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Imr 8208 xbr

15K views 44 replies 19 participants last post by  fatelvis 
#1 ·
Hey guys,,,I just bought a pound of the New IMR powder 8208,,,,I downloaded and printed the Data off there website,,,"but" just wondering if anybody out there has tried it and what were your results !!! I have a 100rds of New LC Brass ready to go,,so just figured I would check around ! Thanks,,,GI6
http://www.imrpowder.com/8208xbr.html
 
#2 ·
If it is within the acceptable Burn Rate for a Gas Gun I would be willing to try it, but I'll let You be the Guinea Pig, tell us what You find, all the Website says is how Wonderful it is, nothing else!
 
#3 ·
Hey Trung,,yea I hear ya,,its the Greatest,,Bestest,,most Wonderful powder to come along since the Chinese invented Gunpowder to begin with,,,GI2 GI2 I figured what the heck,,,they say its good for 223,,308,,probably 30-06 also,,maybe ya could just buy "One" powder and be all set,,Hmmmmm,could it be that easy ????? GI2 I will check it out for sure this weekend,,& hopefully someone else has given it a try !!!! I'll keep ya posted,,GI6
 
#9 ·
This sounds interesting,,I love the 125 TNT bullets,,,I just bought another box of 500 @ Gander MT,,,,they were actually a fair price so I jumped on them ! Anyways,,thats interesting Phil,,you say the Hvy bullets don't work as well. GI4 But it looks like jywolfe got his to shoot pretty decent,,but then every gun is different. So,I guess I will get to work myself.Where did you guys get your starting info ?? I downloaded and printed a bunch of info off of Hodgdon/IMR website for all bullets in all the calibers that I have,,starting load for all bullets:
125 grn:42.0 for a SFIRE,,?
125 grn: 46.0 for a SIE SP
150grn NOS BT: 40.0
155grn SIE HPBT: 41.0
168 HPBT: 39.0
I was going to call the Tech Support Line but never did,,,on the web it says reduce your loads 10%,,,that brings the 168 load to about 35.1,,,thats pretty low,,I want to be safe also,,but just wondering how you guys came about the charges you did ! GI2 I see a couple of you guys already around 40/42 grains with the 168s,,which with all things being equal,,that is a fair charge for this "burn rate" of powder considering it is in the IMR4895 area. Well I want to Thank everyone for there input,,,its much appreciated,,,,I think I'll go sneak to the reloading bench and fill a few cases so I will have some rds for tomorrows range session !!! Thanks again,,GI6 GI6 GI6
 
#6 ·
I'm in the process of working on a load for my SOCOM 16 using this powder. I chose it because it is supposed to be a little faster than IMR 4895 and I wanted something faster for the shorter barrel. I tried a load with the 22" standard barrel in my other rifle but it didn't perform well, to be honest though I didn't work on the load very much.

On the SOCOM I'm using a heavy bullet right now but I wanted to see what it would do with a load that I can also use for hunting deer and elk. I've been getting 1.25" - 2" groups at a 100 yards off of sand bags. I'm not done yet but I think I will end up with no better than 1" groups, but that is more than acceptable for hunting and considering it is supposed to be more temperature stable than IMR 4895 I will probably stick with the powder for the SOCOM and if it performs well in the long gun I might use it with it too, but I don't think that will happen. Here is the load I'm currently using (all the standard warnings apply).

Cartridge OAL - 2.81"
Bullet - 168gr Hornady A-Max
Case - WCC, TTL 2.005"
Primer - Winchester Large Rifle
Powder - 42.4gr IMR 8208 XBR

I know several people who have switched to this powder for their 5.56 ARs and they all get very good groups (less than a half inch at 100 yds). I intend to test lighter bullets, something around 150gr, and I'm very confident that I will get tighter groups with the lighter bullets.
 
#10 ·
Doesn't like heavy bullets? Well if I can get groups like this with a SOCOM 16, after only working on a load for a week or so, then I don't know if I would agree. If I can't get any tighter I might agree but I've actually had 1.25" groups so far. Time will tell but if a 16.25" barrel can get this kind of group with a 168gr A-Max then I'm pretty impressed. I'm sure something lighter will do better but for my do all hunting rifle I think this is pretty good. 5 shots, 100 yds from a bench with sand bags, winds were variable from 0 - 5 mph or so with gusts up to 10 mph. I was the cause of the spread, I shifted my cheek weld.

