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Posted: 5/15/2011 8:42:22 AM EDT
| I've been reading with great interest the AR15 reloading data page relating to the .223 Remington cartridge. I've reloaded several thousand .223/5.56 cartridges and believe I've been following the "books", I don't guess, and I cross reference all my loads with at least two sources. My question is, have I been loading my bullets too deep? 90% of my loadings have been with the Hornady 55 gr. FMJBT w/cann. All are 24.0 to 26.0 grains of H-335, 450 CCI primer, LC brass. Data is from Speer RM # 14, page 202. I've been loading to a COAL of 2.215, most of you guys seem to be leaving your loads a bit longer. I fire these only in my AR 15's. Opinions please. |
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You will see a wide range of OAL in published data. You can sort through some references and see that the system used for testing the load is shown in some books.
For example, some Seirra data is sorted between AR loads and bolt gun loads. In most cases, the AR loads are further sorted according to "magazine length" or "single load" length as in the case of the famous 80 grain 600 yd loads. You can find OAL lengths in several references being shown at less than 2.25" and the 55 gr boat tail will certainly fit deeper than for example the 77 grain magazine length load. The 2.215 length would only be a concern if your loads were showing problems now. If your system is functioning well and you don't see distress signs, you already have your answer to the first order. To know more than this, you need to measure velocity and pressure. But why bother if you are happy with the load? You could probably find another manual that shows a different OAL and go longer if you were no longer comfortable with 2.215, but with the combination you have I think you are GTG. If you move out to 2.250, you just need to watch your cases for indicators as in any reloading development. A chronograph will also help determine if there was any advantage to doing so. |
| Hornady manuals list the overall length with 55fmj's and 55 SP's at 2.200". For years I've loaded the 55 gr. Hornady FMJ's and SP's to 2.215 up to 2.230". I find that 2.220" is ideal, it puts the cannelure where I want it to crimp, and they feed and function perfectly in different AR's and a bolt rifle. Hornady 55 fmj's have a blunter tip than some other 55 fmj's such as Win and military style bullets. With the longer sharper tips of other fmj's the oal would be around 2.250". Nothing wrong with the length you load them to.and I haven't seen any accuracy improvement seating them longer. |
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Quoted:
I've been reading with great interest the AR15 reloading data page relating to the .223 Remington cartridge. I've reloaded several thousand .223/5.56 cartridges and believe I've been following the "books", I don't guess, and I cross reference all my loads with at least two sources. My question is, have I been loading my bullets too deep? 90% of my loadings have been with the Hornady 55 gr. FMJBT w/cann. All are 24.0 to 26.0 grains of H-335, 450 CCI primer, LC brass. Data is from Speer RM # 14, page 202. I've been loading to a COAL of 2.215, most of you guys seem to be leaving your loads a bit longer. I fire these only in my AR 15's. Opinions please. It all depends on what length you trim to, and do you seat to mid cannelure? 
LC brass trimmed to 1.750, Hornady 55 gr FMJBT seated to mid cannelure, they come out to 2.220 for me. Remember with rifle rounds the cases have greater volume than pistol rounds. So OAL is not near as critical (pressure wise) as pistol rounds. If you are happy with your loads and they shoot good with no pressure signs, you are fine.... |
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