10mm Auto Longshot data inside :) (Platform - CBOB)

G37

G37

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I just came back from the range and thought I'd post my favourite results from both yesterday and today.

One, it's nice to share data and two, it's a great place to store information that won't get lost for future reference ;)


Pistol: Dan Wesson Commander Classic Bobtail - 108mm (4.25") barrel
Pistol mods: Aftec Extractor only (everything else 100% from factory)
Cartridge: 10mm Auto
Powder: Hodgdon Longshot
Brass: Winchester (New)
Primers: Winchester LP
OAL: 32mm (1.260")

*Chrony Alpha is used in all testing and is positioned 10ft from muzzle.*


TARGET LOAD / PLINKING AMMO
Bullet: 165gr Plated Round Shoulder bullet ("no name" from Reliable)
Charge: 6.2gr
Shots: 876.7fps / 861.5fps / 864.3fps / 861.7fps / missed :redface:
Average velocity: 866fps

Notes: Light & easy on the gun. Brass ejects within 4 feet of me (a little weak). I will move to a lighter recoil spring for these in the future.


10mm BB-GUN
Bullet: 165gr Plated Round Shoulder bullet ("no name" from Reliable)
Charge: 4.8gr
Shots: 557.4fps / 603.8fps / 631.6fps / 586.1fps / 564.1
Average velocity: 588.6fps

Notes: .22lr shorts anyone? The slide will move back enough to #### the hammer, but the "spent brass" is instantly rechambered. No jams were experienced it is very consistent in its function (i.e. having to manually work the slide after each shot). I want to move to a heavier recoil spring so that the hammer isn't cocked. :D


CCW (if we could)
Bullet: Nosler 135gr HP
Charge: 10.4gr
Shots: 1417fps / 1424fps / 1396fps / 1403fps / 1435
Average velocity: 1415fps :cool:

Notes: Oh Yeah! Nice sound. Nice feel. Brass is being thrown a little on the far side... 10 ft from where I am standing; I want to move up one recoil spring. I love this load so far. Very light shiny spot around the primer strike (light primer flow? I'll see of a heavier recoil spring fixes this).


WOODS CARRY (if we could)
Bullet: 180gr XTP HP
Charge: 9.4gr
Shots: 1270fps / 1280fps / 1285fps / 1289fps / 1298
Average velocity: 1284fps

Notes: Problematic. kicks hard (my poor gun). Reliability was horrible as almost each round jammed when trying to chamber. Brass was being thrown 16ft away or more :eek:... definitely too much for the gun. I've read that recoil springs of 24# or 26# are required for these heavy loads. I will try again in the future with new springs. Brass looks good though, the primers are flowing as a result of a weak recoil spring (I hope) and not because of the pressure; the primer strikes are almost completely covered up. Either way, I feel comfortable with it using only NEW brass.
 
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Thanks for sharing!

I've got some 10mm loads using 800X ready to go to the range. I'll post my results as well after I get a chance to fire them.
 
"...Brass looks good though, the primers are flowing as a result of a weak recoil spring (I hope) and not because of the pressure; the primer strikes are almost completely covered up. Either way, I feel comfortable with it using only NEW brass..."

As a relatively experienced reloader this would concern me. A very un-subtle indication of high pressure regardless of which recoil spring you might be running in the pistol...


blake
 
mudgunner, as an experienced reloader, maybe you could explain something to me. I cooked up some hot 10mm loads that I shot out of two different guns. In the first, the primer strikes were completely covered up, and some primers were even pierced. In the second gun, there were no pressure signs on the primers.

I've been trying to wrap my head around the mechanics of this. How can one judge pressure levels from primer appearance when they vary depending on which gun did the shooting? Does the chamber affect pressure?
 
Thanks Mudgunner49.

I was under the impression that recoil spring (if not strong enough) causes the brass to eject prematurely which is one reason why you get the primers as I described.

Either way, I agree with you and it does concern me. If the "symptoms" remain after a recoil spring change (going to 24# from 18#) I am going to lower the charge; I'll update this thread with results :)

-----------
Edit to add the following link:

http://www.realguns.com/archives/023.htm

Just found this. Interesting read. My primers on the 180gr charge looked like the primer at the very right of this pic:
primesamp.jpg


From the site: "Flattened Primers as a function of pressure: Flat primers exist in degrees, and the degree determines cause. As seem to the right - a primer flattened around the face and firing pin indentation would normally be viewed as a primer exposed to high pressures, as long as the radius along the perimeter of the primer was intact."

Interesting.
Well, I'll try it out with new spring, if no change (and it sounds like there might not be any according to this writer) then I might have to lessen the charge after all... or try some 800X ;)
 
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G37 said:
Thanks Mudgunner49.

I was under the impression that recoil spring (if not strong enough) causes the brass to eject prematurely which is one reason why you get the primers as I described.

Either way, I agree with you and it does concern me. If the "symptoms" remain after a recoil spring change (going to 24# from 18#) I am going to lower the charge; I'll update this thread with results :)

-----------
Edit to add the following link:

http://www.realguns.com/archives/023.htm

Just found this. Interesting read. My primers on the 180gr charge looked like the primer at the very right of this pic:
primesamp.jpg


From the site: "Flattened Primers as a function of pressure: Flat primers exist in degrees, and the degree determines cause. As seem to the right - a primer flattened around the face and firing pin indentation would normally be viewed as a primer exposed to high pressures, as long as the radius along the perimeter of the primer was intact."

