In order to participate in the GunBroker Member forums, you must be logged in with your GunBroker.com account. Click the sign-in button at the top right of the forums page to get connected.
IMR 8208 XBR
guntech59
Member Posts: 23,188 ✭✭✭
I picked up a pound today on the recommendation of the shop owner. He showed me some targets he had shot this morning from his 20" barrel, 5.56mm RRA AR. I have known him for years. He is a better shooter than I am so my results may not be quite as good as his.
Matched up with CCI 400s and a 69gr SMK, it gave 1/2" at 100yds and 1.1" at 200yds. This was with 23.0 gr.
Anybody here tried it? What results?
I already did a search. I only came up with posts from February with no clear answers.
Matched up with CCI 400s and a 69gr SMK, it gave 1/2" at 100yds and 1.1" at 200yds. This was with 23.0 gr.
Anybody here tried it? What results?
I already did a search. I only came up with posts from February with no clear answers.
Comments
Anybody tried it in 22-250, 222 Rem or 17 Rem Fireball?
Also how does it meter compared to H335?
Regards to everyone, Craig
I thought 8208 was a bulk powder for years that bench rest guys liked for lack of temp sensitivity and seemed to perform well for many. I have not tried because it is hard to find in my area, would like to try in my 223 and 204. I will at some point when I get my hands on some.
There is an article in Hodgdon's 2010 Annual Manual on it. They tested it in .204, .223, 22-250, 6.8SPC and .308.
This is not, according to the article, the same 8208 that was used by the benchrest guys in 22 and 6mmPPC. It does draw many comparisons though and has the same properties. Maybe they just found the recipe and renamed XBR because it is "totally extreme, dude".[:o)] Actually, I know it is due to it's temperature insensitivity.
I am no expert on benchrest shooting or their favorite powders. There is another, sort of lead in article, in the same book giving the history or the original 8208. Looks interesting. I'll have to read it later.
Edited to add: bpost1958, in the lead in article there is a discussion of the XBRs use in your 6mmPPC. Apparently it is the cat's * for accuracy and getting 3380fps with 31.5gr using a 68gr bullet.
Sounds like it make be worth your time to do some experimenting. Understanding that the guy (Jim Carmichael) was paid to write the article.
"It will be amazing if it can improve the results obtained by Varget."
That will of course depend on your results obtained with Varget and your desire to accomplish the test comparison.
# Leading competitive bench rest shooter Mr. Lou Murdica won numerous matches with it in 2009, starting with Heavy Varmint Grand Aggregate at the Cactus Classic.
# August 2009 Mr. Jim Carmichel won the International Benchrest Shooters Association's 40th Group National Championships, Heavy Varmint Grand Aggregate. Because temperature conditions change, bench rest shooters vary charge weights during a day's competition. What is significant here is that Jim shot the exact same load of IMR 8208 XBR both days to win the event.
Given a fair test, my guess would be that it should be an appropriate powder of choice based on the range of temperatures in your geographic area. However, if Varget is your desired choice then there is very little to test and your decision is easy.
I've used a couple of pounds of this already and we are currently using it in 2 cartridges for competition. Longer term data will tell the tale.
Best.
bpost1958,
"It will be amazing if it can improve the results obtained by Varget."
That will of course depend on your results obtained with Varget and your desire to accomplish the test comparison.
# Leading competitive bench rest shooter Mr. Lou Murdica won numerous matches with it in 2009, starting with Heavy Varmint Grand Aggregate at the Cactus Classic.
# August 2009 Mr. Jim Carmichel won the International Benchrest Shooters Association's 40th Group National Championships, Heavy Varmint Grand Aggregate. Because temperature conditions change, bench rest shooters vary charge weights during a day's competition. What is significant here is that Jim shot the exact same load of IMR 8208 XBR both days to win the event.
Given a fair test, my guess would be that it should be an appropriate powder of choice based on the range of temperatures in your geographic area. However, if Varget is your desired choice then there is very little to test and your decision is easy.
I've used a couple of pounds of this already and we are currently using it in 2 cartridges for competition. Longer term data will tell the tale.
Best.
All that you said was in the article I referenced above.
I am hoping for similar results, if I am up to shooting that well. I don't really anticipate groups of .3 and below like they got but, you never know.
If it works out well, I will try it in my 22-250 as well. I use that for winter varmint hunting and summer rifle league. A temperature difference of 50 to 70 degrees. It would be nice to have one load instead of two for the rifles.
IMR 8208 XBR (min: 21.0gr - max: 23.8gr)
WCC03 brass (once fired) full length sized (SB)
CCI400primers
Sierra 69gr SMK
OAL: 2.260"
Three shots per group for initial testing
22.5gr: triangular group, 1.4" x 1.0"....not impressed
22.8gr: Shots slightly stringing up and right, 1.0" x .4"....better
23.0gr: two touching, one on top of the other and a called flyer,
high right, .7" x 1.4". The two touching measure .35".
It'd be nice if I could keep THAT group together!
23.3gr: strung horizontally 2.2" but only .1" difference in height.
my fault, I'm sure
23.6gr: nice triangle, .5" x .6"
I have loaded up five each of the last three loads to confirm. The crappy groups at 23.0gr and 23.3gr were probably my fault. It was getting dark and I started rushing my shots. I will try them again with five shots to validate.
The rifle cycled perfectly with all loads. No over-pressure signs on primers or brass, even at .2gr under max.
Even though it was raining on and off, I had a great time!
The first three at 200 went into just under an inch. The last two were lower and really opened it up. I should have stayed with three![:I]
I have a 2-7X40 Swift scope in this rifle. A little better quality and more magnification would probably help.....along with younger eyes.
A friend is supposed to bring his chrony to the range next week so I can see what kind of velocity I'm getting
I also worked up a nice load for the 22-250. 6 powder charges and three primers later....3 sub .6" three shot groups in a row with the winner. I'll shoot that one through the chrony, too.
Now I can't wait for winter again to compare results between 65 degrees and -1 degrees. That is the real test.