Colt McCloud, SASS #65003L Posted March 29, 2011 Share Posted March 29, 2011 1/ Just changed length of my rounds for my 73 - 357 from 1.428 to 1.5 and they work great(Don't ask why I changed!) . Used them first time back home in the cold weather and found them to be very dirty with a lot of blow back that I didn't have before. Could it be effected by the extreme cold or does the fact (likely) the lead is not going as far into the casing lend itself to more blow back? If so, I'd be interested in knowing the technical reason. 2/ Have been loading some 38S on my Dillon SD using a new batch of used Winchester casings. Have found the odd one is hard to push (lever down) for the last half of the case as if binding. Have examined my setup and all is good with the finished rounds being checked and gaged and all are good. Any thoughts or experience with recently acquired Winchester brass? Inquiring minds need to know! Thanks in advance for responses. Colt Link to comment Share on other sites More sharing options...
Appalachian Alan Posted March 29, 2011 Share Posted March 29, 2011 Are you still crimping the same amount. Less crimp means less powder burned Link to comment Share on other sites More sharing options...
Jackson Rose, SASS #45478 Posted March 29, 2011 Share Posted March 29, 2011 If you are loading new brass try tumbling first or lubing the brass before sizing. There is a protectant on the brass to prevent tarnishing. Tumbling usually takes it off. Link to comment Share on other sites More sharing options...
Garrison Joe, SASS #60708 Posted March 29, 2011 Share Posted March 29, 2011 1) Bet you might be using Clays powder. It and a few others are harder to light up at cold temperatures. When loaded as light as lots of pards load, those powders become erratic on the pressure they generate, sometimes a little dirty, etc. The erratic (low) pressure then makes the case fail to expand to seal the chamber on a 73, and you get blowback. Folks normally have to bump their load by 5% more Clays powder when the temps get cold. A slightly longer overall length should not make much difference on blowback - although leaving a little more "empty" volume in the case does lower chamber pressure slightly. Hint - ClayDot powder is much less sensitive to cold weather, I have found. 2) Run a single case at a time in your SDB to really find out what station is binding - but I'll bet it is the sizing station. try: * Check for dirty shell plate not letting the case enter the shell plate fully, thus being just a hair crooked in the sizing die. * Check that the case is exactly aligned when priming * Check for case exactly aligned under each die, including seating die. * Clean the insides of the dies * Lube cases with a shot of Hornady OneShot or another spray lube that you don't have to remove * Compare the rim thickness (slap on a caliper) of the new Win brass with older Win brass and the other brands you run that still run smooth. If the new brass is thicker, sounds like a bad lot of brass that maybe you can ask to be replaced. (Removed this part of reply, due to a mis-reading of the OP.) * If you are running used brass that is new to you (like range brass) then you probably have a few cases from someone's gun with a large chamber. Brass swelled up, maybe helped by fairly high pressure loads. Use some good sizing lube and you should be able to power through it. Good luck, GJ Link to comment Share on other sites More sharing options...
Buck D. Law, SASS #62183 Posted March 29, 2011 Share Posted March 29, 2011 Colt, in general I have found that I have more problems with Winchester brass than any other brand you would typically find. It's not significant enough for me to attempt to avoid using it. No scientific study you understand, just general observation. If you're only having this problem with recently aquired brass, I'd be suspicous of the sizing or loads of the person it came from. Once you have loaded it one time, does the problem go away? Link to comment Share on other sites More sharing options...
Charlie Harley, #14153 Posted March 29, 2011 Share Posted March 29, 2011 Cold weather can definitely cause some powders to burn slower and leave lots of extra residue. Blowback is caused by insufficient pressure to expand the case and seal the chamber. Seating depth might have a small amount to do with it, but temperature will have more. Make sure you're still putting a firm crimp on the bullet, even if you have to crimp into the smooth side of the bullet instead of into a crimp groove. Firm crimps definitely will help with complete powder combustion. As for Question #2, I'll bet the problem is in the sizing station with some dirt on the shell plate that is causing the case to not line up straight with the die. Remove the plate and clean thoroughly and I think you're problem will clear up. If the problem were thick walled brass, the loaded case would show a bulge where the bullet seated and then pressed out a bulge at its base. The other items suggested before are good to check also. The problem will clear up pretty quickly. Link to comment Share on other sites More sharing options...
