VV 3N37 Light Loads - Lovin’ it!

[markr6754]

*CAUTION: LOAD DATA BELOW PUBLISHED DATA.

I finally got around to shooting some trial loads, looking for a lighter recoil in 9mm. My wife wasn’t a fan of my new Kimber Micro 9 Crimson Carry. She felt it too snappy for her. I wanted to make some softer loads that might make for easier shooting, as I really like this pistol, and wanted her to like it too!

My powder choice was Vihtavuori 3N37. My thought process involved using a powder I have, that has a large standard load on 9mm.

I elected to start with 5.0gr, under a Berry’s 124gr CPRN, seating a bit lower than Vihtavuori recommendations, but well within SAAMI spec (1.120” vs 1.142”).
Winchester WSP primers, WIN 1x reloaded brass, and final processing with Lee FCD.

Other trial loads using all the same components:
[email protected]”
[email protected]” (VV published starting load for 124gr Rainier RN)
[email protected]”

My first shot felt good. Nice soft recoil, but did it do what I wanted? I was concerned trying an underbook load ...so I shot one round, checked for a puka in the paper, and checked for a loaded round in the chamber.

Everything looked good, the pistol looked good...no unburnt powder...the hole was right where I wanted it. Let me try another...also very nice. Good feel, good placement...I fired 5 more. The slide locked open on last round. Okay...so far so good. I tried another full magazine, and another till all 25 rounds were fired.

Let’s try 5.2gr at 1.130”. Pretty sure they’ll fire fine based on the previous test. They did. Tried them in Kahr CM9, sweet. How about a Ruger LC9s? Oh yeah baby.

The last loads are standard from VVs load manual, 5.4gr and 5.6gr. Standard VV C.O.L. for 9mm. They were nice too, but the recoil was a bit more than I wanted for my wife to try...but my son and I didn’t find any load objectionable.

I’m ready to try a larger quantity of 5.0gr, and will trial a few C.O.L. variants to ensure that this is indeed a load I can use with my wife. I hope to one day have a chrono to use, but that’ll have to wait until I can use an outdoor range (and buy a chronograph).

 

[Walkalong]

N320 will do what you want better than 3N37. Save the 3N37 for rip roaring loads.

 

[markr6754]

N320 will do what you what better than 3N37. Save the 3N37 for rip roaring loads.

I was advised to try 147gr bullets with N320, HP-38, or WST...all powders I have on hand. Don’t have the 147gr bullets, though. Looks like time to go shopping.

 

[Walkalong]

Those powders will work just as well with the 124s you have to make a nice soft shooting load.

 

[ATLDave]

I was advised to try 147gr bullets with N320, HP-38, or WST...all powders I have on hand. Don’t have the 147gr bullets, though. Looks like time to go shopping.

Heavier bullets are softer shooting for a given momentum/power-factor. Lighter bullets tossed at the same speed as a heavier bullet will have less recoil. N320 is almost magically good at doing both of these things.

One thing to remember is that the gasses (and soot-particles) from burned powder are part of the recoil forces on the gun... that's why smaller charges of faster powder (such as N320) usually contribute less recoil than the larger charges necessary with a slower powder (such as 3N37). Now, a 1 or 2 grain difference in powder charge weight doesn't seem like it should be a big deal in terms of meaningful contribution to recoil. However, you have to remember that the gasses leaving the barrel are going quite a bit faster than the projectile (especially in a pistol), so their mass gets multiplied by a larger velocity for a momentum/PF calculation.

There's one other dynamic to consider in this: A lot of what is perceived as recoil by shooters - particularly sensitive or new shooters - is not the physical movement of the gun up or to the rear (actual recoil), but the blast of the gasses exiting the barrel. That felt-and-heard blast is subconsciously integrated by our brains into the overall sensation of recoil.* Anything you can do to knock down the amount of gasses exiting the barrel will likely help your sensitive shooters feel that they gun is not recoiling harshly.

