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Discussion Starter · #1 ·
I was wondering if anyone here has ran an M1A/M14S ...18 and/or 18.5 inch bbl through a chronograph ? If so.... I have a few questions ......

1. Could you specify the actual type of bbl you used along with the results?

2. The type or types of loads used.

3. For those who have tried this : How does it truly compare to a 22in bbl?

4. Any other info concerning the use of a chronogragh to find the rifle/bbl length/ specific load of ammuntion...etc... would be great if it pertains to this topic.

Note: I have one other question pertaining to barrels..... What exactly does the term "short chambered" mean, as well as 7.62mm NATO chamber? M118LR chamber?


My reason for asking is that I do not have a chronogragh, and am looking for actual muzzle velocities for comparison sake.

2 of my favorite loads for my rifles = WIN Q3130, and FED M852 OTM...... but am always interested in other loads as well.

Thanks in advance.
 

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I can't help you with a chronograph. A friend of mine has a computer program that calculates Q3130 from my 18" barrel at 2,661 fps. As technical as he is I trust his number. I hope this helps some.
 

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Discussion Starter · #3 ·
I can't help you with a chronograph. A friend of mine has a computer program that calculates Q3130 from my 18" barrel at 2,661 fps. As technical as he is I trust his number. I hope this helps some.
Thanks for the info. I did not know about a computer program that could do this. I wonder how close it is to the actual?
 

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Thanks for the info. I did not know about a computer program that could do this. I wonder how close it is to the actual?
Knowing him I'd say it'd be right on the money. If I ask him a five word question on ballistics I get five pages of answer back..GI2 He's a great guy.
 

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The only information i have on this was a range report off of a different website that showed 20fps loss in a range of factory loaded ammuntions. (between 22" and 18.5")

It was also in a bolt action.

I dont know if its credible either.
 

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Discussion Starter · #6 ·
I figured that someone would have a chronograph here, and would have tried out the various bbl lengths.
 

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last time I chrono'ed an 18.5 I got 2671 from Aussie F4 ball from my Crazy Horse.

When I called Federal I was told 50 FPS loss per 2 inch of barrel. I chronoed several loads and found this average to be very accurate so that is all I have to offer this threadGITEN
 

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Note: I have one other question pertaining to barrels..... What exactly does the term "short chambered" mean, as well as 7.62mm NATO chamber? M118LR chamber?

"Short chamber" is a term used to descibe the level of machining for the chamber. A short chamber has enough metal left for the builder to finish the chamber to specs after the bolt and barrel have been installed.Barrel makers say around .010", but this amount varies. In any case it is a small amount and is and a finish reamer is typically used to do this.

7.62mm NATO chamber? M118LR chamber?

These are terms used to describe finished chambers for respective ammunition. There are slight amounts of difference(some people will think it is huge) in the two.
 

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Recently I did some tests with my 22" (loaded model) and 16.25" (SOCOM 16 model) barreled rifles. I set my chrony at 15' and fired all rounds from a bench. I used 147gr Win. White Box and 168gr Fed. Gold Medal Match. Basically the speed differences averaged about 145 fps slower with the shorter barrel but each brand of cartridge had a different variance. The velocity differences were greater with the slower, heavier 168gr bullet.

Here are the results.

147gr Winchester White Box
Winchester claimed that the muzzled velocity should be about 2800 fps
The loaded model averaged 2846 fps
The SOCOM 16 averaged 2726 fps

Both gave groups of 2"-3" from a bench at 100 yards.



168gr Federal Gold Medal Match
Federal claims a muzzle velocity of about 2650 fps
The loaded averaged 2601
The SOCOM 16 averaged 2430

The SOCOM gave groups that were about 2" and the loaded produced about 1" groups.

And by the way, I use a ballistics software package called QuickLOAD and it usually comes within about plus or minus 50 fps of the real world. You can get closer than that with a little tweaking but you have adjust for each rifle/powder/bullet/environment combination so I usually just go with the default info and use it for a general guide when I start working a load up.
 

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Recently I did some tests with my 22" (loaded model) and 16.25" (SOCOM 16 model) barreled rifles. I set my chrony at 15' and fired all rounds from a bench. I used 147gr Win. White Box and 168gr Fed. Gold Medal Match. Basically the speed differences averaged about 145 fps slower with the shorter barrel but each brand of cartridge had a different variance. The velocity differences were greater with the slower, heavier 168gr bullet.

Here are the results.

147gr Winchester White Box
Winchester claimed that the muzzled velocity should be about 2800 fps
The loaded model averaged 2846 fps
The SOCOM 16 averaged 2726 fps

Both gave groups of 2"-3" from a bench at 100 yards.



168gr Federal Gold Medal Match
Federal claims a muzzle velocity of about 2650 fps
The loaded averaged 2601
The SOCOM 16 averaged 2430

The SOCOM gave groups that were about 2" and the loaded produced about 1" groups.

And by the way, I use a ballistics software package called QuickLOAD and it usually comes within about plus or minus 50 fps of the real world. You can get closer than that with a little tweaking but you have adjust for each rifle/powder/bullet/environment combination so I usually just go with the default info and use it for a general guide when I start working a load up.
I've got a Socom, been looking for this data for a long time, great info, thanks!!!
 
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