.40 minor recommendation

[CHA-LEE]

In order to maintain proper slide velocity with Minor .40 loads you have to lighten the slide considerably. For example, I use an 11oz slide with a 10lb recoil spring with my Major .40 loads. Then a 9oz slide with an 8lb recoil spring with my .40 Minor loads. This is on an EAA Witness Limited pistol.

What constitutes 'proper' slide velocity? Since many guns use the same slide for .40 and 9mm, and the slide cycles fine with 9mm minor, why should 40 minor be significantly different?

A 9mm and .40 major will usually produce the same slide velocity. What is different is if you shoot .40 Minor with heavy bullets. There is a LOT less backwards slide velocity when shooting .40 minor loads with heavy bullets. That combined with reduced power recoil springs will make the slide cycle pretty slow. One way to increase the slide velocity in this scenario is to reduce the mass of the slide so it takes less effort to cycle both back and forward. Another way is to use light weight .40 caliber bullets which take more powder to create sufficient fps for Minor loads.

[motosapiens]

A 9mm and .40 major will usually produce the same slide velocity. What is different is if you shoot .40 Minor with heavy bullets. There is a LOT less backwards slide velocity when shooting .40 minor loads with heavy bullets. That combined with reduced power recoil springs will make the slide cycle pretty slow. One way to increase the slide velocity in this scenario is to reduce the mass of the slide so it takes less effort to cycle both back and forward. Another way is to use light weight .40 caliber bullets which take more powder to create sufficient fps for Minor loads.

I guess i'm not sophisticated enough to feel the difference, or maybe not fast enough. my 9mm minor loads and my 40 minor loads feel about the same, using the same recoil springs. (both guns are cz 75's)

[CHA-LEE]

A 9mm and .40 major will usually produce the same slide velocity. What is different is if you shoot .40 Minor with heavy bullets. There is a LOT less backwards slide velocity when shooting .40 minor loads with heavy bullets. That combined with reduced power recoil springs will make the slide cycle pretty slow. One way to increase the slide velocity in this scenario is to reduce the mass of the slide so it takes less effort to cycle both back and forward. Another way is to use light weight .40 caliber bullets which take more powder to create sufficient fps for Minor loads.

I guess i'm not sophisticated enough to feel the difference, or maybe not fast enough. my 9mm minor loads and my 40 minor loads feel about the same, using the same recoil springs. (both guns are cz 75's)

That is not a surprise. Most people turn their brain off right before the gun goes BOOM because they just want the shooting event to be over with. Keeping an active conscious observation (Both visually and physically) of what is going on WHILE the shot fires is a skill that is learned, not given by default. This is why so many shooters can't call their shots effectively.

If you are truly observing what is going on you can usually feel a 2 - 3 Power Factor difference between loads, you should also be able to visually observe how fast or slow the slide is cycling.

Edited February 11, 2013 by CHA-LEE

[motosapiens]

If you are truly observing what is going on you can usually feel a 2 - 3 Power Factor difference between loads, you should also be able to visually observe how fast or slow the slide is cycling.

It takes about 5 or so pf for me to really notice, but I am a fairly new shooter just starting to get close to B classifier times.

It seems to me that alot of master-level shooters are more sensitive to the slide speed, and perhaps they are even waiting on it. They are shooting splits twice as fast as mine, so it makes sense that it would be more of an issue to them. it's definitely long since returned to battery before I pull the trigger again.

It would be interesting to video-tape my 2 guns with similar 125-pf loads and get a feeling of why a slide that weighs the same, and with the same recoil spring, and with about the same amount of powder behind the bullet would cycle at a different speed. I look forward to getting fast enough for it to make more than a purely academic difference.

[roklock]

...What is different is if you shoot .40 Minor with heavy bullets. There is a LOT less backwards slide velocity when shooting .40 minor loads with heavy bullets. That combined with reduced power recoil springs will make the slide cycle pretty slow. One way to increase the slide velocity in this scenario is to reduce the mass of the slide so it takes less effort to cycle both back and forward...

I too am looking for a 40 minor load for an occasional steel match. I currently use n320 & 180 lead for my major load. I just loaded up a couple of different loads but waiting for some better weather to chrono the loads.

My slide has been lightened to 10.6 oz was wondering if going to a 10# recoil spring would also help with the slide speed in the lower PF?

Edited March 4, 2013 by roklock

[Croomrider]

I too am looking for a 40 minor load for an occasional steel match. I currently use n320 & 180 lead for my major load. I just loaded up a couple of different loads but waiting for some better weather to chrono the loads.

My slide has been lightened to 10.6 oz was wondering if going to a 10# recoil spring would also help with the slide speed in the lower PF?

I have an STI based 6 inch limited gun with a slide weight of 12.9oz with all parts ready to shoot. I run a 12.5 recoil spring and it will shoot my son's G-35 minor loads just fine, and I have used them in a steel match. They are 3.1gr Clays behind a Precision Moly 170 which makes about 135PF.

Mike

[Jammer1911]

I am looking for a 40 minor load for S&W M&P Pro 40.

Bullet will be 180 gr Bayou Bullet

Powder will be Clays

WSP

OAL = ????

Thank you

[thermobollocks]

I've only had the courage to go down to 3.1 grains of Clays in a 180, which still makes roughly 135 PF.

I've read in places that Clays with the 180s can cause pressure spikes, but the only explanation I've heard is if there's air between the primer and the bullet, the primer can stuff the bullet into the lands, so that when the powder finally ignites, the bullet doesn't move as freely as it should and you get potential finger separation issues.

[fastarget]

In cases of large air gaps, long aol and little powder there has been reports of detonations, not sure the bullet in the lands has any merit.

[roklock]

I too am looking for a 40 minor load for an occasional steel match. I currently use n320 & 180 lead for my major load. I just loaded up a couple of different loads but waiting for some better weather to chrono the loads.

My slide has been lightened to 10.6 oz...

So I was out on Sunday with two loads...3.9 gr N320, 180 Bayou, OAL 1.185 and the other one was 4.2 gr N320 everything else the same.

20 shots each load, most accurate was the 3.9 gr, power factor was 142 (cloudy, temp around 48 degrees). The 4.2 PF was 150.

I dropped in a 10# recoil spring and even with a lightened slide I was waiting on the slide to return. Wow!! I was surprised and not sure what direction I am going to try next.