Load development, should I go higher?

[El Jason]

I'll try and get some pictures on tomorrow, but here's the quick and dirty.

Winchester M70 .243, Pre 64 Featherweight
Zeiss 3-9 scope

Barnes 85 grain TSX
CCI 200 Primers
WW Brass
Hogdon Superperformance Powder (max charge 45.8 grains)

Load 1: 43.7 grains, group looks like the "5" side of a dice, measures 1.4"

Load 2: 44.0 grains, group is a tiny 3 shot group vertically above a tiny 2 shot group, 1.4"

Load 3: 44.3 grains, groups is a vertical string, 1.9"

Should I try a CCI250 primer with the ball powder? Up the charge? Drop to 43.8? Call it good and drink beer?

Edit: the horizontal dispersion on loads 2 and 3 is about .25". Shots were fired Load 1, 2, 3 in sequence, allow barrel to cool for 3-4 minutes, repeat.

2nd edit: My insomnia compelled me to go down and load up two test loads of 45.0 grains and 45.5 grains.

 

[tarheel]

I'd try to determine why it's stringing before moving on to different loads. Sounds like you have the azimuth nailed down. I recall my own Win 70 would string them until I floated the barrel, but you've probably already gone that route.

 

[Curvebow]

There are a lot of powders that will work. For my 243, I have used H380 and IMR 4350. I've never tried Superformance with 243 loads.

Beyond the powder, I doubt that changing to another standard primer will change much.'

Some of the issues could be the bullets. Now, I know that Barnes bullets have changed much over the years; and I have no new experience with them. But, in the past the original Barnes shot like crap out of my 7mm-08. I could get 1/2" 3-shot groups using Nosler Ballistic Tips, but Barnes shot over 3".

If you're still not satisfied and have free floated the barrel, or don't want to go that route, I suggest trying a different bullet. Some guns like Barnes, some don't.....

 

[Rancho Loco]

shoot load 1 and 2 at 200 yards and observe results.

 

[emrah1028]

Featherweight, right? Maybe you need even more time to cool between shots. Never used Superformance, but if it's a ball powder, I would definitely back down a tad and try magnum primers. Maybe you'll get a better, more consistent burn shot to shot.

Emrah

 

[Speeddmn]

If you haven't, try seating depth. My buddies 243 likes them as long as possible. He is shooting 105 AMAX's and with Hornady brass, WLR primers with some R-17 it shoots consentient 1/2 moa.

 

[earlybird]

If you haven't, try seating depth. My buddies 243 likes them as long as possible. He is shooting 105 AMAX's and with Hornady brass, WLR primers with some R-17 it shoots consentient 1/2 moa.

This is good advice BUT I'm guessing the featherweight doesn't have a fast enough twist to spin the 105's

 

[Speeddmn]

This is good advice BUT I'm guessing the featherweight doesn't have a fast enough twist to spin the 105's

doubtful, but even my buddies tikka t3 is on the verge of not fast enough. But with a few extra thousandsth, we get to put a bit more powder in to keep the pressure safe and make it a few fps faster.

 

[tarheel]

If you haven't, try seating depth. My buddies 243 likes them as long as possible. He is shooting 105 AMAX's and with Hornady brass, WLR primers with some R-17 it shoots consistent 1/2 moa.

Interesting. I've started working up loads for three larger calibers with RL-17 but never considered it for the .243 since IMR 4350 does so well with the 95 PT. I'll have to add it to the mix and see what comes of it. The 17 should give me the extra FPS I'd like without crowding the pressure limits.

Mine also won't group with the 105's.

 

[Rancho Loco]

shoot them at 200 and quit goofing around.

 

[El Jason]

shoot them at 200 and quit goofing around.

I will, but I don't have immediate access to a 200 yard range. The hotter loads didn't give good results.

What are you thinking the 200 yard groups will show me?

 

[El Jason]

Featherweight, right? Maybe you need even more time to cool between shots. Never used Superformance, but if it's a ball powder, I would definitely back down a tad and try magnum primers. Maybe you'll get a better, more consistent burn shot to shot.

Emrah

Superperformance is an extruded ball powder.

 

[Rancho Loco]

I will, but I don't have immediate access to a 200 yard range. The hotter loads didn't give good results.

What are you thinking the 200 yard groups will show me?

lessens parallax and form issues that might effect your 100 yd groups. you might like what you see..

 

[El Jason]

lessens parallax and form issues that might effect your 100 yd groups. you might like what you see..

Roger that. I have to get more boolits, and it will be sometime next week before I'm able to stretch out the range.

Thanks!

 

[Tjay]

My findings with Superformance and with TSX bullets.
1. Super shoots better at max loads or near max.
2. Super sometimes likes mag primers to get best results.
2. TSX''s like to be seated at or near the front groove.

YMMV

 

[El Jason]

Just to satisfy my curiousity, because I don't wait very well, I took my last 10 boolits and loaded them up with Load 1 and Load 2 using CCI 250 primers instead of CCI 200s.

Here is Load 1 (5 shot group) with CCI 250 primers, which was about 1.4 " in the shape of a "W" with the 200 primers.


Here is Load 2 (5 shot group) with CCI 250 primers, which was about 1.4" in a VERTICAL line with the 200 primers.


Obviously Load 1 is getting pretty close to what I want. I'll shoot it at 200 yards (and more) next week.

What gives with Load 2? Why would the dispersion change 90 degrees like it did?

 

[Cheaha]

I think it is interesting that you would have such a change with only 0.3 grain change in load. I usually start test loads at .5 grain increments. Leads me to think it may be a heated barrel issue. Did you allow the barrel to cool between shots/groups? All suggestions above should be explored: glass bedding, seating depth, free floating, etc. Just remember to change one thing at a time, so you know what worked!

 

[El Jason]

I was shooting two shots, then letting the barrel cool about 4 minutes. I would shoot 1, then 2, alternating.

 

[El Jason]

My findings with Superformance and with TSX bullets.
1. Super shoots better at max loads or near max.
2. Super sometimes likes mag primers to get best results.
2. TSX''s like to be seated at or near the front groove.

YMMV

I tried near max with CCI 200 primers and got poor results

See above pictures for CCI 250 primers

I am seated so the front groove is just above the case neck.

 

[El Jason]

As an interesting note on Load 1, the top two shots were 1 and 2, and the bottom were 3, 4, and 5. it measured 0.9".