85.5 versus 90A-Tip in 22 Nosgar

[Rocketvapor]

Made a range trip to have the wife make a final decision on Berger 85.5 or the Hornady 90A-Tip and set scopes for a 600yd F-Open match this Saturday. Was an abnormally cool day (started at 80F, 84F when we finished).

For background, the shooter, my wife, shoots about 1.5MOA @ 600yds, shooting from a rest and bag.
Last 4 midrange scores of 559, 570, 565, 569.

The rifle is a kitchen assembled AR-15, 28", 1:7, 5R, 0.219"/0.224" shooting annealed twice/third fired 22 NosGar cases (weight sorted to a grain), CCI 450 (unsorted), SB6.5 powder (weighed to much better than +/- 0.1gr).
Charge for the 85.5 was 31.4gr, and a GUESS starting charge of 31.0gr for the 90A.
The 90As where seated deep , case length of 1.760", bullet length of 1.276", cartridge AOL 2.417".

The velocity started off low with a cold clean barrel. Even if you don't believe the accuracy of the Shotmarker it should show a trend. The 20 shots shown in the picture posted below were shot in the order 5 shots each 85.5/90A adjusted up 0.3 mils then 5 shots each 85.5/90A as listed in the picture.
For the 10 shots with the 85.5/31.4 load the ES=70, Avg=1977, SD=30.
For the ten shots with the 90A/31.0 load the ES=54, Avg=2051, SD=19

Later that morning Flo shot 10 more of the 85.5/31.4 load (no screen shots)
1989 2024 2025 2029 1980 1982 2007 2031 2020 1998 ES=40, Avg=2009, SD=19
Then 10 more of the 90A/31.0 load;
2040 2036 2004 2038 1998 2033 2050 2052 2032 1999 ES=54, Avg=2028, SD=20
All shot at a sort of typical F-Class slow fire pace.
On the previous range trip to test jump with the 90A, on a much warmer day,
S.D. of 30 shots (3 different seating depths) was 16, ES 55, mean 2059@ 600yds.
Avg velocity of all 50 shots with the 90A, two trips warm and cool day, was 2051fps@600yds.
No muzzle velocity measurements but backtracking with a calculator it's close to 3000fps. 2940fps.


So, finally the question;
Why isn't the POI of the 90A-tip with a higher B.C. and loaded faster higher than the 85.5 @ 600yds?
I can get the 90A-tip load going faster than the 85.5 load, 31.0gr of powder was a guess and the A-tips are seated deeper into the case, but the higher B.C. and higher velocity doesn't make sense with POA/POI.
Maybe the groups are too big to really tell. The girl does pull a shot or two

 

[TheOfficeT-Rex]

What's the difference in zero at 100 yds?

 

[Rocketvapor]

Haven't had the chance to re-zero in a while.
Just barely have time for a little practice and a monthly match.
If fact, have only shot the 90's at 600 for two practice sessions. Also haven't done any load work with the 90s, just a little jump testing.
Charge was a guess.
100yd zero was set with the Berger 85.5, shot @ 300 and 600.
85.5s @ 600 hasn't changed (maybe a tenth of a mil).
Maybe after this Saturday's match just a couple shots @ 100 would be a good idea.

 

[TheOfficeT-Rex]

Haven't had the chance to re-zero in a while.
...
If fact, have only shot the 90's at 600.
Maybe after this Saturday's match.

My money says one hits higher than the other at 100.

But now you have at least a little data, and a couple sighters, so it doesn't really matter for the match, eh? Good luck

 

[Rocketvapor]

She's either pulling a round here and there, or my reloading (not a chance ) is causing some fliers.
Pulling out all the stops for this batch.
Running the A/C to drop the RH in my little reloading corner before I open a new pound and sorted out primers.
CCI450 seem to be pretty consistent @ 3.66gr average with most +/- 0.2gr.
Sorting primers?

EDIT 8/19/23:
Sorted some more of the CCI 450 and found a few light ones about 3.615 and two heavy outliers of 3.77 and 3.78 grains.
Hundreds fell right about 3.66grains avg.

Hate to admit it but she's out shooting me lately.

 

[Rocketvapor]

All done with Flo's match rounds. Took about 3 hours, including breaks, but no naps.
Sighters, score rounds, and some for a 100yd zero check.

NAP TIME, then do my ammo.

Mine is done. Time for late night X-Files on free TV

 

[ifgator]

Let’s us know how it goes

 

[Rocketvapor]

Thanks.
Got ammo, guns, fans, mats, rest and bags, tools and spare parts ready to load in the truck-butt crack of dawn.
My barrel, with about 3300 rounds down the pipe is likely going south. The wife's rifle, about 700 rounds seems to be doing fine still.
I would like to get my scores back up, maybe when the new barrel comes in, but am excited about the wife heading toward Midrange Master.
For a long while she saw load development as a science experiment, but is now on board
Have to get rid of those fliers though.
Gotta get a couple Naps in today.

 

[Rocketvapor]

Made the 600 Midrange match today.
Did not shoot any of the 85.5, so no 100yd comparison this time.
My scores were pitiful and not enough wind to use as an excuse.
Flo got an agg of 93.67% (187,183,192) so not quite Master yet.
Her third relay, the 192, had an 8, avg 2088, SD 20.9
Time to do a ladder with charges under the 90 A-Tip, I just feel there is potential there.