16" and 223 velocity

M

MikeinFresno

New member
Ive got a DPMS 223 upper with their 16" heavy SS fluted BBL, 1-9. It shoots 40gr bullets great at 5/8" and 3500ish. I wanted to shoot 55-60 and cant get the velocity I think i should have for the bullets to work well. Ive tried many powders and can get almost 3000fps, but with pressure. 2850-2900 is do-able.

So the thot in my mind is to get an 18 or 20, but this thing is heavy enuf already. Im torn cuz it shoots 40s so good and dont want to loose that, but my mind tells me I need to be 3000+ for the heavier bullets to work. Im gonna try some 50 Vmax next and may be split the difference.

Comments......................
 
Just shoot the 60s at whatever vel. is accurate. The coyote won't notice that it was 2900 or 3000.

I fall into the details trap all the time (BC, fps, ect.). But in reality with my usual 100 yard shots, it doesn't make a bit of freakin difference....
 
An accurate .223 60 gr. V-Max at 2,800 - 2,900 fps is a very good coyote load. Once at that performance threshold an extra 100 fps for called coyotes means nothing really. Especially if that extra little bit of velocity loses accuracy, strains the brass and/or the firearm, cost more to shoot, ect.
 
Slower Vel . is much better for less fur damage .
here is a load you will like
52 gr. Speer H.P. # 1035
26 gr H-335 .
pretty much same as Black Hills Blue Box Load . only better bullet for fur .
Accurate as all get out and puts them down with reliability . Easy on barrel etc. try it youll like it .
Here is a cool link about barrel length .
http://www.accuratereloading.com/223sb.html
 
I have the same gun and mine loves 40gr v max. Iv shot 60gr sierra varminters with great accuracy, it was a moderate load of benchmark and went around 2900fps. I didnt notice a bit of difference, niether did the recievers. Shootin the 53gr v max not with a warm load of benchmark havnt chronyd it yet.
 
lower velosity mentioned above is the reason the original Colt's were 1/12 twist and we shot hollow point until a little convention called the GENEVA Convention so we changed to 1/9 then 1/7.

Every inch u loose from 24" barrel is 30-55 ft/sec if your base the result of the manufactures load. Now in your case you can get the velocity with a 1/7 twist but the round will get a little squirrel y the further out due to smaller grain actually causes premature spindrift compared to the regular spin drift that no one should aver have a problem with BC usually a .308 is the smallest caliber you ever talk about it
 
Lighter bullets shed velocity faster than heavier ones, even though the lighter one started out at a faster muzzle velocity. The heavier bullet will drift less too.
 
A friend of mine likes the 40 grain vmax for fox and coyotes. Says they go in and explode in the animal. Rarely a exit and very fur friendly. I have a load for the 40 and also just worked up one for the 60 vmax. My limited experience with them is either will work. You wouldn't have to get a longer (heavier) barrelled upper, but if ya want to go for it! Speed shouldn't make much difference if you know your bullet drop at various distances.
 
Originally Posted By: Kiloxjlower velosity mentioned above is the reason the original Colt's were 1/12 twist and we shot hollow point until a little convention called the GENEVA Convention so we changed to 1/9 then 1/7.



I could be wrong but I don't think the Geneva Convention imposes arms limitations as you imply. Actually the treaty you should refer to is the Hague Convention and the United States was never a signatory of that particular document. We did honor it for many years but weren't actually bound to it by international law or doctrine. Probably a nitpicking point, but just thought you might be interested.
 
Your correct, I mis-stated the limitations. . . . .

A hollow-point combined with the twist of 1/12 when actually in combat as a projectile from the 1/12 , the round would freaking hit a limb or graze one and fly-off the grid. They then Changed the twist and fount the FMJ-BT had a better trajectory and velocity. I posted this for the fact that the SP1's first generation have 1/12 twist and alot of people don't know that. But then again not many probably care
 
A lot of people have chased the 'velocity' numbers at the cost of accuracy and barrel life...Later, they cry because someone else shoots tighter groups or they wind up having a shot out barrel earlier than most others...

My most accurate loads are usually between .4gr and .7gr below max published loads...and my 1/9 barrels will handle bullets from 40gr to 69gr, with great accuracy...Whatever I'm aiming at has never complained that my bullets were too slow..

As long as a hollow point or ballistic tip bullet is moving at 1,000 fps or more, it will function just fine on impact..If you can't put it where you want it, then the shot is an exercise in futility...
 
Meter Velocity Trajectory Drift
0 3,100 -2.5 0
100 2,751 4. 1.1
200 2,420 5.8 4.9
300 2,115 0 11.8
400 1,883 -15 22.4
500 1,569 -42.9 38


Above is XM155 and Below is XM193



Meter Velosity Trajectory Drift
0 3200 -2.5 0
100 2774 2.8 1.3
200 2374 2.7 5.8
300 2012 -4.9 14.2
400 1680 -23 27.6
500 1373 -56.2 47.5

Given:

"NATO specifications for SS109 (U.S. M855) Ball require a 61.7 grain(q 1.5 grains) with a hardened steel penetrator at a velocity of 3,025fps(q 40 fps) from a 20 inch barrel 25 meters from the muzzle.
Typical velocity 15 feet from the M16A2's muzzle is around 3,100 fps.
The accuracy requirement from a test fixture equates to a maximum of approximately four MOA over the 100 to 600 yard range. Typical accuracy of average lots in an M16A2 is about 2+ MOA. This round must also penetrate a nominal 10gauge SAE 1010 or 1020 steel test plate at a range of at least 570 meters(623yards). The M193 round will penetrate this same plate reliably at 400 yards, and about half the time at 500 yards.
The 5.56mm and 7.62mm NATO rounds will penetrate it reliably out to 700 yards or more. Nominal ballistics for M193 and M855 Ball rounds are given in an accompanying table. The tables were constructed from the latest data supplied by the
U.S. Army Ballistic Research Laboratory at Aberdeen Proving Ground,
Maryland.
5.56 NATO Ball Ammunition Ballistic Comparison
based on Aberdeen Proving Ground Data

* Drift for 10 mph wind.
M193 Ball ammunition fired in M16A1 rifle with 250 meter battle sight zero.M855 Ball ammunition fired in M16A2 rifle with 300 meter battle sight zero.

XM855 .304 B.C


here's a chart if anyone wants a basic way to start reading ballistics
 
Originally Posted By: MikeinFresnoso from experience it seems that the bullets do expand and work at the 2800-2900 just fine

Thx guys

Many of those rifle bullets designed for quick and rapid expansion will reliably expand down into the 1,500 fps - 1,600 fps range.
 
True, but those evil hollow points, have found their way to our wars over in the "Sandbox" They just try not to advertise it to much, and they are not nearly as common as the green tips..
 
Last edited:
Back
Top