Post by rhoadskill on Oct 5, 2018 18:46:16 GMT -8
For a couple of years now I have been running my 123gr SST loads in an upper I built with a 10.5" .264 LBC 8 twist BHW barrel. It shoots wonderfully! Velocity is right around 2200fps and to 300yds it is surprisingly accurate. I have a 1-4 Vortex Viper PST on it and often wish there was more magnification for longer shots at targets.
This summer my son saved his lawn mowing money so that he could buy parts for a build. We were planning to buy the same barrel but then we saw that he could get a 9 twist 14.5" for quite a bit less. He decided it was the better value so we bought it. After getting the upper built we took it out to a private range to dial in. I started on steel at 50yds. After 5 rounds we had it to where I figured we could take it to a full-sized steel IPSC target at 100yds. Shots were all over. Some left, some right, some high, some low, every once in a while I would actually hit the target, but not often. Corrections did not seem to translate at all. So I went back to 50yds, dialing in there again then went back to 100yds. Same results. After a few iterations of this I thought it might be a scope problem (SWFA SS 1-4x24). I then took the scope off of the new upper and put it on my 10.5" upper. With 2 rounds at 50yds then 4 more at 100yds it dialed right in.
The range owner happened by and I explained what we were fighting with. He also runs Grendels and happend to have some Federal American Eagle loads with 90gr Speer TNTs. We put the scope back on the new upper and ran some of the Federal ammo through it. I shot 2 at 50yds then 2 sighters at 100yds, followed by 3 more for a group. Those last 3 were about .75" apart. He also had 2 rounds of factory Hornady 123gr SST ammo so I then shot those at the 100yd IPSC target. Neither one hit. Going back to the Federal ammo I was able to stack a couple more on the previous 3.
When we were considering the 14.5" 9 twist barrel I did some looking and concluded that it should stabilize bullets up to around 130gr, but what I did NOT take into consideration was velocity. With this barrel being shorter, I am concerned that the 123gr loads do not have enough velocity to stabilize given the slower twist rate. I have not chronoed with the new barrel but I would guess my loads to be at least 2300fps given that they are 2200fps out of the 10.5" barrel. The barrel obviously shoots the 90gr TNTs quite well. However, not only did we plan to target shoot with this upper but we also planned to hunt deer and pigs with it. Because of this we really want to be able to run the 123gr bullets as we have had good terminal performance from them thus far.
So, it seems to me that a 14.5" 9 twist cannot stabilize the 123gr SSTs. Does anyone have experience that can confirm or refute this theory? Trying to decide if we have a barrel that won't work for our needs or if I am missing something.
This summer my son saved his lawn mowing money so that he could buy parts for a build. We were planning to buy the same barrel but then we saw that he could get a 9 twist 14.5" for quite a bit less. He decided it was the better value so we bought it. After getting the upper built we took it out to a private range to dial in. I started on steel at 50yds. After 5 rounds we had it to where I figured we could take it to a full-sized steel IPSC target at 100yds. Shots were all over. Some left, some right, some high, some low, every once in a while I would actually hit the target, but not often. Corrections did not seem to translate at all. So I went back to 50yds, dialing in there again then went back to 100yds. Same results. After a few iterations of this I thought it might be a scope problem (SWFA SS 1-4x24). I then took the scope off of the new upper and put it on my 10.5" upper. With 2 rounds at 50yds then 4 more at 100yds it dialed right in.
The range owner happened by and I explained what we were fighting with. He also runs Grendels and happend to have some Federal American Eagle loads with 90gr Speer TNTs. We put the scope back on the new upper and ran some of the Federal ammo through it. I shot 2 at 50yds then 2 sighters at 100yds, followed by 3 more for a group. Those last 3 were about .75" apart. He also had 2 rounds of factory Hornady 123gr SST ammo so I then shot those at the 100yd IPSC target. Neither one hit. Going back to the Federal ammo I was able to stack a couple more on the previous 3.
When we were considering the 14.5" 9 twist barrel I did some looking and concluded that it should stabilize bullets up to around 130gr, but what I did NOT take into consideration was velocity. With this barrel being shorter, I am concerned that the 123gr loads do not have enough velocity to stabilize given the slower twist rate. I have not chronoed with the new barrel but I would guess my loads to be at least 2300fps given that they are 2200fps out of the 10.5" barrel. The barrel obviously shoots the 90gr TNTs quite well. However, not only did we plan to target shoot with this upper but we also planned to hunt deer and pigs with it. Because of this we really want to be able to run the 123gr bullets as we have had good terminal performance from them thus far.
So, it seems to me that a 14.5" 9 twist cannot stabilize the 123gr SSTs. Does anyone have experience that can confirm or refute this theory? Trying to decide if we have a barrel that won't work for our needs or if I am missing something.
