Compressed Loads?

[jski]

Here’s the deal:

I’ve been experimenting with 38 Shorts. First, I called Starline and asked if their 38 short brass could sustain 38 +P pressures. He replied 357 pressures. So that isn’t an issue. Second, I’ll be firing these using a 357. Third, I’ve been following FortuneCookie45’s load recommendations, so I should be good there.

Well, I went out and purchased 158 gr HPs from Berry’s. Now these are longer than the simple RN Berry’s 158 gr bullets. I’m loading 3.3 gr of Titegroup. When I seated the 1st 6 rounds this must have introduced a small bulge in the brass. They were very tight in the chamber. Remember, they are longer (than RN bullets) and I seated them further into the case as a consequence.

So I removed the decapping pin from the resizing die and ran them thru. Now the cartridges fit fine, they’re no longer a tight fit in the chamber.

These are certainly compressed loads and was wondering how this changes the behavior of the load?

 

[ArchAngelCD]

IMO if the brass is that short as to compress a charge of only 3.3gr of Titegroup your pressures are going to be very high. I looked on the Hodgdon load data site and I think the 38 Short brass you are using is about the same as 38 Short Colt brass. With a 135gr bullet the max charge is 2.7gr so I'm thinking your charge is way too high. I would drop it back a bunch and see what you get.

 

[jski]

I backed off about 1/10” in the seating depth and the problem with tight chamber fits went away. I did continue to:

• seat the bullet
• crimp the case
• resize the case (again)

That makes a nice looking round.

I based the 3.3 gr charge on the following:

This is similar to FortuneCookie45’s 38 Short recipe.

 

[Blue68f100]

If your resizing the case after the bullet is seated your swaging the bullet down, making it smaller. This will cause loss of neck tension. The crimp may hold it but you may end up with leading due to the bullet being under sized.

 

[buck460XVR]

These are certainly compressed loads and was wondering how this changes the behavior of the load?

Being compressed loads is not what is bulging the brass. the bulge created by the bullet is a good thing for the most art as it shows there is good neck tension. This is especially true when using a bullet without a cannelure in a revolver, which is what those Berry's are. As has been said, resizing rounds with lead or plated bullets like Berry's, does pose the risk of swagging the bullet down and creating loss of neck tension. Bad thing for a bullet with no cannelure in a revolver. Swagging down a plated bullet also poses the risk of reduced accuracy from a bullet already known for "meh" accuracy.

Compressed loads do not automatically make for high or over pressure. Some powders like to be compressed and some don't. Titegroup, being a fairly fast powder, probably won't like it.

 

[jski]

If your resizing the case after the bullet is seated your swaging the bullet down, making it smaller. This will cause loss of neck tension. The crimp may hold it but you may end up with leading due to the bullet being under sized.

True but we’re talking a very small amount of swaging. And the bullet is plated.

 

[jski]

Being compressed loads is not what is bulging the brass. the bulge created by the bullet is a good thing for the most art as it shows there is good neck tension. This is especially true when using a bullet without a cannelure in a revolver, which is what those Berry's are. As has been said, resizing rounds with lead or plated bullets like Berry's, does pose the risk of swagging the bullet down and creating loss of neck tension. Bad thing for a bullet with no cannelure in a revolver. Swagging down a plated bullet also poses the risk of reduced accuracy from a bullet already known for "meh" accuracy.

Compressed loads do not automatically make for high or over pressure. Some powders like to be compressed and some don't. Titegroup, being a fairly fast powder, probably won't like it.

After I backed off ~1/10” in seating depth, I don’t think there is much compression, if any. Not really much before I backed off in all honesty.

One other thing: I never see the bullet bulge in factory ammo, why?

 

[tightgroup tiger]

One other thing: I never see the bullet bulge in factory ammo, why?

Because the factory new brass hasn't been stretched out from firing it.
You won't see the bullet bulge on mine .38/.357 either,

because I use Redding dual ring dies to resize them with.
The single ring resizing dies are the only dies that leave bullet bulges, and that can be defeated by only resizing the case for the length of the bullet your loading.
Not trying to argue with you, but just saying.

 

[AJC1]

I dont have any idea how TG would act as a compressed powder as I've never loaded a case where that's even close to possible. It's not something I would be inclined to try.

 

[jski]

I dont have any idea how TG would act as a compressed powder as I've never loaded a case where that's even close to possible. It's not something I would be inclined to try.

Let you guys know if I see any signs of excessive pressure.

 

[jski]

Because the factory new brass hasn't been stretched out from firing it.
You won't see the bullet bulge on mine .38/.357 either,
View attachment 1056925
because I use Redding dual ring dies to resize them with.
The single ring resizing dies are the only dies that leave bullet bulges, and that can be defeated by only resizing the case for the length of the bullet your loading.
Not trying to argue with you, but just saying.

