Being relatively new to the world of bolt guns, I have been very happy with the 700 AAC SD. My first concern was putting together the most accurate package. Scope, rings, stock, trigger, bullets, brass, powder, load, etc. all play into this and I kept reading that 168g and 175g HPBTs were the bees knees when it came to accurate long range bullets. I am curious about what kind of results people get with 200g+ bullets out of a 20" 1:10 twist barrel.
- Thread starter vegasjeepguy
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So far it looks like no one is sending 200g+ bullets down range through a 20" barrel...
I'm no expert here but it would be very difficult to get enough velocity for bullets that heavy for long range out of any 308, especially a 20"
Let me clarify. I'm not looking at going out to 800 yds with a 200g bullet. Just curious what kind go performance can be had up to 500 yds.
Maybe this will help?
208 Amax in 20" .308
FWIW, I'm very interested in trying this as well in my AAC-SD, but would be using H4350. If the 208 ever comes back in stock I'm gonna give it a whirl. If it doesn't work out I can still use them for subs in my 300 BLK, not much to lose.
208 Amax in 20" .308
FWIW, I'm very interested in trying this as well in my AAC-SD, but would be using H4350. If the 208 ever comes back in stock I'm gonna give it a whirl. If it doesn't work out I can still use them for subs in my 300 BLK, not much to lose.
Thanks for the link. Sounds like a question that hasn't really been tested.
I agree, picked up some 200 grain smk's fir my ssd and dont really know what to do with them..... Maybe a good subsonic round?
Ive loaded hornady 195 BTHP's under a few different powders, accuracy was never fantastic but I didn't develop the load very much as the weather changed between tests.
This was a bone Stock SPS tac at the time, I'll post some more results tomorrow when I wake up.
This was a bone Stock SPS tac at the time, I'll post some more results tomorrow when I wake up.
Guy over on M4C ran stability numbers for me for the 208 AMAX and 220 SMK out of a 10 twist barrel.
subsonic the 220g SMK and 208g AMAX are not stable in the barrel. 1.4 is considered minimum stability. 1.38 for the 220g SMK and 1.2 for 208 AMAX. He said he played with the 220g SMK out of his 1/10 gun subsonic and he said at 100 yards it was a 1-2 MOA gun, but out to 300 yards it was a 10 MOA gun.
supersonic they both are "stable enough" according to him. He calculated at 2400 FPS for both. 1.82 for 220g SMK and 1.58 for 208 AMAX. So they will be stable.
subsonic the 220g SMK and 208g AMAX are not stable in the barrel. 1.4 is considered minimum stability. 1.38 for the 220g SMK and 1.2 for 208 AMAX. He said he played with the 220g SMK out of his 1/10 gun subsonic and he said at 100 yards it was a 1-2 MOA gun, but out to 300 yards it was a 10 MOA gun.
supersonic they both are "stable enough" according to him. He calculated at 2400 FPS for both. 1.82 for 220g SMK and 1.58 for 208 AMAX. So they will be stable.
Now that makes sense. Looking at the ballistics it seems I run out of elevation past 600 yds with a 220g bullet. I've got 420"+ of bullet drop and velocity under 1000 fps at 800 yds.
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below is some data based on the formula [(C x bullet diameter in inches squared) / bullet length in inches] C= 150 when <2800fps and 180 when >2800fps.
a 180gr accubond bullet needs a 10.31 twist rate when going less than 2800fps and 12.37 above 2800.
a 200gr accubond bullet needs a 9.55 twist rate when going less than 2800fps and 11.46 above 2800.
a 208gr Amax bullet needs a 9.30 twist rate when going less than 2800fps and 11.3 above 2800.
a 220gr SMK bullet needs a 9.55 twist rate when going less than 2800fps and 11.46 above 2800.
I would still try them in the 1x10 and find out, because the 1x10 will be too fast for lighter bullets and cause the same issue. good luck!
a 180gr accubond bullet needs a 10.31 twist rate when going less than 2800fps and 12.37 above 2800.
a 200gr accubond bullet needs a 9.55 twist rate when going less than 2800fps and 11.46 above 2800.
a 208gr Amax bullet needs a 9.30 twist rate when going less than 2800fps and 11.3 above 2800.
a 220gr SMK bullet needs a 9.55 twist rate when going less than 2800fps and 11.46 above 2800.
I would still try them in the 1x10 and find out, because the 1x10 will be too fast for lighter bullets and cause the same issue. good luck!
I posted a thread on this a few months ago. It's somewhere out there but since we can't use google to search the site anymore I don't know how to find it. There are a few people on the hide who have done it and do it. As soon as I can afford reloading supplies I plan to try it out.
I've never tried it but I ran it through a ballistic calculator and what I found was that below about 800 yards or even further it isn't useful. Lighter bullets have much less drop at shorter distances and all other things being equal there is no real advantage to heavier ones. Where it does become interesting past 1000 yards. Most of the data I've looked at suggests that most 168 or 175 grain loads fired out of the AAC-SD go subsonic prior to 1000 yards, but a 208 amax fired at about 2400 fps or slightly below will stay supersonic past 1200 yards. There is also significantly less wind drift and past around a thousand yards the drop becomes less than the lighter rounds.
If you were going to use them inside 200 you certainly could and the twist would keep them stable. They'd just drop quite a bit more than lighter bullets at that distance.
I've never tried it but I ran it through a ballistic calculator and what I found was that below about 800 yards or even further it isn't useful. Lighter bullets have much less drop at shorter distances and all other things being equal there is no real advantage to heavier ones. Where it does become interesting past 1000 yards. Most of the data I've looked at suggests that most 168 or 175 grain loads fired out of the AAC-SD go subsonic prior to 1000 yards, but a 208 amax fired at about 2400 fps or slightly below will stay supersonic past 1200 yards. There is also significantly less wind drift and past around a thousand yards the drop becomes less than the lighter rounds.
If you were going to use them inside 200 you certainly could and the twist would keep them stable. They'd just drop quite a bit more than lighter bullets at that distance.
I posted a thread on this a few months ago. It's somewhere out there but since we can't use google to search the site anymore I don't know how to find it. There are a few people on the hide who have done it and do it. As soon as I can afford reloading supplies I plan to try it out.
I've never tried it but I ran it through a ballistic calculator and what I found was that below about 800 yards or even further it isn't useful. Lighter bullets have much less drop at shorter distances and all other things being equal there is no real advantage to heavier ones. Where it does become interesting past 1000 yards. Most of the data I've looked at suggests that most 168 or 175 grain loads fired out of the AAC-SD go subsonic prior to 1000 yards, but a 208 amax fired at about 2400 fps or slightly below will stay supersonic past 1200 yards. There is also significantly less wind drift and past around a thousand yards the drop becomes less than the lighter rounds.
If you were going to use them inside 200 you certainly could and the twist would keep them stable. They'd just drop quite a bit more than lighter bullets at that distance.
I've never tried it but I ran it through a ballistic calculator and what I found was that below about 800 yards or even further it isn't useful. Lighter bullets have much less drop at shorter distances and all other things being equal there is no real advantage to heavier ones. Where it does become interesting past 1000 yards. Most of the data I've looked at suggests that most 168 or 175 grain loads fired out of the AAC-SD go subsonic prior to 1000 yards, but a 208 amax fired at about 2400 fps or slightly below will stay supersonic past 1200 yards. There is also significantly less wind drift and past around a thousand yards the drop becomes less than the lighter rounds.
If you were going to use them inside 200 you certainly could and the twist would keep them stable. They'd just drop quite a bit more than lighter bullets at that distance.
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