.45 300SST, What Does It Need?
Jan 16, 2009 22:25:16 GMT -5
Post by Dave W on Jan 16, 2009 22:25:16 GMT -5
To get rid of the low flier if that is what you would call it. Every group I have shot at 53.5gr of H4198 has had one shot that drops out of the group, usually the 2nd or 3rd shot. It was too close to gun season and the range was too crowded to use the chrony other than twice. On the last range trip before deer season I used the chrony and the shot that dropped low in the 4 shot group that is a little left of center on the target on the left, timed right with two of the three shot cluster.
I thought maybe the load needed a little powder so I tried 54gr that day and you can see the spread got worse from the 2 shots marked. Moved out to 250yds and had the same thing except the wind moved the group further left. I used a different POA for this group to verify my drop at that distance.
The target on the right shows more of the same. I tried a different knurl texture on the lower 3 shot group and the POI changed by roughly 3" but the vertical spread improved a little, thought this was interesting.
I included these two targets to show that if it is me then I'm consistently doing something inconsistent. I shot other groups like this on rainy days so the targets got pitched but they all have the same theme.
I haven't tried altering the charge weight by a 1/10 of a grain or two mainly because I have never seen that much improvement when doing so with either the .50 or the .45 when shooting saboted loads. A 1/2 grain of powder increment has always been the difference between sub MOA or plus MOA, but maybe this is a different animal.
I also have not been swabbing, the nearly .5 MOA 200yd group I shot this summer with the 250BE was shot on a fouled barrel with no patching so I decided to try it with the 300SST but maybe that needs looked at also.
Since I have not experienced this with the 250 or 275BE's which are not sized for my barrel, I thought maybe sizing the bullets may be causing this, maybe some kind of jacket separation from the core, maybe I'm reaching here though since Harley and SW never mentioned it but they are only stepping down a small amount when sizing. Might try some Bonded SW's in the future.
Any thoughts or ideas are appreciated.
The load was 300SST- 53.5gr H4198- 2/.030 veggie wads.
All groups were shot at 200yds with the exception of the 250yd group with temps in the 25*-50* range. All the groups are approximately 2.5" and the 250yd group was approx. 3.5"
I thought maybe the load needed a little powder so I tried 54gr that day and you can see the spread got worse from the 2 shots marked. Moved out to 250yds and had the same thing except the wind moved the group further left. I used a different POA for this group to verify my drop at that distance.
The target on the right shows more of the same. I tried a different knurl texture on the lower 3 shot group and the POI changed by roughly 3" but the vertical spread improved a little, thought this was interesting.
I included these two targets to show that if it is me then I'm consistently doing something inconsistent. I shot other groups like this on rainy days so the targets got pitched but they all have the same theme.
I haven't tried altering the charge weight by a 1/10 of a grain or two mainly because I have never seen that much improvement when doing so with either the .50 or the .45 when shooting saboted loads. A 1/2 grain of powder increment has always been the difference between sub MOA or plus MOA, but maybe this is a different animal.
I also have not been swabbing, the nearly .5 MOA 200yd group I shot this summer with the 250BE was shot on a fouled barrel with no patching so I decided to try it with the 300SST but maybe that needs looked at also.
Since I have not experienced this with the 250 or 275BE's which are not sized for my barrel, I thought maybe sizing the bullets may be causing this, maybe some kind of jacket separation from the core, maybe I'm reaching here though since Harley and SW never mentioned it but they are only stepping down a small amount when sizing. Might try some Bonded SW's in the future.
Any thoughts or ideas are appreciated.
The load was 300SST- 53.5gr H4198- 2/.030 veggie wads.
All groups were shot at 200yds with the exception of the 250yd group with temps in the 25*-50* range. All the groups are approximately 2.5" and the 250yd group was approx. 3.5"
