1700+ fps out of a 40 S&W = Too Hot!

[atblis]

I believe that was with a 22 lb recoil spring.

 

[jimbobborg]

1700+ out of a .40? OMG.

put it in a carbine, then maybe. Anyone make a 10mm lever gun?

There's a company that converts Marlins from rimmed cartridges to various rimless cartridges, including 10mm. Not cheap, but pretty cool. I posted on it a while back in the rifle section.

 

[kstone803]

And I thought 12gr of blue dot under a nosler 135 was snappy!

12gr longshot over a 135gr is a fairly well known "nuclear"40 load, the powder is incredible, you run out of room before you get over pressure, have hit stupid velocities in 10, 38super and 460 Rowland with it. Lots of people turn their nose up at 40, but you can load it from 300-600FPE from standard 9mm power all the way to match moderate 10mm loads, not much else can do that in an auto.

I try to tell ppl that 40 is the best round if you reload due to this. It's super versatile. You won't get it as soft shooting as IDPA minimum 9mm guns but it has a huge weight and speed range.

 

[Minuteman]

Thanks Jim!

 

[ken792]

Impressive. I really need to start loading 10mm. I've had my 40 MOS for nearly a year.

 

[Biggfoot44]

10mm levergun ? Sure ! It's called .38-40 , in a modern M92 clone . ( For those not up to speed on traditional ctgs,.38-40 uses .401 bullets. For that matter, the traditional 180gr .40 load duplicates a black powder loaded .38-40 from an SAA. This PSA sponsered by What old is new again, and nothing is truely new.)

 

[alucard0822]

And I thought 12gr of blue dot under a nosler 135 was snappy!



I try to tell ppl that 40 is the best round if you reload due to this. It's super versatile. You won't get it as soft shooting as IDPA minimum 9mm guns but it has a huge weight and speed range.

Can easily load from 135-200gr bullets 300-600FPE(or 800+FPE in the OP's case). The heavy 200gr bullets are really long with better sectional density than a 230gr 45, at about the same power level. Won a local bowling pin match with plated 200s over a soft load of CFE pistol in my GLOCK 27 carry gun, very light recoil, but tossed the pins like a bowling ball. Have also shot a steel challenge match with the same pistol using 135s under a light load of Clays just about 1,000FPS, every bit as mild as a 9mm minor load, and being 40 has greater case capacity and is more efficient, you can make the same power factor at a much lower pressure with a really soft muzzleblast. Then crank up a midweight load in a tough bullet, and take it hunting, or have a significant increase in power over 9mm. I love my 10s too, but one downside is the large primers, so the relatively thin case head gets deformed easily with hot loads, the 40's small primer actually makes it more forgiving, and most brass now has thick case webs to fight smileys and ruptured cases caused by the chambers in early 40 cal models.

 

[StaFrosty]

Was your 10mm AR a blowback action?

Yes it is and I am going to get a heavier recoil spring. With off the shelf loads it does real good but it kicks the empties out all over the place.

 

[atblis]

I'd like to do a 10mm AR or a 357 SIG but a DI.

 

[Squaregrouper]

Underwood 125gr Gold Dots in .357 Sig were averaging 1650fps out of my USPc w/o significant increase in recoil. Polygonal barrel gave less resistance perhaps?

 

[atblis]

357 SIG is often so well supported, it's possible that you're running well north of 40 kpsi. In fact, to obtain that velocity in that short of a barrel, I'd say you'd have to be. Underwood is stating 1475 fps for their 124/125 gr loads. I would guess that was in a normal length barrel, 4 something inches. You're beating that handily in a shorter barrel. Now the 90 gr bullets will go that fast easily with reasonable pressures.

I have some reservations about Longshot. I think it get's spikey in certain situations, and I think it has varied lot to lot. 800X is the only powder I've seen that you can't seem to put enough in to get pressure signs like I am seeing with Longshot. Going back and looking at some of my brass, the pressures are getting high enough that headstamps are getting obliterated. This was a load published by Hodgdon in 2002. Were they wrong? Did the powder change? It's possible there's something wrong with my loads or the barrel, but there's only so much you can screw up with a straight-wall pistol case.

ETA: I suspect when Underwood came up with the load it was inside SAAMI pressures, but for whatever reason, in your pistol it is now not.

 

[jimbobborg]

I'd like to do a 10mm AR or a 357 SIG but a DI.

Uppers here http://bazookabrothers.com/pages/shop/7?category=2

 

[atblis]

So hold on, could you guys see the picture in the original post all this time? I just changed it.

 

[jimbobborg]

So hold on, could you guys see the picture in the original post all this time? I just changed it.

Yes, but not in your other post.

 

[atblis]

I lowered the powder charge to 11.5 gr (current max from Hodgdon). Velocity is now 1650 fps average. Still getting a slight smiley. Let me know if the picture shows up

Primers could look worse. At this point I don't think they mean that much in an auto pistol

 

[jimbobborg]

I can see the pictures. I've seen pressure signs on my 10mm brass and primers as I approach nuclear loads.

 

[jimbobborg]

10mm levergun ? Sure ! It's called .38-40 , in a modern M92 clone.

Good luck finding one. I haven't seen a 92 clone in 38-40, ever. And yes, I looked. One on Gunbroker now, but most people are looking a 357 or 45 Colt.

 

[jimbobborg]

Since I have some free time at work, I checked the loads for 40 versus 10. Longshot isn't even mentioned in the 10mm section, and it's actually slower than the 40 load. ???

 

[BUFF7MM]

Since I have some free time at work, I checked the loads for 40 versus 10. Longshot isn't even mentioned in the 10mm section, and it's actually slower than the 40 load. ???

Which book? Hornady is showing Longshot for 180 and 200 grain pills in the 10mm data

 

[jimbobborg]

Which book? Hornady is showing Longshot for 180 and 200 grain pills in the 10mm data

Hodgdon's online book shows the 135s sans Longshot. They're also 5,000 psi lower than SAAMI specs for the 10mm.