Can I use these?

C

cdoc42

New member
This seems to me to be like a dumb question coming from a reloader with 47 years of experience, but it just occurred to me today.

I have been loading 125gr Remington, followed by Winchester, ".38-.357" hollow-point bullets that measure .356" in diameter for my use in .38 Special and .357 Mag.

I started to reload some 115gr for 9mm tonight and one of the posts here that I saw today gave me the impression that most are using 124gr for their 9mm.
That makes sense if one wishes to compare it to .38/.357.

I recently bought Berry's 9mm 124gr bullets that measure .356" and it struck me that there should be no reason why I can't use the inventory of Winchester 125gr (cannelured) .356 that I have for 9mm.

But I want to be cautious, so I ask: can I do this?
 
9mm is typically 0.355 for jacketed and .356 for plated or lead
38/357 is typically .357 for jacketed and plated, and .358 to .359 for lead.

As I understand it you have .356 berrys for 9mm, and some .356 winchesters. Are the winchesters jacketed?

which are you trying to use in what?

using a .356 jacketed in 9mm could result in some pressure increases in in 9mm. However given you work the load up from start I would think it would be ok.

using under sized bullets in 38/357 can result in poor accuracy or low velocities due to a poor gas seal, but it should be ok as well.
 
Last edited:
"As I understand it you have .356 berrys for 9mm, and some .356 winchesters. Are the winchesters jacketed?

Yes

which are you trying to use in what?

As I related above, ".....I recently bought Berry's 9mm 124gr bullets that measure .356" and it struck me that there should be no reason why I can't use the inventory of Winchester 125gr (cannelured) .356 that I have for 9mm."

Interestingly, you mentioned .38/.357 are typically .357 for jacketed/plated. The Winchester bag specifically states the jacketed hollow-points are for .38/.357 but my measurement of them is .356.
 
What measuring tool did you use and what is your process for checking its calibration?

I'd trust a good micrometer to declare ".356" If a pair of typical calipers said .356, I'd say its likely between .355 and .357.

I wouln't trust a new,calibrated Browne and Sharpe calipers to be a qualifying measurement of less than .0005. A coat of Magic Marker ink can go .0005

Jacketed bullets are more forgiving of being a little undersize. Cast bullets that are undersize at all allow gas jetting around the projectile. That heat cuts the bullet and lead sprays your bore. Cast bullets need to be bore size or slightly larger.

I just do not have enough experience with plated bullets to say much about them.
 
Shadow9mm said:
using a .356 jacketed in 9mm could result in some pressure increases in in 9mm. However given you work the load up from start I would think it would be ok.

using under sized bullets in 38/357 can result in poor accuracy or low velocities due to a poor gas seal, but it should be ok as well.
Click to expand...


A lot of nonsense there.

9mm barrels and 38/357 barrels have the same barrel groove diameter specs, which are 0.355" + 0.004". So, anything between 0.355 and 0.359 is within spec.
https://saami.org/wp-content/upload...FP-and-R-Approved-2015-12-14-Posting-Copy.pdf

Therefore:
If a .356 bullet is oversize in a 9mm barrel then it's also oversize in a 38/357 barrel.

If an undersize bullet in a 38/357 causes poor accuracy then an undersize bullet in a 9mm causes poor accuracy - since they have the same barrel specs.

I have a 9mm cylinder for a 357 Magnum Ruger Blackhawk. It has a barrel groove diameter of 0.3577". My 9mm handload with a 0.355" bullet shot 24 shots into 1.40" at 25 yards.
 
74A95 said:
A lot of nonsense there.

9mm barrels and 38/357 barrels have the same barrel groove diameter specs, which are 0.355" + 0.004". So, anything between 0.355 and 0.359 is within spec.
https://saami.org/wp-content/upload...FP-and-R-Approved-2015-12-14-Posting-Copy.pdf

Therefore:
If a .356 bullet is oversize in a 9mm barrel then it's also oversize in a 38/357 barrel.

If an undersize bullet in a 38/357 causes poor accuracy then an undersize bullet in a 9mm causes poor accuracy - since they have the same barrel specs.

I have a 9mm cylinder for a 357 Magnum Ruger Blackhawk. It has a barrel groove diameter of 0.3577". My 9mm handload with a 0.355" bullet shot 24 shots into 1.40" at 25 yards.
Click to expand...

And yet when I slugged 2 different 9mm guns they came in at .355. And 2 different 38/357 at .357. And manufacturers specifically make 2 distinctively different bullet sizes.....

Sammi spec for 9mm is 0.3555 -.003
Saami spec for 357 is 0.3580-.003 with jacketed

Only way to tell for sure what you have is to slug the barrel

And with revolvers you have to take into account the cylinder throat.
 
