8208XBR 90gr 223 Loads?

[Ned Ludd]

Laurie,

That was quite a recitation on the product. I cannot say where I got my data directly. A post somewhere along the line gave a list of values and I just cut and pasted into a word document because I didn't have a list of values. I can say that I use the H4350 number in my ballistic solver for 1000 F-Class and it tracks very well.

I am attaching the file for your examination. Like I said, I cannot vouch for its veracity.

Thanks again.

David

well it won't let me attach the .doc file so here is its contents

* = degree Fahrenheit

Varget .19 fps per *

H1000 .21 fps per *

H4895 .23 fps per *

H4350 .29 fps per *

H4831 .36 fps per *

Benchmark .44 fps per *

AA4350 .47 fps per *

Retumbo .49 fps per *

Imr4064 .53 fps per *

Imr8208xbr .59 fps per *

Imr4350 .64 fps per *

RL10x .71 fps per*

Imr3031 .73 fps per *

Alliant AR comp .77 fps per *

Hybrid 100v .78 fps per *

Ramshot Hunter .86 fps per *

Imr4895 .87 fps per *

Ramshot Magnum .87 fps per *

Alliant Varmint pro .89 fps per *

Ramshot Tac .91 fps per *

AA2520 .98 fps per *

Ramshot Biggame .98 fps per *

PP2000MR .99 fps per *

Magpro 1.01 fps per *

VV N150 1.08 fps per *

AA4064 1.11 fps per *

Imr4227 1.17fps per *

Imr4831 1.19 fps per *

HS-6 1.21fps per *

H110/W296 1.24 fps per *

VV N160 1.24 fps per *

Lil' Gun 1.31 fps per *

W748 1.32 fps per *

Imr4320 1.32 fps per *

Imr7828 1.36 fps per *

H414/W760 1.42 fps per *

RL17 1.42 fps per *

H380 1.44 fps per *

RL15 1.52 fps per * from 50* and up

RL25 1.59 fps per *

RL19 1.61 fps per *

H50bmg 1.64 fps per *

US869 1.68 fps per *

RL22 1.71 fps per *

This file may have originated from personal recorded temperature/velocity data compiled from a number of different shooters. As such, it may represent a reasonable guideline for estimating temperature-dependent velocity excursions with the various powders, but it will never be a reliable substitute for doing your own testing with your own specific setup. I also pinched this file on the internet some time ago, from Sniper's Hide I believe, and converted it into a different format. My recollection is that the individual responsible for putting it together described it as originating from himself and some friends that got together and compiled a bunch of their personal data/observations over some period of time. I find it useful on occasion and the values seem to correspond reasonably well to what you'd expect simply looking at the single- and double-base powders listed.

As to the original question about 8208XBR and 90 VLDs, I initially tested/calibrated several powders in that general burn rate neighborhood for QuickLoad, including H322, Benchmark, 8208 XBR, H4895, IMR4895, Varget, and IMR4320. The procedure I employ for this is to first use the factory preset burn rate (Ba) in Quickload to estimate the charge weight associated with MAX pressure. I then identify the predicted charge weight associated with the first OBT node below MAX pressure. I then reduce that predicted OBT charge weight by another 2% for safety reasons. In this case, the predicted OBT Node for a 30" barrel is Node 4, which corresponds to a barrel time of 1.3684 ms. I then determine average velocities for loaded rounds with the reduced charge weight of each powder using a MagnetoSpeed chronograph. At home, I then adjust the burn rate (Ba) for each powder until the predicted and actual velocities match, then increase the charge weight using the newly adjusted Ba value until a barrel time output very close to the predicted OBT is reached. In my hands, working OBTs are typically just a tick longer than those in the Table (i.e. just a tick slower).

The table posted below is a summary of the OBT predictions for the various powders generated using the following parameters: 30" barrel, COAL = 2.640", 90 VLD bullet OAL = 1.250", case length = 1.750", case vol. = 31.11 gr, temp = 82 degrees F. It is important to note that these values may not be safe in a different setup due to differences in Lots of powder, primers, bullets, case volume, chamber dimensions, etc. Always start low and work up in small increments.

