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Change the powder charge or the spring?
Posted: Thu Jun 07, 2012 12:16 pm
I am trying to find a good combination of powder charge and spring for my gun. I am shooting a Mountain Competition Pistol .45 Wad Gun and moving to using cast 185 grain semi wadcutters (Saeco # 130 mold). I have an Ultradot Matchdot on a slide mount with a 10 lb spring. The gun is pretty new and this setup has worked well for a 200 grain semiwadcutter with 4.0 grains of Bullseye. It certainly shoots far better than I can hold.
I started with the same 4.0 grains of Bullseye and the 185 grain bullet. The load seems to be very accurate, again the limiting factor is clearly me not the gun. However, with this load, the slide does not lock back at the end of a magazine, and once did not go all the way to battery. That tells me that the charge and spring combination does not fully cycle the slide and that I either need to up the powder charge a tad, or put in a softer spring. I have 8 and 9 pound springs at hand and so I could change either the charge or the spring.
One additional fact: the felt recoil with a 4.0 powder charge and the 10 lb. spring is really light ( I have a sprinco recoil reducer installed.)
I know the correct answer is to try both changes, one at a time, but I thought I would seek your advice on which to try first and any advantages of one route over the other. I would like to keep the low recoil if possible.
So, first, is my reasoning correct, and, if so, what do you suggest also, if I go with increased powder, would you suggest .1 or .2 grains more to start?
Thanks for any help you can supply.
Posted: Thu Jun 07, 2012 2:19 pm
I would bump the charge up 0.1 gr at a time till you find that sweet spot. It may only take a 0.2gr change from where your at. I would hold off on the RS spring change unless your know for sure you will not shoot the heavier loads.
I keep my guns with the recommended springs and adj the charge. This allows me to shoot any loads without worrying about damaging my gun.
Posted: Thu Jun 07, 2012 5:14 pm
Welcome to Guntalk-Online.com.
Believe it or not you may have to up the spring tension to 11# or 12#. What may be happening is your slide is actually unlocking the lugs prior to the recoil energy being maximized for cycling the action. A good clue is that part about the insufficient energy to seat the new round. Some spring swapping and testing may be in order. A too weak spring can cause symptoms that look like one that is too heavy.
Posted: Mon Jun 11, 2012 4:02 pm
Thanks, Bullseye and others.
Well, I have been to the range and am now more confused than before.
The first trip, using either the 9 or10# spring and about 20 rounds each of 4.1, 4.2 and 4.3 grains of bullseye behind a 185 gr cast semiwadcutter and a COL of 1.190, everything seemed to work.
Hoping to stay with the 4.0 load, I took the 4.0 load to the range today and tried 8, 9, 10, and 12 # springs.
The slide locked back on empty for all except the 12# spring, which stovepiped on occasion.
All springs failed to push the slide all the way to battery intermittently, including the 12#.
Dropping the magazine when the slide has not gone all the way usually allows the slide to move all the way forward.
This leads me to suspect something about the feed is not right. The only thing I can identify is that the next bullet in the magazine moves forward maybe 3/16" which may be interfering with the bullet going into the chamber.
I pulled the firing pin for safety and ran a bunch of shells through the gun with different COLs, but couldn't find anything that looks like an answer to me.
The longest COL #1.230# did not pull forward, and is about as long as the magazine will allow. I have 4 magazines (all pretty new metalform elites which came with the gun) and all perform the same.
Frankly, I am baffled. The first rounds always feeds smoothly, but when I cycle the gun slowly to look for some interference or feel some drag, I can't find a thing and the slide stops short of battery. Lifewise when I let the slide go forward at full speed.
This would seem to take thespring weight out of the equation, because the slide is not being driven back by firing, but by hand, and none of the springs does the job all the time.
Unless you folks have some helpful ideas, I will be on my way to the local gunsmith for a consultation.
Someone wise would probably quit with the 4.0 load, but I hate to quit when I don't understand the problem, and now this doesn't seem spring-related.
Posted: Mon Jun 11, 2012 6:45 pm
The next question would be are you running a magazine that has a wadcutter style release on the feedlips? Or are you running GI style feedlips?
Posted: Mon Jun 11, 2012 9:04 pm
Thanks again for all your attention to my problem.
