Flat nose versus round nose

[Rowe-75]

I just bought 7, 50 round boxes of Remington UMC 147gr fmj 9mm lugers at my local Farm and Fleet because they were on sale for a price I couldn't pass up. Now, I have never bought or shot 9mm in the 147gr bullet so I was a little concerned when I opened up one of the boxes and the bullets have a flat nose much like the 40 S&W rounds.

After some thinking I have come to the conclusion that for a 9mm to be able to pack 147gr bullets they have to give the bullet a flat nose as opposed to the round nose due to overall length, correct? Does a flat nose bullet have any pros or cons as compared to a round nose like the 115gr WWB I have been shooting? One more question, should I be concerened about FTF with the flat nose or will it feed just like my 127gr Winchester Ranger JHP's?

Looking forward to hearing some facts and opinions on the matter,

-Jeremy

BTW, Will be shooting them through a 75B fullsize that is well broken in (2,500+ rounds).

[Cesar]

The only issue you may have as I see it - bullet hitting slide stop. You can test it before going to the range by taking slide off the gun and with slide stop in it's place in frame, insert loaded mag, see if that lifts stop or is very close to hit it during round feeding from mag and into chamber.

[Rowe-75]

Thanks Cesar, I checked them and they didn't hit the slide stop. Also, I just came back from my friends house in the country and sent about 70 of them without a hitch. Seems like a pretty dirty powder though, worse than WWB. Gotta do some serious cleaning now.

Can anyone comment on if flat has different ballistics then round, and if my guess to my own question is correct?

-Jeremy

[Cesar]

Every bullet has it's own ballistics. Did you mean - accuracy? They are not gonna be less accurate than RN (round nose) bullets, and yes, to increase total bullet weight, they have to add more lead in it's nose area to keep bullet lengh and thus round (OAL) lengh withing specs.
There is a somewhat benefit to RNFP (round nose flat point) bullets - they become semi-wadcutters and make nice holes in paper targets

[Rowe-75]

Thanks Cesar,

You have answered my questions on this topic theroly.

To add more more to this thread... Since you are watching it and know much about bullet specs, would the RNFP have a comparative advantage to a RN in stopping power / knock down? Not as a self-defense round (JHP's are top dog for SD obviously for expansion) but what I have learned (or should I say read) is the semi-wadcutters have been a proven round for taking down larger game with a "small" round that rips through mass and keeps going causing severe damage throughout.

In short, I am wondering if these RNFP's would expand or cause more of a knock-down thump compared to the RN I practice with.

I can't really test different loads since I spend my money on rounds and not ballistic gel.

Thanks for the insightful info Cesar,

-Jeremy

[Cesar]

In short - yes, but penetration would be more limited with flat tip if we compare bullets of same weight.

[Wobbly]

A flat point may have issues in a 1911 Dan Wesson due to the limited amount of barrel tilt in the older design, but I hardly think it will contribute anything towards a FTF in a modern full-tilting barrel like a CZ.

On the other hand, FP bullets often have a blunter ogive that may strike the rifling in the short leade CZ. I would remove the barrel and drop a cartridge into the naked barrel until you hear the mouth of the case seat against the end of the chamber. Then twist the cartridge around. Remove the cartridge and see if there are any marks on the bullet's nose indicating it's resting on the rifling.

 

[Radom]

A flat point may have issues in a 1911 Dan Wesson due to the limited amount of barrel tilt in the older design, but I hardly think it will contribute anything towards a FTF in a modern full-tilting barrel like a CZ.

On the other hand, FP bullets often have a blunter ogive that may strike the rifling in the short leade CZ. I would remove the barrel and drop a cartridge into the naked barrel until you hear the mouth of the case seat against the end of the chamber. Then twist the cartridge around. Remove the cartridge and see if there are any marks on the bullet's nose indicating it's resting on the rifling.

 

+1.  I have never loaded FPs in 9mm, but this is because I have never found them "on the cheap," not because of any significant difference in ballistics. 

[jameslovesjammie]

The truncated cone design or a round flat bullet design will have MUCH better stopping power if you ever have to use it to shoot an animal (2 legged or 4).  The reason is that it opens up a much wider temporary wound cavity than a pure round nose bullet.  It may not penetrate as far, but you want the bullet to expend all its energy into the target, not exit and possibly hit someone else.

For target shooting there will be little to no difference.  If it loads and is reliable, I'd say shoot it!

[Wobbly]

After some thinking I have come to the conclusion that for a 9mm to be able to pack 147gr bullets they have to give the bullet a flat nose as opposed to the round nose due to overall length, correct?

Jeremy -

That is correct, AND in addition a 147gr is going to be longer in the body. Given a specific chamber and the same exact nose on a 124gr and a 147gr, the 147gr must sit deeper into the case. So much so that you need to take note of the level of the powder relative to the depth of the longer bullet.



Shooting 147gr in 9mm means that low density ("fluffy") powders like Unique (that are in the right speed range) have to be ruled out simply due to the issue of reduced case volumes under the bullet.

 

[jameslovesjammie]

the 147gr must sit deeper into the case.

This is also why most 147's are of the bevel base design.  The jacket of a 9mm case is thicker at the base than it is at the mouth.  The 147 protrudes farther inside the case that a flat base bullet, which can bottom out before reaching the proper seating depth and causing a slight bulge in the case.  Different manufacturers have different wall thicknesses, and 9mm cases seem to be all over the board in terms of consistency.

[Rowe-75]

Thanks a ton rfwobbly1 and jameslovesjammie, very insightful information! One of these days when I start reloading, the information on low density powders will be very handy to know.

-Jeremy

[Wobbly]

I put a chart in the front of my notebook of the average level my most-used powders come to inside a 9x19 case. It really helps. I know the seating depth (OAL - Bullet Length), so a simple comparison tells me if I'm going to get a "compressed load".