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 BLC-2 and .223 vs. 5.56 velocities/pressures
Deadeye_Jack  [Member]
11/16/2008 6:16:18 PM
Got a question about BLC-2 and load data. I recently began working up loads for my M4 carbine (16" bbl) using 55gr Hornady FMJ bullets and BLC-2 powder. I began chronographing in groups of 5 and when the loads reached 27gr, just 1/2 grain below max, the velocities still seemed way less than I expected even with a 16" bbl. A five shot average at 27gr was only 2,767 fps @ 15'. Factory .223 loads run about 2,890fps from this barrel, so I was disappointed.

Since there were no signs of unsafe pressure, I worked up to an even 28 grains of BLC-2, which is half a grain over the max listed in the Hodgdon manual. Now, don't jump on me just yet, because I looked at the data carefully and the pressure listed for the 27.5 gr max load is 48,500 CUP, which is well below the 55,000 SAAMI limit. I decided to proceed carefully.

I loaded 5 rounds @ 28gr and shot them through the chrono, examining each case for pressure problems before firing the next. No flattened primers or other problems were observed, and the average velocity for the 5 shots was 2,948, which is about what I'd expect to see from good-ol' M-193, the load I'm trying to duplicate. Case length and COL are also identical to factory M-193.

So I guess this is my question, just how much hotter is M-193 pressures vs. SAAMI max pressures? I am sure that I am running near the 55,000 CUP SAAMI limit with these loads, but what are 5.56 pressure limits?
ARsR4ME  [Member]
11/16/2008 6:34:32 PM
What was the temp outside when shooting?
lazyengineer  [Team Member]
11/16/2008 6:53:35 PM
My manual says you can take 55 gr bullets up to 28.1 gr of BL(C)-2 max load. Gun and primers also affect the load. If it were me doing the load development, I'd be comfortable loading it at the 28.0 if there's no pressure sign.

HOWEVER, when developing loads with BL(C)-2, I keep the ammo in a cooler with a heatpad. I regulate the temperature to around 90F. I don't know if all that is so necessary. Something I think there's a little bit of the Telephone Game when it comes to BL(C)-2, but in any event, this removes any doubts about temperature safety with this powder in my mind.
Deadeye_Jack  [Member]
11/16/2008 6:55:54 PM
Originally Posted By ARsR4ME:
What was the temp outside when shooting?


Mid 50's. Not too cold in these parts yet.

Deadeye_Jack  [Member]
11/16/2008 7:01:18 PM
Originally Posted By lazyengineer:
My manual says you can take 55 gr bullets up to 28.1 gr of BL(C)-2 max load. Gun and primers also affect the load. If it were me doing the load development, I'd be comfortable loading it at the 28.0 if there's no pressure sign.

HOWEVER, when developing loads with BL(C)-2, I keep the ammo in a cooler with a heatpad. I regulate the temperature to around 90F. I don't know if all that is so necessary. Something I think there's a little bit of the Telephone Game when it comes to BL(C)-2, but in any event, this removes any doubts about temperature safety with this powder in my mind.


Yeah, that's how I'm leaning too. In my mind at least it's the pressure signs that tell the real story. After looking at the primers on my 28gr loads and then comparing them to once-fired factory loads, I simply can't tell any difference. They look good to go in my opinion. BTW, what manual are you using that lists the max at 28.1?

OptionX3  [Member]
11/16/2008 7:07:08 PM
Maybe you should try different powder? I use WCC844 (surplus H355) 24.55gr with Hornady 55FMJBT, CCI #400 load. Out of my 16" 1-7twist M4 barrel, it will avg. 3015fps (mid 80's temp). I get decent accuracy, and it's slightly faster than commercial AE .223 loads, slightly slower than LC m193 load. It works for me. Also. it shoots avg. 3320fps out of 24" barrel.
OptionX3  [Member]
11/16/2008 7:09:25 PM
Also, BLC-2 is suppose to be one of the most temp. sensitive powders. Varget and other extruded powders are least sensitive.
GUNSFORHIRE  [Team Member]
11/16/2008 7:14:45 PM
I have an 8lb Keg of BL-C 2 and I need to use some of it...I bought it because I wanted to try something that would meter a little better in my Dillon...I havent got around to it yet....Thanks for reminding me!

I plan on using 75gr Hornady and 77gr SMK's....wish me well!
Deadeye_Jack  [Member]
11/16/2008 7:28:17 PM
Originally Posted By OptionX3:
Maybe you should try different powder? I use WCC844 (surplus H355) 24.55gr with Hornady 55FMJBT, CCI #400 load. Out of my 16" 1-7twist M4 barrel, it will avg. 3015fps (mid 80's temp). I get decent accuracy, and it's slightly faster than commercial AE .223 loads, slightly slower than LC m193 load. It works for me. Also. it shoots avg. 3320fps out of 24" barrel.


