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First are you having any difficulty chambering your reloads? If not, then your chamber probably isn't too tight( see below about tight necks possibly)). I have not checked your loads for overpressure, but assuming they are oK, pull the bolt and hold the barrel up to a bright light source and look carefully at the chamber. see any evidence of rings or rust pits? If so that's why your cases are sticking. If not cycle a fired case and look carefully at the extractor. Is it jaming?. If you load an unfired case FROM THE MAGAZINE, then pull back the bolt does it jam? If so it's your extractor. Make absolutely sure you don't have a bolt thats binding up because of improper scope mount screws or other things that will cause the bolt to drag. Finally, measure the case at the belt. Compare it to an unfired case. If the belt has expanded more than .003 your loads are way too hot. Make absolutely sure you don't have a tight neck chamber by making a cerrosafe cast and measuring all the dimensions. Although I have never seen one, it's possible that your chamber could have been made with a reamer that produces a tight neck. Normally a 450 Ackley reamer will produce a very large neck but anything is possible. If so, your pressures will skyrocket even with normally safe loads. You might try first neck reaming a few cases, loading them as before and seeing if this is the problem. Don't waste your time trying to headspace a 450 Ackley off the shoulder, that isn't where your problem lies. I'll run your loads on quickload as soon as I get a chance.-Rob [ 10-23-2003, 04:54: Message edited by: Robgunbuilder ] | |||
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Check for pierced primers, sometimes thats a culpritt....What Robgunbuilder sez....then again maybe your loads are too hot...Do you use a chronogaph..Some barrels are tight so you might slug yours...You just have to investigate all the factors... | |||
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resize and make a dummy round... NO PRIMER close the bolt let trigger down open bolt does it still stick? jeffe | |||
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<Timberghost> |
Rob, Chamber is smooth like a mirror. Unfired rounds feed like butter,very smooth and eject great. After reading your reply, I fed some fired brass through it. They all stuck in the chamber just as bad as when they were fired. They also chambered hard. I even tried the same round over & over. It stuck every time. This is a "blanking" push feed gun, but that shouldn't be causing the case swelling in front of the webbing should it? Ray, The 400gr A-Frame chrono'ed at 2412ft/sec with 84grains of IMR4064. | ||
One of Us |
A-square might also use Bertram Brass as there supplier Have you tried another type of Brass ?? | |||
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Timberghost- OK, now outside neck ream a few fired cases. Remove about .003-.004 from the neck of the case all the way back to where the neck meets the shoulder. Now reload the case with your normal load and see if the cases stick on firing. If not problem solved. If so make a Cerrosafe cast! Also. are you making 450 Ackley cases from .375 H&H brass by fireforming?-Rob | |||
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<Timberghost> |
Rob, The first cases were factory headstamped A-Square .450 Ackley. The second cases are Hornady basic magmum. They are straight wall and I neck them down with my FL sizer die. I will try the outside neck turning and let you know how that goes. I hadn't considered a tight chamber at the neck because the unfired rounds chamber smoothly. Thanks for the ideas , Ghost | ||
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Timberghost- I have no experience with either make of brass. I've always made my 450 ackley brass by taking .375 H&H brass adding about 15 grs of Bulleseye and some corn meal to fill the case and sealing the case with some soap. These rounds fireform well enough to reload perfectly. I now suspect you are dealing with a combination of a tight necked chamber and that using the Hornadyand/or A-square brass is giving you some whopping pressures. If so thank God you didn't start out with a max load! If you have a micrometer, what is the outside neck dimension of one of your loaded rounds? I have some 450 Ackley reamer specs here and it might be very informative. Turn a few case necks down .004-.006 inches, reload them and on firing, I'll bet no more sticky extraction problems.-Rob | |||
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<Timberghost> |
Rob, I don't have a mic, but the calipers read 0.477" on a loaded round neck. The A-square book says 0.486" at the mouth and 0.487" at the base of the neck. The fired brass is roughly 0.485" but its hard to measure without flexing the case some. Thanks so much for your help, Ghost | ||
