Unexpected results 38 spl.

[Zendude]

38 special load data seems to significantly vary among different sources. Maybe cross check a couple of other sources?

 

[sequins]

Nope. No difference in remaining case volume when two wadcutter bullets (but different base design) of the same weight are seated to the same OAL.

In case anyone else is well meaning but incorrect, like me, I'll break down where I went wrong.

One assumes that if you subtract the volume of a cone (skirted void in a HBWC) from a cylinder (DEWC) that would increase case volume by the volume of the cones void.

However, if both bullets are 158gn the lead is still somewhere, and the length of the skirt will consume volume equivalent to the volume of the cones void.

I'm sure this is obvious to most but it didnt occur to me until I considered things more thoughtfully so I thought I'd post my detailed retraction just in case. The load data is identical and I only use DEWC so I hadn't really thought that hard about it I guess.

Oops.

 

[fxvr5]

In case anyone else is well meaning but incorrect, like me, I'll break down where I went wrong.

One assumes that if you subtract the volume of a cone (skirted void in a HBWC) from a cylinder (DEWC) that would increase case volume by the volume of the cones void.

However, if both bullets are 158gn the lead is still somewhere, and the length of the skirt will consume volume equivalent to the volume of the cones void.

I'm sure this is obvious to most but it didnt occur to me until I considered things more thoughtfully so I thought I'd post my detailed retraction just in case. The load data is identical and I only use DEWC so I hadn't really thought that hard about it I guess.

Oops.

Correct. The material is just displaced, i.e. it is moved from one place to another. Thus the remaining case volume is not changed. Just the shape of the remaining volume has changed.

 

[PapaG]

If a hollow base wadcutter and a plain (non-hollow) base wadcutter bullet of the same weight are seated to the same overall length, there is no difference in remaining case volume. The hollow base does not create more space in the case.

A hollow base is a hole. A solid base is not. The hole is empty space. Oops. Disregard this reply. I agree. Missed the "same" depth. Apologies to all. If the base of each were seated to the same depth, the h.b. would have more space but nose would have to be extended out of the case. When people confuse seating depth with oal we get in trouble.

 

[fxvr5]

Don't feel too bad guys. The hollow-base thing has tripped up lots of folks. After all, a hole is a hole, and therefore . . . .

But people usually get it when they put some thought into it.

 

[mjsdwash]

Freak occurrence? I first loaded 38 with 158 with 3.5gr Bullseye. Chrono said 1050 average. Not sure why. A few years later, different bottle, now its 750, Weird thing is, I remember the 1050 having less recoil.

 

[ArchAngelCD]

Thanks for that..makes perfect sense.
I tried N330 because that's what I have for 9MM. Also Bullseye.
Both acted as I would expect.


Yeah, it's a button head.. supposed to fly better from the (little) research I've done. I do have *some* HP-38, but didn't try it. How about Unique for a slower powder?
Thanks for the replies, gentlemen. I'll just save the TG for another load.

Every button head WC I have loaded also had a hollow base and was soft. (10-12 BHN)

Nothing wrong with either HP-38/W231 or Unique. Give both a try and see which is more accurate your gun. I really like W231/HP-38 for most of my .38 Special loading.

My favorite .38 Special loads:
158gr LSWC over 4.0gr W231
148gr HBWC over 3.2gr W231
148gr DEWC over 3.4gr W231

 

[kidneyboy]

I load a lot of Acme BNWC's with 3.1 grains of Bullseye. Very, very accurate load for me.

 

[Steve C]

You definitely have some issue. I have loaded 158gr LSWC's on top of 3.8grs of Tightgroup (max load Hodgdon's data) and got 877 fps from a 4" S&W 67 and 781 fps out of a Colt Detective Special with 2" barrel. I would say your velocity reading is excessively high for your load.

One it could be the reading that you are getting from your chrono. I have seen higher than expected velocities when the chrono was placed too close to the muzzle of the pistol and was getting readings from the smoke and gass passing over the chrono. Moving the chrono at least 4 to 5 yards away from the muzzle brought the reading down to what was expected.

The other possibility could be an over charge. 2.8 gr of Tightgroup should be a relatively light charge leaving plenty of empty space in a .38 special case. Check your scale to make sure you don't have a poise set incorrectly if using a balance or you don't have the units set to grams rather than grains if using an electronic scale or have the scale set next to an electronic interference source like a fluorescent light ballast.

