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Azar Offline OP
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I took an old military surplus Russian Mosin-Nagant M44 to the range today with some handloads. I've shot this same handload a number of times in this same rifle. I've reloaded for a number of years, but this is a first and I'm curious if any of you can shed some light on what's happening.

My first shot of the day seemed normal when the trigger was pulled. Nothing off about the recoil, report, or the hole on paper. When I pulled the case from the chamber there was a very large dent in the case at the bottom of the shoulder down into the body. It definitely gave me pause and caused some concern. I've never seen that happen and have no idea what would cause it. I decided I'd shoot a second shot to see if it happened again. If it did, I would take the rounds home and pull the bullets until I could determine what was causing it.

The second shot was fine and so I continued to fire the remaining rounds (15 in total). Shot #12 also caused a dent in the case body, though not as severe as the first shot. All of the other 13 shots had normal looking brass after firing.

Here's the details of the load:
7.62x54R
0.311" 150g PPU SPBT bullet
PPU Brass, 2nd firing
Neck sized with Lee Collet Die
CCI 200 primer
47.0g H4895 (1.0g above Hodgdon starting charge)
2.868" COAL, 2.863" COAL, 2.855" COAL (3 strings of 5 shots each)

For the first shot I had failed to arm the chronograph, so I'm not sure what the velocity would have been. However, for shot #12 which also dented the case, the velocity was 2,737 fps which was 148 fps above the rest of the string average (2588, 2600, 2603, 2565). However, there were also two shots in string #2 that were of similar velocity (2,751 & 2,755) which did not create any dents in the case. Why I'm getting I'm getting 1 to 2 shots per string with velocity ~150 fps above normal is also puzzling to me as each powder charge was hand weighed to be exactly 47.0g. I know that is pointless, especially in a milsurp rifle, but old habits are hard to break. smile

Any ideas?


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Might just be a low power load.

Usually it dents when the charge is low because it don't have enough pressure to seal the chamber.

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Yep or it could be time to anneal.


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Azar Offline OP
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What's odd, is that I tested in 0.5g increments starting at 40.0g up to 49.5 grains. So I've tested loads 7.0g below this load. This was also the 7th, 8th, and 9th 5 shot groups tested at this exact load. If low pressure is causing the dents, why didn't it occur in previous testing of this load or the loads of much lower charges?

Also, this is only the 2nd loading of these brass cases, so I don't think it's an annealing issue.

But thank you for the feedback.


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IIRC, the 7.62x54R seals on the rim. If the shoulder does not have good engagement, gas will leak back and dent the case. It's cold here in Utah (I bet you have noticed). That powder is temperature sensitive. Cold weather, light charge = no shoulder seal = dented case.


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Denton,

It's entirely possible that you are correct but it still doesn't make sense on why it's happening now vs. why it's never happened before.

I started handloading this bullet at the beginning of the year in January, in weather comparable to what we experienced yesterday. The first loads I tested were this exact same powder, primer, case, and bullet but at 40.0g of H4895. My notes show that load was tested on January 29th at 10:30am and the weather was 30F, nearly identical to the weather at the range at the time I was there yesterday.

Also, In Janurary the case was brand new and not previously fire-formed to my chamber. IIRC, the cases grew on average of about 0.030" upon firing, so I know there was no shoulder engagement at all when loads 7.0g lighter were fired in similar weather. These cases were once fired and neck sized using a Lee Collet Die so the shoulder should have had a much better seal than previously, but this load and lighter loads have never done this before.

Also, H4895 is one of Hodgdons Extreme powders and is supposed to be less sensitive to colder temperatures.

Lastly, why would the other shot that dented the case show ~150fps higher velocity than all the other shots in that string? Wouldn't that imply greater pressure on that shot vs. the others?

I'm just stumped. But I do appreciate any and all feedback.


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I have seen that before (a long time ago) but have forgotten what caused it. Not a 308" projectile by mistake?


Update: My trusty rusty Speer Reloading Manual #10 says that shoulder collapse is not common and can result from too much freebore when using slow burning powders and it also says "particularly in magnum chambers". Your powder doesn't seem to be all that slow for that cartridge and projectile though.


