In answer to your question, Sd has nothing to do with rings and bases however you indicated in your original post you were not happy with the groups you were getting at 100 yds. Tight SD does not equal tight groups at 100 yds. Long range tight SD is a must. What good quality scopes, rings,bases,proper bedding, good barrel etc has is the power to make you smile or frown when you go down to look at your target. Why did I ignore your question about lowering your SD? Because you asked it in the context that you wanted to improve your groups, I suspect if you find a load with an SD of 0.00 you will still have the accuracy problem. Sorry if I offended you.
No offense taken,I just thought you misunderstood my question.Thanks for clearing that up.I am hoping to see alot of improvements when I get my new savage this week.I agree with most people,it is crucial for long range hunting to have a low SD,I am just trying to figure how to lower it.
What is the biggest culprit of a large spread in S.D.?I am trying to lower mine on a 300 win mag load(180gr. SMK)I have tried IMR7828 and H4350,WLMR primers and CCI primers,various seating depths.The best I have gotten was about 60.I am shooting a Browning A bolt,maybe that is the problem?
My groups are any where from 1 1/2''-2 1/2'' @ 100yds.I am sure I can tighten these groups up if I could get more consistant velocities,I am not sure where to start.
To get .300WM into 0.5" and less, one needs to pay more attention into everything so to speak. Try different primers, maybe H4831SC powder, and bring that load into 3000fps range and fiddle with the powder charges and try to jump the bullet from 0.7 to 1.5mm.
If nothing helps you mah have to seriously look into some benchrest accuracy techniques. Your barrel also may have certain limitations
It usually just takes a lot of tinkering with componants but my lowest SDs has consistantly came from loads on the hot side of the scale and on loads that the propellant most nearly fills the case. Good luck.
What maximum accurate velocity one can get using 200SMK/200SPBT?
Thanks to you all.
I'm not hyjacking the tread, but this pertains to both questions. Every rifle has it's own personality - so to speak. Some will handle hotter loads than others due to a variety of things including but not limited to freebore, chamber demensions, rate of twist, number of rifles, quality of bore, size of bore, lenght of barrel. You just have to start testing and watch close for pressure signs.
I used to re-load but now I "hand-load".
-- Well, at least I try --
For a 300 Win Mag if you can't get R22 or H4831 to work with 180 to 200gr class bullets, then something is usually wrong with the shooter or with the rifle. That case just loves those powders. I've seen it time and time again. My last 300 Winny I used 72gr R22 with Fed 215 primers shooting 180gr Nosler BTs for a deer load out of a Sendero. That load would group consistantly at 100yds. Probably the best shooting factory hunting rifle I've ever owned.
Then I decided to take it to a registered match one day and shoot it in LG class just to see what it would do. Everything was just as I hunted with except I used an attachment to the front sling swivel to help it semi-ride the bags better and added shims under the rear of the 1 peice base mount to get on paper. I still used my Leupold VX-II 4x-12x scope with the Nosler bullets though.
My first group in competition was 16"?? for 5 shots at 1000yds. And it was all vertical. The group was only about 6 or 7" wide.
Well I adjusted the load and shot it several more times that shooting season. When it was all said and done I had gone to Fed 210s and bumped the load up to 75gr R22 and everything else staying the same. My smallest group that summer was 7.???" for 5 shots from a 100% box stock rifle using hunting bullets and a VarX II 4-12 scope. Sure wish I never sold it.
The moral of the story is the Fed 215 load with 72gr of powder shot great at 100yds and I killed a lot of deer and "stuff" with it at varying ranges. The Fed 210 load with 75gr of powder didn't shoot as good at 100yds but it got rid of the up/down at long range. And I couldn't tell you what the SD was.
The paper told me want I needed to know to make that rifle shoot. When it works on paper the chrono numbers are always there to support the group or else it won't group. But if you concentrate on the spread of the SD, those numbers don't always produce good groups.
So don't get too hung up on SD and chronographs. Work on the load! The primer,powder (type & wgt), and seating depth are where you make your money in load deveolpement. That is 90%+ of the game right there. If you aren't in that 90% bracket all the neck turning, shooting across the chronograph, deburring flash holes, etc, etc is just wasting time and equipment.
In fact, if using some of the longer range bullets that have long lengths, they may not shoot super tight groups at close range but if the standard deviations are low, they can shoot amazingly good groups at longer range.
Can you explain this?
Specifically, what is meant by super tight.
Prefer some statistical data to suport this.