Slowing down .223...?

[Rsadams]

What are the drawbacks to slowing a .223 bullet down from 2900+ to 2700+ fps.. I am firing it in a 5.56 chamber and right now useing 24.5gr of TAC and the accuracy is good.. Of course just useing a Hornady 55 gr fmj.. I am not seeing pressure signs and was thinking of bumping it up to 25gr...

Will I be losing the yaw effect of the fmj if used for defensive rounds with it that slow..??

Just for more info it's out of a 16 inch barrel and useing a 5.56 chamber in a M4..

 

[joshb]

First, I don't see a problem shooting at 2700 fps if the accuracy is good. Most "defensive" shots will be way under 100 yards. More like under 50 ft.
Second, If you're loading a "defensive " round, why are you shooting FMJ. I want the expansion of hollow points.

 

[Rsadams]

115 views one response.. thank you.... I am not loading defensive rounds but you never know these days... Just loading rounds to play with but the tryed and true 24.5gr markm load is way slow in my rifle... Just a question...

 

[vegas]

I've loaded 55gr that slow before and haven't experienced any issues. Accuracy was on par with my 3000 or fps loads and I didn't suffer any reliability issues. Ymmv but as long as your gun is still reliable, I say motor on.

 

[rob67gmc]

How is bumping it up from 24.5gr of TAC to 25gr going to slow you down from 2900+ to 2700+ fps or is this two separate thoughts?

 

[IdahoSharpshooter]

A good HP/SP load will work much better than the FMJ, considering that the "yaw effect" has yet to be proven in battle. I did 3 tours in RVN, Army Rangers, and we could not show it.
Center Mass hits with SP or HP bullets will do the job if you can hit your target.
Current milspec 223 uses what the military refers to at OTM. We civilians call it Open Tip Match = hollowpoints. 77gr projectiles are the latest iteration. I would guess 75+% of the shots were under 100 yards.

 

[Someoldguy]

115 views one response.. thank you.... I am not loading defensive rounds but you never know these days... Just loading rounds to play with but the tryed and true 24.5gr markm load is way slow in my rifle... Just a question...

I believe part of the problem is the way in which you posed your question/questions.

The 'yaw theory'/affect was claimed possible due to the 1-14 twist of the original M16 rifles. This selection of twist rate resulted in marginal stability of the bullet, and IF the velocity remained above 2,700 FPS there was the additional claimed fragmentation of the bullet at the cannelure groove, resulting in further tissue damage. The barrel length specification was also 20". The 14.5" barrel length of the M4 significantly impacts the velocity of the bullet, resulting in disappointing performance on target, as the velocity requirement above 2,700 FPS is significantly more difficult to achieve, thus terminal performance on target is not satisfactory. Your barrel length of 16" is likely the source of the reduced velocity you are experiencing, IF I read your post correctly. Additionally, it was decided that accuracy of the M16 at longer ranges was unsatisfactory. (Past 200 Yds). Therefore, the decision was made to change the twist rate from 1-14 to 1-12. This improved accuracy at longer ranges, but also severely impacted effectiveness at shorter ranges, as the more highly stablilized bullet was less inclined to yaw at impact, and thus resulted in small diameter holes in the target as opposed to yawing , fragmentation and much higher damage at extended range with the 20" barrel, let alone the 14.5" M4 or 20" barrel you have specified. You have not mentioned the twist rate of your barrel, so this is an additional consideration. All this according to Wikipedia. Yes, eye-rolls shall ensue. If you've a better information source, please post. I'm all ears.

Secondly, I have not researched TAC nor your claimed velocity DECREASE by changing your charge from 24.5 grains to 25 grains, but TYPICALLY, when you charge the case with more powder, the result is a velocity INCREASE, not a decrease as you have asserted. Also, the terminal velocity of the M193 cartridge is listed as 3,250 FPS with the 55 grain FMJ bullet, which is significantly higher than your high velocity of 2,900 FPS.