 

[Jonesy814]

My regular wadcutter load is 3 grains of Titegroup under a Speer, 148 grain hollow based executives. The are fairly mild even in J frame

 

[Chuck59]

What where the velocities for 5 at 2.8 gr. Titegroup at 1.290.?

Did you shoot a "calibration" round over the chronograph? I do, my calibration round is a 158 LRN with 3.5 grains Bullseye in a 38 Special case. I have fired enough of these rounds to know if the chronograph is out of alignment. I have been shooting down a case of 22lr Rem Target SV for rifles. The velocities you measured are unreasonable for a 148 grain bullet with 3.1 grains Titegroup, especially for a snubbie!

Either you put a lot more powder in the case or the chronograph was off axis, or powder residue confused the machine. What type of chronograph did you use?

That's why I started this thread. I'm well aware that over 1000 fps is unreasonable with this load. I wasn't about to shoot 5. The recoil was bad enough on the first that I pulled the 4 remaining test loads I'd made to make *sure* I had loaded 2.8 gr. Measured 2.8 gr. and loaded another. 1053 fps, and heavy recoil. Enough of that..
What I didn't say in the first post was after that, I tried my pet load to test the chrono, and it was normal. Tried test loads of N330 and bullseye at a low charge and they were both in the high 600s.

OP, you loaded a shorter OAL with a different style bullet and did not start at the minimum. While I cannot say I have never done this, and guessed wrong as you did, that is what got you in trouble. Been there, done that. Welcome to the club, it tends to make us more careful after that.

Y'all be careful out there.

The Lyman manual said start at 3.1 and max at 3.5 with Titegroup at 1.327"
Because of the shorter OAL, I thought 2.8 at 1.290" would give a good margin of safety to start with.
Is there such a thing with Titegroup that under charging can cause a pressure spike?
I'm well aware that what I experienced *isn't* normal. I'm trying to understand the issue.

 

[drband]

One it could be the reading that you are getting from your chrono. I have seen higher than expected velocities when the chrono was placed too close to the muzzle of the pistol and was getting readings from the smoke and gass passing over the chrono. Moving the chrono at least 4 to 5 yards away from the muzzle brought the reading down to what was expected.

I agree.

My suggestion is to move the chronograph back to a minimum of 5 yards and try again. 3 yards should be OK but maybe that's too close to a snubby?

 

[forrest r]

If I were a gambling man I'd put my $$$ on something wasn't right with the chronograph.

2.8gr of titegroup should of got you in the +/- 720fps with that bullet/1 7/8" bbl combo. If you ever shot a 1000fps+ 148gr/158gr bullet/load out of that snubnosed revolver, you'd know it. More importantly, titegroup isn't going to get to the 1050fps+ mark without blowing up that j-frame with that wc bullet.

 

[Walkalong]

Because of the shorter OAL, I thought 2.8 at 1.290" would give a good margin of safety to start with.

A reasonable assumption, but something is wrong. My thing is it sounds like you have the recoil to go with the velocity the chrono gave. Maybe not, hard to tell.

Either the space under the bullet is less than everyone thinks, or the chrono is lying, and you misread recoil. Dunno.

 

[Chuck59]

A reasonable assumption, but something is wrong. My thing is it sounds like you have the recoil to go with the velocity the chrono gave. Maybe not, hard to tell.

Either the space under the bullet is less than everyone thinks, or the chrono is lying, and you misread recoil. Dunno.

Basically, that is why I started this thread. I've shot a lot of wadcutters out of this snubbie. It was the heaviest recoil by far that I've ever had with it. I'll let this thread die a natural death, but think I'll take my .357 magnum out and try a couple more just for grins.

 

[mcb]

Something is funky 3.1 gr of Titegroup should not be pushing a 148 gr bullet that fast out of any pistol.

I am using Titegroup in 38 Special and am putting 4.3 gr under a Hornady 158gr XTP and I am getting no where near those velocities from a 4-inch model 10. My load basically replicates Hodgdon's 38 Special +P published data on their web based database. They report 905 fps from a 7.7 inch barrel. I get 860 fps from my 4-inch model 10.

I am also using Titegroup in my 38 Short Colt competition load. 3.3 gr of Titegroup under a 160gr coated lead RN bullet load to an OAL of only 1.19 in a Short Colt case and I am only getting ~880 fps from a 5-inch barrel. Don't use this load in anything but a 357 Mag Quickloads is predicting pressures clear up around 28 ksi.

