Why are my .38 special 158 grn keyholing?

[JohnhenrySTL]

My handloads were keyholing, atleast leaving goofy long triangular holes out of various revolvers today, smiths and rugers. The load is 3.4 grains of bullsye under 158 grain semi wad cutters. Length was based on crimping groove. Not all loads keyholed, but interestingly enough most keyholed in one particular target. I wondered if it was the paper. I like this load alot. What are possible dangers? I have been told sometimes those bullets just do that. I feel it's more to do with the short barrel of a 442. Although it happened in a 686 and gp100 also. I've seen it alot, but usually not with my equipment. What is causing this?

 

[9mmepiphany]

A picture of the "keyholing" would sure give us a better idea of what is happening.

My first thought is that you don't have your target on a solid/stiff backing

 

[JohnhenrySTL]

I didn't take pictures. But a flimsy target makes sense. Thanks.

 

[340PD]

^^^^Good advice^^^^

Get that target on a solid cardboard backer. You are shooting out of different guns so it is probably not a overly leaded barrel.

 

[Jim K]

A flimsy and/or DAMP target can cause tears that look like keyholing. The amount of dampness in the air can be a big factor and very frustrating, since the "keyholing" comes and goes in a seemingly unpredictable manner.

Jim

 

[Vern Humphrey]

The question is, what soft of groups are you shooting? If your bullets are actually key holing, you should have a group about a foot wide or more, with some shots missing the entire target.

If the shots are in a nice group, then flexing and blowing of the target is the likely culprit.

 

[Anmut]

Good advice

 

[Double Naught Spy]

I had a short barrel 1911, Vern, that keyholed with certain ammo that would not stabilize. At 15 yards, it shot 4-8" groups and I wasn't missing the target.

With that said, I had an AR15 with a shot out barrel that shot some bizarre groups at 50 yards that were in excess of 2' and I could not hit a human sized target more than randomly at 100 yards. At 25 yards, the groups were closer to 3" and only keyholed rarely. At 50 yards, maybe half would keyhole.

The scary part was that at 100 yards, you could sometimes hear the WHRRRRRR sound as they bullets tumbled in the air, after the report died off.

The point is that depending on the amount of instability and the distance being fired, the size of the grouping can vary considerably.

 

[Vern Humphrey]

The point is that depending on the amount of instability and the distance being fired, the size of the grouping can vary considerably.

Indeed it can. But my experience is that when you see keyholes you see large groups -- and if you see small groups, your ammo is behaving up to par.

 

[rcmodel]

The load is 3.4 grains of bullsye under 158 grain semi wad cutters

It would take three totally leaded barrels for three revolvers all to tumble what is basically a 'factory duplicate' load in use for 100 years.

My vote goes to the free hanging paper target trying to get out of the way before the bullet cuts a clean hole through it.

Use a target backer of some kind, and I bet the problem is resolved.

rc

 

[oneounceload]

My first thought is that you don't have your target on a solid/stiff backing

Yep, see it all the time at the indoor range when folks just hang a paper target; put it on a stiff piece of cardboard and it goes away.

 

[CajunBass]

I about went into a "full bore, linear panic" once when I saw what I thought was keyholing from one of my guns or the other. I eventually figured out it was a thin paper target stapled between two boards that was the culprit.

A piece of cardboard was a cheap fix.

 

[MutinousDoug]

Do you know what diameter the 158 gr bullets were sized to? If they were inadvertently sized in a 9mm/.356" sizer, that could affect down range performance and probably result in a lot of leading as well.

 

[Master Blaster]

Measure the bullets with your dial calipers if they are under sized then that is your problem. Like the previous poster said they may be sized for .356 9mm instead of .358 for .38 special.
That would cause the failure to engage the rifling spin and stabilize and would result in the tumbling bullets.

 

[JohnhenrySTL]

I infact believe the particular target was installed by a friend of mine who pays very little attention in genereal while at the range. I only noticed the funny shapes on one target. They were all in about baseball sized groups at 15 yards. They were not far apart from each other.

I have seen confirmed keyholing before. My friend bought a ak74 from one of those companies that gun smiths hate. It is one that I think randomly installs surplus gun parts together and sells them a bit cheaper than the genuine versions.I think it may be out of eastern Europe. His gun would put horintal holes in paper. We were told it actually had a barrel for 5.56's. This was alost 10 years ago. I forget the company. It was something arsenal.

I loaded 2.9 grns off bullsye over 158 grn swc. I heard about that recipe on here, it was 2 or 3 years ago, but out of my 442, I noticed funny looking shapes in the paper at 25 yards. I was told by a range officer it was my short barrel. I doubt him in retrospect. I think it was that puny charge.

I prefer my loads to stick with factory energies.

If my reloads were keyholing out of my guns, I would be pretty dam worried I was doing something wrong. Pardon my random blog. Thanks for soothing my mind.