M1A magazine

W

william boggs

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What is the max. overall cartridge length that can be loaded in a factory Springfield magazine an function? It seems to that a long target bullet will have to be seated very deeply if the 2.8" overall spec. is necessary. Will the factory throat allow a longer seating?
Thanks
 
right............
my gun had a very long throat...mag length is the limiter.....you should be able to do 2.830 in the mag...but its not likely that will be close to the lands.

hornady non secant shoulder bullets put the lands closer with mag length.
my ar10 t liked the 135's....
mike in co
 
MiA magazine

Sounds like I might have to load them single shot for a long overall length. I imagine someone makes an adaptor.
Thanks for the info.
 
william boggs said:
Sounds like I might have to load them single shot for a long overall length. I imagine someone makes an adaptor.
Thanks for the info.
Click to expand...

William, when chambering single rounds in the M1A, DO NOT let the bolt fly home. Without the drag that would have been created by stripping the round from the magazine, the bolt will be moving much faster than normal. Because the M1A has a floating firing pin, this extra speed and the abrupt stop when the bolt slams home can cause a SLAM FIRE. NOT A GOOD THING!

Another potential problem with a floating firing pin is; if you do seat a bullet long enough to reach the lands you could have an OUT OF BATTERY DISCHARGE, A VERY BAD THING!

For more information on the subject I suggest that you visit this site;

http://m14forum.com/

I hope this is helpful,
Dick
 
that was two more good reasons on why to buy an ar10 over the m14.
the firing pin on an ar cannot readh the primer till the bolt is closed.
the cam portion of the carrier and bolt work to provide a faily safe enviroment.
mike in co
 
as long as the reciever safety bridge in the m14/m1a is in spec, its firing pin can not touch the primer until the bolt is in battery either! the second reason is applicable to the AR family of rifles also.
 
ConRich said:
Without the drag that would have been created by stripping the round from the magazine, the bolt will be moving much faster than normal. Because the M1A has a floating firing pin, this extra speed and the abrupt stop when the bolt slams home can cause a SLAM FIRE. NOT A GOOD THING!
Click to expand...
And this is why NOBODY makes (or sells) single shot load adaptors for the M1A/M14 family of rifles.

Mike in Co,

This is not a flame, but the AR series of rifles had its issues with slam fires as well. When the M16 was first introduced, it had slam fire issues on the range. Redesigning primer cups (Remington made thicker and harder cups) and lightening the firing pin were both required before the issue was reduced to acceptable (read: near zero) levels.

Note: The more things change, the more they stay the same. Both the M1 Garand and the M14 required lighter firing pins to reduce the danger of slam fires.
 
but they do make and sell single loading devices for both the ar10 and the ar15.....
i wanted an m14 since i was in high school, owning one cured me of that....
ar's are a whole new game....

i seldom argue with asa...this is one of those cases...

mike in co
 
lefty o said:
as long as the reciever safety bridge in the m14/m1a is in spec, its firing pin can not touch the primer until the bolt is in battery either! the second reason is applicable to the AR family of rifles also.
Click to expand...

Lefty,

Have you not heard about Murphy?

Dick
 
ive heard of him, but left my tinfoil hat somewhere. in other words, the AR series of rifles is just as prone to the mentioned problems as is the M14 platform, but since i wont let my paranoia paralyze me, i own and shoot both AR's and M1A's. if murphy runs your life, must be tough never getting out of bed!!
 
i completely disagree with this statement.
first the ar10 has a spring on the firing pin....so it does not bounce around. drop a loaded rifle from 2 stories on the muzzle...yep it might go off...but not in everyday life.
and
again go look at the geometry of the carrier/bolt and firing pin on an ar. the firing pin cannot reach the the bolt face til the lugs are turned in locked position.
i have never seen of a DOCUMENTED slam fire in an ar15....i dont use or build m16's
mike in co
lefty o said:
ive heard of him, but left my tinfoil hat somewhere. in other words, the AR series of rifles is just as prone to the mentioned problems as is the M14 platform, but since i wont let my paranoia paralyze me, i own and shoot both AR's and M1A's. if murphy runs your life, must be tough never getting out of bed!!
Click to expand...
 
mike in co said:
i completely disagree with this statement.
first the ar10 has a spring on the firing pin....so it does not bounce around.
Click to expand...
Mike,

This is only true of the AR-10 and rifles such as the HK-416. Most AR-15 clones don't have a firing pin return spring, and neither do SR-25s. Can't speak about the DPMS .308 rifles, never handled one before.

...again go look at the geometry of the carrier/bolt and firing pin on an ar. the firing pin cannot reach the the bolt face til the lugs are turned in locked position.
i have never seen of a DOCUMENTED slam fire in an ar15....
Click to expand...
Had one in an AR-15. Rifle went bang as soon as the bolt closed, trigger was never touched. Probable causes were improperly resized brass, a bullet seated too long, or a high primer - or a combination of two or more of these causes. It can and does happen, but is not that common. (Thankfully.)
 
asa,
or a bad trigger. everyone i talked to people about it, had a home 'smithed trigger.

think about this:
the firing pin cannot move forward of the bolt face untill the bolt is closed. inspite of the speed of the action, as the bolt/carrier slow down as the bolt begins to engage, the firing pin will move forward as it is free floating. there is only a very short distance of movement from that position to the front of the bolt face. i do not believe there is enough inertia available from that position to fire a primer when the bolt is fully closed. ..to me the physics says it cannot happen.
triggers every time
mike in co

Asa Yam said:
Mike,

This is only true of the AR-10 and rifles such as the HK-416. Most AR-15 clones don't have a firing pin return spring, and neither do SR-25s. Can't speak about the DPMS .308 rifles, never handled one before.


Had one in an AR-15. Rifle went bang as soon as the bolt closed, trigger was never touched. Probable causes were improperly resized brass, a bullet seated too long, or a high primer - or a combination of two or more of these causes. It can and does happen, but is not that common. (Thankfully.)
Click to expand...
 
2 things and only 2 things cause a slam fire, and thats #1 a firing pin stuck in the forward position, and #2 a high primer. a homesmithed/hacked trigger dropping the hammer is not a slam fire. in proper working order none of these rifles will slamfire when fed quality ammo. doesnt matter if they have a rebounding firing pin, or a floating pin.
 
lefty,
an ar15 firing pin cannot stick forward... ....well the bolt/carrier/cam pin hold the pin back till the lugs engage.
i do not believe the flat face of the bolt wil set off a high primer....
so we are left with bad triggers.....

mike in co

mike in co
lefty o said:
2 things and only 2 things cause a slam fire, and thats #1 a firing pin stuck in the forward position, and #2 a high primer. a homesmithed/hacked trigger dropping the hammer is not a slam fire. in proper working order none of these rifles will slamfire when fed quality ammo. doesnt matter if they have a rebounding firing pin, or a floating pin.
Click to expand...
 
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