Test loads in .223 Rem. with strange results???

[bgokk]

I loaded some mixed military cases, primed with CCI #400, 24.5 gr., of IMR 3031 (all charges weighed) and Sierra 55 gr. spitzer. This load is 0.5 grs. over the start load in the Speer Manual #14.

I expected them to chronograph at 3000 fps +. Boy was I surprised. In my son’s Rem. 700 they averaged 2246 and from my NEA single shooter only 1490. :???:

We shot some .22LR high speed from a S&W Mod. 41 to test the chronograph and it showed around 1100 fps. I also shot 3 rounds over the screens with my 45/70 and the load showed 1743 fps with 49 Grs. from the same can of IMR 3031 pushing the Lee 457-340-F (339.4 gr.) These two restored my faith in the chrono. :smile:

The powder was from a sealed (new) container. The primers were some that I had for years. I thought the primers were probably bad, but then that would not explain the almost 1,000 fps. difference in the same load from the two rifles. Besides there would be lots of unburned powder if the primers were weak. Right? :?:

I don’t have a clue as what could cause this large a deviation from the book velocity and even more mystifying is the huge difference between the rifles. :groner:

I would like to hear from the forum members as to what might be the cause.

Wade in guys I listening. Thanks! [smilie=b:

[StarMetal]

I loaded some mixed military cases, primed with CCI #400, 24.5 gr., of IMR 3031 (all charges weighed) and Sierra 55 gr. spitzer. This load is 0.5 grs. over the start load in the Speer Manual #14.

I expected them to chronograph at 3000 fps +. Boy was I surprised. In my son’s Rem. 700 they averaged 2246 and from my NEA single shooter only 1490. :???:

We shot some .22LR high speed from a S&W Mod. 41 to test the chronograph and it showed around 1100 fps. I also shot 3 rounds over the screens with my 45/70 and the load showed 1743 fps with 49 Grs. from the same can of IMR 3031 pushing the Lee 457-340-F (339.4 gr.) These two restored my faith in the chrono. :smile:

The powder was from a sealed (new) container. The primers were some that I had for years. I thought the primers were probably bad, but then that would not explain the almost 1,000 fps. difference in the same load from the two rifles. Besides there would be lots of unburned powder if the primers were weak. Right? :?:

I don’t have a clue as what could cause this large a deviation from the book velocity and even more mystifying is the huge difference between the rifles. :groner:

I would like to hear from the forum members as to what might be the cause.

Wade in guys I listening. Thanks! [smilie=b:

Hodgdon online shows a compressed load of 24.6 with a 55 gr at 3233 fps. My Hornady manual setting here shows 24.7 at 3100 fps.

I would have to say if it is indeed 3031 powder that your chrono has to be wrong even if the 22 rimfire and 45-70 showed right.

Did you notice the cases were pretty full before seating the bullets? Maybe pull one down and check your powder charge again. Primers wouldn't cause that much difference and far as unburned powder, 3031 is pretty fast stuff. Pull a case down and weight the charge again and report back. Also you had the chrono far enough away from the muzzle to not catch the muzzle flash right?

Joe

[runfiverun]

i set mine 10' out if i don't i get all kinds of readings it will start stop and restart again.
but it will flash out like 5500 fps.

[bgokk]

Hodgdon online shows a compressed load of 24.6 with a 55 gr at 3233 fps. My Hornady manual setting here shows 24.7 at 3100 fps.

I would have to say if it is indeed 3031 powder that your chrono has to be wrong even if the 22 rimfire and 45-70 showed right. Bought 3/13/09 and was sealed this was the first used and the 45/70 was loaded from the same measure.

Did you notice the cases were pretty full before seating the bullets? YYes. some more than others(from measure) thats why all were weighed. Maybe pull one down and check your powder charge again. Primers wouldn't cause that much difference and far as unburned powder, 3031 is pretty fast stuff. Pull a case down and weight the charge again and report back. Also you had the chrono far enough away from the muzzle to not catch the muzzle flash right? Start screen was 15 feet from muzzle.

Joe

runfiverun I have that happen before and learned my lesson 15 feet to start screen

the powder level was appx. 1/2 up the sholder of the case. The OAL for the 223's was 2.255" so not much if any compression.