And thirdly, are your cited velocity figures/readings from your chronograph/radar, or simply data gleaned from a reloading manual/manuals? It is not uncommon for real-world results to conflict with published data from a testing lab, to some degree.

If you are interested in self-defense rounds, the primary consideration is maintaining a projectile velocity on target above 2,700 FPS for the 5.56x45 NATO/.223 Rem utilizing 55 grain bullets as you have specified. This is true for both FMJ and JSP/JHP bullets. If you insist on utilizing this rifle for self-defense, then alternatives to the 5.56x45 NATO M193 round must be considered, as suggested previously. If you are not, then I fail to understand the basis for your questions. (?) Additionally, this is primarily a benchrest shooting forum. If you are interested in tactical/military rifles, then there are other internet forums with members better suited to answering your questions.

If you expect clear and concise answers, clear and concise questions are necessary.

 

[Rsadams]

I never said it slowed when increasing charge in my question.. I simply asked what the down side of slowing it down was.. seems clear.. of course with less barrel comes less speed but markm load was for M4s...

I also stated that if I was to use them for self defense... I am looking for an accurate load right now and have plenty of 5.56 defensive rounds...

 

[ebb]

The down side is the bullet goes SLOWER. BC gets lower the slower a bullet goes, the Sierra chars show several different BCs at lesser speeds you get lesser BC. That means more wind drift and more bullet drop. It also means less down range energy. At some point (not 2700fps) the case will have such a small amount of powder in it that detonation will occur, or the rifle will not have enough energy to cycle the bolt. On the plus side it means less recoil if 223 recoil is a problem. And another plus is it takes less powder to load a case.

 

[Kurz]

This is just an example of the range of loads considered by Sierra for their products.

Test Specifications/ Components Firearm Used:
Colt AR-15A2 HBAR
Barrel Length: 20"
Twist: 1 x 7"
Case: Federal Trim-to Length: 1.750" Primer: Rem 7 1/2



I think there has been far too much emphasis put on Win. 748 and TAC as being the powders of choice for the AR15 platforms especially with the shorter 16" barrels. Reality is that they are really too slow for this cartridge/55 gr. bullets and short barrels. You are essentially wasting powder without gain. I personally run faster powders which actually burn cleaner and yield better velocities at the same pressures. This of course runs against what the powder manufacturers state because they make more money when you waste powder.

I also suggest getting a chronograph when testing loads. It will help separate the wheat from the chaff when reading suggested load information.

Good Luck with your project.

 

[Outrider27]

The yaw effect was real, but only when the target was soft, like a human body, with the projectile essentially traversing the body sideways. Performance in hard targets like car doors was the normal, straight line with the round hole one would expect from FMJ rounds. Unless the AR has a 1 in 14 twist, forget the yaw effect. It hasn't existed for decades, since the DoD reduced AR twist to 1 in 12. Modern fast twist uppers for handling heavier projectiles don't have a prayer of duplicating the soft target yaw effect that early military ARs often exhibited.

 

[Someoldguy]

The yaw effect was real, but only when the target was soft, like a human body, with the projectile essentially traversing the body sideways. Performance in hard targets like car doors was the normal, straight line with the round hole one would expect from FMJ rounds. Unless the AR has a 1 in 14 twist, forget the yaw effect. It hasn't existed for decades, since the DoD reduced AR twist to 1 in 12. Modern fast twist uppers for handling heavier projectiles don't have a prayer of duplicating the soft target yaw effect that early military ARs often exhibited.

Somebody 'gets it'. Praise the Lord and pass the ammunition.

 

[Rsadams]

Thank you .. I have a crono.. if I am reading your chart correctly I am wasting 1grain of powder if that useing a cheaper powder than vvnt... I would say this is out of a standard 20 inch barrel... Thanks for your input I will just run some distance and crono test next time I go out with it.. I am just trying to find a good range load without having to run full power loads but am shocked to see how slow it is compared to standered .223 much less 5.56.. All rounds ran across my crono out of my barrel for comparison.. especially since I am out of standered .223 range according to the hornady manual and into 5.56 territory...

