38 special load with 125 gr JHP

[Resjudicata]

I'm working on a NRA Action Pistol load for my 5" barreled 627. I have been loading for autos for several years now.

I have noticed that it seems to take a ton of powder to make these bullets go about 1050 fps. Compared to what it would take with a 9mm or 40 S&W.

I'm wondering if anyone has tried seating JHP bullets deeper than normal like you would do with a wadcutter. This should theoretically give the velocity and pressure without using a ton of powder.

Any thoughts? Anyone tried something like this?

Thanks,
Chris

 

[OKFC05]

Well, you have my curiosity.
What exactly are you trying to do, a power factor, or such?

Why are you trying to push a 125gr jhp to 1050fps for competition in a .38 special case?

You have my curiosity because everyone I know in IDPA uses 158gr to make minor power in .38.

 

[cp1969]

You would be navigating uncharted waters if you decide to do that, and risky ones at that. Plus, you will be increasing the jump to the forcing cone which usually isn't good.

If you are determined to shorten up the oal, though, you ought to consider trimming the brass back so that you can still use the cannelure or crimping groove. Kind of a .38 Special Short. But again, you'll have to work the loads up on your own.

If it was me....I'm lazy; I'd just put in enough powder to do the job.

 

[Jellybean]

Seating your bullets deeper would certainly raise pressures and velocities and you could use less powder seating them deeper to get the same velocities.

Look at the relationships between cartridges like the 9mm Luger vs. .38 spl, .45 ACP vs. .45 Colt and .38-40 vs. .40 S&W. The auto rounds have much less case capacity but have higher pressure levels and can be loaded with the same powders to get to the max. loads using less powder.

A couple problems you may encounter are, 1) the case walls get thicker the more you get away from the mouth, so seating a bullet too deep will eventually cause bulging that may cause chambering problems. 2) If you seat the bullet deeper than the ogive, you will have to find a way to crimp or hold them in place or they will shift from recoil affecting accuracy.

If you cut your brass too short you will loose pressure when the bullet has to travel through the cylinder without having a case around it. This is also usually detrimental to accuracy from tests that I have done on shortened brass.

 

[Resjudicata]

Seating your bullets deeper would certainly raise pressures and velocities and you could use less powder seating them deeper to get the same velocities.

Look at the relationships between cartridges like the 9mm Luger vs. .38 spl, .45 ACP vs. .45 Colt and .38-40 vs. .40 S&W. The auto rounds have much less case capacity but have higher pressure levels and can be loaded with the same powders to get to the max. loads using less powder.

A couple problems you may encounter are, 1) the case walls get thicker the more you get away from the mouth, so seating a bullet too deep will eventually cause bulging that may cause chambering problems. 2) If you seat the bullet deeper than the ogive, you will have to find a way to crimp or hold them in place or they will shift from recoil affecting accuracy.

If you cut your brass too short you will loose pressure when the bullet has to travel through the cylinder without having a case around it. This is also usually detrimental to accuracy from tests that I have done on shortened brass.

That was what I was looking for. Another set of eyes to see what I'd missed. With the wadcutters being lead I guess they don't bulge out the brass as much as a jacketed bullet would. And, a wadcutter still has a crimp groove to use where a jacketed hollow point would not.

For the other responders:

I'm trying to get 1000+ fps for use in Bianchi Action Pistol. This speed or greater allows for a shorter lead on the moving target stage. I don't shoot IDPA but I do shoot USPSA and I agree that generally in those sports a fast powder and heavy bullet is the sought after load.

Seating a bullet lower into a 38 special case would not actually increase bullet jump since the bullet would be held within the case and would have the same bullet jump as any other 38 special load.

In the end, I agree with the other poster that this may just be trying to do something that isn't necessary. I may play with it later in the year just for fun. I tried some loads last night and 5.1 grains of Titegroup under the 125 grain Zero JHP is a great load for accuracy and feel in my gun. I'll run it over the chrono this weekend to make sure I'm in the 1000 fps area.

Thanks,
Chris

 

[OKFC05]

Ah, I get the game now.

I've tried the max loads of Titegroup in .38 and .357 cases (for a different reason) with several bullet weights.
According to my chrono notes, I was well over 1000fps with 125gr Rem JHP in .38 case out of a 4" 686.
I think your load will do the trick.

 

[Resjudicata]

Ah, I get the game now.

I've tried the max loads of Titegroup in .38 and .357 cases (for a different reason) with several bullet weights.
According to my chrono notes, I was well over 1000fps with 125gr Rem JHP in .38 case out of a 4" 686.
I think your load will do the trick.

That's good to know. How much Titegroup were you using for your load?

Chris

 

[OKFC05]

That's good to know. How much Titegroup were you using for your load?

Chris

A "fat" 5.0gr, if you understand what I mean.
Statistical mean max prob 5.05 or so.

 

[Steve C]

A .38 spl GFL case loaded with 6.0 grains of Unique lit by a WSP primer pushes a 125gr Remington JHP bullets out the muzzle of my 4" M66 at 1,053 fps average.

If 6 grains is a "TON of powder" in your mind then I guess its not what you want to hear. The only way you can increase velocity and keep the pressure within the allowable .38 spl range is to use a slower powder that produces a greater volume of gas and exerts "push" over a longer period of time. You can try seating the bullet deeper but with fast powder and small volume in a relatively large case I doubt if you'll gain much. Get a chrono and try it and let us know what your results are.

Remember that higher pressure doesn't necessarily equate to higher velocity and after a certain point with a powder incremental gains in velocity will get proportionately smaller per unit gain in charge weight and pressure. At extreme pressure the velocity of the bullet will be 0 as it remains in the barre or chamber and the case and cylinder KB's.

 

[Jellybean]

Quoted from Steve C:
The only way you can increase velocity and keep the pressure within the allowable .38 spl range is to use a slower powder that produces a greater volume of gas and exerts "push" over a longer period of time.

Steve, why is the only allowable pressure range that of the .38 spl.? The pressure level isn't set by the case you're using but rather the firearm it's used in. A 125 gr. bullet at 1000+ fps is easy in a 9mm Luger and that can be easily duplicated in a .357 mag. revolver. If you trim your .357 cases to get the same case capacity as the 9mm, or seat the bullet to the same spot, you should be able to use printed 9mm load data safely since they have similar pressure limits.

 

[cp1969]

Seating a bullet lower into a 38 special case would not actually increase bullet jump since the bullet would be held within the case and would have the same bullet jump as any other 38 special load.

I see what you're saying but maybe we don't use the same definition of the word 'jump.' When I say jump, I'm talking about the distance traveled before it hits the rifling. In your case, your bullet would be doing more accelerating in the cylinder than normal and be traveling faster when it engages the forcing cone and rifling. With more of a slower powder, the bullet would be doing most of its accelerating in the barrel.