Copying Military 7.62x51 cartridge for FAMAE 542

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cancer

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Shot some random stuff through my new (to me) FAMAE 542 today. The various handloaded stuff I cooked up for my M14 shot 6-12 inch groups with the FAMAE (at 40m :eek:). Was starting to get concerned. Then I shot some old Spanish surplus though it, wow. Sub MOA. One ragged hole with 5 rounds. The old stuff was made by S&B and dated 1979. Crazy how different the dispersion was.

Does anyone know anything about this stuff? Any ideas how to make anything similar to this? Test bullet was a 146.5gr FMJBT. Stick powder.
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I have used the SB 79 ammo with good success, it shot very well in my Ishapore FN. I never shot it over a chronograph but my understanding is it was intended for CETME rifles and was downloaded to less than NATO specs.

...handloaded stuff I cooked up for my M14 shot 6-12 inch groups with the FAMAE (at 40m )
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Results this poor do not come from simple variances in load parameters, something is mechanically wrong with your rifle to produce groups like this. Are the bullets striking sideways? Or hitting the flash suppressor on exit from the muzzle?
 
B said:
I have duplicated M80 ball velocity using 45 grns of 4064. Accuracy is fantastic across several rifles.
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+1 to that load with the imr 4064. I'm using the hornady 150gr fmjbt bullets, and any large primer i have in stock. My all around "better than oem" plinker load for all my 308's.
 
BattleRife said:
Results this poor do not come from simple variances in load parameters, something is mechanically wrong with your rifle to produce groups like this. Are the bullets striking sideways? Or hitting the flash suppressor on exit from the muzzle?
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No kidding. I was a bit surprised also. But, no. No keyholes, nothing weird. I know the FAMAE has a reputation for lousy groups, but my opinion was 180ā€™ed with these SB ā€˜79s. The rifle is clearly really picky about ammo.
 
cancer said:
What kind of bullets and brass?
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I have worked up using LC and R-P brass so far. The 45 grns is under max for service rifle so you could get away with mixed brass at the expense of some overall accuracy. I use Campro and Hornady 150 FMJs with Murom primers. I bought 25,000 when they were cheap.
 
The SB brass has a very low web. i would not use it in any rifle that has any unsuported part of the chamber, like a M14. The web is lower than on most commercial boxer brass.

Military brass usually has a thick web.

The difference in group size is difficult to fathom. I would think it is something mechanical. Did you load 7mm bullets in error? Powder charge too low? Bullets hitting the flash suppressor?
 
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cancer said:
No kidding. I was a bit surprised also. But, no. No keyholes, nothing weird. I know the FAMAE has a reputation for lousy groups, but my opinion was 180ā€™ed with these SB ā€˜79s. The rifle is clearly really picky about ammo.
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I have had excellent success with this ammo....especially when I "mexican matched" it. As noted prior, it was said that the ammo was somewhat under standsrd velocity and pressure. SB in this case is Spanish Santa Barbara ammo.

On another note. Their are some things I learned the hard way in regards to Famae 542 accuracy. I was getting 3 to 5 inch groups initially. I found that the stock screws had come loose, and had been so for some time before being discovered. Fixed that with minimal improvement. Then I noticed the pinned on flash hider wobbled a bit.
Put a threaded hider on it. Better. Then i decided to do stiff up the gas block by inserting some aluminum foil between it and the barrel, making it a tight fit.
Accuracy much improved !
 
Ganderite said:
The SB brass has a very low web. i would not use it in any rifle that has any unsuported part of the chamber, like a M14. The web is lower than on most commercial boxer brass.

Military brass usually has a thick web.

The difference in group size is difficult to fathom. I would think it is something mechanical. Did you load 7mm bullets in error? Powder charge to low? Bullets hitting the flash suppressor?
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The only major difference was the worst group was from Barnes TSX 150 gr bullets. I t could be that the differences from copper vs lead really made a big deal.
 
Take the standard military load and drop the velocity by 10 percent in virtually any calibre and the accuracy will improve. The military is looking for reasonable accuracy and high wounding/killing ability. They get this by driving the bullet to limit of stability, so that it upsets easily. 4064 is virtually never the "best" velocity load for a cartridge, but it is normally very accurate. If the Spanish load is accurate, it's probably because the velocity is lower, not despite it. Try dropping loads by 10% and seeing what happens. Remember too that civvy 308 is hotter than milspec 7.62.
 
enefgee said:
Take the standard military load and drop the velocity by 10 percent in virtually any calibre and the accuracy will improve. The military is looking for reasonable accuracy and high wounding/killing ability. They get this by driving the bullet to limit of stability, so that it upsets easily. 4064 is virtually never the "best" velocity load for a cartridge, but it is normally very accurate. If the Spanish load is accurate, it's probably because the velocity is lower, not despite it. Try dropping loads by 10% and seeing what happens. Remember too that civvy 308 is hotter than milspec 7.62.
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I concur...
My 308 accuracy load is 42.5gr Varget with 168's, starting load by most manuals, but very accurate even out to distance.
 
enefgee said:
Take the standard military load and drop the velocity by 10 percent in virtually any calibre and the accuracy will improve. The military is looking for reasonable accuracy and high wounding/killing ability. They get this by driving the bullet to limit of stability, so that it upsets easily. 4064 is virtually never the "best" velocity load for a cartridge, but it is normally very accurate. If the Spanish load is accurate, it's probably because the velocity is lower, not despite it. Try dropping loads by 10% and seeing what happens. Remember too that civvy 308 is hotter than milspec 7.62.
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Not so. The pressure limit of NATO and SAAMI is about the same, around 62,000 psi. I have seen IVI ball loaded to over 60,000 psi.

Most lots of commercial ammo I have tested have been in the range of 55,000 to 58,000; although i did see some Winchester Match at 62,000.


The story about 7.62 being loaded to 55,000 is because the military spec called for 55,000 CUP. CUP is a different measuring system. When quoted as transducer psi, the NATO limit is about 62,000 psi.
 
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