For me personally, the take home message from these powder tests was that H4895 represented the best combination of overall velocity, ES/SD, pressure, resistance to temperature-dependent velocity excursions, kernel size, and probably a few other parameters I have forgotten. Further testing also revealed that H4895 was capable of producing very respectable tight groups, so I have pretty much used it exclusively with 90 VLDs in the .223 Rem for F-TR ever since then. The downside to H4895 is that running loads at around 57K psi is quite hard on brass; I get maybe 3-4 firings before the primer pockets are toasted. With the exception of IMR4895, no other powder I tested was predicted to be capable of producing the same velocity at OBT Node 4 as H4895. Most were predicted to run anywhere from about 2800 to 2830 fps, including 8208XBR. The predicted pressures were also not dramatically different than with H4895, although in practice (as opposed to theoretical QL predictions), Varget does seem to be a little easier on brass than H4895. Further, Varget does appear to tune in very close to the velocity region as predicted by QuickLoad for OBT Node 4, usually around the 2820-2830 fps range.

For whatever you think they might be worth, according to these QL predictions, I can't imagine why 8208XBR couldn't be made to work with the 90s. The expected velocity would be in the 2820-ish fps range, it has relatively fine kernels, it's not hideously temperature-sensitive...the list goes on. If you can generate acceptable precision with it, it should work just fine.

 

[AJC]

Laurie,

That was quite a recitation on the product. I cannot say where I got my data directly. A post somewhere along the line gave a list of values and I just cut and pasted into a word document because I didn't have a list of values. I can say that I use the H4350 number in my ballistic solver for 1000 F-Class and it tracks very well.

I am attaching the file for your examination. Like I said, I cannot vouch for its veracity.

Thanks again.

David

well it won't let me attach the .doc file so here is its contents

* = degree Fahrenheit

Varget .19 fps per *

H1000 .21 fps per *

H4895 .23 fps per *

H4350 .29 fps per *

H4831 .36 fps per *

Benchmark .44 fps per *

AA4350 .47 fps per *

Retumbo .49 fps per *

Imr4064 .53 fps per *

Imr8208xbr .59 fps per *

Imr4350 .64 fps per *

RL10x .71 fps per*

Imr3031 .73 fps per *

Alliant AR comp .77 fps per *

Hybrid 100v .78 fps per *

Ramshot Hunter .86 fps per *

Imr4895 .87 fps per *

Ramshot Magnum .87 fps per *

Alliant Varmint pro .89 fps per *

Ramshot Tac .91 fps per *

AA2520 .98 fps per *

Ramshot Biggame .98 fps per *

PP2000MR .99 fps per *

Magpro 1.01 fps per *

VV N150 1.08 fps per *

AA4064 1.11 fps per *

Imr4227 1.17fps per *

Imr4831 1.19 fps per *

HS-6 1.21fps per *

H110/W296 1.24 fps per *

VV N160 1.24 fps per *

Lil' Gun 1.31 fps per *

W748 1.32 fps per *

Imr4320 1.32 fps per *

Imr7828 1.36 fps per *

H414/W760 1.42 fps per *

RL17 1.42 fps per *

H380 1.44 fps per *

RL15 1.52 fps per * from 50* and up

RL25 1.59 fps per *

RL19 1.61 fps per *

H50bmg 1.64 fps per *

US869 1.68 fps per *

RL22 1.71 fps per *

So varget is the hottest burning powder around? Seems like a barrel killer, maybe I should switch. Thanks for this.

 

[Ned Ludd]

So varget is the hottest burning powder around? Seems like a barrel killer, maybe I should switch. Thanks for this.

The value in the above Table means that Varget is predicted to exhibit the least change in velocity with respect to changing temperature (i.e. 0.19 fps velocity change per degree F). It has nothing to do with how "hot" Varget burns; that is a totally different number. Among the powders in a similar burn rate, Varget is not the hottest burning powder available.

 

[AJC]

The value in the above Table means that Varget is predicted to exhibit the least change in velocity with respect to changing temperature (i.e. 0.19 fps velocity change per degree F). It has nothing to do with how "hot" Varget burns; that is a totally different number. Among the powders in a similar burn rate, Varget is not the hottest burning powder available.

So that's a temperature stability number not a flame temp. Good to know

 

[Beau]

Varget is pretty darn hot, burning temp-wise. FWIW. You will get better barrel life out of cooler powders.

 

[AJC]

Varget is pretty darn hot, burning temp-wise. FWIW. You will get better barrel life out of cooler powders.

Is there a heat range chart for powders. I have been wondering about varget vs tac and a few others.

 

[Beau]

Is there a heat range chart for powders. I have been wondering about varget vs tac and a few others.

Yes, there is a pretty good one embedded in this Excel barrel life calculating spreadsheet. I believe it is taken from Quickload.
http://www.accurateshooter.com/technical-articles/excel-formula-predicts-useful-barrel-life/