.40 CAL Reloading 180gr vs 165 or 155

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.40 CAL Reloading 180gr vs 165 or 155

Postby VMAX97 on Sun May 07, 2017 10:27 pm

I was reading an article about the issues with reloading 180 gr bullets for .40 and was wondering what other guys were reloading for projectiles in .40 CAL. I am currently loading 180s but would consider 165s, there might be an advantage on reducing potential setback pressures without a downside of power factor adjusting for the lighter bullet with speed. Does this increase felt recoil or is does this equal out?
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Re: .40 CAL Reloading 180gr vs 165 or 155

Postby dleong on Mon May 08, 2017 8:50 am

The .40 S&W is by far my favourite handgun caliber to shoot and I handload thousands of them each year. My current recipe calls for a 155 gr. FP projectile (usually Berry's or Rainier, whichever is on sale) atop 5.4 gr. of Universal at an OAL of 1.140" with a very light taper crimp. This load is good for around 1020 fps out of the 4.9" barrel of my CZ 75B, which is the gun I used to develop the load years ago. It is a nice, soft-shooting load that doesn't beat up the brass or the gun, and is surprisingly accurate across the couple dozen semis I have in that caliber.

I do not know if this load meets the minimum PF requirements for practical shooting competitions, but I am not concerned with that as all I am doing is putting holes in paper.
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Re: .40 CAL Reloading 180gr vs 165 or 155

Postby Seismic Sam on Mon May 08, 2017 9:03 am

VMAX97 wrote:I was reading an article about the issues with reloading 180 gr bullets for .40 and was wondering what other guys were reloading for projectiles in .40 CAL. I am currently loading 180s but would consider 165s, there might be an advantage on reducing potential setback pressures without a downside of power factor adjusting for the lighter bullet with speed. Does this increase felt recoil or is does this equal out?


You get a shiny new obfuscation trophy from the 800 lb. reloading troll. Congratulations!!

First, could you define what "potential setback pressures" are?? Never heard of those before.

As far as going from 180 to 165 grain bullets, calculate how much faster a 165 grain bullet must be going to make the same (major?) power factor, and then refer to a reloading manual to see if there are loads that go that fast.

As far as "felt" recoil is concerned, there is NO way of calculating how your nervous system interprets the kick of the gun. IIRC, shooting really hot 500 S&W loads (325 grain .500" JHP @ 2000 FPS :( :o :shock: :? ) doesn't feel as bad as shooting lighter loads because the incredible shock wave from the load temporarily overloads your nervous system so that you don't remember feeling it as much.

As far a REAL recoil is concerned, it can be calculated from the MASS (not weight) and velocity of the bullet, and crbutler or somebody else will be along with the equation shortly.

Edit: After some cogitation, I had an idea about what the "potential setback pressure" might be related to, but then realized I was backing thinkwards. When the gun is fired, it recoils BACKWARDS, so that the bullets in the ammo still in the gun would tend to move FORWARD. The only problem you might have is a FTF from the bullet sticking out too far. About the only thing that causes setback is the bullet hitting the feed ramp in an auto and pushing back into the case from the impact, which could potentially result in a KABOOM. Taper crimp is something you measure in mils, and you probably want 2-3 mils for a 40 and at least 5 mils for a Smith 500.
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Re: .40 CAL Reloading 180gr vs 165 or 155

Postby crbutler on Mon May 08, 2017 8:34 pm

For USPSA I'm still staying with 180 gr jhp for match loads. I did load some acme coated rnfp bullets to the same power factor without problems. I usually have them just under 1000 fps as that was what I did with the old major and saw no real reason to change it. The current major PF is 165, so now you need 917 fps to make that

To be honest, if you are consistent, 180s are fine. I've shot 10's of thousands of them without issue.

In my 2011 guns I run them a bit long... 1.175 oal as that's what the gun likes. Because of that, I am not going to state specifics of the load.

If you load to the same power factor, in general the heavier bullets shoot softer, but the gun cycles slower. It really depends on what you like the feeling of. I will say 220 grain cast lead bunny fart minor loads feel like no recoil, but the gun cycles so slowly if feels off to me, so I don't do that anymore.

Lots of data out there to choose from.

My competition loads are VV N320. I've used everything from bullseye to blue dot in the .40. As long as you aren't trying to make it into a 10mm, and are not shooting an older Glock, it's pretty straightforward but the volume is a bit low, with higher pressures so it's not as forgiving a cartridge for new loaders.
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Re: .40 CAL Reloading 180gr vs 165 or 155

Postby Bessy on Tue May 09, 2017 9:32 am

Power factor equation is (Weight*Velocity)/1000 = power factor

The general consensus among competition shooters is that 180gr will get you to major power factor with the least amount of felt recoil in 40. Infact nearly across the board using a heavier projectile at a slower speed to reach a given power factor is going to produce less felt recoil on the shooter. This is the reason why 147gr's are favored in 9mm, 180gr are favored in 40, and 230grs are favored in 45acp. If there wasn't a competitive advantage competition shooters would be using the lightest bullet possible because they are usually cheaper.

I've loaded many many 10's of thousands of 180gr 40 rounds. It's certainly safe to do provided you are just trying to make major and don't hotrod anything. I typically shoot for 172pf which for a 180gr projectiles is around 955fps. I would urge caution with the 40 round in general. The case volume is low, and it's not the most forgiving round. If you can, try to load long.

With regards to...

Seismic Sam wrote:As far as "felt" recoil is concerned, there is NO way of calculating how your nervous system interprets the kick of the gun.


Here is how you would measure it for yourself. Load up two different batches that both make the same power factor (say 165gr at 1042fps and 180gr at 955 fps). Run a drill where you shoot a target six times quick as you can. Time it using a shot timer. Do it a few times to get a better dataset. Which ever load gives you the fastest splits between shots on average is allowing a faster shot to shot recovery. The timer doesn't lie. If there is no tangible difference, you probably haven't reached the point where you need to worry about this crap, so just shoot whatever is cheaper, or whatever makes me feel better about yourself.
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Re: .40 CAL Reloading 180gr vs 165 or 155

Postby VMAX97 on Tue May 09, 2017 10:19 am

Bessy wrote:Power factor equation is (Weight*Velocity)/1000 = power factor

Seismic Sam wrote:As far as "felt" recoil is concerned, there is NO way of calculating how your nervous system interprets the kick of the gun.


Here is how you would measure it for yourself. Load up two different batches that both make the same power factor (say 165gr at 1042fps and 180gr at 955 fps). Run a drill where you shoot a target six times quick as you can. Time it using a shot timer. Do it a few times to get a better dataset. Which ever load gives you the fastest splits between shots on average is allowing a faster shot to shot recovery. The timer doesn't lie. If there is no tangible difference, you probably haven't reached the point where you need to worry about this crap, so just shoot whatever is cheaper, or whatever makes me feel better about yourself.


************************************
Thank you! That is a great drill and makes sense and your information was very helpful
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Re: .40 CAL Reloading 180gr vs 165 or 155

Postby Bearcatrp on Tue May 09, 2017 3:43 pm

I was loading 180 gr but recently changed to 155 gr. Little more velocity and distance than the 180 gr bullets. Go with what works for you.
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