*There's a lot of interesting research in the golf world on a parallel phenomenon - the way that the sound of a golf club/ball impact is integrated by a golfer's brain into how they perceive impact to feel. Further afield, your brain does the same with smell and taste, integrating a lot of input that is purely smell with no taste component into our perception of flavor.

 

[markr6754]

Heavier bullets are softer shooting for a given momentum/power-factor. Lighter bullets tossed at the same speed as a heavier bullet will have less recoil. N320 is almost magically good at doing both of these things.

One thing to remember is that the gasses (and soot-particles) from burned powder are part of the recoil forces on the gun... that's why smaller charges of faster powder (such as N320) usually contribute less recoil than the larger charges necessary with a slower powder (such as 3N37). Now, a 1 or 2 grain difference in powder charge weight doesn't seem like it should be a big deal in terms of meaningful contribution to recoil. However, you have to remember that the gasses leaving the barrel are going quite a bit faster than the projectile (especially in a pistol), so their mass gets multiplied by a larger velocity for a momentum/PF calculation.

There's one other dynamic to consider in this: A lot of what is perceived as recoil by shooters - particularly sensitive or new shooters - is not the physical movement of the gun up or to the rear (actual recoil), but the blast of the gasses exiting the barrel. That felt-and-heard blast is subconsciously integrated by our brains into the overall sensation of recoil.* Anything you can do to knock down the amount of gasses exiting the barrel will likely help your sensitive shooters feel that they gun is not recoiling harshly.

*There's a lot of interesting research in the golf world on a parallel phenomenon - the way that the sound of a golf club/ball impact is integrated by a golfer's brain into how they perceive impact to feel. Further afield, your brain does the same with smell and taste, integrating a lot of input that is purely smell with no taste component into our perception of flavor.

That is a lot of good information. I'll have to read it over a couple more times before I can a slight beginning of a grasp on the info. Sadly, I'm doing all of this without aid of a chrono....I don't have one, and I can't set one up at my indoor range. Luckily, I live quit close to this range, so it's not a problem to work a load, test it, go home to modify, return and test again (although I haven't exactly done this).

Clearly, my mind had this all backwards....I believed slower powder = softer shoot, especially if I loaded light. Clearly I was wrong...there's more to this hobby than putting nice bullets in nice brass over a nice powder. But that's also why I post in forums. Read, test, chat, read, test, chat...rinse and repeat often.

 

[ATLDave]

Some relevant reading for you:

http://www.shootingtimes.com/ballistics/measure-relative-handgun-recoil/

http://www.shootingtimes.com/reloading/power-factor-recoil-bullet-weight-gives-edge/

 

[Walkalong]

What powders and bullets do you have on hand?

 

[markr6754]

What powders and bullets do you have on hand?

I have VV N320, VV 3N37, HP-38, CFE-P, Silhouette, and WST

In 9 I have Hornady 115gr HAP and 115gr XTP, Berry’s 124gr Plated RN, and soon to arrive Everglades Ammo 115gr Concave Jacketed RN.

 

[Jim Watson]

I think N320 or WST would be better for light loads.
For that matter, I have sub-Minor loads with HP38.

 

[Toprudder]

There's one other dynamic to consider in this: A lot of what is perceived as recoil by shooters - particularly sensitive or new shooters - is not the physical movement of the gun up or to the rear (actual recoil), but the blast of the gasses exiting the barrel. That felt-and-heard blast is subconsciously integrated by our brains into the overall sensation of recoil.* Anything you can do to knock down the amount of gasses exiting the barrel will likely help your sensitive shooters feel that they gun is not recoiling harshly.

*There's a lot of interesting research in the golf world on a parallel phenomenon - the way that the sound of a golf club/ball impact is integrated by a golfer's brain into how they perceive impact to feel. Further afield, your brain does the same with smell and taste, integrating a lot of input that is purely smell with no taste component into our perception of flavor.

I could not agree with that more! I've gone through a similar situation with model airplanes, mufflers, and propeller selections.