Successfully metering IMR Hi-SKOR 800-X powder

[OSOK7]

Okay guys .. I'm new to the CZ Forums ..
UPDATE: Did have 700X in the title as well and since have removed it as getting a small enough charge with 700X seemed impractical.
However, you will see some mention of it in the first few replies /posts.

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On the metering .. Seems to be a popular topic with the shortage of certain powders.
I use a Redding BR3 or BR30 measure with the RIFLE micrometer
measuring tube in it ..
You have to adjust it pretty low, however, the disc / surface area is larger with a shorter depth to hold the powder so the flakes are less apt to stick or bridge in the measure tube ..
You still need to drop the charge slower than most and tap the handle once you drop the charge.
Doing this way I have been able to throw 6.0 gr charges for my 9mm 124 Gr RN all day with no need to trickle charge ..
At the range, the velocity spread for 5 rounds was 8 fps ..
Hope this helps ..

Randy

[fotog54]

6.0 grn.  !  Was that 800x?


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[OSOK7]

oh sorry .. IMR Hi-SKOR 800-X ... the big flaked powder .. ( too big )
BTW .. that 6.0 gr load is for the 800-X .. not the 700-X

[IDescribe]

Your thread title says 700X.  Have you had any luck there?

[OSOK7]

I dont use 700X, but others have mentioned it not metering well either  ..
so I assumed it would apply to that as well .. I guess I can take that off the title ..
Seemed like the concept would still be the same ..

[IDescribe]

The 700X flakes are smaller, so they likely don't react exactly the same. 

But more importantly, and why I asked:

6.0gr with 800X looks like a +P charge with a 124gr RN per the Hodgdon load data.  I wasn't sure with the rifle button if that was the smallest you could get the charge, or if that is actually your ideal load for the purpose you load it.  And if that IS the smallest you could get the charge with the rifle button and 800X, I was wondering what the smallest you could get with the 700X would be.  Because if the smallest you could get with 700X with the rifle button was 6.0gr or higher, that would make it useless for 700X in 9mm.

[OSOK7]

oh okay .. I see where you are going ..  I'll go check right now .. lol
I know its less .. not sure how much .. yet ..
Okay .. 0.8 gr is as low as it will go .. with the 800X
Its a new BR3 so perhaps its made differently than the older ones? IDK ..
Does seem like when I went from 6 gr of 800X setting to .. bullseye .. without adjusting .. the bullseye weighed much more ..
Perhaps its a denser powder and along with the smaller flakes weights there is more powder per unit of volume?
Maybe its the same situation with the 700X ?

I'll take the 700X off the title and make a comment on it.

I noticed that in my barrel with my barrel length .. anything charge higher than 6.0 gr of 800X does nothing for
my velocities.. Listed charges for 800X are all over depending on what you read .. I get around 1070 fps for velocities ..
I also figured if I'm not getting faster velocities, then why place the addition stresses on the slide, frame, etc ..


Randy

[Wobbly]

oh sorry .. that 6.0 gr load is for the 800-X .. not the 700-X.

The similarity ends with the name. Don't get sucked into thinking they are "similar", or "almost alike except". The name is merely a dream of the Marketing Dept, and we never base reloading decisions on anything that crowd tells us. 

For reloading purposes, consider that the only "similar" powders that exist come in the SAME can.

 

I noticed that in my barrel with my barrel length, any charge higher than 6.0 gr of 800X does nothing for my velocities. Listed charges for 800X are all over depending on what you read. I get around 1070 fps for velocities.

I also figured if I'm not getting faster velocities, then why place the addition stresses on the slide, frame, etc ..

Max speed for 800X is around 1100 fps. 1070 is close enough that you may have reached it, considering that you are not using an 8" barrel, at a different altitude, etc, etc. See the cartoon...



At Maximum Load bullet velocity and powder load diverge. Bullet velocity hardly changes after that point, but you should not assume that chamber pressure has also flattened out. In fact, chamber pressure continues to rise, and very, VERY fast. This because the efficiency of the burn increases (and therefore the chamber pressure) with the load.

The first people to blow up their guns are always the ones looking for "only 10 more fps" from their load.