Last edited:
Many years ago a local gun shop sold 9mm bullets rather cheap by the pound. I slugged the bore on my S&W revolver and it was .356 so I bought a couple pounds of the 9mm bullets. I had to use a smaller expander plug but other than that, they loaded OK and shoot pretty well. I don't recall exactly how they grouped but I do remember that I was pleased with the results. So if your revolver has a tight bore, why not give them a try.

Tony
 
Shadow9mm said:
And yet when I slugged 2 different 9mm guns they came in at .355. And 2 different 38/357 at .357. And manufacturers specifically make 2 distinctively different bullet sizes.....

Sammi spec for 9mm is 0.3555 -.003
Saami spec for 357 is 0.3580-.003 with jacketed

Only way to tell for sure what you have is to slug the barrel

And with revolvers you have to take into account the cylinder throat.
Click to expand...

I've slugged seventeen 9mm barrels. Of those, only 2 were less than 0.3560". The total range was between 0.3553" to 0.3578".

I've slugged eight 38/357 barrels. Their range was from 0.3532" to 0.3577".

Yes, bullet makers make two different bullet sizes. But my Ransom Rest results have shown that undersize bullets are as accurate as bullets that are the 'appropriate' size. See my previous post.
 
74A95 said:
I've slugged seventeen 9mm barrels. Of those, only 2 were less than 0.3560". The total range was between 0.3553" to 0.3578".

I've slugged eight 38/357 barrels. Their range was from 0.3532" to 0.3577".

Yes, bullet makers make two different bullet sizes. But my Ransom Rest results have shown that undersize bullets are as accurate as bullets that are the 'appropriate' size. See my previous post.
Click to expand...
I have had problems with undersized bulletsin my gp100. But the cylinder throats are .3585 and I am generally shooting lead. Jacketed are more forgiving. Best thing is to slug the barrel, and load a few to try. Did not say it was unsafe or it would not work. Just that it might not work well, but it should work. Only way to know for sure is to try it.
 
I reloaded some Berry's 124gr HP with both Blue Dot and Unique, and the latter gave a much better group at 15 yards.

I also loaded 5 of the Winchester 125gr HP with Blue Dot. All chambered and fired without fault, but the hollow point lead tip was slightly deformed upon seating. Accuracy was comparable to Berry's.
 
Deforming the nose of a bullet seldom affect its accuracy. Deforming the base nearly always does.

You just need a different seating stem for those soft nose HPs. A temporary fix can be done with sealing wax. Melt some into the cavity of the seating stem and insert the HP bullet. when set hard it will seat quite a few bullets before it gets loose and fails.

As long as a "technically" oversize bullet chambers, it will squeeze down the bore just fine. Yes, it will raise pressure some, but with regular load levels its not going to be dangerous and likely isn't going to be significant. Doubtful your gun, or you will notice any difference with a bullet just a couple thousanths "too big".

Use them.

or sell /trade them to someone who will.
 
That's correct. You have to bear in mind the pressure can upset (bump up) a bullet. It's easier to do to a soft bullet, but even a jacketed one will bump up some.

Bart B. has pointed out previously that the military match team armorers found best rifle accuracy was achieved with bullets about four-tenths of a thousandth over groove diameter. But a significant range of sizes can be shot down a bore. I have a surplus French MAB with a .309 groove diameter, yet the 32 ACP bullet it's designed to shoot is normally 0.311 in commercial ammo. Doesn't bother it. It won't win any shooting matches, but does what it is designed to.
 
44 AMP said:
Deforming the nose of a bullet seldom affect its accuracy. Deforming the base nearly always does.
Click to expand...

It depends on the amount of damage/deformation.
https://www.theboxotruth.com/the-box-o-truth-49-damaged-bullet-accuracy-and-the-box-o-truth/
https://www.youtube.com/watch?v=C9Dylxy3zJc



44 AMP said:
As long as a "technically" oversize bullet chambers, it will squeeze down the bore just fine. Yes, it will raise pressure some, but with regular load levels its not going to be dangerous and likely isn't going to be significant. Doubtful your gun, or you will notice any difference with a bullet just a couple thousanths "too big".
Click to expand...

How much will pressure increase? I've haven't found much in the way of evidence on how much it increases. Do you have a source for that? Thanks in advance.
 
Given the discussions here, with increased pressure a consideration with jacketed bullets, I reduced the charge of Blue Dot with the Winchester 125gr HP to 6.8gr, as opposed to 7.0 with Berry's plated bullets, in the face of a max charge of 7.1gr. Berry's actually provided a much better group with Unique, though.

