# .356" 9mm bullets onto .38 sp case??



## mccoy

I'm doing this experiment: I'm loading my 38 sp cases with 9 mm, 125 grs RNBB .356" diameter hard-cast bullets and a suitalble powder load (I've no idea of suitable, just starting from moderate amounts).

I found I have to flare the case much less, also the bullets tend to 'float' into the seating-crimping die and i can't roll-crimp much (Lee ordinary dies, no factory crimp). Usual bullet diameter I use for .38 sp is .358".

i wonder if you guys ever heard of this maybe peculiar idea? Can you think about potential problems?

Purpose is mainly economy for paper-punching and may be good accuracy, but also present unavailability of RN bullets for the .38 sp caliber..

I got this idea from some guy here but I wonder if you ever heard of it or tried to do it yourself...

I Purchased 1000 bullets so I'd like to shoot them all somehow before I maybe give up this idea.


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## TOF

.355 or .356 bullets in a .357 barrel will have a poor gas seal and probably yield lower velocity and poor accuracy. If not copper jacketed the hot gasses leaking past the bullet may cause lead to melt and deposit on the barrel making it much more difficult to clean.

Also watch for bullet setback. Fire one round then check cartridges remaining unfired for overall length. Setback can in extreme cases cause Kaboom's which you don't want.

That is what I think will happen.

Give us a report after you try them.

Good luck.


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## mccoy

Nice to hear from you again, TOF.

Your thoughts are not very encouraging, I prepared a score of those though to test on saturday, I'm sure going to report back.


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## Concealed45_1911

I agree with TOF, of course it depends on the actual groove diameter of your .38, different manufactures have different specs, and they all have a tolerance. If you got one and the low end of tolerance from a manufacture with the smallest specs you might have a winner.

Just be careful, might shoot it from a vise and string.

Mike


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## Baldy

TOF is dead on right and I would like to add low powder charges of some powders and the wrong bullet can cause a preasure spike which can damage your gun. I would not do it if it were my choice. Accuracy will be bad and get worst from leading the barrel.:watching:


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## DJ Niner

Well, I don't know if I'd recommend it to other folks, but I can say that I've done it myself with no problems. It's better if the bullets have a driving band that is a little bigger than the rounded (ogive) portion, so you can apply a light crimp just ahead of the full-caliber driving band, to keep the bullets from "walking" or inching forward as you shoot the other rounds in the cylinder. I used load data found in the excellent Lyman reloading manuals; both the 46th and 47th editions list 92 grain and 121 grain round-nose cast bullet loads, and the old spiral-bound 45th edition shows 75, 112, and 121 grain cast bullet loads. Based on this, I don't think you and I are the only ones who have tried (or wanted to try) flyweight slugs in our .38s. :mrgreen:

Accuracy was good-to-excellent in my .38s (2 different ones), with minimal leading, but I was pushing the bullets very slowly (around 700 FPS, IIRC), for use as a small game and plinking load. I also used it to introduce a few new shooters to centerfire revolver shooting, after they had learned the basics with rimfire guns and wanted to move up a bit in power (recoil is even lighter than .38 wadcutter target loads). These loads will also work smoothly through a speedloader, unlike many sharp-edged wadcutter or semi-wadcutter rounds.

Light-bullet loads like this may become more popular as the price of lead (and lead bullets) continues to skyrocket; no need to have a full-weight 158 grain slug just to punch paper or ventilate a bunny, varmint, or tin can. However, having adjustable sights on your revolver is fairly important to use this type of load effectively, as the vast majority of fixed-sight guns will not shoot it very close to point-of-aim.


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## mccoy

DJ niner,
I tried it today and agree it's a pretty low-recoil combination, close to a .22 caliber...

I experienced no probs, no leading, keeping close to the lower-bound powder amounts.

Not very accurate compared to the 158 grs. SWC I shoot as rule, but my reloading technique was not accurate too.

Economy is just exceptional. Using these bullets and the hungarian powder 'Rex' (which is very popular in Italy and works well) cost of ammo is kept down to one half the cost of caliber .22 factory ammo.

Very very good to train at rapid fire and using moonclips/speedloaders.

About the loading data: DJ niner, did you use powder amounts indicated in the .38 tables or 9mm tables???


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## DJ Niner

I used the .38 data. I cannot recommend using data for other case sizes, even as a starting point for target loads; there are just too many variables, in my opinion. If you try to be very conservative/safe and start REALLY low, you run the risk of sticking a bullet in the barrel because of too LITTLE powder, and the difference in the amount of airspace in a 9mm and a .38 casing is HUGE. That WILL affect the burning rate of your powder, and therefore, your pressure curve.


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## mccoy

I tried another batch yesterday.

This time I took more care in the reload details and I added more power.

4.2 grs of the hungarian yellow Rex powder, similar to the Winchester 231 as to burning speed.

They were real good.

I believe the experiment has been succesfull and can begin mass production.

The potential problems hinted at in previous posts may probably occur with soft lead alloys or hot loads.
I'm only going to use hard-cast bullets and midrange loads.


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