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Posted: 9/23/2009 7:39:07 PM EDT
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My Bushmaster Xm15-E2S has been locking up. It happened 3 times so far in the past 2 weeks only on chambered live rounds. It locks up about a half an inch before completely chambered. I have to slam the buttstock on the ground to free it. It seems to only happen with my reloads. The O.A.L checks out and the brass isn't bulged. They chambered fine in my other ARs, and will rechamber in this gun also if tried again.
Heres a pic: 
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Ditto, ammo test gauge should be in order. I will tell you if the cases are being full sized, the cases are OAL trimmed correctly, and even if you are applying too much bullet crimp pressure and slightly buckling the cases at the shoulders.
As for setting up 99.9% of the sizing dies, you want the bottom of the sizer to kiss the shell holder under ram pressure. If you set the depth of the sizer without loading ram pressure of a case being sized, then chances are the sizer bottom is no where close to the shell holder under tension. So to recap, Cases first full lenght sized (sizer set up correctly), Next the cases trimmed/unified to the correct OAL. Then when crimping the bullets, only a light amount of tension is needed, since too much tension will buckle the shoulders. Also to point out, if you are not unifying the cases in OAL, then when you batch reload, some cases will be under bullet crimped, while others over crimped with the shoulders buckling. Bottom line here, time to go back to reloading 101 basics since it seem the problem is stemming from such alone. |
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All I am using is a Lee Classic reloader kit with a Lee case trimmer and case length gauge. So there is no adjusting. I have not been crimping the bullets, as they seem to be tight the way it is. It takes literally at least a hundred hits to remove one of the bullets with a kinetic bullet puller. So there should be no bulging at the neck unless it is doing it when I "pound" the bullet in.
BTW I just started reloading. I am using Hornady 55g FMJ bullets, 20 Grains of H322, CCI small rifle primers, and Lake City brass. |
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All I am using is a Lee Classic reloader kit with a Lee case trimmer and case length gauge. So there is no adjusting. I have not been crimping the bullets, as they seem to be tight the way it is. It takes literally at least a hundred hits to remove one of the bullets with a kinetic bullet puller. So there should be no bulging at the neck unless it is doing it when I "pound" the bullet in. BTW I just started reloading. I am using Hornady 55g FMJ bullets, 20 Grains of H322, CCI small rifle primers, and Lake City brass. Lee classic kit ? The one you use with a wooden / plastic mallet ? Not completely sure , but do not think they 100% FL re-size ? God bless Wyr |
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From the website... "Accuracy is better than most tools because it only sizes the case neck. "
http://www.leeprecision.com/html/catalog/cleeloader.html |
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Yeah it is, I though it completely resized it when you pound the brass into the sizing tool. Maybe it just sizes the neck? Most, it not all semi autos will need FL sizing. The hand LEE loader can still be useful at the range to load and test, previously FL sized cases. 458 |
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Yeah it is, I though it completely resized it when you pound the brass into the sizing tool. Maybe it just sizes the neck? Most, it not all semi autos will need FL sizing. The hand LEE loader can still be useful at the range to load and test, previously FL sized cases. 458 Not really, since in auto actions, the case is blown out from the chamber dimension slightly as it leaves the chamber during the pull under pressure (unlike a bolt action where the case is retained in the chamber until all the bore pressure has dropped. In an auto action, you want to full size the case unless you are sledding, even then you will end up going after the forward assist to confirm that the bolt has locked home. |
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Some interesting thought and I was hoping to find a possible soulation to my similar issue. Only I am having issues with getting loaded unfired rounds to eject with out a 'little' extra help. Prepped brass will function just fine, it is loaded rounds. I am using a RCBS Rock Chucker press, RCBS small base dies and a wilson cartridge gage. Bullets range from 55 gr FMJ to 69 sierra MKHP. Commerical rounds function as they should.
