Need Some Help with 6BR 21” Criterion 8tw Load Development

[Ccrider]

Had some free time so I stsrted load development on a Savage model 16 stainless action, large shank criterion 1:8T 21" bull barrel.

Could not find much data using a short barrel. I decided to start out with 29.6gr Varget and 87gr Vmaxs.

Using a 4.5-14 Meuller scope. Not exactly the remedy, but I didn’t want to pull a scope off of any of my other guns and I have a Delta Stryker coming in later this week.

Figured I would play with seating depth first:



It has been windy15 -20 and I don’t claim to be well versed at reading the wind, although I did my best.

Looks like to me, these bullets are going to shoot best jammed into the lands, though I could be wrong.

I am going to load some .028 and .032 just to see what happens.

What are your thoughts?

Thanks

 

[MTSLW]

Jammed looks to be your best option. I would start 1gr below what your load is now and go up in .2 increments to at least .5 above. Shoot them all in the same group and look for consistency in velocity. Better yet if you can shoot at distance and check vertical spread and velocity that would be better still.
A better scope would also be a great start. I don't know how trustworthy a Mueller is. There is quite a bit of vertical stringing so I would make sure you're letting the rifle recoil the same each time and have a solid rear rest. All the criterion's I've seen in a BR or variants would shoot almost everything well under an inch and mostly .5 or better. If your groups are much worse than than I would look to things other than the loads. Good luck!

 

[Ccrider]

Jammed looks to be your best option. I would start 1gr below what your load is now and go up in .2 increments to at least .5 above. Shoot them all in the same group and look for consistency in velocity. Better yet if you can shoot at distance and check vertical spread and velocity that would be better still.
A better scope would also be a great start. I don't know how trustworthy a Mueller is. There is quite a bit of vertical stringing so I would make sure you're letting the rifle recoil the same each time and have a solid rear rest. All the criterion's I've seen in a BR or variants would shoot almost everything well under an inch and mostly .5 or better. If your groups are much worse than than I would look to things other than the loads. Good luck!

Well, the scope leave a lots to be desired for target shooting. I was just antsy and wanted to get some shooting in.

The circles are 1”. I should have measured and put group sizes in as this would have been more helpful. I measured the groups and put the sizes on the photo below. I was thinking groups 4 and 7 may also be worth looking into to see if the results are consistent. What do you think.

I will go ahead and put my PMii on if I get another chance to shoot before the new scope gets in. Thanks for your response.

 

[Ccrider]

Had a chance to work on this load some more this afternoon. As before, all shots at 100 yards.

As suggested, I jammed all loads and started at 28.6 and worked up in .2gr increments up to 29.6. I

My new scope came in so I mounted it first and zeroed it in along the way.

I had cross winds 5-12 mph and have not mastered reading the wind.

My es was acceptable except for 12 at 23. This was a one shot anomaly as the shots read 2833, 2815, 2815.

It may be that this gun will my shoot these 87gr Vmax bullets much better than .5 moa.

Next I will work up to 31.6 or until I see pressure signs. I will also load 5 shots jammed with 29.2 and see how it does.

Any suggestions will be appreciated.

Thanks
CC

 

[dmoran]

Got to be a bit of a pessimist here, but I would take any results shot with a Meuller scope with probability to be subjected to POI error, due to reticle shifting from shot to shot. They are not a stable scope - IME.
Sorry if I'm offending anyone with my input here, and take from it what you want.
Donovan

 

[Ccrider]

Got to be a bit of a pessimist here, but I would take any results shot with a Meuller scope with probability to be subjected to POI error, due to reticle shifting from shot to shot. They are not a stable scope - IME.
Sorry if I'm offending anyone with my input here, and take from it what you want.
Donovan

I dumped the Meuller scope and used my new scope on the last group. It is a Delta Stryker 5-50. Pretty nice scope. Not as nice as the Schmidt and Bender, but very capable.

The Meuller did fine for what it is. No change or shift in point of impact and the glass is clear enough. Just did not have the magnification that I needed.

 

[urbanrifleman]

I see a node at 29. Probably another one at 30.5, and another at 32.

Bart told me to do the powder workup first at hard jamb. Find the nodes. I would suggest you are only going to be looking at the upper node.

 

[Ccrider]

I see a node at 29. Probably another one at 30.5, and another at 32.

Bart told me to do the powder workup first at hard jamb. Find the nodes. I would suggest you are only going to be looking at the upper node.

