[smf]

May I ask two questions? B.C.- does a higher bc eventually mean a flatter trajectory? If so why would that be? I'm trying to understand some of these things that occur to me.Thought I'd ask around this board from some of the members that seem to KNOW this stuff.

and would a longer barrel length mean greater muzzle velocity? or add to accuracy?


Thanks,I have learned some here and appreciate the output of knowledge given here.

I also would like to thank the supportasniper program because I know an active duty sniper in Iraq now tha has recieved a scope from the program.I hope he is making good use of it!

Semper Fi
Tom

 

[muzzleblast]

I'll take a shot at it...Probably be a lil off, but...

BC does mean a flatter trajectory because a high BC means the bullet is more aerodynamic. So, the less it has to fight to stay in the air, the further it goes...More efficient.

Barrel length does increase velocity because the bullet is kinda sheltered in the barrel and hasn't hit the bad effects of open air yet...And it builds up speed because the reaction of gas pressure build-up and being pushed out the tight squeeze of the barrel has more time.

Don't think it matters for accuracy, but I could be wrong there.

 

[JRP3]

I would think that barrel length only helps up until the powder is completely burned, at which point the barrel would actually start to slow down the bullet.

http://www.tacticaloperations.com/pandsnewsdec2004/index.html

John

 

[muzzleblast]

Yeah, that makes sense too...Too much barrel...

 

[Scatch Maroo]

I stand corrected! :lol:

Scatch Maroo

 

[spade]

Actually i dont think so scatch, because in an engine there are pulses of the exhaust gases. The proper sized piping will produce a scaveging effect due to the creaton of a vacume between pulses, pulling the exaust gases out of the pipe.

Stociomenty is a fun subject, but i dont think it would apply here due to the fact that their is only one explosion... as opposed to 9500 per minute ( 4cylinders people) .

But then again i dont know much of anything about anything so i could be wrong.

 

[Ballistic_Coefficiency]

Ballistic Coefficiency is the numerical equivilent (number representing) to the reality of a projectiles potential ability to resist gravitational pull... wind resistence... berometric pressure... air density... ect ect. Basically anything that would slow down a bullet in flight. The higher the B.C. number... the "better" the projectile is for long range shooting.

As far as barrel length goes... it does increase velocity given a particular caliber and ammunition's maximum velocity has not allready been reached with the shorter barrel. All Bullets B.C. are messured at factory ammunition velocities for that given caliber and weight bullet. Therefor... to achieve full B.C. ratings for a given bullet... the bullet must be traveling at least at standard factory velocity for that given caliber and bullet weight. Factory ammo should reach full BC potential out of all standard barrel lenght for its particular caliber. 24 inch barrels are what is usually used for testing... allthough you can normally reach full BC out of 20 - 22 inch barrels for a .308 and 18 inch barrels for .223 / 5.56. Larger... magnum calibers require longer barrels... 26" or so.

BC

 

[Ballistic_Coefficiency]

I also would like to thank the supportasniper program because I know an active duty sniper in Iraq now tha has recieved a scope from the program.
Semper Fi
Tom

If i may ask... why did an active duty sniper need a scope from the adopt a sniper program? Curious is all...

BC

 

[smf]

Why he needs a scope?

All I can say on that is that he now has a Mark IV on a Barrett.

As to why he had to get it from a program? I can only imagine.I can't offer you a rational explanation.Might be something like ten pounds of sh*t in a one pound bag? Mismanagement? Maybe something as simple as a real upgrade from what they had.I can't tell ya but I'm glad he has it.The military should field as many snipers as we can put through the school without degrading the training.With one shot a sniper could save many lives as you well know.

Thanks for the answer on B.C. and barrell length.

 

[ekaphoto]

I also would like to thank the supportasniper program because I know an active duty sniper in Iraq now tha has recieved a scope from the program.
Semper Fi
Tom

If i may ask... why did an active duty sniper need a scope from the adopt a sniper program? Curious is all...