Powder from the same can/measure was used in the 45/70 load. That is another reason it is so confusing.

[StarMetal]

One other thing. Are you sure the big weigh on the scale beam is set in the right spot? There are very fine notches between them like say on the RCBS case. I've done this myself and I alway recheck the that weight position.

Joe

[EOD3]

Sounds like it could be powder contamination but it'd have to be something limited to the .223 brass.

Did you remove the primer crimp from the military brass. If not, the primer would likely be damaged.

Make sure the primer flash hole isn't blocked with cleaning media. A little bit of walnut hull goes a long way.

I can't think of anything else off the cuff. :smile:

[carpetman]

I had a similar experience. I don't have a chronograph but a guy at the range let me use his. The cast bullet load for my .243 should have been around 2400 fps according to the book. It was reading 2900 fps. Other loads I had in other rifles all read about what I expected. The owner of the chronie said all his loads were right on . Still dont know if reading was actual or there was a fluke with the one load??

[bgokk]

One other thing. Are you sure the big weigh on the scale beam is set in the right spot? There are very fine notches between them like say on the RCBS case. I've done this myself and I alway recheck the that weight position.

Joe

Joe

I first checked the scale to 0.0 then set it for 24.5 and used it to adjust the measure.
I observed that the powder in some cases came to about the base of the shoulder and others were near the base of the neck. At that point I rechecked my scale setting (it's in an adjoining room still not fully settled in new house) and then weighed each charge. some were .2-.3 grains low and the ones that looked too full were .5 to .7 grains heavy. Got to get a better powder measure.

[EOD3]

Joe

I first checked the scale to 0.0 then set it for 24.5 and used it to adjust the measure.
I observed that the powder in some cases came to about the base of the shoulder and others were near the base of the neck. At that point I rechecked my scale setting (it's in an adjoining room still not fully settled in new house) and then weighed each charge. some were .2-.3 grains low and the ones that looked too full were .5 to .7 grains heavy. Got to get a better powder measure.

Small drop tube on the powder measure and "bridging"...

[carpetman]

bgokk---Looking for a better--more accurate powder measure. They are slow but the Belding & Mull is very consistent with any type powder I have used.

[StarMetal]

I can attest to the accuracy of the Belding & Mull. First and only powder measure I've bought and owned. I thought about getting a Reddng benchrest measure, but said what the heck. The B&M is plenty good enough.

I'd say maybe your scale is off, but that load of 3031 would fill the case up pretty much and it sounds like it is. In order to get the velocity that you did you wouldn't be very much past half a case full.

Joe

[Echo]

Doesn't make any sense, and I'm NOT flamin you. I believe there was 24+ grains of powder in the cases (since the level came up to and into the neck). Powder bridging could be a reason for the different amounts thrown. Still doesn't explain the gross variance in MV. One of life's mysteries...
>
B&M measures show up on eBay often, and if you wanted one, that would be a good way to obtain one. I don't have one, and haven't used one, but they have the reputation of being the most reliable out there. But - I don't think your powder measure is the problem.

[lurch]

I would start by switching primers if at all possible. This load is similar to my old pet load for my Sako custom 223. I was getting 3400 with commercial brass, CCI450, Rem 50gr PLHP and 26gr of 3031 (Note: I would not suggest that hot a load unless you carefully work up to it). If you have some, try the 450's and back off the charge a bit to start with.

[StarMetal]

Come on lurch, get real, the guns fired, no primer is going to make that much velocity difference. We're talking dang near 1000 fps difference.

Joe

[runfiverun]

that much powder and the velocities that low really point to the wrong powder.. something like 4831 or 7828 which looks fairly similar to 3031.
but is so much slower your velocities would be waay off.

[Houndog]

Was it cloudy when you chronographed your loads? When I try to chronograph loads on a clear sunny day or from clear to overcast pattern I sometimes get wild velocity readings even with the use of sunshades. There's no way you are getting 1000FS variation in your loads with even a 2 GR variation in powder unless you mixed loads with 3031 in one case and say 4831 in the other or you had some type of contamanate in the cases causing you trouble. I find you will have REAL sooty cases form low pressure if that's the case and bad primers that partially light your powder charges usually hangfire or misfire a bunch. I'd suspect the chronograph more than your ammo, but that's just me.

