06-18-2019, 02:49 AM
(This post was last modified: 06-19-2019, 07:34 PM by bachekermooni.)
I will do the write up tonight. For now, the groups - Sorry.
Edit:
Temp was low to mid 60's. I had not cleaned the rifle from last session. As always, I sent a clean, dry, plastic brush (bore tech) down the bore, twice before starting to shoot.
All loads are with CCi 450 and new Lapua brass.
First group was 87 BTHP on top of 30 Gn of TAC. Great group even though the ES was over 50 fps. Then I shot the 90 TGK on top of 30 Gn of TAC. Disappointing despite an 8 fps ES. So I loaded three more and set them 0.04" from the lands (previous ones 0.02" from lands). Slight improvement, but still a no go. This one had an ES of 21.
OK. Plan B. Switched to CFE. Did a 0.2 Gn load increase with the sample TGKs I had left. Awesome results. The 90 TGK barely gets into the case powder area, despite its length. According to Sierra tech team it has a 0.214" bearing surface - wow. It sure does not look like it.
Out of TGK, I switched to CFE with ELD-X - loaded with 31 Gn of CFE. Shot a decent group with great ES. But the last case required a bit more force to seat the bullet and when fired, need a tad more force to open the bolt and a little shiny brow on the case head. Odd. It had the exact same speed of the second shot - 3011 fps.
ELD-X is not as long as the TGK and it has a chubbier ogive. So it takes a lot more of the powder space in the case. Actually the ELD-X COL, touching lands, is almost 0.050" shorter than TGK.
In the end, 90 ELD-X remains a work in progress. The 87 BTHP with 30 Gn of TAC is a viable load that can be used all the way up to and including deer. I ordered a box of TGKs and will finish its load development after the July 4th holiday. If it performers as advertised, and with its 0.490 BC, I should get close to 1000 Ft.Lb of energy and over 2100 FPS at 500 yards. Impressive.
Edit:
Temp was low to mid 60's. I had not cleaned the rifle from last session. As always, I sent a clean, dry, plastic brush (bore tech) down the bore, twice before starting to shoot.
All loads are with CCi 450 and new Lapua brass.
First group was 87 BTHP on top of 30 Gn of TAC. Great group even though the ES was over 50 fps. Then I shot the 90 TGK on top of 30 Gn of TAC. Disappointing despite an 8 fps ES. So I loaded three more and set them 0.04" from the lands (previous ones 0.02" from lands). Slight improvement, but still a no go. This one had an ES of 21.
OK. Plan B. Switched to CFE. Did a 0.2 Gn load increase with the sample TGKs I had left. Awesome results. The 90 TGK barely gets into the case powder area, despite its length. According to Sierra tech team it has a 0.214" bearing surface - wow. It sure does not look like it.
Out of TGK, I switched to CFE with ELD-X - loaded with 31 Gn of CFE. Shot a decent group with great ES. But the last case required a bit more force to seat the bullet and when fired, need a tad more force to open the bolt and a little shiny brow on the case head. Odd. It had the exact same speed of the second shot - 3011 fps.
ELD-X is not as long as the TGK and it has a chubbier ogive. So it takes a lot more of the powder space in the case. Actually the ELD-X COL, touching lands, is almost 0.050" shorter than TGK.
In the end, 90 ELD-X remains a work in progress. The 87 BTHP with 30 Gn of TAC is a viable load that can be used all the way up to and including deer. I ordered a box of TGKs and will finish its load development after the July 4th holiday. If it performers as advertised, and with its 0.490 BC, I should get close to 1000 Ft.Lb of energy and over 2100 FPS at 500 yards. Impressive.