Possibly, but the BLC-2 is very clean and can be used for the heavier bullet loads as well as the 55's. I plan to eventually start working up some loads for 69 and 75 gr bullets as well and BLC-2 seems well suited for a wide range of them.

lazyengineer  [Team Member]
11/16/2008 8:16:30 PM
Originally Posted By GUNSFORHIRE:
I have an 8lb Keg of BL-C 2 and I need to use some of it...I bought it because I wanted to try something that would meter a little better in my Dillon...I havent got around to it yet....Thanks for reminding me!

I plan on using 75gr Hornady and 77gr SMK's....wish me well!


My fav 75 gr/ BL(C)-2 load is 24.5 gr BL(C)-2 with Wolf SRM @ 2.260 OAL for 2738 fps. I've pushed it up to 25.5 gr, but started seeing pressure signs there.
stiles  [Member]
11/16/2008 9:21:05 PM
Are you sure some of your numbers are not PSI via a piezoelectric transducer and some are from a copper crusher, it makes a difference.

Originally Posted By Deadeye_Jack:
So I guess this is my question, just how much hotter is M193 pressures vs. SAAMI max pressures? I am sure that I am running near the 55,000 CUP SAAMI limit with these loads, but what are 5.56 pressure limits?


SAAMI pressure for the 223 Rem is 50,000 PSI (yes you do see many manuals with some loads that go up to 51,000 PSI). M-193 is not to exceed 55,000 PSI via a piezoelectric transducer. The way SAAMI and NATO use piezoelectric transducers are very different and their standards for pressure barrels are also different.

I wonder how the Europeans do shooting and reloading the 223 to CIP pressures in an AR, it's only a mild 62,000 PSI
SMJayman  [Member]
11/16/2008 10:21:44 PM
m193 comes out of my 16" AR at around 3100 fps. 55gr slugs I've reloaded with BL-C(2) at 27.4-27.5ish come out at 2880 with little deviation from that number. While I could probably push that up some, I like having some margin for error. It runs my AR quite nicely and it is pretty accurate. (Not like match rounds, but these are cheap FMJ.)

Why do you want that extra velocity? Do you really need it?
MikeinGA  [Member]
11/16/2008 11:27:37 PM
I loaded for my AR CAR in .233 & my AR rifle in 7.62x39 this last spring with BL-C(2) max load and it shot ok. This summer when the temp was over 85 deg. F. both rounds over pressured. I backed off 1 grn. from max on both(.233 & 7.62x39) and worked ok, but this month when it was cold out they shot about as good as Wolf. I changed over to H4598 and works for me in both rounds. I didn't want to have summer and winter loads. That's IMHO.

Mike
Deadeye_Jack  [Member]
11/16/2008 11:36:58 PM
Originally Posted By SMJayman:
m193 comes out of my 16" AR at around 3100 fps. 55gr slugs I've reloaded with BL-C(2) at 27.4-27.5ish come out at 2880 with little deviation from that number. While I could probably push that up some, I like having some margin for error. It runs my AR quite nicely and it is pretty accurate. (Not like match rounds, but these are cheap FMJ.)

Why do you want that extra velocity? Do you really need it?


Well, The extra velocity is pretty important to me in this case because I'm squirreling away defensive ammo right now and once velocity drops below about 2,700fps the FMJ bullets tend not to fragment reliably and aren't especially effective. If I were loading soft points or hollow points I wouldn't worry about it as much, but the FMJ's definitely need the speed to achieve a decent effective range.

Also, the bulk of my stash is M-193 and that's what my optic and irons are zeroed for. If I can keep my handloads in the same velocity ballpark as what comes out of the box, the POI can be close enough for them both that I won't have to worry about it when switching from one to the other. I want the loads to have essentially the same trajectory out to at least 250m or better. I need to shoot some groups pretty soon to see how close I am.

Deadeye_Jack  [Member]
11/16/2008 11:45:37 PM
Originally Posted By stiles:
Are you sure some of your numbers are not PSI via a piezoelectric transducer and some are from a copper crusher, it makes a difference.

Originally Posted By Deadeye_Jack:
So I guess this is my question, just how much hotter is M193 pressures vs. SAAMI max pressures? I am sure that I am running near the 55,000 CUP SAAMI limit with these loads, but what are 5.56 pressure limits?


SAAMI pressure for the 223 Rem is 50,000 PSI (yes you do see many manuals with some loads that go up to 51,000 PSI). M-193 is not to exceed 55,000 PSI via a piezoelectric transducer. The way SAAMI and NATO use piezoelectric transducers are very different and their standards for pressure barrels are also different.