Originally Posted by mauserand9mm
Originally Posted by mauserand9mm
Originally Posted by Raspy
Whatever you said...everyone knows you are a lying jerk.

That's a bold assertion. Point out where you think I lied.

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Could it be as simple as you have some crude rolling around in the chamber?

Has the rifle and some loads popped any primers?

How many times has the brass been fired? weakness on some points on your brass, that it is starting to wear out, another shot or two, and where the dent was, will cause a case split.

I've had some fireball brass that was doing fine, and was on its 15th reload. Then 9 of out 10 rounds, ejected with just the bottom half of the case, and left the upper half, struck in the chamber..... bore snake took those right out with no issues...

Looked at the second batch of 10 rounds, also on their 15th reload, and with the old reading glasses on, you could see a real fine, circular crack, almost around each case.... fired the first two, and same experience. Otherwise brass looked fine.

Lesson # 27,005 on something else that can go wrong with handloading ammo.

Blow out chamber with a airhose, try a new batch of brass, if you can drop floor plate, do that also to clear/clean that...

I question if it is the powder having an issue.. Is the brass &/or the primers some sort of odd ball foreign manufacture, that is reloadable, but not really intended so.. because its made for 3rd world countries, like somewhere in Africa or Asia. Plenty of junk shows up on our shores, in time like these, and other problems created by the M.F DemocRATS.


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Originally Posted by Azar
Denton,

It's entirely possible that you are correct but it still doesn't make sense on why it's happening now vs. why it's never happened before.

I started handloading this bullet at the beginning of the year in January, in weather comparable to what we experienced yesterday. The first loads I tested were this exact same powder, primer, case, and bullet but at 40.0g of H4895. My notes show that load was tested on January 29th at 10:30am and the weather was 30F, nearly identical to the weather at the range at the time I was there yesterday.

Also, In Janurary the case was brand new and not previously fire-formed to my chamber. IIRC, the cases grew on average of about 0.030" upon firing, so I know there was no shoulder engagement at all when loads 7.0g lighter were fired in similar weather. These cases were once fired and neck sized using a Lee Collet Die so the shoulder should have had a much better seal than previously, but this load and lighter loads have never done this before.

Also, H4895 is one of Hodgdons Extreme powders and is supposed to be less sensitive to colder temperatures.

Lastly, why would the other shot that dented the case show ~150fps higher velocity than all the other shots in that string? Wouldn't that imply greater pressure on that shot vs. the others?

I'm just stumped. But I do appreciate any and all feedback.

Well, you've got me stumped too. smile


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The only time I`vee seen something like your photo, is when a case was fired in a chamber with a little oil in it. The oil was in the barrel, and had run back into the chamber when the rifle was standing up in the gun safe. Oil is trapped between the chamber walls and case, and boils from heat of ignition, causing gas, causing dent. The pic of the case shows what I think is soot in the dent.
I run clean patches on the end of my rod into each chamber before shooting now.
I`ve also had a thread from a cleaning patch left in a chamber, the brass came out with a perfectly formed image of the intruder in it.

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Azar Offline OP
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My first thought was that it was possible there was something in the chamber when the trigger was pulled. In fact, now that you mention it, there was a very fine thread of red plastic sitting on top of the magazine after I inspected the chamber after firing the first shot. It's possible it was in the chamber when the first shot was fired.

Some obstruction or oil could possibly explain the dent in the case of the first shot, but I don't believe would explain the smaller, but similar dent in the case on shot #12. If there was oil or something else in the chamber, I would think it would have been cleared about by shot #12 or at least caused more issues in cases 2-11 & possibly 13-15.

This is only the second loading of these cases. They are made by PPU (Prvi Partizan) for reloading. This isn't brass from recovered from factory produced ammo, but bagged brass sold to handloaders.
I used CCI 200 primers, not anything foreign made.
Primers and powder are kept on shelves in a more-or-less temp. controlled garage (radiant heat in the floor an HVAC vent in the ceiling).
I've never seen popped primers in this rifle.

Thanks again for the feedback.

Last edited by Azar; 12/07/22. Reason: additional info

“There are three things all wise men fear: the sea in storm, a night with no moon, and the anger of a gentle man.”
― Patrick Rothfuss, The Wise Man's Fear

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