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Timber--All of my books call for the neck to measure .481. The loaded dimension of .477 is OK...If your case neck is measuring .485 after firing, that may stick if chamber is tight in neck.I say may, because if the chamber was tight in the neck, the fired brass shouldn't be .485 in the neck. Unless the barrel is so tight that you are getting high pressures, with the powder you are using.Take a fired case and cut off neck and see if it extracts easy.If you are in the load developement stage and want IMR powders you should use 4350 for starting.Ackley's in a lot of cases are being loaded with too fast of powder. DB Ball powders would be better if you have a real tight rifle, like W-760 or H-414.The BIG BORE BOOK shows slower powders with 500 gr than you are using...Ed. | |||
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Timberghost, Unless A-Square has changed their brass you will probably find the brass is too soft and that is where your problem will be. Fireforme a Winchester 375 H&H brass to 450 Ackley and load the same load to prove this. I've had the same problem with A-Square brass in my 500 A-Square. Take care, Dave | |||
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<Timberghost> |
Hubel458, I don't have any data for slower powders than 4320 in 3 books(including Ackleys) or the internet . I have considered slower powders to lower pressure, however I am filling the case close to compressing with 4064 and 4320. This makes me think that ball powders might be the answer . Can you send me some data or post it here? I would start low and work up carefully due to the history of stuck cases in this rifle. | ||
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Timberghost- Well good data and it helps alot in the diagnosis! I'll check my reamer dimensions and see what I get. If your loaded round is .477 and a fired case is .485, it sure sounds like there is enough neck clearance, assuming the neck is actually concentric?. Please measure the belt of a fired case vs an unfired one. If you have access to some DYECHEM, spray a fired case, let the die dry, then chamber it and tellme where the rub marks are. Try trimming your case back about .020 in the unlikely event that your crimping the bullet into the leade. Try making some cases from .375 H&H brass, trim as described and a load with IMR 4350. I also like to use WW760 in that case, but I don't remeber my load exactly. I'll look it up tonight!. If that doesn't solve the problem, you need to make a cerrosafe chamber cast and see exactly what you have there.-Rob [ 10-23-2003, 19:32: Message edited by: Robgunbuilder ] | |||
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One of Us |
My A-Square brass has sticky extraction every time. I would start over with some other brass and see if the problem recurs. | |||
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<Timberghost> |
Rob, I talked with a friend today. He will do a chamber casting with the cerrosafe for me next week. I will post the exact measurements when I get the gun back. All, Any load data with the slower powders would be greatly appreciated. I have a gap in powders, and knowledge of them, from IMR4320 to H-4831. I am a safe reloader and would start well below any listed data. I just don't know where to start. Black powder season(9-days) for deer in Oklahoma starts Saturday, so I will be gone all but Tuesday-Thursday "damn job and all". | ||
<Timberghost> |
Rob, Belt of a fired case is 0.528" and an unfired case is 0.528" ? 1/4" above the belt(where its sticking)a fired case is 0.513" while an unfired case is 0.506" Thanks, Ghost | ||
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Timberghost, I used WW 748 in my 450 Ackley. The A-Square manual shows 80 grains of WW 748 for a velocity of 2067 fps with an average pressure of 30,700 PSI. Your Ackley should be a small amount less than this pressure wise. Your starting load that you used shows an average pressure of aproximately 50,000 PSI. You could back that load down to 76 grains with the 400 grain bullets and pressure problems should not be a factor. Rob, A-Square brass sucks and my 500 stuck hard with a 600 grain bullet at barely 2200 fps. Is it possible all the brass measurements will be unreliable due to the soft brass not springing back like a good quality brass would. That's why I aslo mentioned using Winchester brass. When I switched to Norma brass all my problems went away as well as Art Alphin. Take care, Dave | |||
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Timberghost- No belt expansion and the brass measurement above the belt sounds normal. I think there is a consensus that the first thing for you to do is you should fireform a few cases from WW .375 H&H brass( as described above) and see if the problem goes away. Try 80-87 grs of WW760 and a Fed 215 under a 500 gr Hornady crimped to the cannelure.-Rob [ 10-24-2003, 06:39: Message edited by: Robgunbuilder ] | |||
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Let me try a different direction, what action is the rifle built from and do you know the brand of barrel? | |||
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