I wonder how the Europeans do shooting and reloading the 223 to CIP pressures in an AR, it's only a mild 62,000 PSI


I'm using data from the Hornady manual and (for this load at least) it definitely lists the pressure in CUP. Oddly, out of the 15 loads/powders listed for 55gr bullets, 10 of them are measured in CUP while 5 are in PSI. It pays to pay close attention when comparing numbers off the loads in this book!

Molon  [Team Member]
11/17/2008 12:44:53 AM
Originally Posted By Deadeye_Jack:
Got a question about BLC-2 and load data. I recently began working up loads for my M4 carbine (16" bbl) using 55gr Hornady FMJ bullets and BLC-2 powder. I began chronographing in groups of 5 and when the loads reached 27gr, just 1/2 grain below max, the velocities still seemed way less than I expected even with a 16" bbl. A five shot average at 27gr was only 2,767 fps @ 15'. Factory .223 loads run about 2,890fps from this barrel, so I was disappointed.

Since there were no signs of unsafe pressure, I worked up to an even 28 grains of BLC-2, which is half a grain over the max listed in the Hodgdon manual. Now, don't jump on me just yet, because I looked at the data carefully and the pressure listed for the 27.5 gr max load is 48,500 CUP, which is well below the 55,000 SAAMI limit. I decided to proceed carefully.

I loaded 5 rounds @ 28gr and shot them through the chrono, examining each case for pressure problems before firing the next. No flattened primers or other problems were observed, and the average velocity for the 5 shots was 2,948, which is about what I'd expect to see from good-ol' M-193, the load I'm trying to duplicate. Case length and COL are also identical to factory M-193.

So I guess this is my question, just how much hotter is M-193 pressures vs. SAAMI max pressures? I am sure that I am running near the 55,000 CUP SAAMI limit with these loads, but what are 5.56 pressure limits?



As someone already mentioned, M193 runs 3100+ fps from a quality 16" chrome lined NATO chambered barrel, yet you say you expect around "2948" fps from your barrel for "good-ol M-193." 27 grains of BL(C)-2 under a Hornady 55 grain FMJ bullet runs around 2900 fps from my Colt 16" barrel. Are you sure that your particular barrel isn't the issue here?
AeroE  [Moderator]
11/17/2008 8:16:50 AM
I'll bet that an interested person could find pressure and speed information for M-193 and M-855 ammunition in the Reloading Resources.

http://www.ar15.com/content/page.html?id=398


The SAAMI maximum pressure for .223 Remington is 52000 psi CUP and 55000 psi when measured with a piezo gage.


The point of checking brass for signs of over pressure is to find out whether a load is safe. Without measurement equipment, the decision has to be made based on the traditional indications. A chronograph is an aid too, but it is not a primary means of determining pressure. Factors such as bullet construction and throat roughness must also be considered.

It's also a good idea to use loads with some head room for high temperatures. Guns might not blow up, but high pressure batters hell out of an AR mechanism, and everyone loves to fish blown primers, or the pieces, out of the trigger mechanism. The last thing you want to happen in the shtf scenario while shooting up the stash of emergency ammo is to have a bolt fail through the cam pin slot.
Deadeye_Jack  [Member]
11/17/2008 10:00:17 AM
Originally Posted By Molon:
Originally Posted By Deadeye_Jack:
Got a question about BLC-2 and load data. I recently began working up loads for my M4 carbine (16" bbl) using 55gr Hornady FMJ bullets and BLC-2 powder. I began chronographing in groups of 5 and when the loads reached 27gr, just 1/2 grain below max, the velocities still seemed way less than I expected even with a 16" bbl. A five shot average at 27gr was only 2,767 fps @ 15'. Factory .223 loads run about 2,890fps from this barrel, so I was disappointed.

Since there were no signs of unsafe pressure, I worked up to an even 28 grains of BLC-2, which is half a grain over the max listed in the Hodgdon manual. Now, don't jump on me just yet, because I looked at the data carefully and the pressure listed for the 27.5 gr max load is 48,500 CUP, which is well below the 55,000 SAAMI limit. I decided to proceed carefully.

I loaded 5 rounds @ 28gr and shot them through the chrono, examining each case for pressure problems before firing the next. No flattened primers or other problems were observed, and the average velocity for the 5 shots was 2,948, which is about what I'd expect to see from good-ol' M-193, the load I'm trying to duplicate. Case length and COL are also identical to factory M-193.

So I guess this is my question, just how much hotter is M-193 pressures vs. SAAMI max pressures? I am sure that I am running near the 55,000 CUP SAAMI limit with these loads, but what are 5.56 pressure limits?



As someone already mentioned, M193 runs 3100+ fps from a quality 16" chrome lined NATO chambered barrel, yet you say you expect around "2948" fps from your barrel for "good-ol M-193." 27 grains of BL(C)-2 under a Hornady 55 grain FMJ bullet runs around 2900 fps from my Colt 16" barrel. Are you sure that your particular barrel isn't the issue here?



