6GT help, new to reloading

[Checkmate101]

First, I already messed up by not taking pictures sooner and I also deprimed the brass prior to pics, so the info will be lacking a bit here. I realize I’ll probably have to repeat some of this.

I am brand new to reloading, these are the first 22 rounds I have ever loaded myself. I am worried I am seeing some signs of pressure where I didn’t think I would have already.

My main question is: does this seem like I hit pressure too early? If I start seeing an ejector mark, how far would you back down from there?

My goal was to run the 112s around 2825-2850 and be quite safe. I really don’t want to be near the edge of pressure and problems when I am learning to reload. Would rather shoot mild loads than worry about a change in conditions messing with me too much. Maybe this bullet is too heavy to run that fast with N150? I appreciate any/all the help in advance.

Recipe:
N150: 32.0 - 33.8 gr
Brass: GAP hornady
CCI 450
Barnes MB 112g

Rifle:
ARC CDG
6GT 26” bbl

Weather: 45 F, raining.


I only tested for speed on these reloads and to look for pressure signs before loading a bunch of rounds for the range to test. I figured they would be fairly mild, but that is only based on what I have seen with similar cartridges (dasher, bra, etc) as I haven’t found much data on the powder/bullet combination I chose.


Pics:
As mentioned, I already deprimed and I don’t have the order they were in or what the charge weights were.

The last two show an ejector mark. Pretty faint, I hope the pics show it well enough. These were the last 2 (shot 2 shots at 3/10th intervals to get speeds) at 33.8g charge weights.

Speeds ranged from 2758 - 2888 measured on a magnetospeed.

ETA: I just realized I put this thread in the wrong subsection. Must have misclicked the 6BR section. Please move if needed.

 

[Bill Norris]

If this is new brass you may see that slight marking. If you feel uncomfortable with what you see back down a grain or so to fire form the brass. What twist is your barrel?

 

[Darkside]

What he said ^^^^^^^^.
Seeing the primers helps alot also.

 

[Checkmate101]

Yeah, it is virgin brass. It is a 1:7 twist, rifle was used when I bought it, but standard .120 freebore when new.

I know I messed up by depriming it before remembering to take pics. I often forget to remove my idiot hat when doing important things.

Biggest thing that has me worried was not knowing how to “read” the brass yet. The charge that I would ideally like to run is around 33.5 gr. I didn’t notice any heavy bolt lift on any of these charges.

 

[Checkmate101]

If this is new brass you may see that slight marking. If you feel uncomfortable with what you see back down a grain or so to fire from the brass. What twist is your barrel?

Does fireforming the brass help deal with pressure? With once fired am I less likely to run into the ejector marks?

 

[Bill Norris]

Yea once you fire form the brass it has expanded to fit the chamber more precisely from it's original size. Probably will lessen the look of the head stamp somewhat. Honestly, I don't see an issue with your pics so far but as mentioned would be better to view the fired primers as well.

 

[Checkmate101]

Yeah, I definitely won’t make that mistake again. A friend was helping me go through the steps and learn to set dies as well, so I forgot to take pics while trying to retain all the info.

 

[J.D.Erwin]

what Bill said your on the right path.

 

[Bill Norris]

Does fireforming the brass help deal with pressure? With once fired am I less likely to run into the ejector marks?

WARNING ABOUT DIFFERENT BRANDS OF BRASS - Different manufs. of brass will dictate different wall thickness and especially if there is a difference in primer size the head area will be different thickness. (For instance swapping from large primer to small primer brass) When swapping from one given brass to another it is ALWAYS safer to weigh for comparison as wall thickness will definitely have a huge bearing on load development.

 

[Checkmate101]

WARNING ABOUT DIFFERENT BRANDS OF BRASS - Different manufs. of brass will dictate different wall thickness. When swapping from one given brass to another it is ALWAYS safer to weigh for comparison as wall thickness will definitely have a huge bearing on load development.

I can definitely understand that. I only have the GAP hornady stuff. Don’t plan on switching as I learn to reload.