FWIW: Try some Accurate Arms 2230 in your 223 and I'll almost bet you'll forget 3031! 2230 is a ball powder that runs very well in almost any type powder measure. It's some of the least expensive powder out there, and was developed for the military specifically for the 223.

[Storydude]

Recoil feel funny? Report sound weak?

I take all chrono readings with a grain of salt....Mie's said my .22 shorts are hitting 3500 FPS and my .223 loads have been as low as 900fps...

[MT Gianni]

The difference between the 2 guns that you shot lets me think the problem is with the Chronograph seeing or reading that bullet. 1000 fps between two different guns is just too weird. Change battery, check screens and verify that the same distance is used for all guns. It is strange that it would read the m41 as "OK" but I suspect Chrono problems because of the difference between the NEF and the Remington @ 1000 fps.

[archmaker]

I would suspect the chronograph, let me ask this question. Do you know where the bullet hit at 50yds, 100yds and 200yds with no change in sight or holding?

I am thinking if you are actually shooting that slow and compare to a ballistic table then you can see if it is your chronograph or the load itself.

I just looked in my speer reloading manual and 55gr Spitzer sighted dead-on at 100 @ 3000fps will be about 3.6 low at 200yds, one that is going 2000fps (as low as the chart goes) will be 10+ inches low at 200yds.

No matter what the chronograph says you should be able to estimate the speed of the bullet based upon the drop, I would believe the estimate you get from the bullet drop to be right and then you can determine if it IS your load or chronograph.

[SierraWhiskeyMC]

IMR 3031 really is tough to meter due to bridging. Those little logs really like to join up and hold hands.

I'm surprised that 24.5gr of IMR 3031 is just 0.5gr over start. In Lyman #45 reloading guide, that's the maximum load for a 55gr jacketed using Remington cases and Rem 7-1/2 primers. Velocity supposed to be 3076fps out of a 20" 1:12" twist Colt AR-15 barrel.

Note that military brass usually has less interior case volume than commercial brass. You need to make sure to not mix military and commercial brass. I also subdivide by manufacturer, and with military brass by armory and year when possible.

Check your primers carefully for signs of overpressure, perforation, and gas leaking around the edge of the primer pockets; and check your bolt faces for signs of gas cutting. This can happen very quickly. If you used a hand primer pocket reamer on milsurp cases, it's very easy to ream the swaged pocket too much.

Compare primer strikes between those fired in the two rifles. Your headspace may be significantly different, which could affect the depth of the primer strikes, and thus ignition.

CCI 400 primers are very thin at the bottom of the cup compared to other makes/models of small rifle primers. Not a good idea to use them with relatively fast powder in a hot load; you will likely wind up with pierced primers.
http://www.benchrest.com/forums/showthread.php?p=411589

IMR 3031 is a really good powder if you can deal with the bridging idiosyncrasy. But, I suggest that for those particular primers, you need to use a slower powder. Varget would be a really good candidate. IMR4320 and IMR4895 are a couple more.

If you're firing an AR-15 variant, you really want clean-burning powders like Varget or IMR 4895.

[lurch]

Come on lurch, get real, the guns fired, no primer is going to make that much velocity difference. We're talking dang near 1000 fps difference.

Joe


Joe,

I doubt that it would make that much difference as well. It is a place to start though. If by some weird albeit unlikely chance that poor (really poor) ignition is to blame (from contamination, off lot of primer, whatever...) then this could possibly show a difference. I have seen different primers make surprising difference in pistol a cartridge (.44 using an old Herter LP primer vs. a CCI mag cap and 2400 powder: went from ~1100fps to ~1500fps), though I have not had the chance to see it happen in a rifle.

It was implied that there is a not a lot of unburned powder. That does throw some water on the poor ignition theory which is what a bad primer would cause, but I would not completely rule it out just yet.

There is a lot of information we don't have so accurately diagnosing the problem is not possible at this time. Were the velocity readings consistent? What was the spread and standard deviation? Were there enough rounds fired to make these numbers statistically meaningful? And a host of other questions...