I see the bullet bulge with brand spanking new Starline brass.

 

[Barbaroja]

True but we’re talking a very small amount of swaging. And the bullet is plated.

.001” can completely make or break accuracy. I feel like your shrugging off a lot of good advice in this thread. Your making an awful lot of assumptions about your charge weight and if it’s it’s ok to compress.

 

[tightgroup tiger]

I see the bullet bulge with brand spanking new Starline brass.

You usually will see more bulge with Starline, Their brass is thicker than most of the other brass mfgs brass is for the same caliber.
I don't like Starline brass for 9mm because of that. I'll put it this way, I don't mix it in with any of my other head stamps when I sort brass.

 

[jski]

.001” can completely make or break accuracy. I feel like your shrugging off a lot of good advice in this thread. Your making an awful lot of assumptions about your charge weight and if it’s it’s ok to compress.

I’m not shrugging off any advice, just thinking out loud … so to speak.

I don’t believe it is compressed since I backed off the seating depth.

 

[AK Hunter]

Some powders like extruded or rod powders compress well, others like smaller granular structure powders don't compress well
Titegroup is not one I would attempt a compressed load.

 

[docbrown]

I get that you want to try something different, but with the availability of 38 Special and 357 brass, why bother? Titegroup is not one of the powders I have on my list of "friendly" powders. I know pressure can spike quickly in a 9mm case, and the 9mm has a case capacity of 13.30 gr H2O. The 38 is going to be similar in volume, however, you are trying to cram a 158 grain bullet in the case, which will cause pressures to spike like in a 9mm. Another consideration is, what if someone were to get those rounds mixed in with an actual 38 revolver. Your 357 might be able to take those pressure spikes, but an older Colt or S&W chambered in 38 will not. I put this in the category of "Can it be done? Maybe. Should it be done? No". Not trying to beat up on you, but some things are not worth losing fingers, eyes or noses over.

Edit:
Also, part of the reason you may be having chambering issues is that 38 Short is larger than .357. More like .361 for the bullet and .386 at the base as opposed to .357 and.379 for 38 Spec/357 My Lyman 49th edition lists 2.2 grains of TG as the max load for that cartridge with a 160 grain LRN bullet. That loading gives a pressure of 12,100 CUP. an extra grain of TG will not just add 50% pressure, but could easily double or more the pressure.

 

[buck460XVR]

True but we’re talking a very small amount of swaging. And the bullet is plated.

Plated bullets are the worst when swagged using a resizing type die. While the lead core is swagged, the copper plating springs back, loosening itself from the lead core and leading to possible separation in the barrel when shot. The slight bulge in the brass from the bullet should not hinder chambering in a revolver if everything else is correct. I personally like to see it. No real need to resize.

 

[jski]

I went to the range today with the 38 Shorts. They were very mild, even when compared to 38 Specials, BUT the cases were very difficult to extract and accuracy was atrocious, regardless of whether or not I resized the round after seating the bullet.

Here are some of the case heads:

 

[someguy2800]

True but we’re talking a very small amount of swaging. And the bullet is plated.

small changes in bullet diameter make big differences. Do not run loaded rounds into a sizing die.

 

[someguy2800]

You can easily confirm if you were at a compressed load by measuring how far down the powder is from the neck, but a compressed load would not cause case bulging. The reason you were getting bulging from the sounds of it was because you were seating the bullet too deep. Cartridge cases are tapered so if you seat a bullet into the part of the case where the case wall starts to thicken it will bulge out the case walls.



Hard to extract cases are a sure sign in a revolver that pressure is way too high. Changing seating depth can dramatically affect pressures in small volume cases, so as case volume goes down, the powder charge must also go down, or else the pressure will go up.

 

[jski]

small changes in bullet diameter make big differences. Do not run loaded rounds into a sizing die.

Understood!

But there are too many variables to identify one as the culprit tho. The thing that would argue against it being the cause is that I saw the same results from the exact same loads that hadn’t been resized after seating.

I believe I’ll put the 38 Shorts aside for awhile and focus my efforts elsewhere.

 

[jski]

You can easily confirm if you were at a compressed load by measuring how far down the powder is from the neck, but a compressed load would not cause case bulging. The reason you were getting bulging from the sounds of it was because you were seating the bullet too deep. Cartridge cases are tapered so if you seat a bullet into the part of the case where the case wall starts to thicken it will bulge out the case walls.

View attachment 1057141

Hard to extract cases are a sure sign in a revolver that pressure is way too high. Changing seating depth can dramatically affect pressures in small volume cases, so as case volume goes down, the powder charge must also go down, or else the pressure will go up.

The visuals help. Examples are the best way for conveying ideas!