.38 Special LSWC keyholing

Daimler1989 · May 14, 2020

Hello all,

I noticed some interesting effects with one of my .38 Special handloads. Hornady 158 grs LSWC HP and 5.2 grs VV N340, chronoed 833 ft/s from my Model 27 4" tends to keyhole. I don't think this velocity might be too much for the swaged bullet, so what might be the reason? The load is keyholing as well from my 27 5" and my 13 3". Some impacting sideways with the 13 even at short distance...

on the other hand: Speer 158 grs LSWC HP and 5.8 grs Vectan Ba9, chronoed 879 ft/s from my Model 27 4" behaves as it should. I can't imagine the bullet being much harder than the Hornady as it is swaged as well (AFAIK).

Is there something I should have missed about the bullets or the
propellant or the guns?

regards from Germany
Ulrich

Nevada Ed · May 14, 2020

You might try a few medium loads with 330 or 320 powder if you have any
to see if the keyholing will stop.

Hard to tell if it is bullet fit or speed that is doing it, until you
try out a few different things, to narrow it down.

Sorry that 158 bullet is not behaving.
Good luck.

Qc Pistolero · May 14, 2020

Load no 1 keyholes in 3 different guns and shoots straight with load no 2.Problem not with the guns.
Check if any difference in diameter of the 2 brands of bullets.
While I'm not familiar with Vectan powders,it might be a different rate of combustion changes the behavior of the bullets.I'd try as suggested by Nevada to make sure.
Depth of hollow point,if much different changes the lenght and balance of the bullet.Too long a bullet might not stabilize well in the long twist of the S&W(1:18 3/4'').So check total lenght of both bullets.
Please feed us back on what you find as it might help other shooters.Good luck.

max · May 14, 2020

The Hornady bullets are swaged lead and are very soft. It is possible that you are loading them hot enough that they are not engaging the rifling and just going down the barrel like it was a smooth bore. I had that happen with some lead 9mm bullets years ago.

RodD · May 14, 2020

Bullets stripping in rifling. Soft alloy snd too much pressure. Try to recover a fired bullet and look at the rifling engraving.

Daimler1989 · May 15, 2020

RodD said:
Bullets stripping in rifling. Soft alloy snd too much pressure. Try to recover a fired bullet and look at the rifling engraving.

Thanks everyone for your input, really appreciated. I checked a bullet I retrieved some time ago, rifling engraving seems not to be existing consitently. I tried some photographs, sorry for the quality.

regards
Ulrich

boatbum101 · May 15, 2020

IMHO the Hornady bullets are too soft & / or undersized for your gun . The Speer bullets are harder than the Hornady believe it or not . To acertain what the problem is I would : 1) Measure cylinder throats as they need to be larger than bore diameter . If not they need to be honed or reamed . In a revolver bullets are sized to cylinder throat diameter . 2) Slug the bore . Drive a greased pure lead ball or fishing sinker thru barrel . Take the sized slug & check cylinder throats . It should pass thru all throats with no more than light finger pressure . If not cylinder throats are too small & need to be opened up as stated above . S&W have 5 groove barrels & one needs special tools to accurately measure bore diameter . 3) Check barrel for tight spots / bore restriction , if present for best results tight spots should be lapped out . If all that checks good I'd either get different lead bullets or jacketed & see how they shoot . Soft lead swaged bullets are for mild lower pressure loads . If sized to fit & with a good lube they should be good at velocity of your VVN-340 load . I use swaged lead bullets ( Zero brand ) in my 38 special ( 148gr HBWC ) & my 45acp target 1911's ( 200gr SWC ) . My loads run around 720fps for the 38 & around 780fps for the 45's . I hope this helps . Personally I do not use either the Speer or Hornady swaged lead bullets as they cost more than the Remington , Zero or Magtech swaged & usually do not shoot as well . Does your 27 have a newer EDM barrel ? Because of rifling design they do not shoot lead as well as the older vintage broach rifled barrels . They do just fine with jacketed .

Nevada Ed · May 15, 2020

in post #6,
the marks on the bullet looks very light, which makes me believe that this brand might be just a little undersized for your barrel?

Here is a picture of two lead bullets at target speeds out of my 38 J frame snub nose.

stansdds · May 16, 2020

I agree with Nevada Ed, the lack of engraving says undersized bullet, especially since you get the same results in different revolvers of the same caliber.

johngalt · May 16, 2020

Years ago I experimented with Viht N310 and Hornady 148 HBWC. They were impressively accurate but very sensitive to the load. At 2.7 gr, they worked great. Much higher and they started to wobble much more than with Bullseye. I suspect pressure spikes much more quickly than with Bullseye.

