I'm having some issues at longer range with accuracy. I'm using 169 gr and getting 3050 fps. Half moa at 100. When I get to around 600 it's starts to get around moa, and once out to 925, it's way off. It's not me, I have many rifles that I can consistently shoot that range and further. I've adjusted bc to match verified drop. Any ideas or suggestions? I'm starting to think about switching bullets but not sure where to even go.
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7 saum with hammer bullet question
- Thread starter Jpron
- Start date
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Sounds like you are not stabilizing the bullet properly. Hammer Hunter 169 requires a 1/8.5 minimum twist. Most factory rifles chambered in 7 SAUM are 1/9 or 1/9.25.
ELDMs. If you are running a LA then run the 180s, very solid option at distance.
Several questions would then arise.
Verify the twist rate of your barrel. I have seen several over the years that were not the same twist as stamped on the barrel. Try another bullet to see if it does the same thing. Stability or wind are the two most likely causes of a bullets accuracy falling apart at distance. Because a bullet in flight looses velocity faster than rotational spin it should get more stable at distance.
I once built a rifle for a particular bullet and it never once shot it well for some reason. I switched bullets to a similar weight bullet and it has shot great for 4 years since.
Verify the twist rate of your barrel. I have seen several over the years that were not the same twist as stamped on the barrel. Try another bullet to see if it does the same thing. Stability or wind are the two most likely causes of a bullets accuracy falling apart at distance. Because a bullet in flight looses velocity faster than rotational spin it should get more stable at distance.
I once built a rifle for a particular bullet and it never once shot it well for some reason. I switched bullets to a similar weight bullet and it has shot great for 4 years since.
Quicksilver338
Well-Known Member
What powder and primers are you using? Neck tension?
Hopefully the 7saum barrel I have coming does have the 8 twist I ordered.
Sorry for the side note, but what is the maximum rpm for a cup n core bullet and do mono's have a higher threshold for staying together? I guess until they start melting as there's no jacket to separate from?
Sorry for the side note, but what is the maximum rpm for a cup n core bullet and do mono's have a higher threshold for staying together? I guess until they start melting as there's no jacket to separate from?
Seabeeken
Well-Known Member
Never heard of a mono coming apart. C&C bullets, depends on the bullet.
many yrs ago i loaded a hornet bullet in a 220 swift just to prove to a friend it would drive it fast enough to vaporize it. He didnt believe me so i proved it. He still couldnt understand the bullet never got to the target. Kept telling him to watch the vapor trail stop at about 75 yds and thats where the bullet was gone.. sorry, i digress
many yrs ago i loaded a hornet bullet in a 220 swift just to prove to a friend it would drive it fast enough to vaporize it. He didnt believe me so i proved it. He still couldnt understand the bullet never got to the target. Kept telling him to watch the vapor trail stop at about 75 yds and thats where the bullet was gone.. sorry, i digress
I'm no purist by any means, but maybe a higher BC bullet would be the answer to tighter groups at those ranges.
No guarantees with anything but I'd bet that's what KWDDT was suggesting up above. Good luck with it.
No guarantees with anything but I'd bet that's what KWDDT was suggesting up above. Good luck with it.
Correct. I enjoy the hammer bullets but at distance it is just hard to beat the ELDMs, either 162s or 180s, depending on the action length. Easy to just grab a factory box of the ELDMs and see how they shoot. That will give you a good idea if they may work better.
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