 
#11 ·
Well, we all know that our rifles run at about 50000psi chamber preasure or a smidge over and like both the 168 and 175 at about 2600fps this seems to be the node that most rifle shoot there best at.

with XBR-8208 43.3grs pushes a 168 at 2700fps@ 61500psi. I dont think droping the speed down to 2600fps is going too drop preasures down to a tolerable level.

XBR-8208 42.5grs pushes a 175 at 2664fps@ 61800psi, downloading to 2600fps isn't hard too do but the preasure level is still way up.

I picked this info out of the Hodgdon Basic Reloading Manual. I'm all for trying new powders but I think I will hold off from this one in a M1a.
 
#13 ·
I agree with your numbers (I got them from the same place) but I know of at least one other person that has used the same load as I am and I know that my pressure signs are not bad yet but they are about as high as I plan on pushing things. The primers are getting pretty flat but they still have a small gap around them and I have no bolt marks on the base of the case. From what I've seen so far I know that I wont try that 43.3gr load.

There is one other thing, I know I'll get jumped on for this but I'll address it anyway. From the research I've done the 50,000 psi value seems to be a misnomer. Sources say that the military specification of 50,000 psi max for the chamber pressure was actually measured in Copper Units of Pressure (CUP) and not with a piezoelectric sensor that measures actual pressure in PSI. The two are very different and there is no reliable relationship between the two so an accurate conversion between them isn't available, but most of the references that I have found say that the 50,000 CUP (not PSI) value that the government specified for the chamber pressure of the M14 comes pretty close to being the same as around 58,000 - 60,000 PSI (depending on who's data you refer to) using a piezoelectric transducer.

Even though I believe this to be true I recommend that anybody that wants to run hot loads be very careful and pay close attention to pressure signs.
 
#12 ·
Those pressures are too high for my liking as well.
 
#14 ·
Copied & Pasted from the IMR webpage

IMR 8208 XBR The latest in the versatile IMR line of fine propellants, this accurate metering, super short grained extruded rifle powder was designed expressly for match, varmint, and AR sniper cartridges. Ideally suited for cartridges like the 223 Remington/5.56mm, 308 Winchester/7.62mm NATO and the 6mm PPC, shooters will find IMR 8208 XBR totally insensitive to changes in temperature, while yielding max velocities and “tack driving” accuracy. Clearly, the competitor’s “choice” and the Varmint Hunter’s “dream powder”.
 
#15 ·
IMR 8208 XBR The latest in the versatile IMR line of fine propellants, this accurate metering, super short grained extruded rifle powder was designed expressly for match, varmint, and AR sniper cartridges. Ideally suited for cartridges like the 223 Remington/5.56mm, 308 Winchester/7.62mm NATO and the 6mm PPC, shooters will find IMR 8208 XBR totally insensitive to changes in temperature, while yielding max velocities and “tack driving” accuracy. Clearly, the competitor’s “choice” and the Varmint Hunter’s “dream powder”.
Well said 9th !!! And when my "Varmint" just happens to be a 10X in the middle of a circle,,,I am all for making the X go away !!!! GI2 I am at the bench right now,,,just came up to check a few things on here !!!! I'll Be Back !! GI8
 
#16 ·
1967 National Match Rifles

There is a discription on how CUP testing was done for M118 National Match Ammunition, but also in that same parigraph it goes on to say, this calculated result is not a true pressure reading. However, this system does provide an adequate measure of the safty of the cartridge.

OK? but I never have seen a value assigned in CUP with or without a Peizoelectric transducer for a M14 so how much is to much?

I have seen, plenty of not to exceed 50,000psi for both the M1 and M14 rifles, I reload my ammo to duplacate US Military velocity specs with commercial powders I also assume that the pressures they generate are close/simular but not into extreem levels, I assume this as fact as I have not blown myself up, lost a eye yet or beat my rifle to death.

CUP can be whatever its wants to be and while I maynot be able to directly compare CUP to PSI I can compare PSI to PSI, and anything over 50,000psi isn't good for longevity so says Uncle Sam and a few people that are smarter than me, 60,000psi can't make it better.

You are more than welcome too run whatever powder you want, I think I will say on the fence for awhile and just watch the show.