BC

What most people don't think about is the military buys from the lowest bidder that meets the specs. The specs are usually not set by someone in the field, but by the pentagon. A former coworker is a retired naval officer and told me a little about how the program works. It involves lots of who you know, Youll get a good paying job when you leave, and good old boy back scratching.Notice what the troops want is not included. My point is our military does not always have the best equiptment available issued to them, but they deserve it. I does seem the equiptment situation is gettting beter, but it takes a long time to get through the red tape and get the gear to the guys who need it most. Lets not forget Clinton gutted the military for 8 years. It takes a long time to build it back.

 

[Ballistic_Coefficiency]

Trust me i know how the military works... :wink:

Im just wondering why some one would choose a MK4 to replace an MST-100? Maybe its the guys personal prefferance... fine with me either way as long as he got what he wanted. Shows the program is working good i guess.

Oh yea... the RFI (Rapid Fielding Initiative) is helping get new gear out to our men and women alot faster than most people know. There have been several field test's of the XM-8 and even the new XM-307. M-4's with ACOG's / Red Dots... ANPEQ's... Tactical Lights and foreward grips are pretty much standard issue with the Army in Iraq right now... same thing with the Marines but not with M-4's... the new M-16A4 instead. Now if we could only get more of those 10 inch SAW barrels out to the grunts. We are starting to recieve the new LAW weapons aswell... its a basic LAW-66 with a few improvements from what i have heard... my unit still has the M-136 84mm AT-4's... but we have our RSTV (Reconassaince Surviellence Targeting Vehicle) that we can carry all of our heavy gear in unlike the grunts who mostly hump everything around on there backs.

 

[mele]

Im just wondering why some one would choose a MK4 to replace an MST-100? Maybe its the guys personal prefferance... fine with me either way as long as he got what he wanted. Shows the program is working good i guess.

What was not mentioned was what branch of the military. The US Army, at least as far as I understand it, does not have a fully fielded system for their barretts yet. In other words, there are a few different scopes found on the XM107's in the Army's inventory. It was not rolled out as a complete system like the M24. I would assume that his had a scope that was not to his liking and he requested something better.

I could also see where they may have been in need of something with a big more magnification to use on the 50's.

MEL

 

[Ballistic_Coefficiency]

My mistake... i foolishly assumed it was a USMC S.S. ... some times i forget im on SC and not Leathernecks forum... yes thats my stupid excuse and im sticking to it :wink: :lol:

BC

 

[mele]

heheh... fair enough!

Of course, I'm fairly certain there are more USMC snipers on these boards than us US Army guys.... though there is a good number of LE Snipers and some foriegn military snipers also.

MEL

 

[smf]

Mele is right.He is an Army sniper.

 

[silent souls = .308 holes]

Why doesnt the Army just issue the same scope that is on the M24 with the Barrett? Is it not .50 cal approved?

 

[Ballistic_Coefficiency]

The Leupold M3 would stand up just fine on the semi auto Barrett. Other than that i have no clue why its not standard issue... like you said... its not like they cant afford it.

BC

 

[ekaphoto]

Why doesnt the Army just issue the same scope that is on the M24 with the Barrett? Is it not .50 cal approved?

Why doesn't the Army do many things? Unfortantually the military procurment system is less than perfect and politics plays a large role. I have heard it is getting better since I got out a few years ago.

 

[Ballistic_Coefficiency]

As i have stated before in another post... the RFI (Rapid Fielding Initiative) is helping out ALOT. M-4's with ACOG's / Red Dot's, AN-PEG-2's... Forward pistol grips with flashlights are pretty much standard issue for the US Army in iraq / asscrakistan. I just dont see how some one is issued a Barrett .50 caliber rifle without a scope or with a scope that wont work...

BC

 

[mele]

The M24 will engage (stretching it) to the maximum effective range of the 10x scope. To engage man size targets out to the 1600-1800m max effective range of the XM107, something with a bit more power would be desirable. Using my 1x for every 100m "rule of thumb" a 16x would be a great fit. A leupold Mk4 M1 16x would be nice, or perhaps a 6.5-20x, though the number of elevation adjustments would be very close. Here is where the 16x M1 is just about taylor made for extreme ranges... it has 140" of elevation adjustment at 100y.

MEL