Thoughts on these fired brass for pressure signs?

T

taseal

Gunny Sergeant
Full Member
Minuteman
Apr 18, 2011
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#1
The bolt wasn't sticky, wasn't hard to operate, and recoil was mild.

no chrono for these...

Virgin Lapua, 175 SMK, H4350. OAL 3.35 I think (forgot to write them down argh) with federal match primers... (.30-06)

I do see some craters on the primer, but I think that's just the way my firing pin is. there is a very slight ejector mark on there. but it's not as bad as I've seen on the forums... I don't think the primers are flattened at all either. no gas seepage from the primer either....

also, the extractor groove is .405 for 55gr, and .405 for the 57 grain too. I had a 58-59 which looked similar, but .405 as well.

any thoughts? you think I'm still within limits and these are too subtle of marks? as far as powder wise, 57 is not too high. it's medium power I'd say. it just brings me to node 5. node 6 is around 55...

dsc01136p.jpg
 
#2
Re: Thoughts on these fired brass for pressure signs?

They look fine to me, it's kind of hard to get a good look a good look at the primers from the flash. de-prime and see if the primers are flat. Also you mentioned the firing pin leaves a good signature, do you by chance have another round, maybe factory to compare it with. Or another hand load.

But then again it's just my opinion,if you feel comfortable with them, crank them out.

memo
 
#3
Re: Thoughts on these fired brass for pressure signs?

I had some 55gr, that didn't look as bad with the crater.

Can someone show me a flattened primer then? I thought I was looking for the primer to fill the gap between the edge Of primer and flash hole to classify it as a flattened primer. How about the ejector mark? That's normal? Especially because it's virgin brass, the headspace was probably one of the reasons why they might be there. With fired brass they might not jump back as much now...

I mean I went all the way to 59 grains, and it didn't look much diff, but that's prett effin high I think... I only need to hit around 57 grains to be where I want to be, so I don't see a point of going higher....
 
#6
Re: Thoughts on these fired brass for pressure signs?

I don't see the ejector marks you're talking about. With the reflection, its hard to see, but they look fine.
 
#7
Re: Thoughts on these fired brass for pressure signs?

I am not an egg-spurt on this one but my rifle will crater some primers like that, depending on the temp and how ma ny rounds I've fired.

To me, it looks like you are right where you need to be, but again I could be wrong.

Anything higher and I might have a concern...safety wise anyway...
 
#9
Re: Thoughts on these fired brass for pressure signs?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">I don't see the ejector marks you're talking about. With the reflection, its hard to see, but they look fine. </div></div>

Here ya go

unledkh.jpg
 
#10
Re: Thoughts on these fired brass for pressure signs?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shoot4fun</div><div class="ubbcode-body">According to Hodgdon's data center you are GTG up to 59 grains with H4350 and the 175 SMK. </div></div>

I've been told that hodgon likes to go high with their numbers...

with QL, I'm already over 60K pressure with 58.5 so...
 
#12
Re: Thoughts on these fired brass for pressure signs?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: The Mechanic</div><div class="ubbcode-body">They don't look to bad but what temp were you shooting in? Was it pretty hot? </div></div>

Yeah, it was a hot day (as usual) it was probably high 80s, low 90s...

I just did my QL with 95 degrees to be on the safe side. here is what I'm shooting for

<div class="ubbcode-block"><div class="ubbcode-header">Code:</div><div class="ubbcode-body ubbcode-pre" ><pre>
Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
+00.0 100 57.00 2710 2854 55772 10270 97.5 1.127 ! Near Maximum !
</pre></div></div>

I want that Node 5. I'm gonna try to fine tune it at the range.

 
#13
Re: Thoughts on these fired brass for pressure signs?

I did notice those ejector marks too.

Do you get those same marks with starting loads?

When brass starts flowing into the ejector area, generally, your going in too hot.
 
#16
Re: Thoughts on these fired brass for pressure signs?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: taseal</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shoot4fun</div><div class="ubbcode-body">According to Hodgdon's data center you are GTG up to 59 grains with H4350 and the 175 SMK. </div></div>

I've been told that hodgon likes to go high with their numbers...

with QL, I'm already over 60K pressure with 58.5 so... </div></div>

I regularly use the Hodgdon site and have never had issue with any load as long as the variables components didn't change.
I have seen/owned a few R700 rifles that showed those ejector marks you're looking at even at the bottom of powder charge ranges. Could be just tolerance slop.
I have QL and the one thing I know is that it makes decisions based on what you input and nothing else.
 
#17
Re: Thoughts on these fired brass for pressure signs?

The Chrono came in the mail today, so next week I'm going to the range with it to get some numbers...

It's possible I might have a hot lot. The Chrono should tell alot. the starting load (55gr) did not have the marks.

What i'll probably do is, start at ~56 grains where I had no marks, and work my way upto ~57.5 grains, and see what happens with the once fired brass. I won't go over, my nodes show I need to be around 57 anyways, and if I'm already getting marks, no need to go higher than 57.5

I'm looking at my 59 grain once, and it looks no diff than the first ejector mark signs. the crater is deeper, but the EJ isn't any more pronounced.

I'm aware of the QL's abilities. as far as cartidge goes, I gave all the data I could. (OAL, COAL, CC, powder temp @95)

I'll compare with the chrono numbers, and adjust Ba and possibly the bullet weight to adjust for bore tolerance.

But from what you see, would you agree 56-57.5 would be safe to work with? I think so. but this is my 1st rodeo, so I wanted some more assurance... lol

btw, primers are FGM210
 
#20
Re: Thoughts on these fired brass for pressure signs?

I don't think those look like they have brass flow into the ejector cut, although the picture probably doesn't show that well. You will often get a scuff like that when the cases are properly sized and crush fit a bit as you close the bolt. If the brass has flowed into the ejector cut under pressure, you will see a sharp raised edge that is really obvious.
 
#21
Re: Thoughts on these fired brass for pressure signs?

These look just like the pics. The area isn't flattened, and it's not really raised. As a matter of fact, at 59 grains, I still was seeing what I saw at 57ish, which is why I'm baffled because 59 is pushing over saami specs afaik.

Like I said, I get a good node at 1.127 which is 57 grains, I'll probably just stick around there. That's 2700 with h4350 and over 2800 with imp 7828ssc.

I'm gonna look and see, but with 7828, I might be able to get to 3000fps with 175smk with about 10% compression

I was thinking of just keep going over 59 to whereever I actually feel the bolt get sticky and see flat pri ers and better looking marks, but I'm honestly a bit afraid. Lol
 
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