Makes sense about the yaw in a 1/7 twist rifle... So if I am not losing anything but speed it makes no difference at the distance I am shooting with iron sights... I just got through with my bolt gun .308 load and wanted to tinker with this rifle while I had time... I will bump it up a notch and try again the case still has plenty of room without getting into compressed loads...

Thanks again...
Shawn

 

[T-shooter]

A couple of good loads that shoot well for me in my 16" AR 5.56 chamber are a Sierra MK BTHP with 25.3 grains of Varget. These fire at an average of 2,730 fps. A good cheap load is the Hornady 62 grain BTHP with 26.0 grains of Varget @ 2,825 fps. These are only $25 for 250. I load all my rounds to 2.300" since there is so much room in a 5.56 chamber. Some magazines will accept a longer round.

https://www.midsouthshooterssupply....ameter-62-grain-bthp-with-cannelure-250-count

My defensive load is a Lehigh 55 grain Controlled Chaos with 28.8 grains of CFE223 with a velocity of 3,050 fps. (28.4 grains will give about the same velocity with a 2.260" COL) These were a solid brass design but it looks like they have since went to a one piece copper bullet. I'm trying to get more info on them. According to them, this bullet needs 2,500 fps at the target to fragment the way it is suppose to. These are hot loads but has never shown any pressure signs in my rifle.

 

[Kurz]

if I am reading your chart correctly I am wasting 1grain of powder if that useing a cheaper powder than vvnt... I would say this is out of a standard 20 inch barrel...

First I would like to say that I was not trying to be derisive with regard to either your question or information. If that's the way I came off, please excuse me, it wasn't intentional. Writing without facial expressions and vocal inflections, as in face-to-face communication, can be difficult sometimes...

The loads in the chart have nothing to do with my comment about efficiency because they are simply load data. There is no other information which we might find usable with regard to the burning of powders, the cartridge/bullet combination, length of the barrel and potential pressure. For this information, most of us run our loads through Quickload to get an idea of the efficacy for each choice and combination. This is the way we eliminate the loads or components which aren't satisfactory for our intended uses, powders being one which is scrutinized.

TAC, Win. 748 and Varget, all show less efficiency (15% powder left unburned) when using the loads suggested in a 16" barrel. Roughly this is equivalent to one entire load (25 gr. approximately) per 7 shots, being wasted. Shorter barrels and lighter bullets often result in less efficiency with these powders. Slightly faster burning powders will result in greater efficiency as long as you stay in the safe range of pressure. I can suggest:
Accurate 2015
Re-10x
VVN-130
VVN-133

Of these, I have found that VVN-133 is the better of those two and better than the others as well. It's a cooler burning but faster powder with the potential for accuracy as shown by the folks who shoot short range benchrest.

What are the drawbacks to slowing a .223 bullet down from 2900+ to 2700+ fps..

As pointed out, drop and drift will increase, although accuracy may or may not suffer depending on the load development. I've seen loads in the lower nodes exhibit good accuracy.

Good Luck with your project.

 

[Rsadams]

First I would like to say that I was not trying to be derisive with regard to either your question or information. If that's the way I came off, please excuse me, it wasn't intentional. Writing without facial expressions and vocal inflections, as in face-to-face communication, can be difficult sometimes...

The loads in the chart have nothing to do with my comment about efficiency because they are simply load data. There is no other information which we might find usable with regard to the burning of powders, the cartridge/bullet combination, length of the barrel and potential pressure. For this information, most of us run our loads through Quickload to get an idea of the efficacy for each choice and combination. This is the way we eliminate the loads or components which aren't satisfactory for our intended uses, powders being one which is scrutinized.

