After researching more of what i needed to learn i realized going to 175 instead of 168 would be best since i enjoy shooting out to 1000y. I bought some Hornady ogive comparators, case length gauges and all that other fun stuff. Since i grabbed all that stuff i decided to get some 175gr SMKs as well for my .308.
I did various measurements... from using the dummy round and loading the cartridge into the chamber with the bullet seated shallow so it gets pushed in as the round seats in the chamber. Also used the Hornady OAL case length gauge. Both times i measured i got similar measurements which were 2.190" measured to ogive. However that put the COAL to 2.770" which is .030" less then the book recommended COAL. I was concerned as ive never done this before. After playing with some fgmm 168s i realized the fgmm rounds were being seated approx .010" jammed (which was the same as the ogive measurements i got from 168s i tried). So i did that with the 175gr rounds i was loading which still made the COAL .020" less than the recommended COAL. I was afraid of the rounds blowing up in my face due to to much pressure, but after checking with some other people saying its fine i continued.
I have the Sierra reloading manual, and the Hodgdon reloading manual as far as Varget powder is concerned. The Sierra stated the load data was 36.3-41.7 min/max, and Hodgdon was 42.0-45.0 for 175gr smk... as you can see these are MAJOR differences, and again i was not sure which one to go by. So again i ask around and everyone said to go by the Hodgdon manual. Since my round was shorter than the recommended COAL i was a little unsure of the higher loads. So i decided to start at 39.5 and worked in .5gr incriments to 45.0gr. Knowing that hind site is 20/20 i wish i would have pushed them higher to 46 or maybe even 47. After doing the ladder test i found there was absolutely no pressure signs at 45.0gr which was the max i loaded to.
Today was a very nice day to go shooting. It was mostly cloudy all day long with a 2-5mph wind. I decided to do this ladder test at 500y. I loaded a few extra of the lighter rounds to ensure i was sighted in. Well that didnt go to well as the sighters all landed low. So i then went to the 168gr i had loaded to use to get on paper and they hit real high. I readjust and load the starting 175gr round which was 39.5 and fire... it hits low (damnit!), I load the next which is 40.0gr and again... low(FUCK!). The next round, 40.5gr lands about 7" low but dead on elevation wise, (for this shot the wind had picked up a little so i had to adjust for windage). The next round 41.0gr was a little higher, just as expected all the rounds a little higher then the ones before. There were absolutely no groupings except for the last 3 (44-45). As i fired these rounds the wind decided to die down slowly so youll see the rounds hit left more and more. But as you can see the top rounds are nice, which makes me wish i had loaded hotter to see which ones were better. The ones with the permanents marker were the spotters and debris from the ones that hit low.
Ill update this as i go again, probably going to start at 43.7-46.1 in .3gr incriments for the next test.
P.S. I posted this on another site as well, just wanted to see your guys take on this as well.
I did various measurements... from using the dummy round and loading the cartridge into the chamber with the bullet seated shallow so it gets pushed in as the round seats in the chamber. Also used the Hornady OAL case length gauge. Both times i measured i got similar measurements which were 2.190" measured to ogive. However that put the COAL to 2.770" which is .030" less then the book recommended COAL. I was concerned as ive never done this before. After playing with some fgmm 168s i realized the fgmm rounds were being seated approx .010" jammed (which was the same as the ogive measurements i got from 168s i tried). So i did that with the 175gr rounds i was loading which still made the COAL .020" less than the recommended COAL. I was afraid of the rounds blowing up in my face due to to much pressure, but after checking with some other people saying its fine i continued.
I have the Sierra reloading manual, and the Hodgdon reloading manual as far as Varget powder is concerned. The Sierra stated the load data was 36.3-41.7 min/max, and Hodgdon was 42.0-45.0 for 175gr smk... as you can see these are MAJOR differences, and again i was not sure which one to go by. So again i ask around and everyone said to go by the Hodgdon manual. Since my round was shorter than the recommended COAL i was a little unsure of the higher loads. So i decided to start at 39.5 and worked in .5gr incriments to 45.0gr. Knowing that hind site is 20/20 i wish i would have pushed them higher to 46 or maybe even 47. After doing the ladder test i found there was absolutely no pressure signs at 45.0gr which was the max i loaded to.
Today was a very nice day to go shooting. It was mostly cloudy all day long with a 2-5mph wind. I decided to do this ladder test at 500y. I loaded a few extra of the lighter rounds to ensure i was sighted in. Well that didnt go to well as the sighters all landed low. So i then went to the 168gr i had loaded to use to get on paper and they hit real high. I readjust and load the starting 175gr round which was 39.5 and fire... it hits low (damnit!), I load the next which is 40.0gr and again... low(FUCK!). The next round, 40.5gr lands about 7" low but dead on elevation wise, (for this shot the wind had picked up a little so i had to adjust for windage). The next round 41.0gr was a little higher, just as expected all the rounds a little higher then the ones before. There were absolutely no groupings except for the last 3 (44-45). As i fired these rounds the wind decided to die down slowly so youll see the rounds hit left more and more. But as you can see the top rounds are nice, which makes me wish i had loaded hotter to see which ones were better. The ones with the permanents marker were the spotters and debris from the ones that hit low.
Ill update this as i go again, probably going to start at 43.7-46.1 in .3gr incriments for the next test.
P.S. I posted this on another site as well, just wanted to see your guys take on this as well.
