OCW Load Development with IMR 8208XBR

[Michael]

Hey all - Weather was nice and I was finally able to get out to the public range (ugh) and do some OCW testing with IMR 8208 XBR. Decided to try this route to a load as my results with ladder testing have been spotty (tough to get somewhere I can shoot beyond 100yds), and I want very temp stable loads. Hope you can see and understand the pics. Load data as follows:

Rifle – AA 19.5 upper, Leopold Mk4 4.5-14

123 Lapua Scenar
CCI #41
AA Brass, New, trimmed to 1.51
Started at 25.6 with foulers and worked up to 28.6
OAL to O-give 1.698

120 Barns TSX
CCI #41
Hornady Brass, fired, trimmed to 1.515
Started at 25.2 with foulers and worked up to 28.2
OAL to O-give 1.726

Range was 100yds. Targets are 2”, with the exception of the ones used at the head/for the AMX shots – they are 3”. Did not use a chrony – public range makes using my CED M2 a pain in the a**, and since I am developing loads, didn’t want to use my MagnetoSpeed.

Weather was overcast, temps 45-50, 60%RH at an altitude of about 2200ft. Shot 3 factory A-max to make sure I was on paper, then shot 3 foulers for each load, followed by round robin shooting of the loads.

I’m very happy with the TSX testing, will go back out to friends place once cows are moved around and continue OCW at 300yds with the 27.6gr load. Developing this load for hunting.

Not real happy with the Lapua testing. This round is kicking my a** trying find a powder that works for me (no luck with CFE, Win 248 and now 8208). Gonna try to find some TAC and try that I guess.

Below is A-MAX group in bull - can cover with a dime. Three shot holes low are foulers, while first group for Lapua is to the right.

[Michael]

TSX groups

[Michael]

Lapua groups.

[Michael]

Sorry above pics are out of order. Title of pics list the charge in each group.

[LRRPF52]

Looks like your rifle likes the factory A-MAX. I bet the 123gr SST would shoot well too. You might also try N530 and N540 with the TSX.

I'm going to be doing some N530 testing here starting this spring. I ended up with 14 lbs of it.

[bluebird]

Great shooting, better than I can do.

[Michael]

Looks like your rifle likes the factory A-MAX. I bet the 123gr SST would shoot well too.

Yeah, I have thought about getting some SST, but I have a few hundred of the Barnes to play with. Figure if I get a good load with the 8208 I’ll call it good.

[LRRPF52]

That 120gr TSX just keeps going through stuff as well, doesn't really care what it is. Even with 1 MOA accuracy, it makes a very capable hunting bullet.

Cue in Mark LaRue Elk hunt from 2007...

[Michael]

All - sorry it took so long to follow up with this thread. It has been a busy few months...got an old M1 carbine, retired from the Marine Corps, bought a new house, Honey do list, etc.

Enough of that...on to the continued load development.

Took the above Barnes load (27.6 of 8208) and got some more shooting done with it. At 300yds, shot 3- 5 shot groups and these groups averaged just under 4". Next step was the Chrony. Used the Magneto Speed and got the following data:

2507
2492
2478
2491
2497
2488
2492
2497
2502
2503

SD = 8
Av = 2494.7
ES = 29
Temp = 85
R/H = 60%
Elevation = 2360

Groups at 100yds continue to be about an inch or a hair more. Gonna try to adjust OAL a bit to see if that tightens up the groups. Read on Barnes’ site (or somewhere else?) that the TSXs should have a bit more jump than other bullets, so I’m going to make a few about .010 shorter and see what happens. May even try a light taper crimp and see what that does.

[tony549]

Great work and thanks for your service.
Some typos?
Av s/b 2494.7
ES s/b 29

[Michael]

Great work and thanks for your service.
Some typos?
Av s/b 2494.7
ES s/b 29

Yep. Corrected. Thanks Tony.