Load Development Ruger Precision Rifle .243

[turkeyfever]

tagging in

 

[just country]

morning, I have a 243AI, shilen very heavy barrel, rem. 721action, timmey trigger.

action trued. I shoot 4320 with 77gr. Lapua bullet 210 fed match. neck sized. will

Winchester brass. constantly shoot .300group.

I have a Ruger M77V. 95gr VLD 4320 powder 210 fed. primer, Winchester brass.

constantly shoots .500 and smaller.

I have owned 6 243's never had one that would not shoot if I did my job. what

is the twist of ur barrel?

lightbulb I have seen experimental military shooting rigs, that shoot

the 105's. the military is testing the 243 for long range shooting using the

variety of 105-108gr. bullets. 10 round box magazine. very impressive.

 

[clemens]

Tagging in

 

[jdmecomber]

It's a 7.7 twist

 

[jdmecomber]

I will probably remember random stuff as I go.
One thing you read about is guys sorting bullets for base to ogive measurements. I decided not to do this. For one it's a factory gun and I am just trying to get it to shoot the best possible without too much effort. All these things don't take that much effort or time. So let's say you want your bullets to jump .025 thousandth, I will load them all about, about .009 too long. Say I just did 40 rounds, then I will measure
base to ogive. At the end I will have 6-8 groups, from .001-.009 too long.
Then I will turn the die down .001 and do that group, turn the die .002 and do that group and so on. Then I have all the rounds at the same amount of jump.

Tip. On your micrometer you have to have a base or anvil because measuring without one can give you false readings of .001-.004

 

[jdmecomber]

Base of loaded round to the ogive of the loaded round in case anyone didn't get that or I am confusing

 

[jdmecomber]

After learning that bench rest reloading was far superior, we are getting closer to our final load. We needed to get extreme spreads down.

We shot 4 primers with H4831sc. I read magnum primers might be a better choice for the slower burning powders we tried them and it appeared the extreme spreads were really and the accuarcy was ok. You could probably develop a decent load with them

All shot with 42.5 grains. 4 shot groups
Primers 250 avg 2930 FPS. 22 ES. 1.26 moa
215 avg. 2940. 30 ES .493 moa
215m 2960. 18 ES 1.2 moa
S&B. 2930. 35.ES .656. moa Three rounds .2ish moa

You can already see the drop in extreme spreads occurring

We then tested 42.8 of 7828 for group size. Russ was shooting these groups. I think he is a little better shot but don't tell him that

42.8 grains. 210 m. 6 shot. First shot cold bore 5 shots .414 moa. Cold bore making it .785 total.

44.2 grains. 210 m. 6 shot. 5 shots. .565 moa with one flyer.

44.2 grains 200 cci. 6 shot. .800 moa

 

[jdmecomber]

Targets

 

[jdmecomber]

Another target

 

[jdmecomber]

I tried to load all on one but it didn't work

 

[jdmecomber]

Last one for this stage of development

 

[jdmecomber]

This next stage we wanted to test some primers with 7828
and try the original load of 42.5 H4831 with the new Bench rest reloading

7828 was getting very close to being our sub 1/2 moa load but we still needed those spreads where we wanted so we chose 6 primers

4 round groups. 42.8 grains of 7828
215. Avg velocity 2920. 46 ES. 1.2 moa
215m. 2900. 32 ES. .8 moa
250. 2860. 47 ES. .6 moa
200. 2900. 31 ES. .9 moa
S&B. 2910. 22. ES. .4ish moa
S&B has been showing 3 rounds in a lot of different groups with less than .250 moa
210 m. 2895 15 ES .126 3 shot. 4th shot making it .456 moa

It appears 7828 with 210m. Is going to make the goal

I did load 10 rounds to see who was better at shooting Russ or myself!
So I loaded
H4831sc with 42.5 grains. 210 m primers
Russ 5 rounds .408 moa
Joe. 4 rounds. .456 moa and I had an uncontrollable muscle cramp in my finger and through the 5th at .840 moa

So Russ wins

9 rounds at .456 and under

We are almost finished. I think our final couple tests we still need to get extreme spreas on h4831sc. I think it will be in the teens or low 20's

Russ and I will each shoot a 6 rounds of 7828 and h4831
Head to head

 

[jdmecomber]

7828 210 m

 

[jdmecomber]

I give up on these pics