Did you weight the bullets are they actually 148 gr

 

[Walkalong]

Did you weight the bullets are they actually 148 gr

Good question, and while we are checking things, do you have any check weights to test the scale?

 

[TfflHndn]

QuickLoad says that load and cartridge length should get you 680 f/s at the muzzle (using data for a .358 148-grain DEWC). Max pressure shows 11,243 psi. Should be a good, safe load. Definitely something odd with the chrono, the case or the characteristics of the gun. It's a mystery.

 

[Chuck59]

Did you weight the bullets are they actually 148 gr

Good question, and while we are checking things, do you have any check weights to test the scale?

I hadn't but I did.. 150.6. Close enough. I like Acme bullets..
I know I said I'd let this thread die a natural death.. but here I am again.
I have two scales, a digital for quick and dirty measurements, and a 10-10 that I use as the bible. Both were saying 2.8.
I'm grasping at straws now.. I bought this brass at a gun show, supposedly once fired. 4 bags of 100 each. Oooh, shiny. Yesterday, I just picked out a couple, dumped 2.8 gr in them and loaded them.
When I dumped the bag out a little bit ago to inspect them..

a fair amount of powder landed on the bench, too. (?) This is what's left in the bag. Hmmm.
Could there have been some other powder in them? Could there have been a mix of powder and a pressure spike? Dunno. Note to self. Buy new brass from now on.
I'm going to file this in the "some things aren't meant to be understood" file.

 

[mdi]

Nope. No difference in remaining case volume when two wadcutter bullets (but different base design) of the same weight are seated to the same OAL.

Have you seen a real hollow based wadcutter? I haven't measured the volume of a hollow base cavity, but it is significant when determining the internal volume of a loaded case. More room in the case, even considering the bullets base, equals less pressure. Most reloaders know that a hollow point bullets of the same shape/design as a flat/round nose bullet is lighter. But can you say the 148 gr, HB is not a bit longer to make up the weight lost by a hollow base than a DEWC? I haven't measured the length of a HB vs a DE bullet so I could be wrong (nah!)...

 

[mcb]

So if you have a WC and HBWC (only hollow on one end) of the same weight, using the same alloy (ie same density) and loaded to the same OAL then the internal volume left for propellant has to be the same if but a slightly different shape due to the hollow base.

 

[fxvr5]

Have you seen a real hollow based wadcutter? I haven't measured the volume of a hollow base cavity, but it is significant when determining the internal volume of a loaded case. More room in the case, even considering the bullets base, equals less pressure. Most reloaders know that a hollow point bullets of the same shape/design as a flat/round nose bullet is lighter. But can you say the 148 gr, HB is not a bit shorter than a DEWC? I haven't measured the length of a HB vs a DE bullet so I could be wrong (nah!)...

Are we really going to do this again!? Seriously?

Read posts 18, 27, 28, 29 and 30 - and edited to add post #46.

 

[mdi]

"Correct. The material is just displaced, i.e. it is moved from one place to another. Thus the remaining case volume is not changed. Just the shape of the remaining volume has changed." As long as there are incorrect posts like this, I will reply. I cannot see how one cannot visualize a large void in the base of a bullet does not increase the total volume of the case. That's like thinking a 38 Special has the same volume as a 357 case; "same bullets, same powder charges and the velocity and pressures are the same, right?". A fallacy repeated several times does not make it a fact! Unable to see/visualize this? Seriously?

So if I put a 1" rod then and a 1" pipe in a glass of water, the glass will hold the same amount of water with either the rod or pipe?

 

[fxvr5]

"Correct. The material is just displaced, i.e. it is moved from one place to another. Thus the remaining case volume is not changed. Just the shape of the remaining volume has changed." As long as there are incorrect posts like this, I will reply. I cannot see how one cannot visualize a large void in the base of a bullet does not increase the total volume of the case. That's like thinking a 38 Special has the same volume as a 357 case; "same bullets, same powder charges and the velocity and pressures are the same, right?". A fallacy repeated several times does not make it a fact! Unable to see/visualize this? Seriously?

So if I put a 1" rod then and a 1" pipe in a glass of water, the glass will hold the same amount of water with either the rod or pipe?

Read those posts again and again. Look very close for the 'same weight' and 'loaded to the same overall length' clue.

edited to add 'same weight'

 

[whughett]

Someone and some people are really overthinking this.