imr 8208 xbr

leanporker · Rookie Member Joined: Sep 25, 2005 Posts: 12

Has anyone tried this new powder? I am currently trying it in a .243 remington r25 with 58 v-max. I couldn't find any loading data for this powder (imr 8208 xbr) with .243. I started out with 38.0 grains and loaded the cartridge to 2.600 length. Speed was around 3500 at 15 feet from muzzle / 20 inch barrel. Accuracy was about .6 at 100 yards. Not a bad guess to start. Really no pressure signs or kick but the primers vary in visual inspections. I mean some are slightly flattened and some look new with just the firing pin dent. I lowered the charge to 37 grains but it seemed to get worse visually, more flattened primers. So I upped it to 39 grains and now all looks better and more consistent. The primers look less pressure. The group size is still around .6. I'm just nervous to go up in charge without any data. Any suggestions would be great. I think this powder may be similar to H4895 in burn rate.

slimjim · Posted: Sun Jan 17, 2010 10:32 pm Post subject: Re: imr 8208 xbr

Looks like they don't have it for the .243 yet. They did have it for the .243 WSSM. Can you ratio it to a different powder. Looks like you should be running 3 to 4 grains less than Varget as a rough estimate - 37 of 8208 would be a starting point. I don't know if I'd go to 40 grains. If your satisfied with the accuracy, stick with what you have.

Why would primers show more pressure indications with a lower powder charge?

58 GR. HDY V-MAX IMR 8208 40.0 3677 50,200 PSI 44.3 3985 63,200 PSI

58 GR. HDY V-MAX Varget 44.0 3739 52,000 PSI 47.0 3975 62,800 PSI

58 GR. HDY V-MAX Varget 41.0 3617 44,800 CUP 44.0 3790 49,800 CUP

slimjim · Posted: Sun Jan 17, 2010 10:34 pm Post subject: Re: imr 8208 xbr

You might also email Hodgdon directly and see if they can send you preliminary data.

Grumulkin · Posted: Mon Jan 18, 2010 7:56 am Post subject: Re: imr 8208 xbr

You have to be a bit careful upping loads in a semiauto. There would be 2 main pressure signs:

1. If the groups are small and then start getting bigger you've gone far enough.

2. Look for scuff marks on the case from the chamber. If there are few or no scuff marks, then the pressure isn't excessive.

I've ordered some of this powder so will eventually be going through the same process you're going through.

aznative · Member Joined: Oct 03, 2005 Posts: 31

I've loaded IMR 8208 a decade or so ago. Still have about 8 lbs left in my loading room. It was a vietnam era powder that works well in the 223. I don't know anything at all about this new stuff with the XBR postfix. Goto this link and scroll down to section 10 page 7 or 10-7 and you will find a listing for what I was using. The stuff worked real well in 223 and flows like benchmark thru a thower.

www.scribd.com/doc/388...ety-Sheets

BTW: flatened primers are not a sigh of excessive pressure. That is a sign of head space. The primer is the first thing to go off. The primer has to push the gasses thru the primer hole which pushes the case forward and the primer rearward which means the case is no longer supporting the rear of the primer. Pressure from either the primer or the powder lighting off, not sure which, expands the primer because it isn't supported by anything and is very thin. At the same time the pressure also pushes the case backward against the bolt head flattening the primer into the pocket. Now a ruptured primer can mean excessive pressure or excessive primer strike. Also, gas leaking around the primer pocket can mean excessive pressure.

Lastly the primer pocket loosening up after just a few reloads can mean excessive pressure. This is the last test I do with a load. I'll take five cases and reload them five times. If the pockets stay tight I'm fairly sure the pressure is good to go. The theory behind this is excessive pressure will keep expanding the rear of the case after each reloading; thus, pressure also expands the primer pocket too. I've had loads that will not hold primers after just three reloadings.

I also look at the back of the case to see if there is any metal flowing into the extractor hole.
Good Luck

yousocrates · Rookie Member Joined: Jan 15, 2011 Posts: 1

no i did not use this power but hope it will work well

Ominivision1 · Posted: Sat Jan 15, 2011 5:42 am Post subject: Re: imr 8208 xbr

Hodgens loading data web site has that powder listed for the 243 with that bullet.

Reloading Data

Dawgdad · Posted: Sun Jan 16, 2011 6:28 am Post subject: Re: imr 8208 xbr

looks like you are matching the starting load suggested by IMR 39 gr 3500 fps max load listed for58 V max is 42.3 gr for 3800 fps... OK i will get some of this too.

chambered221 · Posted: Sun Jan 16, 2011 6:06 pm Post subject: Re: imr 8208 xbr

After seeing this thread it got me thinking that this might be a good powder to try in working a new 70gr load for my 6mm Remington !!!

I went to the Hodgdon data to check it out and they didn't list it. Sad

I did however find the new Superformance was listed........holy cow.....3800+fps (didn't know it was available)

With the long barrel I should be able to break 3900.......not too bad for a 70 grainer. Very Happy

Thanks for leading me there !!!

Dawgdad · Posted: Sun Mar 06, 2011 7:27 pm Post subject: Re: imr 8208 xbr

I may need to get a couple of hundred pounds of this stuff.

I shot my best score ever in a high power match using 23.2 grains of 8208XBR under a 75 gr Hornaday BTHP.

I tried it with the 58 Gr Vmax in the .243 and ran a five shot one hole group at 100 yards at 3700 pfs...

chambered221 · Posted: Mon Mar 07, 2011 10:54 am Post subject: Re: imr 8208 xbr

Dawg, I read a article in one of the monthly rags about this powder !!!

IMR produced this powder years ago and it turns out there was a particular lot number that was highly sought after. It took a while but the right people finally convinced IMR to do another run based upon that particular lot. It now appears that because of it's popularity it will be readily available.