Tight chamber .40

  • 277 Views
  • Last Post 09 July 2017
Bearcat55 posted this 06 July 2017

Hello all, seeking some education and advice. Have a Ruger SR40c which strongly prefers jacketed bullets, but I'd dearly like to wean it over to lead. Doesn't want to quite go fully into battery with any lead bullet I've tried. All the way down to minimum OAL doesn't help. Tried light 145 grain Lee swc, and 180 gn swc and 180 TC.. Sized to 401, appropriately flared and taper crimped. Of course jacketed tend to be a thousandth or two narrow, as expected. My buddy has an identical pistol which has no such problem, his loads or mine. Manufacturing tolerances of course.... Case gauge plunks just fine on all my loads, but my chamber not so well. What now? Rethroat the chamber?

tight-chamber

Attached Files

Order By: Standard | Newest | Votes
Duane Mellenbruch posted this 06 July 2017

Is it failing to go into battery because the cartridge is too fat or because the cartridge OAL is too long?

How have you determined the minimum cartridge OAL?

Attached Files

David Reiss posted this 07 July 2017

I would almost bet the cause is a tight chamber as you suspect. But before you rechamber, make a chamber cast or slug it. If it is truly under specs, then send it back to Ruger to have them fix it. It should normally accept properly loaded and sized .401" CBs. However you may need to size your CBs at .400" to get them to chamber. 

David Reiss - NRA Life Member & PSC Range Member Retired Police Firearms Instructor/Armorer
-Services: Wars Fought, Uprisings Quelled, Bars Emptied, Revolutions Started, Tigers Tamed, Assassinations Plotted, Women Seduced, Governments Run, Gun Appraisals, Lost Treasure Found.
- Also deal in: Land, Banjos, Nails, Firearms, Manure, Fly Swatters, Used Cars, Whisky, Racing Forms, Rare Antiquities, Lead, Used Keyboard Keys, Good Dogs, Pith Helmets & Zulu Headdresses. .

Attached Files

  • Liked by
  • Bearcat55
Bearcat55 posted this 07 July 2017

Measuring OAL with digital calipers against published for the given bullet/load. My cast bullets are sized to .401 (actually .400 at the mouth of the brass) where some factory Winchester reads .397. Case headspace seems ok, but I'm still trying to fully understand the problem, thus my request.

Attached Files

Bearcat55 posted this 07 July 2017

I have no cerrosafe onhand, sure wish I did. Will slug it at least. This should save a lot if time & discussion with Ruger and provide a more clear picture.

Attached Files

beltfed posted this 07 July 2017

All about recent Ruger quality control problems that are being discussed in several forums

beltfed/arnie

Attached Files

GP Idaho posted this 07 July 2017

Bearcat55: A lot of the Ruger autoloaders have this problem. They just weren't built to shoot cast. The problem is the have no throat. My old clunker P97 Dc was totally reliable with jacketed ammo but just hated cast bullets (failed to go into battery) I sent it's barrel off to Doug Phillips (Doug Guy @Boolits.) He throated it cleaned up the ranp and recrowned it. It hasn't missed a beat sense. Gp

Attached Files

Ed Harris posted this 08 July 2017

Interesting.  

I am contemplating having a chambering reamer ground to do a .40 S&W revolver cylinder to be able to swap on my eventual .40/.44 Special Short (aka 10x25Rmm) Ruger Blackhawk.

If anybody has done such a thing, I'd like to know what you used and how it is working.  

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

Attached Files

45 2.1 posted this 08 July 2017

You have one or both of two problems. Either the bullet is too fat to chamber in front of the case neck (interference with rifling which seating it a little deeper might or might not help) or you need to taper crimp it a little tighter. I've had no problem in any Ruger semi-auto I've tried with lead myself when the cartridges are loaded properly.

Attached Files

Ken Campbell Iowa posted this 08 July 2017

consider that * OAL * numbers are a little squishy in predicting how the cartridge will fit any given gun .

because oal only measures the length to nose ... not the diameters behind the nose that might interfere with the magazine lips, the feed ramp, or the throat of the chamber .

just some trivia.... ken

Attached Files

David Reiss posted this 09 July 2017

I really don't like to diagnose an issue like this without the gun in hand. But my days as an armorer still say that it is an bullet diameter issue. While Ruger autos were not used in great numbers by the officers of the department (about 5,000), those that I did encounter tended to have similar issues. Hence our loaded .40 ammo for training had bullets sized to .400. 

This is not an issue limited to just Rugers. I have encountered this with other makes. 9 times out of 10 it was always a bullet sized a .001" or more too big. 

David Reiss - NRA Life Member & PSC Range Member Retired Police Firearms Instructor/Armorer
-Services: Wars Fought, Uprisings Quelled, Bars Emptied, Revolutions Started, Tigers Tamed, Assassinations Plotted, Women Seduced, Governments Run, Gun Appraisals, Lost Treasure Found.
- Also deal in: Land, Banjos, Nails, Firearms, Manure, Fly Swatters, Used Cars, Whisky, Racing Forms, Rare Antiquities, Lead, Used Keyboard Keys, Good Dogs, Pith Helmets & Zulu Headdresses. .

Attached Files

Ed Harris posted this 09 July 2017

Having an interesting email discussion with Dave Manson on dimensioning a .40 S&W revolver reamer.  Since I plan to use cast bullets in it, he will make cylindrical ball seat diameter on the reamer .4015-.4020", rather than .4005-.4010 which he does for jacketed factory ammo.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

Attached Files

Categories
Search
Popular Tags
This Weeks High Earners
Hot Topics
Close