I posted this in another thread but got no responses so I hope It's OK to start my own thread on this issue .
Well I just got back from the range where I tested some 200gr XTP 45 bullets using longshot . I'm confused with the results though and maybe you all have an idea what was happening .
Lets start with what the Hornady book list as min to max laods and what they used to test
OVERVIEW PAGE IN BOOK
Firearm = Springfield 1911 5"
Cases = Hornady
Primer = Win LP
COAL = 1.275
Bullet diameter = .451
Load data
200gr XTP
OAL 1.210
min 6.6gr @ 800fps
Max 8.6gr @ 1000fps
OK now my loads
Firearm = Springfield 1911
Cases = Winchester
Primer = Win LP
Bullet diameter = .451
200gr XTP
COAL 1.240 suggested OAL in book 1.210
Loads and Avg velocities
6.5gr @ 750fps
7.0gr @ 834fps
7.3gr @ 864fps
7.6gr @ 875fps
And here is where it gets odd and I'm not sure how much this has to do with My chrono or not . It started acting up after this .
7.9gr @ Unknown but 4 of 5 shots were 972fps / 952 / 944 / 1159
8.1gr @ unknown but 5 shots were 1165fps / 1157 / 273 / 1161 / 268
So now I'm sitting there looking at those numbers seeing that there is clearly something wrong but not sure what . 8.1gr in the book should be around 950fps but I'm getting 200fps more velocity . I re-look at the brass and I don't see any issue on the head but do notice that from the mouth to about 3/4 of the way down on one side is black-ish but for the most part they all kinda look like this . Now I'm wondering was it the chrono or the loads . Do I shoot the next increment or not .
I did and this is what I got , 8.2gr @ 1149fps / 1157 / 1157 / 1161 / 1156 with a ES of 12 and SD of 4 . OK I'm clearly over pressure/max . I should not even be at 1000fps with that load . Hodgdon website only has 1 load for Longshot and a 200gr bullet . It is a JHP but it maxes out at 7.8gr @ about 1000fps . Is Hornady that far off on there data for those two combined components ?
I obviously stop there and start looking at my notes . There are two things that are different from Hornady to my loads . The cases and what I believe is the COAL . The cases I feel should be less of a factor but you all may know better . There COAL on the first page ( overview ) is 1.275 ( I'm assuming that's a MAX number and NOT what they loaded all test rounds to ) and the bullet data it self says 1.210 so I'm not sure what there test loads were seated at , Mine were 1.240 . Where do you think they seated the 200gr XTP ? I doubt it was 1.210 or 1.275 and I feel that may be the most important question to be answered in order to understand why my results are so different then the book . If they loaded at 1.210 then mine should have less pressure but if they were at 1.275 , my 1.240 would have much more pressure .
It just seemed odd that the velocity was moving as expected then just exploded to way over where it should have been . I should add that this was load development so I weighed each charge and confirmed the scale with check weights before each different charge weight .
Is Longshot one of those spiky powders when you get at the higher end of the charges it starts having unpredictable pressure spikes ?
Any and all thoughts welcome on what's going on here .
Thanks Metal
Since my OP in the other thread I looked closer at the Brass that shot those higher velocities . I see extractor marks and another mark that is in the same place on all cases in relation to the extractor mark .
RED = extractor mark
PURPLE = other mark noted above
GREEN = black soot on cases
You start to see those extractor marks at about 7.9gr . At 7.9gr they are very light marks and get more pronounced as the charge goes up . Now in a center fire cartridge I'd say I need to back off when seeing that . Does the same hold true in pistol loads ? I ask because when I'm doing case prep on once fired factory loaded cases . I often see extractor marks on those cases . Can getting extractor marks be more tolerated in pistol loads ???
Well I just got back from the range where I tested some 200gr XTP 45 bullets using longshot . I'm confused with the results though and maybe you all have an idea what was happening .
Lets start with what the Hornady book list as min to max laods and what they used to test
OVERVIEW PAGE IN BOOK
Firearm = Springfield 1911 5"
Cases = Hornady
Primer = Win LP
COAL = 1.275
Bullet diameter = .451
Load data
200gr XTP
OAL 1.210
min 6.6gr @ 800fps
Max 8.6gr @ 1000fps
OK now my loads
Firearm = Springfield 1911
Cases = Winchester
Primer = Win LP
Bullet diameter = .451
200gr XTP
COAL 1.240 suggested OAL in book 1.210
Loads and Avg velocities
6.5gr @ 750fps
7.0gr @ 834fps
7.3gr @ 864fps
7.6gr @ 875fps
And here is where it gets odd and I'm not sure how much this has to do with My chrono or not . It started acting up after this .
7.9gr @ Unknown but 4 of 5 shots were 972fps / 952 / 944 / 1159
8.1gr @ unknown but 5 shots were 1165fps / 1157 / 273 / 1161 / 268
So now I'm sitting there looking at those numbers seeing that there is clearly something wrong but not sure what . 8.1gr in the book should be around 950fps but I'm getting 200fps more velocity . I re-look at the brass and I don't see any issue on the head but do notice that from the mouth to about 3/4 of the way down on one side is black-ish but for the most part they all kinda look like this . Now I'm wondering was it the chrono or the loads . Do I shoot the next increment or not .
I did and this is what I got , 8.2gr @ 1149fps / 1157 / 1157 / 1161 / 1156 with a ES of 12 and SD of 4 . OK I'm clearly over pressure/max . I should not even be at 1000fps with that load . Hodgdon website only has 1 load for Longshot and a 200gr bullet . It is a JHP but it maxes out at 7.8gr @ about 1000fps . Is Hornady that far off on there data for those two combined components ?
I obviously stop there and start looking at my notes . There are two things that are different from Hornady to my loads . The cases and what I believe is the COAL . The cases I feel should be less of a factor but you all may know better . There COAL on the first page ( overview ) is 1.275 ( I'm assuming that's a MAX number and NOT what they loaded all test rounds to ) and the bullet data it self says 1.210 so I'm not sure what there test loads were seated at , Mine were 1.240 . Where do you think they seated the 200gr XTP ? I doubt it was 1.210 or 1.275 and I feel that may be the most important question to be answered in order to understand why my results are so different then the book . If they loaded at 1.210 then mine should have less pressure but if they were at 1.275 , my 1.240 would have much more pressure .
It just seemed odd that the velocity was moving as expected then just exploded to way over where it should have been . I should add that this was load development so I weighed each charge and confirmed the scale with check weights before each different charge weight .
Is Longshot one of those spiky powders when you get at the higher end of the charges it starts having unpredictable pressure spikes ?
Any and all thoughts welcome on what's going on here .
Thanks Metal
Since my OP in the other thread I looked closer at the Brass that shot those higher velocities . I see extractor marks and another mark that is in the same place on all cases in relation to the extractor mark .
RED = extractor mark
PURPLE = other mark noted above
GREEN = black soot on cases
You start to see those extractor marks at about 7.9gr . At 7.9gr they are very light marks and get more pronounced as the charge goes up . Now in a center fire cartridge I'd say I need to back off when seeing that . Does the same hold true in pistol loads ? I ask because when I'm doing case prep on once fired factory loaded cases . I often see extractor marks on those cases . Can getting extractor marks be more tolerated in pistol loads ???