The Firing Line Forums - View Single Post - 30-06 18.5" chrono data?

Hummer70 · January 25, 2013, 01:46 PM

I agree 260 in a 7600 would be a game winner. I used to have a 18" barrel 742 and the muzzle blast from that sucker was horrible to say the least. At this time I have a Rem 7615 with 16" barrel and in daylight I get a 12" fireball from all the unburned propellant igniting after it does any good.
Without having the noise signature evaluation equipment I had at Aberdeen PG it is a guess but from a perceived noise standpoint the 762 30.06 and the 7615 5.56 is pretty close.

They call it a Police Patrol Rifle and I ordered it with a Youth Stock as I like stocks shorter than 12" They were made short so the rifle could be fired by personnel with body armor. The 7615 has put four out of five rounds in a 2" dot at 300 yards on several occasions.

A loss of 200 fps from 22" down to 18" is about right based on the chronograph readings I have done. I have seen as much as a 400 fps increase in velocity on 357 Mag ammo from 3" to 16" barrel.

I think all things being considered I would tend to gravitate towards a 7600 in 308 and install a Aimtech mount which I have on my 7615 and rapid close in shots are much quicker based on my R U Ready Timer.

http://www.aimtech-mounts.com/

If I were going to a speed/accuracy match this is the combo I would take.

My 7615 also has a Burris Ballistic Plex Scope and is zeroed at 300 yards.

Such timers can give you lots of good tech info regarding time to engage a target from the go beep to the shot being fired. A good course of fire from Fr. Frog's pages uses 6" paper plates at 25 yards and you are timed for X number of 1 shot strings and then a count is made of the hits on the plate as the course is designed to determine speed and accuracy. Speed without accuracy gives misses, accuracy without speed may well get you tagged first.

They also do the same procedure on 6" plates at 50 yards.

As well short barreled rifles burning lots of propellant tend to erode the crown which will open your groups. Rifles exhibiting longer barrels have less muzzle pressure and the barrel should give you a longer useful life.j

As well the barrels from 7600s can be removed and the crown touched up several times many rounds down the road.

January 25, 2013, 01:46 PM	#3
Hummer70 Senior Member Join Date: June 22, 2009 Location: South Carolina Posts: 203	I agree 260 in a 7600 would be a game winner. I used to have a 18" barrel 742 and the muzzle blast from that sucker was horrible to say the least. At this time I have a Rem 7615 with 16" barrel and in daylight I get a 12" fireball from all the unburned propellant igniting after it does any good. Without having the noise signature evaluation equipment I had at Aberdeen PG it is a guess but from a perceived noise standpoint the 762 30.06 and the 7615 5.56 is pretty close. They call it a Police Patrol Rifle and I ordered it with a Youth Stock as I like stocks shorter than 12" They were made short so the rifle could be fired by personnel with body armor. The 7615 has put four out of five rounds in a 2" dot at 300 yards on several occasions. A loss of 200 fps from 22" down to 18" is about right based on the chronograph readings I have done. I have seen as much as a 400 fps increase in velocity on 357 Mag ammo from 3" to 16" barrel. I think all things being considered I would tend to gravitate towards a 7600 in 308 and install a Aimtech mount which I have on my 7615 and rapid close in shots are much quicker based on my R U Ready Timer. http://www.aimtech-mounts.com/ If I were going to a speed/accuracy match this is the combo I would take. My 7615 also has a Burris Ballistic Plex Scope and is zeroed at 300 yards. Such timers can give you lots of good tech info regarding time to engage a target from the go beep to the shot being fired. A good course of fire from Fr. Frog's pages uses 6" paper plates at 25 yards and you are timed for X number of 1 shot strings and then a count is made of the hits on the plate as the course is designed to determine speed and accuracy. Speed without accuracy gives misses, accuracy without speed may well get you tagged first. They also do the same procedure on 6" plates at 50 yards. As well short barreled rifles burning lots of propellant tend to erode the crown which will open your groups. Rifles exhibiting longer barrels have less muzzle pressure and the barrel should give you a longer useful life.j As well the barrels from 7600s can be removed and the crown touched up several times many rounds down the road.