Imr 8208 xbr

Finally got out for some quick work up testing. (22-250 , 55 grain bullet)

conditions were -10 or -19 with wind chill yesterday.

I worked up to to the max load which was 35.8 gr. (according to hodgdon data) if I recall correctly and I fired a 3 shot group with that combination. (and a few other groups below)

group size @ 100 yards was .549 and avg MV was 3750 fps. Not a low pressure load but no major pressure indicators yet. Ill be loading more and will shoot some 5 shot groups but its looking good so far.

case: winchester
primer: wlr
bullet: 55 grain sierra blitz seat at 2.45"
rifle: Rem 700 Varmint 24" barrel.
 
Just a note on Windchill Equivalent Temperature.

A warm body can't be cooled below ambient temperature ( -10 in this case). The rate at which it cools to -10 in the wind can be quoted as an equivalent temperature in still air (-19 in this case). Only warm bodies like you, radiators, bullets in your pocket are affected by windchill. Warm bodies cool to ambient temperature and no more.

Windchill is really a cooling rate expressed in watts/sq meter.

NormB
 
Imr-8208 xbr

Just got my first pound of it.
I have about 50 new .308 winchester Lapua brass cases primed with CCI Benchrest primers and two boxes of Lapua Scenar 155 and 165gr. HPBT bullets.
Also, I have a big lot of 222 Remington brass with many boxes of 50 and 55gr. A-max bullets.
Any starting or middle-of-the road recipes I could try like RIGHT NOW?
PP. w:h:
 
PerversPépère said:
Just got my first pound of it.
I have about 50 new .308 winchester Lapua brass cases primed with CCI Benchrest primers and two boxes of Lapua Scenar 155 and 165gr. HPBT bullets.
Also, I have a big lot of 222 Remington brass with many boxes of 50 and 55gr. A-max bullets.
Any starting or middle-of-the road recipes I could try like RIGHT NOW?
PP. w:h:
Click to expand...

I've finally settled on 8208 for my M14. Went back & forwards a few times.

With the internals swapped the gas system seems to really work well with it.
It took some fiddling around to find it.
### Gas piston, USGI spring, ### spring guide and recoil buffer.

Load:
.308 Winchester brass, chamber formed and neck sized.
Case trim to 2.007/chamfered/pp cleaned.
CCI primer seated at 4-7.
150gr Hornady bullet
44 grains of 8208 XBR.
Light to moderate crimp.

It's very accurate with this load and the gas system operates slick as snot.
Best results are obtained with neck sizing.
Initial loads with new factory brass are way off no matter what the powder.
Post neck sizing accuracy improves by 50%, each subsequent sizing obtaining slightly better results as you progress down the line.

8208 seems indifferent to hot & cold, meters very well and has the consistency of course sand. It's also the same price as the other powders.

Hope that helps.
 
223 Rem (20" 1:9 m700)

77gr Nosler HPBT
22.7grs IMR 8208xbr
CCI400
Lapua brass

2765 f/s avg & .5moa avg @ 100m

188425_10150107667002992_512917991_6489928_3778021_n.jpg
 
Here is a comparison with Varget in my (just sold - sob!) 26" Rem 700P 308. At the high end of the 8208 graph, I started to get primer flattening with my CCI BR primers in Lapua Palma cases.

These graphs were made in the winter around -5 degC, and actually when I shot the 8208 in the summer rain, it slowed down 40 fps!
 

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