After thinking about it some more the most likely (to me) explanation is some form of chronograph malfunction/error. I would still do some testing to rule out the possible primer angle though in light of the fact that they described as "had for years". No they don't go bad if stored decently, but we don't have that info either.

Kurt

[StarMetal]

Joe,

I doubt that it would make that much difference as well. It is a place to start though. If by some weird albeit unlikely chance that poor (really poor) ignition is to blame (from contamination, off lot of primer, whatever...) then this could possibly show a difference. I have seen different primers make surprising difference in pistol a cartridge (.44 using an old Herter LP primer vs. a CCI mag cap and 2400 powder: went from ~1100fps to ~1500fps), though I have not had the chance to see it happen in a rifle.

It was implied that there is a not a lot of unburned powder. That does throw some water on the poor ignition theory which is what a bad primer would cause, but I would not completely rule it out just yet.

There is a lot of information we don't have so accurately diagnosing the problem is not possible at this time. Were the velocity readings consistent? What was the spread and standard deviation? Were there enough rounds fired to make these numbers statistically meaningful? And a host of other questions...

After thinking about it some more the most likely (to me) explanation is some form of chronograph malfunction/error. I would still do some testing to rule out the possible primer angle though in light of the fact that they described as "had for years". No they don't go bad if stored decently, but we don't have that info either.

Kurt


Kurt,

I suspect the chrono too. First thing I do if I get a crazy reading is replace the battery, then go from there.

Joe

[Larry Gibson]

bgokk

I suspect the problem was one of "set up" with your chronograph. You do not mention the kind/model of the chronograph nor the kind of screens. Under some conditions like really bright sunlight or a sharp angle of the light it is easy to get false readings with small speedy jacketed bullets exactly like your .223 loads. The larger slower 45-70 bullets and the slower soft colered .22LR bullets many times give good readings under such conditions. I have run into this very same problem over the years. It was a big enough problem that Dr Oehler offered a free upgrade to correct it with his Skyscreens. I suggest you quit looking at all the esoteric things mentioned and simply chronograph the loads again but under better location of the screens to your chronograph.

Larry Gibson

[bgokk]

Larry, I think that you and the others that say it is a chronograph problem are right. I will work on that idea with my next group of test loads. I need to come up with some sort of easily transported and deployed shade for the screens.

Thanks for everyone's input. I will report back when I get around to another test.

[Jaybird62]

I'll agree that it sounds like the chronograph is having trouble "seeing" this particular bullet. I have it happen frequently with small bullets and harsh lighting angles with my Oehler 35.

[bigdog454]

I would agree that It could be do to lighting on the cronograph or possibly the case's are contaminated with some material ie. oil. I'd try again with the fired cases and see if you get the same readings.

[AZ-Stew]

Larry Gibson is onto the problem, and I see in your last post that you're not using shades over your sensor screens. This is a recipe for erroneous readings.

The only times I've experienced readings grossly out of line with expected results were when trying to use the chrono without shades and when the sun was low in the cloudless sky, allowing the sunlight to come in under the shades. When the sunlight glints off the bullet ogive, or when the screens are reading against a clear, blue sky, false readings are very common. Some days I've had to stop my testing due to a low, afternoon sun in a cloudless sky. Very frustrating. I've had relatively inexpensive chronos from different manufacturers and both have performed this way, while working perfectly when the sun was overhead and the shades were in place. I've read some articles by Dr. Oehler who also mentioned this problem, and you know he wasn't using an "inexpensive" setup.

If you have the original shades for your chrono screens, use them. If you've shot them or they're otherwise unusable, get some replacements.

Regards,

Stew

[BeeMan]

When not using diffusers on chronograph screens and having errors, sometimes it helps to 'paint' the exposed bullet with a black Sharpie or Magic Marker.

[StarMetal]

Larry Gibson is onto the problem, and I see in your last post that you're not using shades over your sensor screens. This is a recipe for erroneous readings.

The only times I've experienced readings grossly out of line with expected results were when trying to use the chrono without shades and when the sun was low in the cloudless sky, allowing the sunlight to come in under the shades. When the sunlight glints off the bullet ogive, or when the screens are reading against a clear, blue sky, false readings are very common. Some days I've had to stop my testing due to a low, afternoon sun in a cloudless sky. Very frustrating. I've had relatively inexpensive chronos from different manufacturers and both have performed this way, while working perfectly when the sun was overhead and the shades were in place. I've read some articles by Dr. Oehler who also mentioned this problem, and you know he wasn't using an "inexpensive" setup.