Well, I also normally get around 3,100 with M-193 from a 16" barrel, but I did my chronographing with that load when it was still nice and warm, and from another carbine. This is in a new carbine that I haven't chronoed anything from yet, so I guess it's at least possible that there's a barrel issue. I doubt it though, since there are just so many other variables at work here.

First, it's a brand new barrel with less than 100 rounds through it. It's a brand-new M&P-15 with what I believe to be one of the new T/C barrels. Also I found out later after looking at my outdoor digital thermometer that it was a lot cooler that day than I originally thought (mid 40's rather than mid 50's). I haven't shot any of these loads in my other M&P, so I can't do an "apples to apples" comparison yet. Since it gets dark about 5:00 now and I don't get home until after 6:00, I'll probably have to wait until the weekend to do any more testing.

This is my first time experimenting with BL-C(2) and I'm much more familiar with extruded powders. If I find that temperature plays such an extreme role with this powder I'll probably switch to something I'm more accustomed to. I know that before I chronoed any of these loads I was having some problems with my chrony.

The battery was dead and I spent about half an hour scrounging around until I found a good one. All that time my loaded rifle was laying out on the bench in the breeze and I'm sure the rounds had plenty of time to get down close to ambient temperature. I may do what another poster mentioned and warm them up immediately before shooting them just to see what they do then.
SMJayman  [Member]
11/17/2008 10:57:09 PM
Velocity equivalency doesn't always equal the same POI, my BL-C(2) 55gr loads actually hit higher than M193. Actually, the more I think about it, the more it makes sense, given the 200fps split. You will need to verify the difference in zero between your load and anything else you use, because I promise you, no matter how close you get, there will be a difference. If you're just slinging them over irons at 25 yards freestyle you may not note it, but it'll be there.

Are you going to be loading pulled M193 bullets? Otherwise your fragmentation envelope won't be the same, either. Many commercial FMJ bullets have a very thick jacket and won't fragment at any velocity. If you are loading up for business you may want to consider lesser amounts of a more expensive bullet which is designed to expand/fragment.
Deadeye_Jack  [Member]
11/17/2008 11:28:55 PM
Originally Posted By SMJayman:
Velocity equivalency doesn't always equal the same POI, my BL-C(2) 55gr loads actually hit higher than M193. Actually, the more I think about it, the more it makes sense, given the 200fps split. You will need to verify the difference in zero between your load and anything else you use, because I promise you, no matter how close you get, there will be a difference. If you're just slinging them over irons at 25 yards freestyle you may not note it, but it'll be there.

Are you going to be loading pulled M193 bullets? Otherwise your fragmentation envelope won't be the same, either. Many commercial FMJ bullets have a very thick jacket and won't fragment at any velocity. If you are loading up for business you may want to consider lesser amounts of a more expensive bullet which is designed to expand/fragment.


Yeah, I've considered that too, but there's so much I just don't know about the bullets I'm using. I'm loading Hornady 55gr FMJ in hopes that it will be a close equivalent. I chose it mainly because it has a deep cannelure like the M-193 bullets (which is critical for fragmentation), but I don't know much about how close their construction is beyond that.

Most expanding bullets (that I know of) in this caliber seem to lack the recommended penetration depth for reliable defensive use, according to FBI standards anyway, so I've shied away from them for that purpose. However, I'm sure there are bullets out there that would fit the bill nicely. I just have to find out what they are.

SMJayman  [Member]
11/18/2008 11:16:54 AM
Those Hornady's are good bullets for the money, everybody loves 'em. I have like 3k of them but haven't loaded any, still going through some old Hirtenberger 55gr FMJs I have. (Which probably aren't as accurate as the Hornadys!)

But accuracy isn't the issue, terminal performance is. Based on that, you may want to look at something like the Barnes TSX in 62gr form. According to the guys at Corbon, who use that bullet in their DPX line, it'll go through like 18" of ballistic gelatin while expanding to .45+. Pricey friggin bullet though, WAY worse than any Sierra or Hornady OTM.
Deadeye_Jack  [Member]
11/18/2008 2:49:47 PM
Originally Posted By SMJayman:
Those Hornady's are good bullets for the money, everybody loves 'em. I have like 3k of them but haven't loaded any, still going through some old Hirtenberger 55gr FMJs I have. (Which probably aren't as accurate as the Hornadys!)

But accuracy isn't the issue, terminal performance is. Based on that, you may want to look at something like the Barnes TSX in 62gr form. According to the guys at Corbon, who use that bullet in their DPX line, it'll go through like 18" of ballistic gelatin while expanding to .45+. Pricey friggin bullet though, WAY worse than any Sierra or Hornady OTM.



Thanks for the info, and I'll definitely look into them.