My system for recovering fired bullets

[mtngun]

I've always wanted to be able to recover fired cast bullets without any damage to the bullet.

So here is my first attempt at bullet recovery. The barrel is full of water. I open the door of the barn loft and shoot down into the barrel. Their is a wire mesh basket at the bottom of the barrel to catch the bullets.


I just completed the system tonight so I've only tested it with a 22 pistol. Seems to work fine for that. I suspect hi-velocity rifle bullets will get beat up by the water, but we'll find out.

[mtngun]

Bad news. ( I shot a couple of reduced 30-06 loads into the water barrel today, and they penetrated the wire basket that was laying at the bottom of the barrel. So apparently a single barrel of water is not nearly enough to stop rifle bullets.

Plan "B" will be to get 2 metal barrels and weld them together. If that doesn't work, I'll have to give up on water and try something else, like sawdust.

Anyway, I did recover one of the 30-06 bullets from the water. This was shot through the funky Shaw barrel, and velocity was low enough (950 fps) that there was no significant obturation.

The other bullet that I fired into the water, a 120 gr. Lyman, is still laying at the bottom of the barrel. I'll post a pic when it is eventually recovered.

I found both gas checks laying in the wire basket, so apparently they get pulled off by the drag of the water.

As best I can tell, the bore riding bands on the loverider did not engrave, or at best merely grazed the rifling. The as-cast diameter of those bore riding bands is about 0.3014". So ....... I may need to re-cut the mold to fatten up the bore riding bands to 0.302" for this funky Shaw barrel.

As for the 0.3071" groove diameter, this barrel has a reverse taper -- the breech end is about 0.307" but the muzzle end is about 0.308". I was hoping that firelapping would fix that, but it didn't. That sucks for cast bullets, but I still plan to give the barrel a chance to prove itself.

[mtngun]

Here's the recovered 120 gr. Lyman, next to an unfired bullet for comparison.

It was dinged up pretty bad by it's trip through the wire basket, so about all I could learn from it is that the groove diameter is 0.3071" - 0.3073".

[mtngun]

This project has been on hold, which seems to be typical of many of my projects. Nonetheless, it has not been forgotten and wheels are turning to create a bigger and better bullet recovery system.

In the meantime here is a 357 bullet that I dug out of the dirt berm, It is a hard (20 - 30 BHN) bevel base, launched at about 2000 fps from a Contender rifle.


Several observations 1) the bevel base did not get squashed flat by obturation, it is still beveled. I'm guessing that gas pressure pushing on the side of the bevel prevents the bevel from being obliterated by obturation?

2) there are no protruding "fins" at the base like you typically see on a flat base bullet. Some people believe that "fins" hurt accuracy and therefore bevel bases can be more accurate than flat plain bases.

3) There is either no skidding or at worst some slight skidding on the front band. You'd need a more pristine specimen to say for sure. But the point is that this was an energetic load, 2000 fps, yet skidding does not seem to be a problem.

[mtngun]

Bullet Recovery System Mark II. It's 11 1/2 feet long, made of 12 gauge steel, and filled with water. 2 ball valves at the bottom allow the bullet to exit without releasing much water.


Plain base, 160 gr., 357 mag revolver at 1300 fps. Note the bottom groove has been nearly obliterated by obturation, also note one side seems more obliterated than the other side. It's not obvious in this crummy photo but the bullet appears to have skidded a little, typical for a revolver bullet.


Gas checked, 180 gr. "loverider", 357 mag Marlin at 1800 fps. The gas check came off in the water. No lube remaining in grooves. No evidence of skidding. The nose mushroomed and shed some weight even though this was a hard cast bullet. This is similar to how this load performs on game.


That's all I had loaded up today, it remains to be seen if this system will stop 2700 fps bullets and if so, what kind of shape will the bullet be in? Water is a pretty "hard" target and so far the recovered bullets look almost as beat up as bullets recovered from a dirt berm.

My goal with this project is to learn how cast bullets fail.

[mtngun]

Retesting the 160 grain plain base 357 mag revolver load: last time I noticed that the bottom lube groove was getting obliterated in the revolver, so I wanted to see if that also held true when the same load was shot from a rifle?

Once again the bottom groove was 90% obliterated from the revolver and the 2nd to bottom groove was about 50% obliterated. The grooves survived mostly intact when fired from the Marlin. Obviously "something" is happening in the revolver that traumatizes the bottom grooves. Whatever that "something" is, it doesn't happen in a rifle.

The revolver bullet skidded a little on the front band. That seems normal for revolver bullets so I'm not going to worry about it.

You can't tell from this photo but the revolver bullet is more smushed on one side than on the other side. That was true of last week's revolver bullet, too. That concerns me. I suspect the revolver bullet is either yawing badly inside the barrel, or else it is entering the forcing cone off center. I suspect the latter because it's a common problem with revolvers. It's amazing that this load shoots as well as it does with the mangled, off center bullet.

Note the base of the revolver bullet is mostly flat while the base of the Marlin bullet is beat up and uneven.


Another view of the bases. Sorry for the fuzzy photo, but the revolver bullet was mostly flat and grainy while the Marlin bullet was mostly shiny but cratered and generally beat up. This load has never been accurate in the Marlin and you wouldn't expect it to be accurate if the base looks like that when it exits the barrel.

I assume the grainy look on the revolver bullet base is due to it being blasted with unburned granules of powder?

