Hornady 6.5CM brass and pressure

[Wendog]

Looking for some input on this hornady brass while testing new loads.

Specs:
Tikka T3X CTR 20"
Hornady brass (factory single shot)
Remington 9 1/2 large rifle primers
H4831
140g ELD-M
COAL - (dont know measurement off hand, will get it)

First time reloading for my 6.5cm. Trying to use what I have on hand until I can get some decent components. I've read online that people have had success with h4831. Figured I would give it a try.

Loaded up a 10 shot ladder starting at 43.1g and increasing every .3g. I am new to GRT but that's where I was basing my measurements off of. I found a load close to max pressure and went down from there. Was using basic settings other than seating depth and bullet length. There was a very slight ejector mark on the first, second none, third, 4th and 5th had very slight ejector marks. 5th had a slight ring and 6th had a noticable ring. The ring is what concerned me, there was never a stiff bold lift or click. I'm not sure if its separation or just marks from the bolt. They're fairly light yet.

Thanks in advance. Sorry for the crude pictures and labeling, it was all done from my phone.

 

[Greyfox]

Your primers don't seem to show any flattening, nor are there any ejector marks that I can see. Maybe the marks are caused by machining marks on the bolt face. I have not tried H4831, but have had good success running H4831sc(short cut). Using Hornady brass, Federal 210M primers and Hornady 143ELD-x, I run 45.6gr. I run out of powder space before reaching pressure with this combo. Very lightly compressed load.

 

[Lefty7mmstw]

we are using 41 h4350 in my kid's 6.5 needmore with a 143 eld-x and getting 2660 to 2700 fps depending on brass lot. h4831 is a rather slow powder compared to h4350; I rather much doubt you are at full pressure yet and possibly under 2600 fps, even at your top charge. I might have to switch to 4831 one of these days with my kid's pipe, as 4350 has been hard to get, but I got i4831 as it's a bit quicker and a mildly compressed case ought to at least get to pressure.

 

[Seabeeken]

I see no pressure signs at all with those loads. In fact, I think you be hard pressed to get enough 4831 in the CM case to pressure it out. While I dont know your COL or H2O capacity, I ran this in GRT. At 47 gr of H4831 shows 106.1 % fill and 61,000 psi. Your 43.1 gr start load shows 48,000 psi which could produce inconsistent ignition

 

[Wendog]

thanks for the replies, the marks on the cases are very superficial and can notice in just the right light. my camera flash didn't do a good job of bringing the out. either way imo were of no concern. the ring around that last case was why I decided to stop. if its machining on the bolt hopefully its just leaving cosmetic marks.

velocities starting at 43.1 and up were:

2442
2470
2516
2543
2509
2549

for reference my average mv with factory 143g eld-x out of a 5 shot string is 2555


I feel like I'm going to test the last 4 round. I should have more noticeable marks or a heavy bolt lift and there's very little sign as of now. thanks for you input guys, very much appreciated.

 

[Seabeeken]

Is your bolt face just rough and scuffing the cases? I'd be surprised if you find pressure signs. GL

 

[Wendog]

Tested the last 4 tonight. As expected everything went good, theres nothing any different than the rest. 3 out of 10 cases ended up with a ring and randomly throughout the string.I'll have to inspect my bolt face closer. Just taking a quick look at it everything seems normal and good to go. I would almost consider loading up a few grains higher to see how it goes but if I remember correct GRT was stating I'm getting close to where would have un burnt powder (probably due to the 20" barrel and slow burn?). Might get a few more grains without diminishing returns.

10 shot string looked like this:

2442
2470
2516
2543
2509
2549
2574
2593
2605
2598

 

[Seabeeken]

Keep in mind, when you finally do see extractor marks, you will be about 10,000 psi over pressure. Compare your data to book loads taking into account the shorter barrel. I think you are about 100 fps from max but by the time you get to 47 gr you will be at 106% case fill and may not get a bullet seated. 105% is usually all the usable case capacity. 4831 is just a tic too slow burning but if it shoots good, go with it

 

[Wendog]

Keep in mind, when you finally do see extractor marks, you will be about 10,000 psi over pressure. Compare your data to book loads taking into account the shorter barrel. I think you are about 100 fps from max but by the time you get to 47 gr you will be at 106% case fill and may not get a bullet seated. 105% is usually all the usable case capacity. 4831 is just a tic too slow burning but if it shoots good, go with it

I was leaning more towards trying out some groups with where I'm at. The last 3 velocity readings were fairly close. Might be something there and it is faster than the factory loads by a bit. I'm assuming I'll see an increase in speed once I'm over 100 rds or so. Probably not much of one but I'm happy with that.

 

[Rob01]

You have any other powders on hand? With a short 20" barrel something slow like H4831 would be my last choice.

 

[Wendog]

You have any other powders on hand? With a short 20" barrel something slow like H4831 would be my last choice.

Unfortunately not. I purchased it at the beginning of the powder shortage for my 7mm rem mag. I wanted h1000 but nobody had any. Missed the boat on 8lbs of H4350 just the other day because I wasn't sure I wanted to spend that much (600.00 CAD plus taxes and shipping).. I think it was a mistake in the end lol.. there will be other opportunities, I have a local gun store that always seems to have powder in its auction but your looking at 110-120 per lb usually..

 

[Rosebud]

Look for Varget, H4350, R16 or 17. Your into some very slow burning powder for this cartridge.

 

[UncleDano]

No pressure signs in any of the photos.
No flattened primers, no cratering, no pierced primers.

 

[Swinehunt74]

Try that powder with ELD147 and watch it shine....