FWIW my .02
 
#17 ·
I'm not arguing with ya' Phil, I'm just saying what I've read. Like you I only know what I've read from people that are more knowledgeable than me. But I do know that my pressure signs are acceptable on my rifle so I'm willing to work with the charge weight I'm using now. It is such a new powder that it will be a while before we see any difinative info from the experts. In the mean time I'm tip toeing through the mine field. DI5
 
#20 ·
Hey guys,,I loaded up about 50 Rd's with the New IMR 8028 & here are my results !! And my disclaimer is that these results are mine and are not to be confused with someone that can really shoot !!!!GI2 Over all I was happy,,,a little more pleased with some than others and the targets will reflect that. As you can see,,the Nosler 168s were outstanding & the 125 TNT bullets have potential,,for some reason my shots & groups with the SMK were lackluster at best,,Hmmmm,was it me,,(probably) was it the powder,,time will tell,,I will repeat the whole process in the weeks to come. I guess bottom line for me is,,I will burn through this can & even try some in my 223/5.56 and see what I come up with,,but over all once it is gone I will sit back and wait,,for more loading info,,,books,,charts,,etc before I try again. I guess I don't see enough of an improvement to go out and switch from my current powders,,(IMR4895,,AA2520,,AA2230,,etc) But on the other hand I applaud IMR/Hodgdon for innovation,,improvement and keeping a open mind to improving OUR sport & shooting in general !!!! GI6

My rifle was a Fulton Armory NM with a Krieger HVY BBL. I also took my time,,felt pretty good about most every shot,,I used sand bags and NM Iron sites,,shooting @ 115 yards (Yea I know weird,,but that's what our bench's are at on our range,GI8,)
All targets have all the info you should need,,,also I did cut back on the loads from what I got off the IMR website,,I figured better safe than sorry. All loads functioned fine,,although extraction was pretty weak,,nothing hung up,,but the brass just kind of flopped out of the gun,,,but like I said,,everything worked fine. I did use the 42 grns for the 125 TNT,,,that was the load listed on the web & they did fly out like a good normal load,,but still not a far or fast as my Standard 150grn FMJ load using AA2520. Well here are some targets,,feel free to ask any questions or post comments,,I'm always open to helping (trying anyways) & learning at the same time,,,GI6 GI6
First shots out of the rifle for the day,,,Cold BBL. (Base Group,different powder for comparison)

After a few min,,BBL was barely warm to the touch,,

Nothing special here,,probably me,,GI8

GI8GI8GI8 Hmmmmmm,what happened here ?

Hmmmmm,,Sierra who !!!!

I think it does like the lighter bullets,,,


This Concludes M1a_Scoutguys,,un scientific and un professional Test of IMR 8028 !!! GI6 GI6 (For Now)
 
#23 ·
I'm working with my SOCOM 16 and 168gr A-Max bullets. I tested 41.1gr of IMR 8208 XBR at 100 yards from a bench rest and got this group (I called the flyer)

I'm going to start moving up in charge weight and see what happens. I was using 42.4gr but I had a to start over due changes I made in the stock.
 
#25 ·
Hey Jon,,,the Website had 39 grns listed for the 168 grn bullet,,& they said knock it back 10% which would of been 35.1,,GI8 I have faith in my ability and faith in my rifle and normally I would of started at 39,,or 40ish like you guys have,,but I said what the heck,,,,I'll drop it back and see what happens !! I have NEVER been a HOT/Max load kind of reloader so I always try and see what shoots the best without stretching the limits,,or my $2000 rifle,,GI2 LOL !!!

But with that said,,all the brass & primers look great, nothing flattened or out of shape.If my camera was better I would take pics for further documentation,,maybe I'll try it later and see if they come out ok. In my next go round I will step it up for sure and get in the area you are Jon,,I think it can take the 40 grns without to much trouble. I will keep everyone posted. What I really need to do it throw a Scope on my Fulton,,it will help take away some of the "Me" factor !!! GI2

On another note I also have a Rem 700 Varmint Special with Hvy BBL in 7mm08 and it drives nails @ 100 yrds with the loads I use,,,it mite be interesting to try the powder in that rifle !!! If I do I'll post my results !! GI6 Hey Jon,,yea I see I mixed the Numbers up on what Powder I was talking about,,Duh,,it is IMR 8208 XBR,,,thanks for brining it to my attention.
 
