Practice load

A smaller charge of a slightly faster burning powder and/or lighter bullet.

Type of pistol?

Most 10mm platforms are offered in other (lesser) cartridges which use lower tension recoil springs. Swapping to a lighter spring and lower charge of faster burning powder will significantly lower recoil and shooting costs. Also keeps fired brass close buy instead of launching it into the next county. (See, I HAVE owned a 10!).

I had a S&W 1006 back when they first came out. I was using a cast bullet I cast using a Lyman mold for the .401 Herters PowerMag. I used Trap100 powder at just enough to cycle the action. At 175gr, it roughly duplicated the FBI load that gave birth to the .40S&W. It was also quite accurate. After T100 was discontinued, I went to Bullseye and HP38. The only 10mm/.40 I have now are a .40Sheild and the G22 I was issued, bearing my badge# for most of my career. I mostly shoot the Lee 180gr TCFN, as the Sheild doesn’t always feed the Lee 155gr SWC. (6-cavity molds!).

Lyman #48 lists 5.9gr as a starting load for either Bullseye or Win231/HP38 with a 175gr cast for 1,115fps. If you’re shooing a G20, you might be able to drop this a tad more and still get reliable function.
With a 175-180gr in my G22, it’s 4.0gr of Bullseye, so I load 4.3gr for about 800fps. With the 10mm, I’m guessing it’s probably 5.0-5.5 to maintain function.

Look at .40 data with faster powders.

I am using 8.1gr ofBE-86 in 10mm under 180s. They are warm, not hot.

ATLDave said:

Look at .40 data with faster powders.

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That would be my suggestion too.

Yeah, making lower-recoiling 10mm loads is very, very, very easy.

Hey, it works for the .38/357 and 44 Spl/44 Mag so why not the 40/10mm?

Bat Rastard said:

I am using 8.1gr ofBE-86 in 10mm under 180s. They are warm, not hot.

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I've only tried 180s so far (plated, and Hornday FMJ). The lowest charge I tried with BE-86 was 7.5gn, where I got 1120fps, compared to the max charge of 8.5 which resulted in 1237fps. BE-86 at 8.3gn is my preferred 10mm load.

I also tried Power Pistol from 7.4gn to 8.2gn. The 7.4gn load resulted in ~ 1050fps.

GooseGestapo said:

Most 10mm platforms are offered in other (lesser) cartridges which use lower tension recoil springs. Swapping to a lighter spring and lower charge of faster burning powder will significantly lower recoil and shooting costs. Also keeps fired brass close buy instead of launching it into the next county. (See, I HAVE owned a 10!).

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My Witness Elite will launch the brass over 20 feet. It came with a 16 lb recoil spring, and I tried up to 22 lb, but it still kicks them out very far. With the 22 lb spring, though, I started having feeding issues, it seemed to work best with 18 lb. I also have a Sprinco recoil kit installed. At this point, I think I need to start shortening the ejector. I hate losing brass!

ArchAngelCD said:

Hey, it works for the .38/357 and 44 Spl/44 Mag so why not the 40/10mm?

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Exactly. The 10mm is basically the semi-auto equivalent of the .357.

Toprudder said:

My Witness Elite will launch the brass over 20 feet. It came with a 16 lb recoil spring, and I tried up to 22 lb, but it still kicks them out very far. With the 22 lb spring, though, I started having feeding issues, it seemed to work best with 18 lb. I also have a Sprinco recoil kit installed. At this point, I think I need to start shortening the ejector. I hate losing brass!

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Yep, it's ejector geometry, not recoil spring strength, that makes Witnesses fling 10mm brass so far. Everyone who tries to settle down the ejection pattern with springs ends up where you ended up - an oversprung gun that won't run reliably and still throws the brass. Not everyone is capable of understanding that, though, and some of them will start complaining about how the gun is now unreliable junk!

ATLDave said:

Yep, it's ejector geometry, not recoil spring strength, that makes Witnesses fling 10mm brass so far. Everyone who tries to settle down the ejection pattern with springs ends up where you ended up - an oversprung gun that won't run reliably and still throws the brass. Not everyone is capable of understanding that, though, and some of them will start complaining about how the gun is now unreliable junk!

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Have any idea how much to take off? I intend to start shorting it up a little at a time, I'm just curious to know where most people end up.

As far as powder choices, don't think about it in terms of using "normal" 10mm powders and backing down... that can work, but you'll still be getting pointless levels of gas and likely some big swings in velocity as you try to make powders work outside their intended pressure window.

Think about typical target powders. I like VV N320 a lot for this application, because it's got a little more bulk than something like Titegroup.

Toprudder said:

Have any idea how much to take off? I intend to start shorting it up a little at a time, I'm just curious to know where most people end up.

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I just decided to live with the vigorous ejection and mark cases for easier recognition. I wanted to have the option to swap top end calibers. I'm using a Witness-based open gun right now and, with 9mm (major), it really needs all the ejector. So if you start trimming, just recognize that you're locking in to the long-size cases... unless you want to swap out sear cages.