combat 5.56mm loads part 2

[1lostinspace]

Ok here are some loads that will equal current and past military loads.


Warning this is only for 5.56mm Nato chambers not for .223

M193
Winchester case CCI 450 Small rifle Magnum primer.
28 gr w748
55gr FMJBT
Trim to 1.750
COL 2.15
This is a max load you should work up to it but you will get about 3250+ FPS out of a 20" AR.

MK262
Winchester case CCI 400 primer
24 gr TAC
77 grain Nosler or SMK
Trim to 1.750
COL 2.26
This is a max load you should work up to it but you will get about 2700-2650

if anyone has a recipe for m855 please add it.

 

[Zak Smith]

I moved this to the reloading forum.

Please note the "REQUIRED READ for those posting Extra HEAVY LOAD Information" thread at the top and heed its advice.

 

[45ACPUSER]

I think that 748 load is way over spec at 28gr. Way over!
This is from the Hodgdon /Winchester site!
Bullet Weight (Gr.) Order BW Powder Bullet Diam. C.O.L. Grs. Vel. (ft/s) Pressure Grs. Vel. (ft/s) Pressure
55 GR. FMJ 55 748 .224" 2.120" 26.2 3170 41,000 CUP

 

[taliv]

lostinspace, where did you get that load data?

you realize that all 55g fmjbt are not M193, right?

 

[1lostinspace]

the Winchester 748 m193 load is out of Speers Manual I have shot over 300 rounds of that load with no signs of pressure that's why I recommend you work up only in a 5.56mm chamber. 5.56mm loads reach up to 65,000 PSI this load is about 58,000 psi.

 

[1lostinspace]

. What types of ammo has the US Military used in its M16s and M4s?

The military has used the following ammo types in 5.56mm (excluding blanks and specialty rounds):
M193: 55gr FMJBT Ball, plain tip.

This cartridge is intended for use against personnel and unarmored targets from 5.56×45mm weapons with a 1-in-12-inch (1:12) or faster rifling twist rate (M16 family rifles and other compatible systems). Its ballistic coefficient is typically .243

M196: 55gr Tracer, short range, red-painted tip.

M855: 62gr FMJBT Ball, green-painted tip.


so to the guy that made the comment that M193 is not a 55gr bthp please explain

 

[1lostinspace]

Tavil maybe your thinking about M855 ss-109

 

[Harley Quinn]

Information that might help some:

http://www.inetres.com/gp/military/infantry/rifle/556mm_ammo.html

This is pretty good stuff.

 

[taliv]

i didn't say M193 is not a 55g hpbt
i said all 55g hpbt are not M193

construction of the bullet is probably not the same
weight of jacket vs weight of core is probably not the same
thickness of jacket is almost definitely very different
profile is not necessarily the same
cannelure is probably not the same
BC is probably not the same

weight is important, but only one of many specs that make up M193

terminal performance of an actual M193 projectile will be vastly superior to that of Rem or Win bulk 55g fmjbt projectiles.


the point is, just matching projectile weight and velocity doesn't equal M193

does the speer manual actually say it's M193 and specify winchester cases?

 

[taliv]

harley, my docs also show 844 powder and CMR 170 (and lists 28.5g of either) not 748

 

[rcmodel]

5.56mm loads reach up to 65,000 PSI this load is about 58,000 psi.

How do you know that?
Do you have a pressure test gun?

Speer lists the data in my book as not exceeding 52,000 CUP, not one word about PSI.

Regardless, AR's don't have any way of gracefully handling a blown case like most bolt guns.

I see no logical reason to push the upper limits with them with reloads.


rcmodel

 

[GunTech]

PMax for 5.56x45mm NATO is 4050 bar, or 58,740 PSI. The reality is that pressure will be much higher unless you have a 5.56, long leade chamber.

28gn is high, as 27.7 is listed as the maximum safe load in military brass. The specification for M193 is 3300fps from a 20 inch barrel, measured at 15 feet. 27.5gn W748 will get you there. Use CCI #41 primers, as these are military spec.

If you really want to duplicate military ammunition, you can buy M193 and M855 bullets, as well as WC844 and WC846 pulldown powder. At $100 per 8 pound jug, Military powders make for cheap plinking ammo. Note however that military powders have a much wider allowable burning rate, and expect to see substantial velocity variations compared to civilian powders.

 

[1lostinspace]

So does anyone have anything good to add?

 

[nitesite]

Originally posted by 1lostinspace
So does anyone have anything good to add?

You've got to be kidding.

 

[snuffy]

1lostinspace
Member


Join Date: 09-15-07
Posts: 30

So does anyone have anything good to add?

I'm real curious why you want to duplicate military m-16 ammo. Do you know something the rest of should know? Do I need to go load EVERY round of .223 I have to be ready for something?

 

[1lostinspace]

I am looking to reload some defensive rounds.
I am interested in extending the frag range of either 75 grain hornady or 77 SMK

 

[goon]

Something else to consider - not all bullets of the same weight are interchangeable as far as load data goes either because there is a good chance that they are shaped differently. That can mean that you end up with less space in the casing with the bullet seated and that equals more pressure. And as we all know, too much pressure equals more parts of you and your gun getting blown everywhere.
That would be bad.
My suggestion for defensive loads is to find something your rifle likes in the weight range you want and buy enough to load a couple mags. I love handloads and would trust mine as well as factory loads for reliability and probably even more for accuracy, but I'd be worried about some DA tearing me a new one if he found out that I had intentionally loaded my own "extra nasty child killing" handloads or some crap like that. Just pony up the $50 and it gives you one less thing to worry less about.
One other thing I'd suggest above anything else when handloading - get several manuals and follow exactly what they say. Start at minimum loads and slowly work up as you watch for signs of excess pressure. Too much of that will kill you.

Anything you read on the net is suspect for two reasons:
1. the guy writing that data on the net may be a ballistician for nosler or he may be a total idiot who just broke out of a nuthouse. You have no way to know which.
2. what is safe in one gun may not be safe in the exact same make and model with a consecutive serial number. You can't trust stuff like this until you have tried them and know for sure that they are OK in your rifle.

Last, why extend the range of defensive ammo? Defensive ammo is not likely to be used very far away so extending the range isn't really necessary for that purpose. As long as it works out to 100 yards or so MAX you should be good to go. Past that, you'd probably have a hard time justifying why you were shooting at them anyway.

 

[Zak Smith]

Per http://www.btammolabs.com/tests/6old.htm the fragmentation distance of Mk262 (mv 2730 fps) is at least 225 yards from a 16" barrel. This is way, way beyond defensive distances (and also about 4x the average police sharp-shooter engagement distance incidentally).

On the legal and moral issues, please revisit old threads on reloads vs. factory ammunition for self defense, or start a thread specifically about those issues in the appropriate forum. However, I assure you that this topic has been covered extensively and there will almost certainly be no new arguments brought to the table.

There's nothing wrong with wanting a full-house load, and a lot of NRA High Power shooters shoot loads this hot in competition. However, one always must ask if it's "worth it." Since we're dealing with relatively low BC bullets, a difference in muzzle velocity of 100 fps translates into very small incremental differences down-range. Besides increased gun and bolt and barrel wear and decreased brass life, there's also all the time and cost spent carefully working up loads for a benefit of maybe 40 fps difference at only 300 yards.

-z