#27 ·
Cool,,thanks for the Update !!! I need to get back to the reloading bench & play with this stuff somemore !! I agree,,the 125 TNT bullets do shoot pretty darn good,,,but I will play with other weights also !!! I'll keep everyone posted !! Also,,some darn good shootin there pbcaster45. FRG1
 
#28 ·
IMR 8208 XBR with a SOCOM 16

I just wanted to update my info. I'm continuing to test IMR 8208 XBR in my SOCOM 16 and I've reached what I consider to be the max powder charge weight for my bullets. I was very surprised at the muzzle velocities as they are on par with a 22" barrel and my groups (from a bench rest) at 100 yards were averaging an inch plus or minus a quarter inch. I am purposely testing with heavier bullets because I intend to use the load for my go-to gun for hunting all the way up to elk out to about 250 yards. Right now, between the group size and the temperature stability that they claim for 8208, I will probably use the powder for hunting purposes (I hunt in the mountains so temps can swing pretty quickly). I intend to load some IMR 4064 and compare it against the 8208 for group size, accuracy, and muzzle velocity. I will post the results when I finish.

Current best load using IMR 8208 XBR with a SOCOM 16.

COAL - 2.81"

Powder - IMR 8208 XBR 42.4gr (I was able to fire 43gr but I groups and pressure signs started getting worse after 42.4gr, pressure signs at 43gr included ejector marks on the base of the brass).

Bullet - Hornady 168gr A-Max

Case - WCC, TTL 2.005" (cases were sorted by weight, all primer pockets were uniformed and flash holes uniformed and chamfered on the inside).

Primer - Winchester Large Rifle

Muzzle Velocity Info -
42.4gr
Chrony at 15 feet from the muzzle
5 shot Average - 2587 fps.
41 fps extreme spread
15 fps standard deviation
Hi 2606 fps
low 2565 fps

I also tested velocities using 41.1gr and got an average of 2501 fps with 5 shots.
 
#33 ·
I like to do load development, so now I'll have to pick up a pound of 8028 err, 8208. I'll post my findings as I get them. Its going to be a while before we get any big temperature swings, so that part will come later. But for now I'll see what it does in warm weather.

Life is good!
 
#34 ·
Sorry guys, it's been so hot here in Oklahoma lately I've just been staying home. Got a break in the weather today (84 degrees) so I finally managed to get out and chronograph my Speer 125 gr. TNT load. It's a very accurate load but I'd like to get the velocity up to 2850 - 2900 fps, and maybe get those ES and SD numbers down. Plenty of information on this thread for the heavier bullets so I'll work with a light one. More to come.

Bullet: Speer 125 gr. TNT
Powder: IMR 8208 XBR 42.1 grs
Primer: CCI-200
Case: Lake City 64
LOAL: 2.695 (2.117 with Stoney Point Gage)
Average Velocity: 2702.48 fps
Extreme Spread: 72.61
Standard Deviation: 27.42


#01 2698.39 fps
#02 2689.39 fps
#03 2731.26 fps
#04 2733.11 fps
#05 2679.27 fps
#06 2677.50 fps
#07 2743.02 fps
#08 2722.66 fps
#09 2670.41 fps
#10 2679.87 fps
 
#35 · (Edited)
Imr 8208 xbr charge weight warning

BE ADVISED THAT (according to QuickLOAD data) 39.4 GRAINS OF IMR 8208 XBR WILL, IN MOST CASES, PUT YOUR CHAMBER PRESSURES RIGHT AT 50,000 PSI AND JUST OVER 40 GRAINS WILL PUSH THE PRESSURES TO RIGHT AT 60,000 PSI (assuming a 168gr Hornady A-Max bullet, a COAL of 2.81", a TTL of 2.005", and a case with a 54.2 gr water volume capacity).
QuickLOAD software predicts that the load I posted in this conversation would produce chamber pressures of over 70,000 psi!! Please be careful. The problem I found with the powder is that the pressures don't seem to produce any really bad pressure signs until you are well above a reasonable load. I pushed my loads up to 44 grains of powder and stopped because I was getting head separations after the second or third reload.

It looks like charge weights for the lighter bullets will max out around 45 grains and for the heavier bullets around 39 grains.


pbcaster, QuickLOAD software ( I have the updated database with 8208 in it) says that you should be able to go up to about 45 grains of powder and get pretty close to the velocities that you are wanting. Using your basic info the software predicts 2924 fps (the real world may be around plus or minus 50 fps) and a chamber pressure of around 50,044 psi. This will fill your cases right to about the 98% mark by usable volume which is the top end of where most loads seem to work well. QuickLOAD predicted that your 42.1 grain load would give 2741 fps with a chamber pressure of 41,139psi.
 
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