6GT help, new to reloading

[Bill Norris]

Thanks for this, that is really helpful. A question it raises for me is: do you do anything different with the cases that have been “at pressure” when you are getting the brighter ejector marks? Do they get culled or just thrown back in the mix knowing that they won’t see that pressure again when you load down from it?

Normally, you can just throw it back in but if the head has grown then I would discontinue those pieces.

 

[ballisticdaddy]

I ran the 112 MB's in my GT when I first got it but used H4350 since I had a bunch on hand:
H4350 - 35.3 grains
Barnes 112's
CCI 450
Velocity 2,819 fps

After doing more load development I now run the load shown below, this load has show very well
H4350 - 37.1 grains
Berger 108 BT
CCI 450
Velocity 2,917 fps

I planned on using Alpha brass but got a great deal on GAP brass and now have over 8 firings and the primer pockets are still tight.

 

[mdram]

I ran the 112 MB's in my GT when I first got it but used H4350 since I had a bunch on hand:
H4350 - 35.3 grains
Barnes 112's
CCI 450
Velocity 2,819 fps

After doing more load development I now run the load shown below, this load has show very well
H4350 - 37.1 grains
Berger 108 BT
CCI 450
Velocity 2,917 fps

I planned on using Alpha brass but got a great deal on GAP brass and now have over 8 firings and the primer pockets are still tight.

i like the 108bt also, 34gr varget, cci450, alpha brass, 2950fps

 

[Checkmate101]

In general, it's made to poor tolerances. Huge burrs in the flash hole, crooked extractor grooves, etc. I've seen a lot of crap with Hornady brass. I've also seen some very good Hornady brass. I had a batch of 20 pieces in 6.5cm that I fired over 20 times before I was annealing...

I doubt its the source of your problem, but it's stuff to look out for.

How far below the shoulder junction is that bullet seated?

I’ll have to get back to you on measurements. Going to be working a good bit. Will definitely update when I get the chance.

 

[Pres100]

I planned on using Alpha brass but got a great deal on GAP brass and now have over 8 firings and the primer pockets are still tight.

I believe that the GAP brass is made by Hornady and the lot made for them has been reported as pretty good.... I have personally had good luck with it so far

 

[josebd]

Can you expand on the hornady brass not being good? Is that all calibers? Specific to the GT? What are the factors that make it not good?

In the reading I’ve done prior to starting alpha definitely seemed superior. I chose hornady as a cheaper way to start as I expect I’ll make many more mistakes along the way. Didn’t want to make them on more expensive brass before know king a bit more of what I’m doing. Figured if I found the need to switch, I would later on, but again - no experience with knowing what to look for to determine if that switch would be needed.

I use Hornady brass for the 6gt,not a thing wrong with it,very accurate

 

[nwmnbowhunter]

Thanks for this, that is really helpful. A question it raises for me is: do you do anything different with the cases that have been “at pressure” when you are getting the brighter ejector marks? Do they get culled or just thrown back in the mix knowing that they won’t see that pressure again when you load down from it?

Measure the web, if it is bigger than your lower charges, then throw them.

Also pay attention to pressure it takes to remove primer in those cases. If it is easier you know the are toast.

 

[nwmnbowhunter]

Another note... the web isn't exactly 0.200 from case head. It is generally in that range or a little further and is the widest point of the case.... near where the sizing die stops sizing.

 

[dgeesaman]

He may have been referring to lubrication from the sizing process as well.

Lubrication from sizing and also any leftover barrel cleaning solution in the chamber. There’s dry and then there’s properly dry.

I agree you don’t have ejector marks yet.

I have some 6BR brass where I put ejector marks in the face each time and they are clear, full, and shiny. I don’t love it but it’s my first pressure sign on that brass and the primers still look good.

Hornady brass has a reputation of being a little soft. Nothing wrong with that but take care it might not hold up for endless firings and you’ll want to watch the brass itself for over pressure signs and don’t assume your primer or bolt will be the lowest pressure sign.

 

[dgeesaman]

Also pay attention to pressure it takes to remove primer in those cases. If it is easier you know the are toast.

I assume this means a separate decapping step, I’d never feel a primer unseat while resizing.

I monitor primer pocket stretch by carefully measuring with the inside tips of my caliper. Loose pockets stretch by a few thou which is easily found that way.

 

[Checkmate101]

Well, this took a lot longer to get back to than I had hoped. However, I learned a ton.

I redid the ladder test and went higher than I ever plan on running it to try to learn to identify pressure better. The last 3 charges started to have a heavy bolt lift.

Pics how the ladder and the last few charged cases closer up.






Groups were better than I expected.



I dialed some elevation on the white target so I didn’t chew up the aim point.

I have the chronograph data, but made some mistakes with the OCW sessions, so I have to separate them out correctly. Otherwise I’d put up the pics.

33.0: Avg - 2867
2865
2857
2866
2874
2881
SD 8.3, ES 24

33.5: Avg - 2901
2885
2901
2909
2905
2906
SD 8.6, ES 25

34.0: Avg - 2939
2922
2939
2949
2927
2956
SD 12.7, ES 34

I planned on running the speed around 2800-2850. Thinking I’ll drop the charges down to 32.0-33.0 and retest in that range. Also will need to do a seating depth test at some point. This was just a guess on the seating depth.

Overall, I’m am pretty happy with the results, being the first time I have ever tested my own reloads for groups and beyond just a ladder test. I’d love additional insight from anyone willing to offer it. Thanks a ton for all the help!

 

[Checkmate101]

In general, it's made to poor tolerances. Huge burrs in the flash hole, crooked extractor grooves, etc. I've seen a lot of crap with Hornady brass. I've also seen some very good Hornady brass. I had a batch of 20 pieces in 6.5cm that I fired over 20 times before I was annealing...

I doubt its the source of your problem, but it's stuff to look out for.

How far below the shoulder junction is that bullet seated?

The boat tail transition is basically at the neck/shoulder junction. I’ll take some pics of this when I get a chance.

I checked the 3 last charges is loaded (34.5, 34.8, 35.1) and could hear powder shaking. I don’t think any were compressed.

 

[ballisticdaddy]

In general, it's made to poor tolerances. Huge burrs in the flash hole, crooked extractor grooves, etc. I've seen a lot of crap with Hornady brass. I've also seen some very good Hornady brass. I had a batch of 20 pieces in 6.5cm that I fired over 20 times before I was annealing...

I doubt its the source of your problem, but it's stuff to look out for.

How far below the shoulder junction is that bullet seated?

I am a definitely not a Hornady fan and by admission am somewhat of a Lapua fanboy but ended up with 600 pcs of GAP brass and after 8 firings it is as consistent as any brass I have ever tried my hand with. Manufactured by Hornady but to GAP standards, nowhere is Hornady stamped on this brass.

 

[Checkmate101]

In general, it's made to poor tolerances. Huge burrs in the flash hole, crooked extractor grooves, etc. I've seen a lot of crap with Hornady brass. I've also seen some very good Hornady brass. I had a batch of 20 pieces in 6.5cm that I fired over 20 times before I was annealing...

I doubt its the source of your problem, but it's stuff to look out for.

How far below the shoulder junction is that bullet seated?

Here is the pic I of the 112 seated to 1.976 using the hornady comparator set.

Does this seem about right? Any reason to do something different if it shoots decent?

 

[LVLAaron]

Looks good

 

[DocDoc]

Use a micrometer caliper .001 over factory is max and back off 1/2 to a grain. Rule of thumb for us oldies from the O'Conner days. That is at the .200 line from the base.