Thanks. I was wondering about where the node was and thought 29.2.

I will keep will finish the powder workup as suggested and then go from there.

 

[urbanrifleman]

Most of the "pet" loads for 90 grain bullets and Varget are right around 31.

29.9-30.2-30.5-30.8-31.1-31.3

That is how I would do it.

 

[Ccrider]

Thanks. I was wondering about where the node was and thought 29.2.

I will keep will finish the powder workup as suggested and then go from there.

Most of the "pet" loads for 90 grain bullets and Varget are right around 31.

29.9-30.2-30.5-30.8-31.1-31.3

That is how I would do it.

Does it matter that my barrel is 21"? I was thinking that it would not burn as much powder as a longer barrel.

 

[urbanrifleman]

Does it matter that my barrel is 21"? I was thinking that it would not burn as much powder as a longer barrel.

No.

 

[zx10mike]

that would be me decided ,it don't like those bulets.asuming you have confidence in the rifle and can shoot.

 

[Ccrider]

that would be me decided ,it don't like those bulets.asuming you have confidence in the rifle and can shoot.

I am new to all of this. I am no expert shooter, but I can take my other 6br and consistently shoot less than .3 inch groups on my good days, and less than that on my really good days.

I bought this gun used for coyote hunting and can't say much about how accurate it is suppose to be. It is magazine fed, and will shoot well under one m-o-coyote, for sure. I am just getting started with load development for it and chose the 87gr vmaxes because that is what my other gun (10tw) shoots well, with 31.5gr of Varget. Time will tell.

 

[tbeasley]

You may try 75 vmax's, they flat out shoot in several rifles that are 6mm of something (6br-.243)
Just my opinion and results but the 87vmax never did really well me.
30.5gr varget put 75vmax in very tiny clusters

 

[Steve Ladino]

Had some free time so I stsrted load development on a Savage model 16 stainless action, large shank criterion 1:8T 21" bull barrel.

Could not find much data using a short barrel. I decided to start out with 29.6gr Varget and 87gr Vmaxs.

Using a 4.5-14 Meuller scope. Not exactly the remedy, but I didn’t want to pull a scope off of any of my other guns and I have a Delta Stryker coming in later this week.

Figured I would play with seating depth first:

View attachment 1039491

It has been windy15 -20 and I don’t claim to be well versed at reading the wind, although I did my best.

Looks like to me, these bullets are going to shoot best jammed into the lands, though I could be wrong.

I am going to load some .028 and .032 just to see what happens.

What are your thoughts?

Thanks

 

[Steve Ladino]

Looks like nice range record keeping. Lots of shots will wear it out quickly. Might be best to pick something pretty good and go with it. You may be on the down side of its accuracy life beings its a used tube.

 

[Ccrider]

Just having fun working up load. If it is worn out, perfect excuse for new barrel.

Got my honey doos done and had time to load next step and shoot them before dark.

Shot the foulers at bottom right first. Loaded the three at 31gr. Had one bad piece of brass. Primer pocket seemed to be smaller. Velocity was +20 higher. Still the three shot group was .345.

Not sure what to make of the data. Did not take any breaks as I was trying to get done before dark.

Where is the node? 30,30.6 or maybe 31?

My trigger pulling was ok and wind was not bad. Only group that is suspect is the last group because it was almost dark. I have got to learn how to line up my back bag and front rest as my recoil was not perfectly straight back and I know this affects the point of impact.

 

[Ccrider]

After doing a lots of playing/testing, I went with my best results using the 87gr vmax: 29.1 Varget jumped .012 off the lands. I am getting consistent 3 shot groups in the .3s or better with this load.

I decided to work up a load with the 95gr Bergers. I did their 6 shot test to determine seating test starting at touching the lands and then 004,.008 and .012 off.

The pictures below show the .008 off and .012. The first three shots were .225. The second three .350. I shot the wrong/same aimpoint for the last 6 shot .012 group.

I expected the 95gr to shoot best either touching or .012. However, they shot best at around 008. I will explain below.

I will try the 95gr jammed into the lands and again at .008. For the last two sets I used 30.5gr Varget. I used 31.3 for the first two sets and got dismal results.

I was using culled 95gr Bergers and ogive length was not very consistent. As a result my measure off the lands varied from .007 to .010. I have some more of these culls and have about decided to load them all and then separate them after measuring them.

 

[Ccrider]

I will give 30.6 a try. I know I am close.