But overall, my impression upon firing these combos, from a practical standpoint, is there is no major difference or issue -from 15 yards -in MY Walther 9mm.
 
The Unique load should reach peak pressure faster, which may be helping with bumping up the bullet.


74A95,

I don't have any data, but you can guess the rise is not dramatic enough to cause gun damage because loading data doesn't give routine warnings about checking your groove diameter to be sure it matches your bullet. However, guns that achieve faster-than-published velocities with the same barrel length, while less common than those achieving slower-than-published velocities, do exist and generally slug out to have tight bores. Indeed, the long .308 Palma match barrels are often made with 0.3065" to 0.3075" groove diameters, partly to try to squeeze every last foot per second out of the bullet to keep it supersonic to 1000 yards. And those are match rifles, so clearly that much bullet distortion is not causing a major precision loss. Also, if you look at military specifications for 30 caliber rifles, blueprints show they accept groove diameters of 0.3065" to 0.3095". That's not for match accuracy, but gives a sense of what won't affect load pressures dramatically.

That said, I don't own a Palma match rifle, so I have never done any pressure trace tests on one to see how pressure compares to other rifles firing the same load. SAAMI's standard allows individual newly loaded rounds to be as much as about 18.3% above MAP. You find that by setting 9 identical pressure rounds just below MAP by 10% of the SAAMI MEV (Maximum Extreme Variation) spec for the cartridge and one round above the MAP by 90% of the MEV range to average out to the MAP value. The CIP allows a little less at a flat 15% over MAP for an individual round in a 10-round pressure test that averages the MAP value. So my expectation is everything will tend to stay under that CIP 15% increase, normally. I just don't have any measurements to confirm it. And occasionally you do run into a gun that can't handle published maximums without showing pressure signs, so the assumptions have to be taken with a grain of salt.

Still, it used to be Palma match host countries had to supply the ammunition and it was usually loaded for maximum velocity for the same supersonic reason, and they never had to be adjusted due to pressure signs that I've ever heard of. Bart B. will know better than I do if that has ever happened.
 
How much will pressure increase? I've haven't found much in the way of evidence on how much it increases. Do you have a source for that? Thanks in advance.
Click to expand...

No, sorry, I have no idea exactly how much the pressure will increase, I'd say that would depend on the precise specific variables of each individual situation. And, that why you won't find much in the way of evidence or a source.

I'm just stating a basic principle, when it takes a certain amount of pressure to push a tight fitting plug through a hole of fixed dimensions, increasing the diameter of that plug (bullet) a couple of thousandths of an inch will require slightly more pressure to push it through the same size hole. Exactly how much more pressure will be needed depends on specific variables, one big one being what the plug (bullet) is made of...
 
One way of looking at it:
The bullet may start out oversize,but passing through the leade into the rifling it will be swaged to not over groove diameter. After that,it is a groove diameter bullet.(assuming lead core,copper jacket normal bullet)

A question might be how much pressure does it take to swage the bullet to bore diameter. Good question,I don't know.

But once again, as soon as the bullet is swaged down,its no longer oversize and so.IMO, should not bump up pressure beyond whatever it took to start the bullet into the bore.

Its a different set of rules if you are pressing a case hardened steel dowel pin into an undersize hole.
 
you also have to take into account the metal. Lead is softer and will stay the size it is swaged. copper has some elasticity to it, and may spring back a little bit maintain pressure on the barrel. Also the jacket thickness and how much the lead inside the jacket will deform would have an effect as well.
 
Shadow,I agree.

But any copper bullet,from a Barnes Solid to a thin jacket match bullet,if it is groove diameter,will have a pressure increase from engraving the rifling. The solid copper or a harder alloy may cause more pressure increase,.but in any case, engraving will be resistance. Engraving will also displace metal . The path of least resistance would be into the groove area, As the bullet is already groove dia, I would think that displacement would have an effect similar to a bullet perhaps .001 oversize. It would have the effect of 17 oz of sugar in a 1 lb bag.

The engraving would bring a slightly undersize bullet up to groove dia. The material has to go somewhere.

I don't know for sure, but maybe engraving ,rather than acceleration is responsible for a limited amount of "bump up"

I still think after an inch or less of travel into the bore, the idea of an oversize bullet is moot.

Where that inch fits into the powder pressure curve...I don't know. Of course,burn rate matters.

But if peak pressure is 4 inches down the bore, the(slightly)* oversize bullet is a proper size bullet well before peak pressure. (I theorize)

Unclenick, am I all wet?

* by "Slightly" I do not mean a .323 8mm bullet in a .308 bore. At some point,its an obstruction.
 
Last edited:
You must log in or register to reply here.
Back
Top