Interesting.
Well, I'll try it out with new spring, if no change (and it sounds like there might not be any according to this writer) then I might have to lessen the charge after all... or try some 800X ;)
Click to expand...

Hey,

That is a very interesting pic.

Your speeds for 180 gr seem to be allright.

I usually can push 200gr bullets that fast(1250-1275 fps) with 800-X out of my 10mm's.

You might want to try 800-X. It seems to be the GOTO powder for hot loads in 10mm.

I too had some primers look like the one on the far right from time to time. Just out of coincidence it was also with a 10mm.

I thought what is probably happening is that the primers are extruding under pressure back into the firing-pin hole in the breechface, and then as the barrel drops into the unlocked position, the extrusion is being sheared off by the edge of the firing pin hole.

Keep us posted.

Now that the snow is receeding I hope to make it out to the range soon too....darn indoor range doesn't allow 10mm.....
 
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Cerdan said:
mudgunner, as an experienced reloader, maybe you could explain something to me. I cooked up some hot 10mm loads that I shot out of two different guns. In the first, the primer strikes were completely covered up, and some primers were even pierced. In the second gun, there were no pressure signs on the primers.

I've been trying to wrap my head around the mechanics of this. How can one judge pressure levels from primer appearance when they vary depending on which gun did the shooting? Does the chamber affect pressure?
Click to expand...

Because every firearm is at least to some degree a individual with all the attendant idiosyncrasies and differences. There are minimums and maximums for all dimensions on a firearm (chamber, bore dia, hardness of barrel steel, chamber leade, rifling depth, etc). If you have a chamber and bore diameter that are at the minimum, or perhaps even a short/steep leade and a load that is getting close to or exceeding the max, you will get high pressure signs. Regardless the fact that if you fire it in another firearm without any pressure signs at all, the pressure is high in that firearm that shows the flattening of primers.

Keep in mind also that the only real and definitive read on pressure is with a pressure barrel and the proper equipment. For a really good description and write-up check out Lee's "Modern Reloading"...

Hope that helps,

blake
 
mudgunner49 said:
Because every firearm is at least to some degree a individual with all the attendant idiosyncrasies and differences. There are minimums and maximums for all dimensions on a firearm (chamber, bore dia, hardness of barrel steel, chamber leade, rifling depth, etc). If you have a chamber and bore diameter that are at the minimum, or perhaps even a short/steep leade and a load that is getting close to or exceeding the max, you will get high pressure signs. Regardless the fact that if you fire it in another firearm without any pressure signs at all, the pressure is high in that firearm that shows the flattening of primers.

Keep in mind also that the only real and definitive read on pressure is with a pressure barrel and the proper equipment. For a really good description and write-up check out Lee's "Modern Reloading"...

Hope that helps,

blake
Click to expand...


I was always under the understanding that flat primers on their own were NOT neccesarily a high pressure condition.

A extremely flattened primer combined with cratering would surely indicate a high pressure charge....but just a flattened primer on its own might be just an oversized chamber.
 
Ooops one more piece of info I forgot about...
Could it be "The Primer" itself???

I've made some really hot .45Super rounds in the past with zero problems... I was using CCI350's (different gun obviously, but no primer problems at all... a little flattening on the side, but very minor).

This is the first time I'm using Winchester LP's and getting the loads "up there." Could the cup on the Winchester be softer??
Like the canary in the mine... perhaps the Winchester LP's are more susceptible to pressure signs than say CCI350's??

Cerdan: What primers are you using?

Either way, more things to experiment with... I love rolling my own. :D
 
CCI 350s are apparently the best primers for 10mm. I was pushing 180 JHPs to 1350 fps out of a Glock with no pressure signs using plain 300s. The primer forms a crater around the striker but my target\factory loads don't look much different than my max loads.
 
350 Mag said:
I was always under the understanding that flat primers on their own were NOT neccesarily a high pressure condition.

A extremely flattened primer combined with cratering would surely indicate a high pressure charge....but just a flattened primer on its own might be just an oversized chamber.
Click to expand...

Roger that - see my quote below:

"Keep in mind also that the only real and definitive read on pressure is with a pressure barrel and the proper equipment. For a really good description and write-up check out Lee's "Modern Reloading"..."

CCI primers are generally (with the exception of mil MG primers) considered to be the hardest, Federal the softest and Winchester somewhere in the middle. This mirrors my own experience, however I haven't hopped around too much, generally using Federal/Winchester and reserving CCI for some specific applications. I have recently used some Wolf primers and they seem a bit harder than Winchester, though not so hard as CCI.

The firing pin "wipe" is generally a sign of early/premature unlocking which may be associated with higher than normal pressure...

Your velocities with the 180's are what the 10mm is supposed to be about!!! :cool: I need another G20 :D


blake
 
2008-04-26

Bullet: Nosler 135gr HP - WINCHESTER LP's
Charge: 10.4gr
Shots: 1355 / 1358 / 1454 / 1426 / 1438
Average velocity: 1406fps

Bullet: Nosler 135gr HP - CCI 350's
Charge: 10.4gr
Shots: 1463 / 1502 / 1497 / 1471 / 1497
Average velocity: 1486fps

So, CCI350's do make a difference in speed for sure (+5~6%)... unfortunately the primer flow is exactly the same (I was hoping the CCI's wouldn't flow like the Winchester primers).
My last chance to see if I can stop primer flow is a stronger recoil spring. If that doesn't work, I start reducing powder :)
 
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