I have never used N340, so I don't know if it behaves the same, but you might try reducing the load and see if the bullets stabilize.

Daimler1989 · May 16, 2020

Thanks everyone,

I guess I have to check other retrieved bullets for rifling marks, but as far as I remember they looked quite ok to me. Hornady LSWC are the only bullets I have problems with keyholing, so the idea of them being undersized might point in the reight direction.

But how can that happen? They are advertised as being .358 in diameter. Cast SWC 158 grs with .357 diameter don't make any problems in my 3 .357 revolvers (27-2 5", 27-3 4", 13-2 3") nor do Speer LSCWHP 158 grs .358 or H&N copper plated SWC .357 158 grs, no matter if they are pushed a little bit harder (the Speer chronoed from my 4" is 879 ft/s, thus faster than the Hornady, but shows no tendency to keyhole). They all seem to have the correct diameter as advertised.

regards from Germany
Ulrich

fredj338 · May 16, 2020

Check the dia of your bullets. Keyholing is almost always a bullet too small or a base with a serious defect. I nly shoot harder cast bullets, but at your vel, the alloy should be fine, susoect bullet size.

fredj338 · May 16, 2020

Daimler1989 said:
Thanks everyone,

I guess I have to check other retrieved bullets for rifling marks, but as far as I remember they looked quite ok to me. Hornady LSWC are the only bullets I have problems with keyholing, so the idea of them being undersized might point in the reight direction.

But how can that happen? They are advertised as being .358 in diameter. Cast SWC 158 grs with .357 diameter don't make any problems in my 3 .357 revolvers (27-2 5", 27-3 4", 13-2 3") nor do Speer LSCWHP 158 grs .358 or H&N copper plated SWC .357 158 grs, no matter if they are pushed a little bit harder (the Speer chronoed from my 4" is 879 ft/s, thus faster than the Hornady, but shows no tendency to keyhole). They all seem to have the correct diameter as advertised.

regards from Germany
Ulrich

It happens all the time, a mis aligned piece of equip & a run gets done wrong. I have had this happen with plated bullets. Simple, just slap calipers on a few & see.

tputto · May 24, 2020

How do you crimp your loads? Did you notice which shots out of the cylinder went sideways? I had some similar Hornady bullets and remember them being slippery in the case, and if not crimped they could be pushed in by hand. I suspect a slippery bullet could be pulled out by recoil and you'd have less pressure and velocity for that bullet, causing the wobble. You can check for that by looking at your remaining rounds after 3 or 4 shots. However, if wobbling occurs even on first shot then it must be caused by something else.

Spokes · May 24, 2020

I have always had problems with that bullet as fred338 said...

Groo01 · May 25, 2020

Groo here
INCREASE the load to similar speed of the one that works.
The soft bullet should be able to swell up to fill the bore IF
the pressure is correct.
Bullseye is good for this as it "hits" [pressure spike] fast and
this allows the bullet to swell.
Also , many think that such a load need not be crimped ,,WRONG....
Use a good heavy crimp to allow the powder pressure push the bullet
from the case,,,not the primer.....
Ever see a factory Match round NOT crimped???????????????????????

mikld · May 25, 2020

max said:
The Hornady bullets are swaged lead and are very soft. It is possible that you are loading them hot enough that they are not engaging the rifling and just going down the barrel like it was a smooth bore. I had that happen with some lead 9mm bullets years ago.

Yep, "skidding" on the rifling can happen easily when driving a soft, swaged bullet......

4barrel · May 25, 2020

N340 is one of my favorite powders. I loaded some 44 mag with it last night. Slow it down to 750 fps? If you have some alox give it a coat and let set over night. Lee is the best. I have tried that bullet years ago but found something I liked better but I never went over 750 fps. I use a medium roll crimp in my 38 wheel guns with that style boolit.

pistolpete10 · May 25, 2020

I've shot a lot of Hornady 148 hbwc bullets over the years.. Never had one keyhole. I do see some wobble, can tell on the target that they don't always hit it dead straight. I don't shoot at high velocity, they ain't made for that. I shoot a light load of 231, keep velocity below 750, use a light crimp. The old bullet lube Hornady used seemed better but I haven't had any leading problems with the new stuff.

Carrier · May 25, 2020

I shoot a lot of the Hornady wadcutters and never had any issues.Out of my 14-3 with a 8” barrel it is a tack driver at 25 yards with 2.7 grains of Bullseye.

.38 Special LSWC keyholing

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