TAC, Win. 748 and Varget, all show less efficiency (15% powder left unburned) when using the loads suggested in a 16" barrel. Roughly this is equivalent to one entire load (25 gr. approximately) per 7 shots, being wasted. Shorter barrels and lighter bullets often result in less efficiency with these powders. Slightly faster burning powders will result in greater efficiency as long as you stay in the safe range of pressure. I can suggest:
Accurate 2015
Re-10x
VVN-130
VVN-133

Of these, I have found that VVN-133 is the better of those two and better than the others as well. It's a cooler burning but faster powder with the potential for accuracy as shown by the folks who shoot short range benchrest.



As pointed out, drop and drift will increase, although accuracy may or may not suffer depending on the load development. I've seen loads in the lower nodes exhibit good accuracy.

Good Luck with your project.

Thanks again.. I just have a bunch of TAC and over a thousand Hornady 55gr fmj stored away after the big crunch a few years ago... I will have to try some vvn133 I like the idea of cooler burning powder... I see what your saying now it's more of a long run thing as far as wasting powder.. you are correct TAC would really like a heavier bullet... Sorry if I'm skipping around a bit..lol

No offense taken it is hard to type what you want to say sometimes... As I said I was shocked at how slow it was when ran across the crono all being that I am out of .223 range and into 5.56 according to the hornady manual , it even has less felt recoil than factory .223. When I pulled the trigger I knew before I looked at the crono that it was under powered... I think a powder change is in need... Alot of people use the 24.5 load of TAC with the 55s and have good luck with it. I don't mind it being a little slow useing iron sights but 200fps is a bit much , even for a plinking round.. I have not ran into this with bolt guns or even pistol rounds normally after one or two outings I have what I am looking for..

Thank you...
Shawn

 

[Rsadams]

A couple of good loads that shoot well for me in my 16" AR 5.56 chamber are a Sierra MK BTHP with 25.3 grains of Varget. These fire at an average of 2,730 fps. A good cheap load is the Hornady 62 grain BTHP with 26.0 grains of Varget @ 2,825 fps. These are only $25 for 250. I load all my rounds to 2.300" since there is so much room in a 5.56 chamber. Some magazines will accept a longer round.

https://www.midsouthshooterssupply....ameter-62-grain-bthp-with-cannelure-250-count

My defensive load is a Lehigh 55 grain Controlled Chaos with 28.8 grains of CFE223 with a velocity of 3,050 fps. (28.4 grains will give about the same velocity with a 2.260" COL) These were a solid brass design but it looks like they have since went to a one piece copper bullet. I'm trying to get more info on them. According to them, this bullet needs 2,500 fps at the target to fragment the way it is suppose to. These are hot loads but has never shown any pressure signs in my rifle.
View attachment 1024001

Yes sir , I think I will give the Sierra matchkings a try next with a little more weight than the 55s maybe the 69s or 77s.. They are cheap when compared to buying for the .308..lol... I honestly haven't had much luck with Hornady fmjs in anything bolt or autos... I just have a bunch of the hornady 55s and tac I bought during the big crunch stored away so I was trying to find a decent load with that combo.. I have the pound open so I will at least go through it at least and see if I can come up with something..

The accuracy is ok with the 24.5 of TAC but as I said it's not even as fast as factory .223.. I am not trying to load for 5.56 territories just about what .223 is fine with me... I have plenty of M193, M855 and TAP etc factory put away for SHTF situations.
After playing around with my .308 tactical rifle I have found out just how important a good bullet really is.. or even a good bullet and powder combo.. I think the problem here , as pointed out is , not a great bullet and not really a correct powder choice equals not a great round..

Thanks again..
Shawn

 

[Rsadams]

How is bumping it up from 24.5gr of TAC to 25gr going to slow you down from 2900+ to 2700+ fps or is this two separate thoughts?

Lol.. no I meant I might bump it up to 25.. if it slows down I think I am done with this combo...lol
I must have not posted that right , you are the second person that read it that way... Please keep in mind guys that I get on really late and sometimes what's in my head doesn't come out in type like it should...

Thank you for your patience....
Shawn