Jefro, SASS#69420 Posted March 29, 2011 Share Posted March 29, 2011 Depends on the powder you are using and how much. A slower burning powder at the low end can be effected by temperature. I've loaded Red Dot and Tightgroup near the low end without any problems, however with Clays or Trailboss I needed to up the charge. Plus going from 1.428 to 1.50 could change the pressure. Run both your old and new load through a chrony to see if there is much of a difference. Good Luck Burn Rates Jefro Link to comment Share on other sites More sharing options...
twelve mile REB Posted March 29, 2011 Share Posted March 29, 2011 I have done the same thing in the past and found no difference that I could determine in burn rate or accuracy. I did find that in my particular rifle the levering got a little less smooth at oal 1.5, settled on oal 1.46 - 1.48 for the best operation. A new lot of used brass may have a few in it from guns with much larger chambers the extra effort is required to bring them down to the proper size at least that was the problem in my case. If the problem doesn't go away with the second resizing then you got a different problem. 12 Link to comment Share on other sites More sharing options...
Lefty Dude, SASS # 51223 Posted March 29, 2011 Share Posted March 29, 2011 Sounds like a crimp issue. If you lengthen your seating position, you must also do a crimp change. Lots of shooters use Clays Powder. There is a better powder out there, Y'all. Link to comment Share on other sites More sharing options...
Driftwood Johnson, SASS #38283 Posted March 29, 2011 Share Posted March 29, 2011 Just changed length of my rounds for my 73 - 357 from 1.428 to 1.5 and they work great(Don't ask why I changed!) . Used them first time back home in the cold weather and found them to be very dirty with a lot of blow back that I didn't have before. Could it be effected by the extreme cold or does the fact (likely) the lead is not going as far into the casing lend itself to more blow back? If so, I'd be interested in knowing the technical reason. Howdy You increased the interior space of the cartridge by almost 1/4". That is a pretty significant amount. All other things being equal, if you have the same powder charge and the same bullet, but increase the interior space of the cartridge, simple physics says the pressure will decrease. The specific powder and the cold may be an issue, but I'd say the overriding fact is you increased the interior space of the cartridge, so the pressure went down. Less pressure and the case does not obdurate as well to seal the chamber, so more blowby. Link to comment Share on other sites More sharing options...
Cypress Sam, SASS #10915 Posted March 29, 2011 Share Posted March 29, 2011 Driftwood is right on everything except his math. 1.428 from 1.500 is .072". A little short of the .250" needed for the 1/4". Link to comment Share on other sites More sharing options...
Colt McCloud, SASS #65003L Posted March 29, 2011 Author Share Posted March 29, 2011 Thank you each and every one of you for your input and suggestions. They helped confirm my suspicions and to identify my problem from my second question. 1/ For the extra blow back I suspected the increased OAL was the main factor for increased blow back and thanks to Driftwood Johnson I got the technical explanation. I have learned previously the effect of cold weather on ammo including primers backing out when hit so now I am even smarter on that one. 2/ For the brass issue: My SD does not like Dominion brass as it is a little too large at the base and won't seat properly. I don't use Dominion brass! I eliminated any problems with my machine and since other brass was not binding when I tested it I can only assume that those few pieces of brass that were binding were slightly over sized, likely from being fired in a larger chamber. The brass I acquired was floor swept stuff and included rounds from many shooters. I am now moving on into a different batch of brass and the "problem" has disappeared. Now as to the mathematical error Cypress Sam. I'll keep an eye for Driftwood and speak to him when I head out his way for some matches this spring. I'll know exactly what he looks like from his avatar!!! Thanks again all Colt Link to comment Share on other sites More sharing options...
Chickahominy Charlie Posted March 29, 2011 Share Posted March 29, 2011 <inserting tongue in cheek> No, no, no.....after reading DJ's intelligent and insightful technical replies in the past, I'm sure that it was merely a typo. You see, .072 is approximately 1/14th of an inch, not 1/4th of an inch. He jess left a "1" out is all..... I've flogged this expired equine several times before, but once more.... I load .38 special at 1.50 OAL (rather than the "book" length of 1.44). It's easy to see when you fire some of each that the fouling is "greatly" (by my humble subjective opinion) increased in the longer length cartridge. Less pressure, and (although milliseconds) less time for the powder to completely combust before the bullet leaves the cartridge. And my difference is even less than .072. FWIW. Chick Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.