Hey all, just a quick question to see if I’m on the right track or playing with fire…
I have been loading for my M&P Pro 40 using 7.8Gr of HS-6 under a 165Gr Berry’s RNFP. This load is right in the middle of the range from Hodgen’s website (7.4 start to 8.1 max) and shoots great, no real complaints at all about it except the guys I shoot with all jump every time I fire (They call my loads the mini 40 hand cannon LOL) Anyway, we have a local competition twice a month around here that is set up very similar to the Ruger Steel plate challenge and I was thinking that a load with a little less recoil would be nice for that so…My main question is what are the (if any) rules for downloading a round? I have read Lee’s 2nd edition on the subject and have tested some rounds and think all is fine but would like some of you with way more experience than me to chime in please.
Here is what I did for testing. 11 rounds of each (one round for testing all by itself and 10 more to test feeding, cycle, etc. All were 165Gr Berry’s and HS-6 powder
7.0Gr
6.8Gr
6.5Gr
All locked the slide with the single round test and all cycled fine (no set back, etc) when I loaded a full magazine of ten and the recoil is noticeably less at 6.5Gr. Again, from what I have read/understand from Lee’s book I should be OK that far below the starting charge for this powder/bullet combo but would like some thoughts from others on the subject as I know going way low is just as dangerous as too much powder.

What type of competition? IDPA has a power rating that is based on bullet weight and velocity. You may want to check their rules if you are competing in IDPA. Otherwise, check the rules for whatever competition you intend to shoot. Most local clubs are not that particular...but check with them too. I down load for my M&PPRO40 too. Currently using Longshot powder, but am ready to run out. Could not find more, but did find 5 lbs of Power Pistol. Will experiment with it on down loading. However, I've read that Power Pistol is intended for higher velocity, so I don't know how it will do for down loading. Oh well. Must work with what you can get these days....Improvise!

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"Know your sword."

It’s just steel plate shooting using the Steel Challenge courses. 5 runs and your highest time is dropped. No power requirements or anything like that though we do have separate classes for rimfire and centerfire. It’s mostly just for fun. Of course our #1 rule(s) are all the safety protocols but rule #2 is to have fun and enjoy it.
I just want to make sure that being @ 12% under the published starting load isn't an extreme drop and that I didn’t just get lucky for 11 rounds of test firing before I set my press up to run this combo.

1 Most steel shooters around here are using faster powders at moderate loads for steel, like titegroup and hp38. In general it is easier and safer to go light with faster powders instead of going light with slow powders. Too light and you get erratic and smoky with slow powders.
2. Never go below the manual starting load with any powder unless you are very sure you know what you are doing.

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Science plus Art

I never go below the published starting load. Some powders don't react well to downloading, they require a certian amount of pressure to burn completely and consistently.

There are reason's for the min. and max. charges. Follow the published data.

Sounds like you know what you are doing. Have you tried a heavier bullet. I have found my heavier bullets react better to downloading on steel.

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Tom
NRA Pistol Inst

Two "No" and one "OK" response, thank you, just trying to learn.
I am a "Go by the book" kind of person, especially when it comes to reloading as I know it can all go downhill quicker than anyone can blink an eye. That’s why I loaded at 7.8Gr of my chosen powder as it is right in the middle of the published data and allowed me the most room for error. But I also know that this (Reduced loads) has been done before, otherwise we would all just buy factory ammo so…. While I can’t quote exactly what the manual (Lee 2nd) edition says word for word as I am at work and don’t have it with me, there is an entire chapter dedicated to the subject (#9 I think??) If I read and understood it correctly then I am more than in the “Safe Zone” for my decreased loads. I don’t want to be quoted as I don’t have the book right here but there was a formula that reduced by 1% as each powder got slower if I remember correctly (It made sense when I loaded the test rounds/did the math) I will re-read and triple check before I load anymore.
Yes, I do understand that powders all vary and they require certain pressures, etc to operate as they should. I can’t explain all of the chemistry and physics behind it and am trying to learn more in that area as well. I haven’t tried a faster powder / heavier bullet combo because those items are not available to me right now, once they are I will try them out as well.
I’m not asking for anyone to give blessings as to what I tried and also am sure the hell not recommending anyone else do it, my knowledge is limited at best in this subject. With that I know I’m not the only person to ever try it, just trying to learn what others have found and also the way outside chance that someone has loaded the same combo. I can say they shot nice, there wasn’t un-burned powder in the barrel, gun cycled as it should. Why does the heavier bullet/faster powder combo work? Not doubting, just wondering. What all could go wrong with what I tried?

I would also vote for min charge of faster powder in your case and I definitely wouldn't go below min charge - it's there for a reason ...

The thing about a heavier bullet is you would think it would shoot lower because it is heavier. It doesn't because it usually kicks the handgun back before the bullets leave the barrel which raises the barrel making them higher. I have found in a revolver I can use less powder with a heavier bullet to a certain point. You don't want to stick a bullet.

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Tom
NRA Pistol Inst

Recoil is king is many shooting sports, without a minimum P.F. the bullet getting stuck in the barrel is a bit less than the "min." load. You have to do some experimenting yourself but only with fast powders. Reduced power springs will come in handy too.

All powders have a range for starting & max. The slower the powder, the less efficient they are when downloading. Slower powders need higher rpssure for best combustion. SO my rule of thumb, when loading powders Unique & slower, I stay above average book midrange. If I want less vel, I drop to a faster powder. Most powders faster than Unique will tolerate even starting loads with decent results. So the faster the powder, the more easily it downloads for better results. IME, starting loads in most semiautos will not give 100% reliable functioning w/ stock springs.
On the load you are asking about, plated bullets want to be loaded between a lead & jacketed. Lyman goes all the way to 6.3gr w/ a 150gr LTC, 5.8gr w/ a 175gr LTC, so you 6.5gr load is in the ball park as long as it functions. You may find it is sooty that low, consider dropping to a faster powder if you want those softer loads.

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NRA Cert. Inst. IDPA CSO

Thanks all for the feedback, insight! Very helpful as always and greatly appreciated!! The heavier bullet/faster powder is starting to make some more sense now. Not 100% giving up on that load but also want to do a lot more research into it.