 

[M1A4ME]

My current powder measure is an RCBS uniflo.  I bought a Lee powder measure after reading that it was pretty good with some powders.  The Lee is boxed up and sitting on the shelf (no better for my use than the RCBS) and I've decided there will be no more 800X on my reloading bench.  I used my Hornady electronic powder measure/scale to load up the last of my 1 lb. of 800X for some .357 SIG loads I put away for the future.

I do remember, many years ago, when my powder measure was a Lyman 55A, that if I played with the adjustment so that the edges of all three "slides" that make up the rotor were even, vs. doing it the way the book suggested, that I could get more consistent charges.  A consistent/uniform shape to the "hole" in the rotor seems to be the best idea.  I always thought that was why the RCBS Little Dandy pistol powder measure worked so well for (again, many years ago).

[Wobbly]

BTW .. the gun is a Sig P228 and can handle +P loads .. but not +P+ according to Sig Sauer

It's my understanding that +P+ is another figment of the Marketing Dept. SAAMI doesn't have a spec for it, so how could any manufacturer condone its use?

 

[IDescribe]

"February 11, 2011, 12:03 PM
I use case body expansion to gauge my 9mm loads. 9mm chambers are conical as are the cases. The higher the pressure, the more the case expands. Typically, a 9mm case expands to .391", a +P to .393", and a +P+ to .394"+. I keep my loads to .390" or less. "

Case manufacturers will use different alloys, which have different spring-back.  Cases of different manufacture will also have different wall thickness, which will create different spring-back.  Then there's the difference in the pistols used themselves. 

Even if the person who wrote this did this with one case type and one pistol, all he did was identify a trend.  And his application of the trend seems arbitrary.  I would not pay much attention to it.



[Mods added missing word "not"]
[IDescribe agrees that word was important to include.  ]

[Wobbly]

At velocities above about 1050 fps  ( 124 GR RN Berry's Bullets - Copper plated ) The recoil would show noticeable signs of increase and at a few with 1080 fps the primers also noticeably flattened.  There was still some of the round edge on the primer, but too much for my liking ..

I see no mention anywhere in the thread as to the brand of primers you're using.

Case expansion.   Someone in another thread, perhaps even another site, mentioned this :
I use case body expansion to gauge my 9mm loads. 9mm chambers are conical as are the cases. The higher the pressure, the more the case expands. Typically, a 9mm case expands to .391", a +P to .393", and a +P+ to .394"+. I keep my loads to .390" or less. "

While case expansion at the head is an accurate way to gauge chamber pressure, loads labeled +P+ are not defined.

So I started in measuring the case heads, shooting, measuring again... With the above in mind ..
But there were cases ( pun intended ) where the load was definitely a +P load and the case wasn't like was mentioned above.
So anyways, I kept measuring and shooting .. Then started to see a pattern that made more sense to me ( need input here ) ..
It's not the end expansion that is as important as the total case expansion as being the difference between the case measurement before shooting the round and case measurement after .. ( which does make more sense to me and I thought I read that somewhere long ago )

Your term "end" is unclear. Are you talking about the head or the mouth of the case?

When doing that I noticed a definite relationship between velocities / pressures and case expansion. Seems that so long as I keep the velocities below 1050 ish the case expansion averages around .003" and the primer looks fine, action cycles fine, etc For the 1080 velocities with the nicely flattened primers the case expansion was around 0.005", quite a bit different.

BTW, The max chamber dimension is at lease .393" in my Sig P228 and only go near that a couple times in all the testing. Which is another story with my ported stainless barrel .. Can't EVEN put a case from the factory barrel into that barrel .. not happening

So is that .003" what seems normal to most folks in this case .. ??

Randy -
? Case expansion would depend upon the available space in which to expand, and the brand of brass. Like the unstated primer brand, you have also not documented your brand of brass.
? Different manufacturers cut their chambers completely differently for an assortment of reasons
? While we're very happy you're here, we do not discuss Sig firearms here. Not to be rude, but CZ owners are not likely to be able to tell you much about how far brass can expand inside a Sig chamber. And your ported barrel, is that a third party product?
? Please restrict your topics to those relevant to CZ firearms or simple handloading/ reloading. I thought your find with the different powder measures was interesting, but this current topic is WAY off base.

Thanks.

[Wobbly]

I would suggest one of the Sig forums or "The High Road.Org" for your non-CZ discussions and musings.