At this time I have no explanation for how the Marlin base got so beat up, other than to say that it was exposed to hot gases for a longer period of time so maybe it got warm and soft ????? Just a guess.


Lessons Learned:
-- "something" is wiping out the bottom grooves of the bullet in the revolver. If it were due to obturation then I would expect bottom grooves to get wiped out in the Marlin, too, since it's the same load at the same pressure. What if the revolver bullet is experiencing the "Paradox Effect?".
-- alternative explanation for the wiped-out grooves: what if the bottom half of the bullet is obturating A LOT in the forcing cone? And then when it enters the rifling the bands get sized back down to normal size but not so much the grooves??? I say that because someone once tried shooting a revolver with its barrel removed and the resulting bullets had grossly obturated bases, suggesting there is some serious obturation going on when the bullet exits the cylinder.
-- "something" is mangling the base of the bullet in the Marlin. Maybe due to getting too hot and soft, but I'm not at all sure???

Things to Try Next Time and Down the Road:
-- test the revolver load in the Contender barrel, too.
-- if the wiped-out grooves are due to the "Paradox Effect" then maybe I should try imitating a Paradox bullet with its oversize groove(s)?
-- if the wiped-out grooves are due to massive obturation in the forcing cone, then maybe a harder bullet would help? These bullets are oven treated WW but the box is dated 2004 so they may have softened to around 20 BHN.
-- I'm up to my ears in projects right now so it may be a loooooong time until I can follow up on this revolver bullet mystery.

[mtngun]

I picked up a cheap USB microscope to take better pictures of recovered bullets. It's better than what I was using before but nothing to brag about. 2MB, but only 640 pixels wide, so it's hard to fit the entire bullet into the frame. Anyway these are the same bullets that I posted before.

160 gr. plain base fired from revolver at 1300 fps. Lube grooves nearly obliterated. Heat treated over 10 years ago so prolly only 19 - 21 BHN.


Same 160 gr. plain base except fired from Marlin at around 2000 fps. Lube grooves are about 50% intact, though it varies from place to place. I'm guessing this bullet may have tumbled in the water, judging by the texture of the bullet and how the bottom band is rounded over. So some of the damage may have been due to tumbling in the water.


180 gr. Loverider fired from the Marlin at 1800 fps. The gas check & lube parted company when the bullet hit the water.

Note how the check shank was engraved by the rifling. I sometimes hear people worrying that their gas check will spin on the shank because it is not tight enough, but as you can see the rifling presses the check into the shank and locks it.

There was very little obturation on this bullet. The top of the check shank measured ~0.326" vs. 0.325" on an unfired bullet. The bottom two bands obturated a 0.002" or so. I *think* these bullets were heat treated a few months ago so they're prolly 28 - 30 BHN.

[mtngun]

Today I shot a few rounds from the TC 357 rifle into the water tank.

First up my 160 gr. revolver load, at about 2000 fps. These cartridges have sat on the shelf for 10 years so the bullets have softened to 19 - 21 BHN.

Why are the grooves wiped out on one side but mostly intact on the opposite side? I am beginning to suspect that the wiped-out grooves are due to the bullet mushrooming and/or tumbling in the water ???

You can't see it in this photo but the base of the bullet was flat and undamaged.


Here's the 155 gr. bevel base at about 2000 fps. They are WW heat treated at 430F in the kitchen oven so they should be about 25 BHN. No mushrooming whatsover. Diameters are pretty much the same as an unfired bullet. No sign of skidding or twisting, No sign of gas cutting, either. The bases were flat and undamaged.

Conclusions and Lessons Learned:
-- so far I have not seen any sign of gas cutting
-- so far I have not seen any sign of skidding or twisting when fired from a rifle
-- spitzers sustain far less damage in the water tank.
-- there is very little sign of obturation even though in theory there was more than enough peak pressure to cause obturation. It may be that there is nowhere to obturate since the bullet already fills barrel and the lube grooves are full of an incompressible fluid.
-- bullets recovered from the water tank usually have no lube left in the grooves but that could be due to the impact with the water. I've recovered bullets from berms and from game that still contained lube.

Things to Try Next Time:
-- obviously I'd like to try some rifle bullets at 2700 fps, just gotta find time.
-- from now on try to use only spitzers in the water tank because they sustain far less damage than big meplats.
-- try softer alloys to see how they compare with regards to obturation and skidding.

[mtngun]

I'm still learning to use my USB microscope so here's a better photo of the same 25 BHN bevel base from the previous post.

What is the weird stuff going on at the bevel? Was the corner of the bevel melting? Gas cutting? Or did it erode due to cavitation when it entered the water?

[mtngun]

155 gr. bevel base fired from a Contender Rifle at ~2000 fps. 17.4 gr. WC297. Alloy was heat treated reclaimed shot at 40 BHN. This load mostly shot decent (2 MOA) but threw the occasional flier. I suspect this bullet would have been one of those fliers.

As usual my photos don't do it justice but this bullet somehow entered the rifling crooked, so that the bullet engraved a lot more on one side than the other side.

A clear shot of the engraving showing that there was absolutely no skidding or twisting, only "yawing." The red dotted line is the line of contact.


Another view showing severe yaw. The uneven base would surely have caused a flier.


Is the washed-out look on the bottom band due to gas cutting? Or is it water-related damage?