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Posted: 9/24/2001 9:47:21 AM EDT
I was wondering if anyone has thought of mixing two different ammo types in their mags?I was think of mixing M855 and either HP or Ballistic Tip in the same mag so that I could have a mixture of high wounding and good penetration for every double tap during a gunfight.I have always thought that was a bad idea in the past but I have been shooting some varmints with this HP stuff and they just seem to make them explode even at 200yds out of a carbine.I like the M855 for penetrating structures and vehicles but it doesn't blow up unless the target is pretty close out of an M4.What do you guys think and have your heard of any good 62gr HP ammo?



SOPMODM4A3
Link Posted: 9/24/2001 9:53:22 AM EDT
[#1]
Link Posted: 9/24/2001 10:00:40 AM EDT
[#2]
You have to pay attention to the BC (Ballistic Coefficient) and MV (Muzzle Velocity) but it could be worked out.  Bullets with the same BC and same MV will have the same trajectory regardless of construction type or weight.

BC can vary with velocity.
Link Posted: 9/24/2001 10:03:44 AM EDT
[#3]
How can BC vary with velocity?  I've always thought is was based on the length, diameter and weight of the bullet.

Please explain.
Link Posted: 9/24/2001 10:04:57 AM EDT
[#4]
It's probably not a good idea unless you hand loaded these cartridges yourself. That way you will know that each shot will produce an even cycling rate despite the different brands of slugs. Don't mix and match different grained slugs. Heavier slugs produce higher pressure and thus a different point of aim and cyclic rate.

I can see some potential problems with intermixing brands of bullets, some use maximum loads some use a light medium load. I think that most professional LEO's and the military keep their ammo segregated. And they mark their mags with colored tape for easy identification. When they need the green tip, grab the green mag, when they need hard ball, grab the unmarked mag, etc.

Try out a couple hundred rounds your way and see what happens, it doesn't hurt to try. I would go with uniform consistency myself.
Link Posted: 9/24/2001 10:05:21 AM EDT
[#5]
Limited range out to 200 yards and I'd just consider the tractories to be close enough to call them the same if you were to use a M855 62grain load and a 55grain or 60grain Nosler or VMax load.   300 and beyond it would show differences more and more, I'd go for trying to match the weights where a 60grain Nosler BalisticTip and a 62grain SS109 bullet are probably fairly close to the same in terms of the bullet's BCs and if the velocities are similar they'll likely be real close.



AR_in_the_woods, bullet BC is a constantly changing value as velocity increases or decreases due to the amount of pressure acting on the bullet as it breaks through the air.   As velocity decreases it's possible for the BC to actually improve as the friction over the bullet decreases with every foot per second of velocity it loses, as the rate of friction decreases the rate of deceleration decreases and at certain points it translates into an increase in bullet BC.    Some of the Sierra loading manuals or the bullet charts will actually list various bullet BCs depending on the velocity you want to drive them at, usually it's a worse BC for the faster you push the bullet and once it scrubs off a certain amount of velocity it's BC will approach the other values given for the other velocities.
Link Posted: 9/24/2001 10:11:00 AM EDT
[#6]
I've alternated JHP,s and FMJ in all my pistols for 25 years, with no ill effects.
Haven't done it in any of my ar's, ak's or .308's.
Link Posted: 9/24/2001 10:13:27 AM EDT
[#7]
Thanks uglygun.
Kind of makes sense but goes against what I've always thought.  I'll have to do a little homework and find out for myself.

Thanks again.

(Edited 'cause my typing is absolutly horrible today.)
(Edited again 'cause I mispelled absolutely!)
Link Posted: 9/24/2001 10:24:25 AM EDT
[#8]
If under 200yds. I'd consider the 55gr. stuff because of the higher velocity.  If you were considering that you would be using the .223 in a residence I would choose a 55gr. ballistic tip or 64gr. Win. Power Point to help reduce over penetration.  There are also 40 & 45gr. offerings to consider if you have a 1x9 twist barrel (1x7 is too fast a twist for the lighter bullets).

With my pistols I make the first several rds. HP and then alternate HP & FMJ lower down.
Link Posted: 9/24/2001 11:41:38 AM EDT
[#9]
Quoted:
You have to pay attention to the BC (Ballistic Coefficient) and MV (Muzzle Velocity) but it could be worked out.  Bullets with the same BC and same MV will have the same trajectory regardless of construction type or weight.

BC can vary with velocity.
View Quote


Even so, the zero will be different. For the short ranges where a mix of ammo would be appropriate, this is likely more of a factor than trajectory.
Link Posted: 9/24/2001 11:50:32 AM EDT
[#10]
Quoted:
Thanks uglygun.
Kind of makes sense but goes against what I've always thought.  I'll have to do a little homework and find out for myself.

Thanks again.

View Quote


The problem of the velocity dependent BC arises because we are basing all of our external ballistics trajectories on tables made from a 'standard bullet type' used in military tests around the turn of the century.

Essentially, relating modern bullets to the 'standard bullet' causes different 'errors' at different velocities, and we minimize these errors by using different BCs.
Link Posted: 9/24/2001 11:57:27 AM EDT
[#11]
Mixing ammo, particularly ball and civilian hollowpoint in a AR mag, doesnt really make much sense. Both types are more than capable of dropping any person with a solid torso hit.

The idea of mixing ammo types in a mag or a belt comes from the military. Of course what isnt noted are the shortages of various types of specialty ammo that forced armorers to resort to this. There was never enough AP or API on hand so it was mixed with ball to streatch the supply.

Tracer appears 1in5 in MG belts because of the incresed cost of the tracer bullet, not because there is anything magic to this ratio. Lots of shooters dont like tracer at all because it is a two way street, they mix and match belts and mags to take them [i]out[/i].

For an AR-15, if you want to change ammo, then change mags, dont bother with mixing, cause its unlikely (unless you handloaded both types to match) that they will strike close to one another.  Any 55+gr load from a AR15 is more than effective on a person, ball or HP, provided you do your part with your aim. Given that, why go about doing something that could make consistant aiming more difficult?
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