I think I read somewhere that the hornady cases have a softer head than the alpha cases. I could be making that up. Would that account for any of the markings I saw?

Overall, I may be overthinking these couple marks. More just trying to be hyper vigilant since I don’t know what I don’t know yet. I’ll remember to post more when I get to testing some more. It’ll be a bit as I have a bunch of work coming up.

 

[Bill Norris]

Would that account for any of the markings I saw? It could very well make a difference. Some brass is definitely harder than others. SAFETY - Never can have too much of it. Eyes & Digits are hard to come by once they are displaced.

 

[LVLAaron]

That's a heavy bullet for the .120 freebore... I think it's a bit too short for the 105 grain bullets, personally. But that freebore was designed for mag fed application.

I'll add two things..
1) Hornady brass is... not good.
2) N150, while my favorite .308 powder, does have some odd burn rate characteristics. If you have another powder... I would try it. (Varget, 4350, n140)

 

[nwmnbowhunter]

Virgin brass can handle more pressure than fired brass. So moving forward you will have to drop down your charge a couple grains and with back up.

Generally it is best to fire form your virgin brass with a mild load and then you can start working up loads on fired brass.

When i start load development i want to KNow my max load so i know I'm not flirting with it.

I start one shot at a time starting at being load and go up in your case by 0.3 grains.

The first sign of pressure is generally ejector marks that get brighter and brighter. Faint ejector mark on a case or two lead to bright ejector marks. I will stop at consistent bright ejector marks... but sometimes you'll start to get slightly heavier bolt lift.

Now that i know my max charge i can be confident knowing i won't get close to it again.

If you only work up loads and stop you really have no idea how close or far you are to your max load..
. You could be flirting with it and get a sudden pressure increase or you could be leaving accuracy or speed on the table. It's best to know what your max charge it. Again this is best done on fired and resized brass.

Another trick is to measure the web area diameter. As your pressure increases you can measure this area and see it get wider and wider.

 

[boltfluter]

Just an FYI, be sure and keep your cases dry when shooting or you will really see some high pressure sighs. Makes it very hard for the case to grip the chamber walls. Carry on.
Paul

 

[Checkmate101]

Just an FYI, be sure and keep your cases dry when shooting or you will really see some high pressure sighs. Makes it very hard for the case to grip the chamber walls. Carry on.
Paul

I should’ve mentioned, everything stayed dry. Was shooting out of the garage into the berm.

 

[Pres100]

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

 

[Checkmate101]

That's a heavy bullet for the .120 freebore... I think it's a bit too short for the 105 grain bullets, personally. But that freebore was designed for mag fed application.

I'll add two things..
1) Hornady brass is... not good.
2) N150, while my favorite .308 powder, does have some odd burn rate characteristics. If you have another powder... I would try it. (Varget, 4350, n140)

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.

 

[Checkmate101]

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

I didn’t size prior to loading these rounds. Just virgin brass that an expander mandrel was run through the necks prior to loading.

For sizing, used hornady one shot. Not entirely sure what I plan on using for sizing lube going forward though.

 

[Checkmate101]

Virgin brass can handle more pressure than fired brass. So moving forward you will have to drop down your charge a couple grains and with back up.

Generally it is best to fire form your virgin brass with a mild load and then you can start working up loads on fired brass.

When i start load development i want to KNow my max load so i know I'm not flirting with it.

I start one shot at a time starting at being load and go up in your case by 0.3 grains.

The first sign of pressure is generally ejector marks that get brighter and brighter. Faint ejector mark on a case or two lead to bright ejector marks. I will stop at consistent bright ejector marks... but sometimes you'll start to get slightly heavier bolt lift.

Now that i know my max charge i can be confident knowing i won't get close to it again.

If you only work up loads and stop you really have no idea how close or far you are to your max load..
. You could be flirting with it and get a sudden pressure increase or you could be leaving accuracy or speed on the table. It's best to know what your max charge it. Again this is best done on fired and resized brass.

Another trick is to measure the web area diameter. As your pressure increases you can measure this area and see it get wider and wider.

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?

 

[LVLAaron]

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.

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?