Small base sizing for .30 carbine?? - Page 2

condor bravo · February 3, 2017, 12:26 AM

More and more cooper rings it seems left in the chamber after each shooting session that can't be helping the situation and perhaps a major contributor towards the chambering hang up. I've been using x-treme plated bullets; would you think a more sturdy fmj bullet would prevent leaving the copper rings in the chamber, and what bullet might you suggest? Invariably each carbine behaves better after chamber cleaning. Today even the military carbine got to the point where the rounds refused to feed and previously this was unheard of. The Inland accumulated more of the copper rings than usual.

condor bravo · February 6, 2017, 10:06 PM

Well I think I've finally got the chambering problem solved. As pointed out several times, the steel sizing die reduces the base to .354 as opposed to .355 for the carbide dies. That's all well and good but not the whole picture. Most of the times the rounds jam when they are only half chambered and at that point are tightly jammed, often requiring taps with a mallet to dislodge and clear the round. This would suggest that the hangups are occurring at the case body and not just at the base.

Back to the carbide dies. It turned out that sizing with the carbide dies reduces the case body near the center some .002 over the steel die at the same location. So the outcome has been to use one of the carbide dies along with the steel die. Using a Dillon 550 the steel die with decapping stem is placed at station1 and a carbide die with the decapping stem removed placed at station 2, leaving stations 3 and 4 for powder charging and bullet seating. This sizing technique, chambering the sized cases without bullets yet seated, for safety considerations, provides excellent chambering without a single hang up and with all five case brands being used.

These newly sized rounds were then loaded with Sierra 110 gr FMJ bullets which hopefully will eliminate the copper rings being left in the chamber by the plated bullets. Test firing with the new rounds will take place in a couple days when the rain subsides here in the southland.

February 3, 2017, 12:26 AM	#26
condor bravo Senior Member Join Date: August 23, 2014 Location: Nevada/Ariz/CA Posts: 1,753	More and more cooper rings it seems left in the chamber after each shooting session that can't be helping the situation and perhaps a major contributor towards the chambering hang up. I've been using x-treme plated bullets; would you think a more sturdy fmj bullet would prevent leaving the copper rings in the chamber, and what bullet might you suggest? Invariably each carbine behaves better after chamber cleaning. Today even the military carbine got to the point where the rounds refused to feed and previously this was unheard of. The Inland accumulated more of the copper rings than usual. __________________ Ouch, the dreaded "M-1 thumb", you just know it will happen eventually, so why not do it now and get it over with??

February 6, 2017, 10:06 PM	#27
condor bravo Senior Member Join Date: August 23, 2014 Location: Nevada/Ariz/CA Posts: 1,753	Well I think I've finally got the chambering problem solved. As pointed out several times, the steel sizing die reduces the base to .354 as opposed to .355 for the carbide dies. That's all well and good but not the whole picture. Most of the times the rounds jam when they are only half chambered and at that point are tightly jammed, often requiring taps with a mallet to dislodge and clear the round. This would suggest that the hangups are occurring at the case body and not just at the base. Back to the carbide dies. It turned out that sizing with the carbide dies reduces the case body near the center some .002 over the steel die at the same location. So the outcome has been to use one of the carbide dies along with the steel die. Using a Dillon 550 the steel die with decapping stem is placed at station1 and a carbide die with the decapping stem removed placed at station 2, leaving stations 3 and 4 for powder charging and bullet seating. This sizing technique, chambering the sized cases without bullets yet seated, for safety considerations, provides excellent chambering without a single hang up and with all five case brands being used. These newly sized rounds were then loaded with Sierra 110 gr FMJ bullets which hopefully will eliminate the copper rings being left in the chamber by the plated bullets. Test firing with the new rounds will take place in a couple days when the rain subsides here in the southland. __________________ Ouch, the dreaded "M-1 thumb", you just know it will happen eventually, so why not do it now and get it over with??