107 SMK vs 108 Berger BT in my 6BRA

[Nature Boy]

I’ve not been really satisfied with the 105 Hybrids and Varget so I’m trying the 107 SMKs and 108 Berger BT Targets using H4895

Here are my load test targets at 100 yards. To explain my notes, average FPS on left, charge weight on top, group distances from center line on right (to get comparison of vertical change between charger weights). Using the “cortina” method.

Looks like a really wide node on the bergers from 29.5 to 30.5 where the groups vertical distance doesn’t change very much. Might even be able to include 31.0

The SMKs had a more narrow window between 29.5 and 30.0

Next step: I think I’ll take the bergers with 30.5 of H4895 and do a seating test, primer test and then shoot them at 500 yards and see how they perform

 

[GlennK]

I’ve not been really satisfied with the 105 Hybrids and Varget so I’m trying the 107 SMKs and 108 Berger BT Targets using H4895

Here are my load test targets at 100 yards. To explain my notes, average FPS on left, charge weight on top, group distances from center line on right (to get comparison of vertical change between charger weights). Using the “cortina” method.

Looks like a really wide node on the bergers from 29.5 to 30.5 where the groups vertical distance doesn’t change very much. Might even be able to include 31.0

The SMKs had a more narrow window between 29.5 and 30.0

Next step: I think I’ll take the bergers with 30.5 of H4895 and do a seating test, primer test and then shoot them at 500 yards and see how they perform

Is this at touch? And what distance are you going for at the end of testing?

 

[Nature Boy]

Is this at touch? And what distance are you going for at the end of testing?

Yes, at touch for both to start out.

I've been shooting 600 yard F Class matches but my home range is limited to 500

 

[GlennK]

Yes, at touch for both to start out.

I've been shooting 600 yard F Class matches but my home range is limited to 500

Touch can be a sensitive area to load around. I would put the bullet in or out of the lands and work up from there at 500yards. The distance magnifies the results

 

[swd]

Put those 107's in the lands until the engraving marks are square and work back from there. And don't be surprised if they shoot outstanding right there.

 

[Curious]

Charge weight increments of 0.5gr are waaay too big, you are jumping over nodes having only 3 charge weights covering a whole grain.

My advice would be to do it again in 0.2gr increments and for fine tuning drop down to 0.1gr.

With H4895 I would be starting at 29.6gr and would expect to finish around 31.2gr somewhere in there you will see much more detailed nodes.

I would pick a random seating depth to start, something like 20 thou jump will be fine as you are looking for POI stability in the first instance not ultimate group size, then again the last test I did with 107 SMKs jumping 20 thou showed nothing bigger than 0.4" and there were groups in the 0.1"s

Looking at your top target you could try 29.8gr to 30.6gr in 0.1gr increments as thats where its looking reasonably stable, personally I always prefer either side of 0.000" for seating depth.

 

[Nature Boy]

Here’s my seating depth test for the Berger 108 BT Target bullets using 30.5g of H4895.

Looks like 0.005 into the lands is leading the pack. I think I’ll skip the primer test, stick with the Fed. 205M and see how it shoots at 500 with a larger sample size.

 

[Clucknmoan]

If you aren’t satisfied with either of those, mine likes the 110’s.

 

[bdale]

Here’s my seating depth test for the Berger 108 BT Target bullets using 30.5g of H4895.

Looks like 0.005 into the lands is leading the pack. I think I’ll skip the primer test, stick with the Fed. 205M and see how it shoots at 500 with a larger sample size.

Bullet doesn't look to be fussy at all

 

[Nature Boy]

Bullet doesn't look to be fussy at all

That’s what I was thinking, and it seems to validate what others have been saying about it being jump tolerant

 

[4xforfun]

Touch can be a sensitive area to load around. I would put the bullet in or out of the lands and work up from there at 500yards. The distance magnifies the results

This. ^^^^^ Stack up bullet runout and press runout. Might be up to .002 runout.

There is a big difference in .001 jam vs .001 jump.

Not so much when you are shooting for a .010 jam and end up with .009 or .011

Just what I have found.....confirmed by others also.

Tod

 

[Nature Boy]

This. ^^^^^ Stack up bullet runout and press runout. Might be up to .002 runout.

There is a big difference in .001 jam vs .001 jump.

Not so much when you are shooting for a .010 jam and end up with .009 or .011

Just what I have found.....confirmed by others also.

Tod

Tod, did you see the seating test I did (above)

P.s. I check run out on all rounds. Everything tested is =< 0.001

 

[4xforfun]

Tod, did you see the seating test I did (above)

P.s. I check run out on all rounds. Everything tested is =< 0.001

...measured from where to where?

 

[Nature Boy]

...measured from where to where?

Not sure what you’re going on about. Did you see the seating depth test I did above? I tested from -0.020 out to +0.020 in and you’re still referring to issues regarding seating to touch.

 

[4xforfun]

Yes, at touch for both to start out.

I've been shooting 600 yard F Class matches but my home range is limited to 500

"Touch can be a sensitive area to load around. I would put the bullet in or out of the lands and work up from there at 500yards. The distance magnifies the results"

Just saying that "at touch"...or .000, is not a good place to be.

1st response was agreeing with GlennK.

Second response was asking about what it was you measured.

Not "going on" about anything. Just trying to help.

Tod

 

[KenOath]

Not sure what you’re going on about. Did you see the seating depth test I did above? I tested from -0.020 out to +0.020 in and you’re still referring to issues regarding seating to touch.

"Touch can be a sensitive area to load around. I would put the bullet in or out of the lands and work up from there at 500yards. The distance magnifies the results"

Just saying that "at touch"...or .000, is not a good place to be.

1st response was agreeing with GlennK.

Second response was asking about what it was you measured.

Not "going on" about anything. Just trying to help.

Tod

I have had similar experience with seating bullets @ the lands in 6 and 7mm, one day it would shoot somewhat consistent the next group or day not. Putting the bullet firmly into lands or out has given me more consistent results, generally .003” in or out, but @ is bad dudu for me to..

 

[Nature Boy]

@4xforfun

And my first, second and now third response to you was “did you look at my seating depth test?”

The point you’re trying to drive home is moot now

 

[KenOath]

@4xforfun

And my first, second and now third response to you was “did you look at my seating depth test?”

The point you’re trying to drive home is moot now

5 in looks good to go for 5 shot groups, then stretch the range..

 

[Nature Boy]

5 in looks good to go for 5 shot groups, then stretch the range..

I have 50 loaded and ready to test at 500 yards. Will shoot them tomorrow if the weather cooperates

 

[4xforfun]

@4xforfun

And my first, second and now third response to you was “did you look at my seating depth test?”

The point you’re trying to drive home is moot now

I quoted another post....post 4. Post 2, 3, and 4 all were referring to "just touch". I read to post 4 and then quoted it. You CLEARLY stated that it was at touch. You hadn't posted anything about your other tests till after post 4...It wasn't moot at the time I posted. The rest of my posts ( after you moved on) were trying to explain. I get that you moved on....just trying to save you a little time THE NEXT time you test.

But, I guess you don't want to hear it, so....


Goodbye LOL