Keyholing problem

Looks like the target is being torn rather than punched by key-holing bullets. Try a cardboard backer instead of OSB plywood. BTW, that load is probably better classified as 357 Mag than 38+P+.

OSB isn't exactly smooth. The places it makes good contact the bullet holes are nice and round. The low spots where paper doesn't contact OSB is probably where the target is torn.
I agree with BBarn.

I've not seen a pistol bullet keyhole.

I also agree with BBarn.

That revolver is a beauty!

+1 "Like" for that revolver. I purchased an Astra .357 Magnum with 3" barrel earlier this year as that barrel length makes for a good truck gun IMO..

You might try some of the more rigid "splatter" style targets as it looks like you stapled your target to a piece of composite plywood, which should be even more rigid than cardboard - I like to shoot these every so often.

One example

https://www.amazon.com/Round-Target-60-Sheet-Pack/dp/B08L7X8KTN

Also agree the 1130 fps average muzzle velocity you've previously posted definitely falls in the range of .357 Magnum territory. Your 3" ported barrel won't typically match up very well with published 357 Magnum cartridge load data as a lot of the load data for handgun use I've looked over uses a 6" long barrel, plus if a standard test barrel was used during load data development that apparatus lacks the gap between the cylinder and barrel that's present in a revolver.

The 38 special yaw angle doesn't make perfect round holes on target. Can be seen better with 148 gr WC, with lower velocity.

I only see one potential bullet profile "keyhole", and that is right side of target 2 inches below the 8. All the rest are tear-outs like others have said.

On another note, you may want to run a fatter bullet.

kidneyboy said:

I also agree with BBarn.

That revolver is a beauty!

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It can happen on both sides, too fast or too slow. It will also very by the barrel. I loaded some 9mm using a powder that was much hotter than previous jug. (suspect powder was mis-marked) The result was ammo that would keyhole from my Glock G17 but did fine from Ruger PCP.

Bullet too heavy and too slow? I shoot the 125 Berry’s in my .357. You may need jacketed billets and a faster powder for that gun. Il

I have seen berry's come apart, generally create a pinwheel of lead "spray" around the hole if the target isn't very far away.

You can push the "flaps" closed and likely see the impact circle (or not) on the paper.

In your ports, do you see any evidence of plating, that would indicate the bullet isn't making it our of the barrel intact?

Lastly, what crimp are you using, with plated bullets you need the least amount of taper crimp you can use to remove the bell and stop. After you load a round that is ready to shoot, pull the bullet. If you have swaged it down in size, while crimping it, all bets are off.

Easiest way to confirm a bullet problem is to shoot a few different style bullets from a different maker.

kelbro said:

I've not seen a pistol bullet keyhole.

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You need to get to the range more often.

Here are some examples of tumble/keyhole.

These are from 38 Special wadcutter bullets. The top picture shows a tumbled bullet, the bottom hole is a full keyhole. Clear evidence is the grease mark, which extends past the clean cutout on the top picture and is along the full length of the tear on the bottom picture.

The only time I've seen bullets (rifle/pistol) keyhole is when they are undersized. The only exception to that is when I had a .25 auto (Lorcin-yuck) years ago that would keyhole every round. The target looked comical in that every hole was nearly a perfect bullet profile with factory Winchester white box ammo.

Another potential cause in some rifles is also twist rate/bullet weight.

More recently I saw keyholing with an Enfield .303 rifle I have. I was shooting cast bullets of .311 diameter from it (knowing full good and well they were too small) and they keyholed. I sized the subsequent bullets at .314 and they shot just fine and pretty accurate for 20gr. 2400 through a 2 groove barrel.

I have also seen keyholing through a Glock 19 when cast are sized to .356. The bullets were bouncing off the log backstop and you could also hear them whizzing through the air due to their in-flight tumble. I sized them to .358 and the gun then shot like a target pistol. I know, I know....."you can't shoot cast lead through a factory Glock barrel".......

BBarn said:

Looks like the target is being torn rather than punched by key-holing bullets. Try a cardboard backer instead of OSB plywood. BTW, that load is probably better classified as 357 Mag than 38+P+.

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This!

Paper targets will tear that's why registered matches use heavier "tag board"! Are the shoulders of the berry's SWC bullets sharp? Many plated SWC style bullets have rounded shoulders that will not cut but tear paper at target velocities. Not sure about >850 fps!

Smiles,

JJFitch said:

Are the shoulders of the berry's SWC bullets sharp? Many plated SWC style bullets have rounded shoulders that will not cut but tear paper at target velocities. Not sure about >850 fps!

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Berry's does not have a SWC 38 caliber bullet on their website.

My first attempt at reloading years ago did that with .38spl. I was advised from this group that I was over-crimping. I lightened my crimp to next to nothing and the problem was remedied.

barrel leading?

murf

The paper is tearing. Some might be keyholes but it’s impossible to tell if it’s a keyhole or tear with some of them. Try again with better backer board or heavier weight paper.

Or you can try a lighter crimp or a lighter load.

What distance were you shooting at?

jski said:

I’d expect a minimum of 1300 FPS to qualify as a 357.

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A factory 158 bullet in a full powered 357 magnum runs 1235 fps from a 4" barrel, so your minimum is a little high.

fxvr5 said:

Here are some examples of tumble/keyhole.

These are from 38 Special wadcutter bullets. The top picture shows a tumbled bullet, the bottom hole is a full keyhole. Clear evidence is the grease mark, which extends past the clean cutout on the top picture and is along the full length of the tear on the bottom picture.

View attachment 950908

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Excellent examples of what I was talking about in the 2nd sentence of #11. Closing the target back up and looking at the marks on it, tell more of the story than what happens to chip board when hit.

In general, pressure, not velocity, establishes whether a load is considered magnum, +P, etc. Barrel length and powder choice can greatly affect velocity. In extreme cases, a 38+P load from an 8" barrel may exceed the velocity produced by 357 Mag load from a snubby. Re: Speer #15, pages 797 and 806 (same as Speer #14 pages 887 and 896).