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Posted: 5/28/2014 2:08:39 PM EDT
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300 BLK in a suppressed AR-15 with a Noveske barrel. Load is 220 grain SMK to 2.26". I was having problems extracting none-fired rounds; having to mortar the gun to get unfired rounds out. No issues with feeding, extraction, or cycling. I thought all was good, I was shooting until empty and happy. Then I tried to extract an unfired round, not so happy. I am using Lee dies, some 300 BLK reloaders have had issues with the sizing die being slightly large. So today I ordered some RCBS AR 300 BLK small base dies thinking that was the issue. I was also thinking about polishing the chamber with some flitz. I took a look at the chamber, couldn't find anything that would indicate I had an issue. So I marked up a round with a sharpie. The bullet (not the case) itself had some marks in it, even the jacket showed some scratches (like it was sitting in the rifling). Then I tried to chamber some of my super loads (thinking it was the Lee dies as I used the same brass and dies); they are 125 grain TNTs I think about 2.15"; and no issues with extraction of those. This makes me think the OAL is to long for this chamber; next time I'll go shorter. However I have about 400 rounds of these loaded.
Any issues shooting them in this gun? |
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I did the COAL max length test http://www.thefirearmsforum.com/threads/determining-rifle-specific-coal.97328/
this gave 2.27, which is odd. So I tried a couple more bullets loaded, some were worse than others for extraction; definite signs on the jacket of being in the lands. I tried the max COAL test with a 210 grain MK and it was much longer 2.3 something. Anyways, I guess I'll shoot these up and use as a lesson learned; unless there is a problem. It is a very low pressure load (I assume based on it being at 1040 fps; and no high P signs). Next time I'll test a couple for extraction, not something I had thought about before; and being in the lands; been loading pistol for a while just started with the rifle. |
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Never had a problem with my Lee 300 blk dies, are you sure die is set correctly? (with a gauge) First thing to do is try to chamber and extract a sized only case. This will tell you if you sizing die is set correctly. If you have problems, sizing die is not low enough in the press. If all of this is good, reduce your OAL. Checked Hodgdon's data, it calls for 2.260. I would go to 2.250. Good luck.
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| Sizing die is good, fired cartridges and none loaded ones (ran through the press) fit and extract fine. Same setup with TNT 125s and a much shorter OAL extract fine. I think I went to far with the OAL for this chamber. The max OAL test gave 2.27 with the 220s, the test recommends going 0.015 to .03 less, so max I should load to would be 2.255. Like you said I probably go no more than 2.25 next time around. |
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