Why has this happened, (bullet drop)
- Thread starter Tikkat1x
- Start date
So finally got my chrono, and time to go out and test my rounds,
223, Sierra 55gr Min, 2972, Max, 3012 and Av 2992. SD 10.9 ES 40.
223, Sierra 69gr Min 2550, Max, 2659 and Av 2625, SD 36.3 ES 109.
243, Hornady 75gr Min, 2660, Max 2739 and Av 2703, SD 27.6 ES 79,
As a rule my groups are decent so never been bothered about the large SD & ES, all 3 groups today were 10 shots each, from 0.9" to 1.1", i didnt take my time as group size was not the concern,
MV was
223, Sierra 55gr Min, 2972, Max, 3012 and Av 2992. SD 10.9 ES 40.
223, Sierra 69gr Min 2550, Max, 2659 and Av 2625, SD 36.3 ES 109.
243, Hornady 75gr Min, 2660, Max 2739 and Av 2703, SD 27.6 ES 79,
As a rule my groups are decent so never been bothered about the large SD & ES, all 3 groups today were 10 shots each, from 0.9" to 1.1", i didnt take my time as group size was not the concern,
MV was
HonestJohn
Well-Known Member
I’d say the .223 should be clocking in around 3,400 and 3,250 respectively, and .243 3,400
Your velocities are anemic at best
Your velocities are anemic at best
More powder . . .
If you can load the brass 3 times before the primers start falling out, it’s not fast enough
I would think N140 is a bit slow for 55gr bullets, I use N130 for 55s in my .223. Also, mind if you’re using Vhit load data, it can be conservative.
I use N133 for the 55gr.
That .243 velocity is ridiculously slow. 34gr of which powder?
N140
A quick play with Quickload suggests a less than 75% load density. No wonder your bullets fall short and your primers fall out and you have that awful spread. More powder/velocity will have you on your way to better and more consistent results. N140 would not be the best choice to get there.
Should be hitting 3400 easilyI use N133 for the 55gr.
Smellydog
Well-Known Member
I load n135 in my 3030 to a greater weight!
I load more of the faster n135 in my 222.
i did previously use 90gr sierra TGK's with N160 best groups were at 41,5gr, no idea of speeds,
and Hornady 87gr with N160 with 43gr, not even sure why i ended up with the 75gr V max,
i can try the N160 with them, but saying all that i dont have need for the 243 anymore and its actually for sale, (but i may end up keeping it)
and Hornady 87gr with N160 with 43gr, not even sure why i ended up with the 75gr V max,
i can try the N160 with them, but saying all that i dont have need for the 243 anymore and its actually for sale, (but i may end up keeping it)
both 20" barrels
Your group sizes suggest that there is nothing wrong with your rifle scope or basic skills set. I presume your are reloading judging by the rounds that you are using. If you have any of the batch left that are known to shoot lower than expected then deconstruct one of them and remeasure your powder charge….. it has happened to us all at some stage that we have bumped a scale and moved a weight or had an electronic scale drop out of calibration….. even when we were sure we hadn’t!
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