If you have the original shades for your chrono screens, use them. If you've shot them or they're otherwise unusable, get some replacements.

Regards,

Stew

I believe myself and runfiverun said something about the chronograph in the first two replied posts. Why do people, such as you, single out and individual that basically repeated what has already been said in a post and say "blah blah blah is onto the problem"?

Joe

[AZ-Stew]

Maybe because bullet "glint" from sunlight reflection, as mentioned in my post and Larry Gibson's, is very different from muzzle flash/blast, as stated in the earlier posts you mention, above. In addition, it correlates with bgokk's statement in his last post (#24), where he mentions the use of a shade in future testing.

Glint and muzzle flash/blast are two completely different ways of generating erroneous readings.

Regards,

Stew

[StarMetal]

Maybe because bullet "glint" from sunlight reflection, as mentioned in my post and Larry Gibson's, is very different from muzzle flash/blast, as stated in the earlier posts you mention, above. In addition, it correlates with bgokk's statement in his last post (#24), where he mentions the use of a shade in future testing.

Glint and muzzle flash/blast are two completely different ways of generating erroneous readings.

Regards,

Stew

Aww shuck, you know that's baloney. One is suppose to read the instructions with the chrono's and we all assume he has. Glint, flash, sun, clouds, sunshields...that's all covered under the statements "I think something is wrong with your chrono". :kidding::kidding:

Joe

[AZ-Stew]

I believe the chrono is fine.

In either the case of muzzle blast/flash or bullet glint, it's a matter of how the tool is being used.

The cure for each of these valid problems is different:

For blast/flash, move the sensors farther from the muzzle. Shading the screens won't make any difference.

For glint, distance doesn't matter. The cure is to shade the area above the sensors and be careful of the angle of incidence of the sunlight.

Just providing another option to help the gent solve his problem. :drinks:

BTW, be careful about yanking my chains. They're still recovering from an old football injury.

Regards,

Stew

[StarMetal]

I believe the chrono is fine.

In either the case of muzzle blast/flash or bullet glint, it's a matter of how the tool is being used.

The cure for each of these valid problems is different:

For blast/flash, move the sensors farther from the muzzle. Shading the screens won't make any difference.

For glint, distance doesn't matter. The cure is to shade the area above the sensors and be careful of the angle of incidence of the sunlight.

Just providing another option to help the gent solve his problem. :drinks:

BTW, be careful about yanking my chains. They're still recovering from an old football injury.

Regards,

Stew

I thought those chains were connected to your anchors. :bigsmyl2:

Joe

[JIMinPHX]

I'm going to jump on the chrony set up problem bandwagon too, but with a little twist.

If you suspect that you are having chrony problems, try shooting closer to the sensor. I find that in marginal light conditions, this makes all the difference in the world, especially with small boolits. If you shoot about 1-3" above the sensor & see very different numbers pop up, then you did not have a very good light background for the sensors to use as a baseline.

Sunscreens are necessary on sunny days & days with broken/moving clouds. They are not needed on days that a photographer would call "cloudy bright". Make sure that you set up the correct distance in front of the muzzle for the type of cartridge that you are shooting. If you have a lot of muzzle flash (like I sometimes get from certain blue dot loads) then just throw your chrony results right out the window until you figure out a way to shade the sensors from the flash.

[bgokk]

If you have the original shades for your chrono screens, use them. If you've shot them or they're otherwise unusable, get some replacements.

Regards,

Stew

I did have the issue shades in place. My reference to "easily transported and deployed shade" is in addition to the as issued set up, as in - front/rear or side light source.

[Larry Gibson]

I did have the issue shades in place. My reference to "easily transported and deployed shade" is in addition to the as issued set up, as in - front/rear or side light source.

Many of the problems I've had were related to one screen in the sun and the other shaded, low angle of sunlight (sun setting) from the side and the screen and the lens getting dirty or having rain drops or moisture condenstation on them. I carry a small box of Q-tips to clean the lens and am careful of the initial set up.

Larry Gibson