Any thoughts? |
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Some interesting thought and I was hoping to find a possible soulation to my similar issue. Only I am having issues with getting loaded unfired rounds to eject with out a 'little' extra help. Prepped brass will function just fine, it is loaded rounds. I am using a RCBS Rock Chucker press, RCBS small base dies and a wilson cartridge gage. Bullets range from 55 gr FMJ to 69 sierra MKHP. Commerical rounds function as they should. Any thoughts? Shoulders buckled due to too much bullet crimp pressure or the sized not correctly sized to begin with (sizer not set under ram tension while sizing a case for the bottom of the sizer to just kiss the top of the shell holder). Cases not first sized, then trimmed to the correct OAL. (read ammo should fall in and out of the test gauge, and the end of the case should not protrude past the top of the gauge for the two above items), Bullets not seated deep enough, and they are embedding into the throat of the barrel at loading. |
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DAMO523
I have checked all of these things in my 'trouble shooting' this issue. I have mic'ed both a new cartridge and several of my reloads. They all mic out just fine. I then chambered one brass that had been prepped. It functioned like it should. Then I installed a primer, still worked as it should. Now here is where I did something a little different, in that I used a 55 gr soft point bullet. It functioned as it should. I have not tried this with a 55 fmj or the 69's. For the life of me, I can not figure this one out. I load for 14 other calibers and lots of different weapons. This set of 223/5.56 for some reason is just different. I even went so far to 'blue' the cartridges that are giving me issues to see what areas are hanging up. Other then the marked coming out of the mag there are no signed that there is a clearance issue. Any other ideas? |
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I am using RCBS small base dies, dated 79. I have about 1/8" distance between the top of the ram and the bottom of the die. I am not crimping the rounds so I do not beleive that I am shoving the shoulder back any. Also in mic'ing the loaded rounds they mic out the same as a factory loaded round.
I even thoguht that the chambers might be rough but considering the this is happening on three Bushmaster's and one Colt, it has to be the loaded rounds. Just not sure where the issue is. |
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I have those same RCBS dies, and the bullet seat die should not be touching the ram/case holder. It will crush the cases. Are you crimping your cases? Been reloading with RCBS dies for longer that I dare to say (read decades). Please show me in writing where it tells you to raise the sizing die off the shell holder any distance since this is in contrary to any thing that I have seen printed by them. http://www.rcbs.com/questions/dies_questions.aspx Here they state to set the base of the sizer against the shell holder, then lower the shell holder and add an additional 1/8 to 1/4 turn more downward (hence base of the sizer will touch the holder when under sizing tension). Only in the case of the neck sizing dies do you not use the base of the shell holder off the bottom of the die, but instead mic/adjust the die until it only sizes the neck to the base of the shoulder. Regarding other systems, such in the use of a progressive presses where instead of a having a single shell holder, you have a carousel multi holder and adjust the sizing dies down until they have achieved the desired amount of sizing set back. |
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I wont dispute you've been loading longer than I, but here's what is written in the instructions included in my dies:
I looked for a document number but I dont see one There is probably an electronic copy but I dont have time to look!?!? Small base die set. 223 rem Part num: 11103 group: A Bullet seating without crimping. "Important: ... do not adjust the seater die down againt the shell holder as it will distort of crush the case." |
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Bullet seating die is not dependent of the case sizing in any way, it is adjusted to either get the cannelure of the bullet aligned to the mouth of the case for crimping, or to achieve OAL for a bullet without such.
Never have I seen the bottom of a bullet seating die anywhere near the face of a shell holder to get the correct seating depth, and this is even on loads for barrels that have very short throats. Simply, in the bullet seating die, the shell holder has no relevance at a constant to what is going on (due to OAL trimming of the case), and instead you need to mic the bullet depth alone against the mouth/case to insure that the depth settings of the such are correct. |
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And the plot thickens!!! Now that I have had a little time to trouble shoot this a little more, I think that part of my problem is the mil brass that I am attempting to use. If I 'lap' the base of the brass a little they function as the should. I have shot commerical loads and then work that brass into reloads and they seem to function OK. Is it possible that the mil brass that I have was out of a M249?
Guess that I will have to use the mil brass that I have in one of my other rifles. |
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Not sure of what dies you are using, but my RCBS small base, and my Hornaday dies will size the brass well past/lower then the top of web section of the cases when set correctly.
The problem with Loose chambered Saw brass is that when it gets blown out (above the web section), when you go to resize it back down, the case walls become very thin at the point (case side wall just above the web) and you end up with the cases splitting there. |
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OP, it appears you need to use a small base die. Are you using brass fired in a bigger MILSPEC chamber in a tighter SAAMI commercial chamber? It is my Bushmaster xm15-e2s 24" fluted barrel that it happens in. Would those have tighter chambers? Are you trimming your cases to length? Long cases will also prevent complete chambering. Yeah I am trimming the cases. |
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Bushmaster does ream their chambers tighter than some other barrel makers (side wall dimensions), but not to the point that it should cause loading problems.
Is if just the section of the case below the web section of the case that is too large, and not the point of base web to inner void side wall that is causing the problems? |
Back off the crimp and your gtg
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