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Posted: 7/5/2007 7:29:20 AM EDT
| I've posed this question inside other threads, but without ever getting an answer. Are the op rods on "Match", and "Super Match" weapons beefed-up to handle the heavier 175gr. ammo; specifically M118? |
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Are you asking specifically about SAI National Match / Supermatch M1A rifles? I don't know about their current models, but my c.1998 M1A/M21 Supermatch had a USGI oprod. I know that the USAMU builds rifles with regular USGI oprods; these rifles are shooting M118. I would expect that all US Property rifles in service derived from the M14 also use the USGI standard oprod. |
| I'm asking specifically about the current production SAI M1A "SuperMatch"? I recently aquired one (a deal I couldn't refuse), nearly new M1A SuperMatch with 40rds down a Hart tube, and the most beautiful wood I've ever seen. I have never owned an M1A, and have read many threads about how the heavier match loads would strain the op rods of standard M14/M1A's as they were designed to shoot 150gr ammo. |
I've never heard of this before; however I'd think a stiffer oprod spring would be the obvious solution if that were the case, instead of manufacturing a specialized heavier-duty oprod; I'd also think that if there was such a need, SEI or LRB would be making them. Sounds like BS to me. |
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USGI M-14 Rifles, both standard and NM, have always used the standard op rod. There has never been an M-14 NM Op Rod. There was an M-1 Garand Op Rod though. M-118 7.62X51mm Match ammo was developed for the M-14 NM. It uses a 173 gr full jacketed spitzer, boat-tailed bullet and is launched at about 2650 fps. This has worked fine since the 1960's. Next was the M-851 Match ammo with the 168 gr Sierra Matchking bullet at about the same velocity. Currently, there is the M-118LR which is also about the same velocity but with the 175 gr Sierra Matchking bullet. The GI Op Rod handles all of these just as well as the M-80 Ball ammo (147 gr). The problems come up when the shooter starts using hotter handloads (and some commercial loads) which have excessive "port pressures". All gov't ammo has specifications that must be met for ammo. Besides velocity and max chamber pressure, there is also a specification for a maximum allowable port pressure. This is the highest allowed pressure that can be bled from the gas port to actuate the gas system/op rod/open the bolt. If this is too high, parts begin to be crashed together too fast and hard. Then, things get bent or broken. Short answer, beefed up op rods aren't needed to shoot M-118, M-118SB, M-118LR, M-851, or M-80. |
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