Re-sighting a Scope - .223 and H335

MacD

Now we all know that H335 is one of the original powders for the 5.56 NATO or .223 as we call the sporting cartridge. My results with it have been good but it hasn't been my best powder. Earlier this week I decided to change the eye relief on the scope on my Savage heavy barrel varmint rifle. I loaded up some cases with 25 grains of H335 and topped them with Hornady 55SP's (#2266) which are bulk buy bullets. Today I hit the range. Sunny and about 18C with not enough wind to move the flags. 5 shots with the first one for the initial sight and correction and the next 4 without any additional adjustment. I was shooting at 50 yards, which is my usual range for sighting in. I used a Caldwell lead sled and took my time. The result for the four last shots was an average group size of just .12 inches (~.25 MOA). I am going to make another batch of the same load to see if this accuracy is repeatable and extends out to 200 yards BTW the average speed was 3060fps but the standard deviation a bit high at 84fps. I wonder if moving the scope forward has any bearing on the results compared to previous with this load?

gelandangan

Jackpot!!

Vince

That load sounds like a keeper Mac...I'll be looking forward to seeing the results at longer ranges.

PaulS

You might be able to get your extreem spread and standard deviation down by either adding or subtracting a bit of powder or adjusting your seating depth a bit shorter or longer.

In my experience H335 likes to be within 3% of the top loads. YMMV

I doubt that moving the scope changed anything due to harmonics - it is not touching the barrel and the action has little to do with harmonics.

Elvis

maybe you inadvertently corrected a parallax issue..either way it sounds like its a good load...many a great load has been stuffed by a chrony...if it works dont F%#* with it Very Happy

SingleShotLover

Elvis wrote:

maybe you inadvertently corrected a parallax issue..

That would be my first thought too. Just moving the scope a bit shouldn't cause any major changes in group size. Some scopes are very sensitive to head position and eye relief...even when they have parallax adjustment. I'm betting that you had to re-focus your eye piece when you changed the scope position too. This could have cured a borderline parallax problem that you weren't even aware of. Good luck...sounds like you have a good load there.

Dawgdad

ES and SD are not always the lowest in the best grouping loads. Don't worry about that if it holds 1/2 MOA or better at 200 yards.

PaulS

Dawgdad,
I agree! as long as the groups are consistent over the range of conditions under which it is used then as you say, "don't worry about it."