|July 8, 1999, 02:23 PM||#1|
Join Date: June 30, 1999
I have loaded 6000rnds of 55fmjbt, once fired mil brass and did the below test prior to loading----I am getting very different results from other reloaders.....If anybody out there has any experience with this powder please reply !!!
DATA: I loaded over 400 rds to test 50rnds for each load with the following results:
55fmjbt/20" ar-15 and mini 14, electronic and balance beam scales, 2 ea in line cronos.
quality control checks: pulled and measured powder on 3 rnds in every batch.
23.0g-----2600fps (open group @ 25yrds)
23.3g-----2700fps ( " " )
23.5g-----2850fps (" " )
23.6g-----2975fps (tighter )
23.7g-----3050fps ( best group and a
deviation of 50fps for 50rnds
23.8g-----3150fps ( good group)
23.9g-----3250fps (not as good as 3150)
23.7@3050fps had the best group and provides for preassure safty
Once agian if anyone has any more information or comments please respond...
|July 8, 1999, 03:06 PM||#2|
Join Date: March 20, 1999
Location: Somewhere in the woods of Northern Virginia
I did a similar test for my new mini-14 a couple of weeks ago, but not nearly as scientific as your tests. I used AA2230 and Hornady 55 SP. My grouping results were similar to yours. With the light load (24.0 gr), the group was very open. With the medium load (25.0 gr), it was considerably tighter and about 1" smaller. The heavy load (26.0 gr) was close to the med. but about .25" larger. So I settled on the medium load. All loads cycled the action with no problems.
Frankly, I'm surprised at the wide range of velocities you got with a powder range of only 0.9 gr. Did you expect this? This means you're probably going to have to weigh each charge instead of using a powder dispenser.