This gets more and more interesting. I knew nothing about magazines except that these are what Dr. Nick supplied with the pistol. In fact, I had wondered what they were so that i could buy more if necessary.
Your post caused me to read several articles by C. Kaukl on 1911 magazines and feeding. I certainly don't know much, but a lot more than before.
My mags seem to be Metalform 45-747M's with round followers.
As best I can measure, the feedlips are parrallel up to the point at which the cartridge rim is released, which I think means they are wadcutter feedlips. I hope that helps with your analysis.
My reading came across a reference to 3 point jams and stem jams. I don't really know anything about either, but he describes stem jams as when the cartridge is not released in time and binds under the extractor. he says these can be cleared in most cases by pushing the slide forward. My jams can be so cleared, but careful watching of the feeding process seems to show the cartridge feeding well until released from the magazine, whereupon the rear of the cartridge jumps up to the point that it is above the cartridge nose and the case hits what I think is called the hood of the barrel and the cartridge does not feed from there. Dropping the magazine at that point usually allows the cartridge to level out and feed the rest of the way, sometimes not all the way without a small push for the last 1/4 to 1/8".
Query, is this a stem jam?
The 3 point jam seems to describe a situation in which the cartridge is nose up into the chamber and caught below the extractor. That does not appear to be my situation. My cartridge jams with the nose slightly down, if anything.
Virtually all the litersture I have found describes flat followers. No mention of round followers, except to mention their existence.
Does this info help?
Posted: Tue Jun 12, 2012 7:00 am
When you first posed your question I knew there could be more issues with the firearm that could cause these problems but I went ahead and just advised on spring weights. Extractor tension, magazine feeding, barrel seating, chamber, throat, lug engagement, and barrel links can also be causal factors, sometimes a little tuning in these areas may be needed. In most cases running the higher powered 230 gr. round nose and 200 gr semiwad bullets don't show these things but when you step down the power and go with the lighter 185 gr. bullets then they start to show in the fit, finish, and timing of the pistol. Since your's is a custom build, what does your builder recommend for use with these types of loads - have you asked them? You should give them a call, they may want to tune your pistol for you to run this load.
Posted: Tue Jun 12, 2012 8:48 am
How much difference is the bullet profiles between the 185 and 200gr? Are you using the same OAL or did you shorten it for the 185gr? Normally you want to be long as possible that feeds good in your gun. But on SWC you have a driving band you must set the bullet back too.
May try different mags. Wilson's 47D
But in any case I would expect a little heavier load for the 185gr pills.
Posted: Sun Jul 08, 2012 4:53 pm
Thanks to all for their suggestions, particularly Bullseye.
This has been an education in the inner workings of the 1911.
I know that Bulleye's last post was the correct advice, given all the things which could be causing the problem, but I was not ready to be without the gun for a long period if i could help it. So, I continued to try to solve the problem and determined that I might just have to use the 200 grain loads that work.
Friday I took the gun back with a variety of loads and springs from 8# to 12#.
I had previously determined that the problem did not seem to be related to any one magazine, it seemed to malfunction regardless of which of the four I have was in use. I normally rotate all 4, for some reason that seems the right thing to do but i couldn't tell you why.
In any event, I just used 2 of the 4 at first and after about 50 rounds, realized that 1 magazine was having all the jams. I then tried the other 2 and they had jams as well. So I have 4 magazines and 3 of them jam and 1 doesn't. Ahah!!
I took them all to my shop and measrued the width and feed lips. The one that works was narrower by .003-.005 inches. A bit of attention with a vise and a small hammer made them all the same as the one that worked.
Today I had a chance to try the gun and all magazines work properly with the reduced 185 grain loads.
I should have realized when I said in my 1st post that the slide went to battery upon ejecting the magazine that the problem was with the magazine, but did not expect to have 3 out of 4 be a problem.
Studing the wear on the magazines showed that the edges of the feed lips on the bad magzines were worn shiny at just the very top edge. Apparently this was the source of friction causing the problem.
Thanks again to all for the help.
Posted: Sun Jul 08, 2012 10:33 pm
When you're running right on the edge performance-wise it doesn't take much to cause a problem. I'm glad you've tuned out the problem and you are fully functional again. Not to mention you got a good look at what makes them work with 185's.