but it looked to me like the extractor did not reach in as far as it should however, I'll not mess with the adjustment until I've made a proper gage to go up in there.
Shims got here a couple weeks ago. I got a pack of 0.005" and one of 0.008". That tiny silver washer on the bench block is one of them.
Just drop 'em in the recess under the extractor spring.
A little bit of trial and error and were spot on with 8# at deflection with 0.024" of shim under the extractor spring
All good to go and cleared for belt duty A sharp eye will detect that I've carried on with the "pinto" motif a bit. The original black sideplate is gone in favor of an updated R1 version. I also changed the trigger pin and magazine catch nut to stainless parts. I think I'll make a stainless grip pin tomorrow
Finally getting this thing to run fault free with heavy full power loads is pretty darn satisfying. Still, I need to fab a proper bar gage and double check the extractor reach so there will probably be another update once I get by butt in gear and make the thing.
Cheers
Bill
Evenin' Gents,
A couple months back I mentioned having occasional ejection faults. It didn't seem to matter what ammo I was using, I kept seeing the same problems with fired cases failing to leave and tying up the gun.
This kinda bovine excrement is bad for my blood pressure
Over the past few weeks I had tried correcting this fault by addressing a number of things.
Today, I went to the range and burned through 100 rounds of 165gr Speer FMJs in Underwood's loading (perfect training companion to Underwoods 165gr GDHP loading BTW. Thanks to 6actual for bringing that to my attention
). Anyway, The gun ran perfectly, not a single hiccup so I thought to share the things it took to get it running right.Initially, I suspected the recoil spring weight might be at issue. I was thinking perhaps the spring was too heavy and either preventing full travel of the slide or closing the slide faster than the brass can leave. I tried progressively reducing the weight of the recoil spring from the original 30 coils to 28, 26, 24 and the 20 coil Wilson spring. This tack was a dead end. None of this meddling had any effect of the ejection problems. In fact the lighter I went in spring weight the further I had the chase brass and I started to see signs of early extraction in the cases.
Clearly messing with recoil springs wasn't the answer so the problem or problems must lie elsewhere. I closely examined the breechface area under the loupe, Right away I noticed the area opposite the extractor was very rough with a significant burr overhanging the breechface.
This is the the spot right here already smoothed out but still dirty after today's range session.
That overhanging burr acted somewhat like another extractor. With the slide off I could slip a case up the breechface under the extractor and as I tipped the casemouth towards the ejection port the rim would catch firmly on that burr.
So, how to fix that... No way to get at that with a file and I certainly didn't feel good about going in there grinding with a mounted stone. What I did was turn down a piece of mild steel hex bar to about the diameter of a 10mm case, chucked that in my lathe and with a little dab of 400 grit lapping compound on the end I carefully ran the slide up over the spinning bar and lapped the roughness and burrs away.
Here's a closer look. It's that shallow radius cut right above the ejector. Nice and smooth now.
I wish I had taken a picture of that area before I cleaned it up, it was truly nasty. Of course everything looks worse under magnification but that cut looked like it was gouged out with a broken hacksaw blade.
Waited for another Saturday to come by and back to the range for testing. Once again I'm back to a full length 30 coil 22# spring installed in the gun. Ejection faults were much less frequent but I was still seeing problems so I turned my attention towards the extractor.
I didn't note any binding and the extractor pivoted freely. Checked the weight at deflection and it was just a hair over 5#. I pulled the extractor for a closer examination. Nothing out of the ordinary. Everything is clean & corrosion free, red spring installed (heavy), only thing I noted was whomever fitted this extractor did not know how to keep a file level & true when cutting on a part. The adjustment pad on the extractor was rolled on the edges with file marks going every which way. Hmm says I, methinks I be needin' a bar gage. For those who don't know, the bar gage is a tool for setting how far the extractor hook reaches across the breechface.
Anyway I eventually got around to calling S&W on the remote possibility I might be able to order a bar gage. No such luck, not even available. But was lucky enough to get a knowledgeable fellow on the phone and not some beancounter. While I didn't get a bar gage I did get the critical dimensions so I can machine one. In discussing my problem It was mentioned that during production, they were looking for at least 8# at deflection for the extractor weight on the 10mm guns and if a one didn't gage there even with the heavy spring they'd shim up the spring to make weight (lightbulb moment).
After thanking the gentleman I navigated right over to McMaster-Carr and added some 316 stainless miniature shaft shims to my running order.
In the meantime while waiting for that stuff to show up and knowing the specs for the GO and NOGO on the bar gage I was able to sort of halfassed gage the extractor with a caliper. Not exactly precise but it looked to me like the extractor did not reach in as far as it should however, I'll not mess with the adjustment until I've made a proper gage to go up in there.
Shims got here a couple weeks ago. I got a pack of 0.005" and one of 0.008". That tiny silver washer on the bench block is one of them.
Just drop 'em in the recess under the extractor spring.
A little bit of trial and error and were spot on with 8# at deflection with 0.024" of shim under the extractor spring
All good to go and cleared for belt duty
A sharp eye will detect that I've carried on with the "pinto" motif a bit. The original black sideplate is gone in favor of an updated R1 version. I also changed the trigger pin and magazine catch nut to stainless parts. I think I'll make a stainless grip pin tomorrow
Finally getting this thing to run fault free with heavy full power loads is pretty darn satisfying. Still, I need to fab a proper bar gage and double check the extractor reach so there will probably be another update once I get by butt in gear and make the thing.
Cheers
Bill
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