Does changing bullet change point of impact when shooting prone?
- Thread starter bored184
- Start date
Proabaly....but maybe not; you might get lucky. Even with the same weight the bullets will not have the same bearing surface, possible different diameter pressure rings and, of course, ogive radius. At least a seating depth test should be done but I would start a new load development test near the current charge weight.
Why would it not change?
Copper alloy, bullet diameter, bearing surface length, etc. can all change internal ballistics.
Internal and external dimensions of the bullet itself can change exterior ballistics.
But you should be well-on-paper.
Copper alloy, bullet diameter, bearing surface length, etc. can all change internal ballistics.
Internal and external dimensions of the bullet itself can change exterior ballistics.
But you should be well-on-paper.
Yes , sometimes dramatically.
At 100, nope. 1000 yep.
CaptainMal
Silver $$ Contributor
Be careful using the same load. With different bullets you just may get dramatically different pressure, even with the same weight.
Expect change. Test. Then you will know.
Expect change. Test. Then you will know.
In your experience what bullets had the same POI @ 100 yards ?
Wasn't addressed to me, but all the .224 77 BTHP from SieBergOsler impact bout the same. Lapua's -L might not. Dunno...ask that Illinois hard dog kid..
Liven The Dream
Gold $$ Contributor
I shoot a fare amount of Palma . .308 with 155 Bullets .
At 1000 yards the the point of impact with a different Bullets can be 1-2 minutes up or down .
At 1000 yards the the point of impact with a different Bullets can be 1-2 minutes up or down .
Ned Ludd
Silver $$ Contributor
1) The #2156 SMK 155 is a tangent ogive bullet; the Hornady 155 a secant ogive bullet
2) OALs differ by ~.060"
3) BTOs differ by ~.020"
4) G7 BCs: 0.237 VS 0.206
Loaded identically, these bullets MIGHT hit the same spot on paper, especially if you are only shooting them at 50-100 yd. At 1000 yd? Not a chance. You'll want to optimize a load for the Hornady bullets independently of what you found to work with the Sierras.
2) OALs differ by ~.060"
3) BTOs differ by ~.020"
4) G7 BCs: 0.237 VS 0.206
Loaded identically, these bullets MIGHT hit the same spot on paper, especially if you are only shooting them at 50-100 yd. At 1000 yd? Not a chance. You'll want to optimize a load for the Hornady bullets independently of what you found to work with the Sierras.
bored184
Silver $$ Contributor
I appreciate all the input. Its one of those situations where I don't remember buying them and I don't know if I will purchase them again. According to the box they are factory seconds sold by midway. I don't want them to just sit on a shelf collecting dust but I don't have enough to do proper load development and then shoot a prone match with.
+1 Perfect way to use them up.
Well at 200 a 150 smk Mexican match shot the same poi as standard m2 ball out of an m1 Garand.
I just assumed anyone shooting Hornady 155 SECONDS, isn’t expecting much in precision.
I see now,thanks . I was asking about 100 yards . To me same POI at 100 is bullet holes touching. I have never had that happen with any combo,but have not really tried very hard .
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