Keyholing problem

[jski]

No one’s commented on the oval beneath the right side 8. That oval is in the particle board as well.

 

[jmorris]

I was trying to in #24. Closing the paper back and looking at it like shown in #11, would be a more accurate tell than a hole left in oriented strand board (OSB) "chip" board, due to the large irregular shapes that make it up. If I shoot a round ball into one of them the hole won't always be round, because of what it is made up of.

 

[kelbro]

You need to get to the range more often.

I have a range out back. 25 yd range, 50 yd range, and 100 yd range. I get out there pretty often

Well over 1K rounds per year, more than half are handgun.

 

[fxvr5]

I have a range out back. 25 yd range, 50 yd range, and 100 yd range. I get out there pretty often

Well over 1K rounds per year, more than half are handgun.

I wish I had a range like that just out my door. That's awesome.

So 500+ handgun rounds a year. Cool. More than most. But some of us do that in one range session.

 

[kelbro]

Yep, I have scaled my collection back quite a bit. Pretty much quit developing loads a while back. Just shoot a few every now and then to stay in practice and smell that burnt powder.

The better half won't let me shoot the deer back there and I don't want to shoot the squirrels that keep messing with her bird feeders so it's just paper these days.

 

[Eugen]

barrel leading?

murf

Leading in my Ruger mkIII 22lr competition slab side caused significant key holing until I addressed the matter.

 

[Mr. Zorg]

I'd expect leading, if present, to be readily visible in a revolver in general swinging the cylinder out of the way, and especially looking at the ports in a ported barrel.

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

Not only this, but whatever load data is being used for velocity comparison(s) should be checked for the reference associated with that data (barrel length, firearm type especially WRT test barrel with no gap for a revolver use load), plus I haven't tried specifically to find any but thus far I haven't come across load data generated using a ported barrel (but such may be out there, just not on typical powder or projectile company load data).

 

[Riomouse911]

At ~1050 FPS, that seems more like a 38 Special load than a 357. I’d expect a minimum of 1300 FPS to qualify as a 357 load.

You’re still not getting the velocity / pressure relationship. They’re not linear nor are they one-for-one. Every powder has a different pressure curve, and Unique’s curve is pretty steep.

I'd expect leading, if present, to be readily visible in a revolver in general swinging the cylinder out of the way, and especially looking at the ports in a ported barrel.



Not only this, but whatever load data is being used for velocity comparison(s) should be checked for the reference associated with that data (barrel length, firearm type especially WRT test barrel with no gap for a revolver use load), plus I haven't tried specifically to find any but thus far I haven't come across load data generated using a ported barrel (but such may be out there, just not on typical powder or projectile company load data).

At least the second thread where it’s been explained by several people to the OP that the load he called a .38 +P+ load is developing near magnum pressures but not approaching magnum velocity.

The powder being used, Unique, is not going to give the magnum velocity OP may think is proper for a “magnum” without the chamber pressure going through the roof long before one gets the desired bullet speed. I seriously hope OP doesn’t blow a gun up and hurt himself by chasing velocity without understanding the various powder burn rates and pressure curves and how dangerous excessive pressure can be.

As for tumbling bullets, other than a straight-line tear in one side of the bullet hole through the paper at several locations on the target (neck, shoulder, right side) there isn’t much to suggest a keyholing issue. It looks like a thin paper target issue creating odd tears in the target like the ones at the bottom of the group here. There is no support behind this paper target so weird rips can result.



Get yourself some heavy tag board targets like these NRA B-16’s that cut clean holes (especially with with WC and SWC bullets) and try them taped tight against a cardboard backer.



Shoot a string at 10, 25 and 50 yds if you can at your range. Then you’ll know for sure whether the bullets are striking at odd angles or are tumbling when they reach your targets.

Stay safe.

 

[GooseGestapo]

I see three full keyholes in the OP’s pic. Several more partial.
I had the exact same problem with the only Berry bullets I’ve ever used

124gr .355” PHP. Bullets were marginally undersized. Plating flaked off VERY easily. Ended up melting them down when processing some range scrap lead.

You’re over driving the bullet. Slow it down. Maybe you’ll see better results. I didn’t.

 

[Thomasss]

If you read the cautionary note on the box of bullets, it says not to load for velocity over 1150 fps. It has something to do with the way Berry manufactures their bullets which can cause key holing beyond a certain velocity. Happened to a friend and once he reduced the load, they shot fine.