Mother load! Old Cor-Bon 135's, Winchester Silvertips

[Intercooler]

The 50 round box of 135's is dated Feb. 10, 1994. Almost 20 years old  Possibly why the rating WAS 1450 FPS.

Anyone have a way to decipher the 20 round box lot number?

I want to research the Cor-Bon history as the 1994 box might have been the very first offering.

[Intercooler]

[4949shooter]

What are you looking to find out?

[4949shooter]

124 "granos" Lol..



I bet Corbon lowered their 10mm velocity from 1450 to 1400 just like all the other ammo manufacturers.

f

I read an article a few decades ago that SAAMI was lowering pressures on both the .357 and 10mm.  The magnum 125 grain rounds went down to 1400 fps from 1450 and likewise the 10mm 135's.

That makes sense. I wonder why..

[Intercooler]

What date the smaller box was manufactured. I suspect being a 20 box that puts it between the new and real old.

[Intercooler]

I'm running the Crossfire 125's out of the Hunter tomorrow as well. Maybe 1800 FPS?

[enidpd804]

124 "granos" Lol..



I bet Corbon lowered their 10mm velocity from 1450 to 1400 just like all the other ammo manufacturers.

f

I read an article a few decades ago that SAAMI was lowering pressures on both the .357 and 10mm.  The magnum 125 grain rounds went down to 1400 fps from 1450 and likewise the 10mm 135's.

That makes sense. I wonder why..

Funhaters.   

[4949shooter]

What date the smaller box was manufactured. I suspect being a 20 box that puts it between the new and real old.

I will see what we can find out.

Edit: The site is down now but I will post the lot number later.

[Intercooler]

   Interesting 10mm results today. I'm really interested in seeing what The Shadow finds when he pulls down these two Cor-Bon 135's versus the newer version. The recoil difference between the 1400 FPS rated versus the 1450 FPS rated confirmed the Chronograph readings.

EAA Elite Limited 4.75" Cor-Bon 135gr JHP 1400 FPS rating 1469, 1476, 1467. Average = 1470.66 FPS/ 648 LBS
EAA Elite Limited 4.75" Cor-Bon 135gr JHP 1450 FPS rating 1527, 1475, 1475, 1511, 1505, 1493. Average = 1497.66 FPS/ 672 LBS. The > 1500 readings I could feel the difference in the string. Perhaps there was a loading issue back then (1994) with this load?

I also ran some previously tested10mm rounds out of my 6" Hunter for those data points.

EAA Hunter 6" Underwood Ammo 220gr Hardcast 1288, 1286. Average 1287 FPS/ 809 LBS
EAA Hunter 6" Crossfire Ammo 125gr Sinterfire Frangible 1787, 1767. Average = 1777 FPS/ 877 LBS falling a little short of the 1800 FPS I hoped to see. The powder he uses make this a quieter and more pleasant recoiling round than other 800+LB loads. It always amazes me!
EAA Hunter 6" Underwood Ammo 180gr TMJ 1373, 1374, 1387. Average = 1378 FPS/ 759 LBS

[The_Shadow]

Very interesting...what about the handloaded stuff?   You test any of those?

[Intercooler]

  Not yet. I will wait until you pull them and verify the weights. Based off of that I will weigh each one just to make sure before shooting.

[Intercooler]

Sent Cor-Bon photos.

[The_Shadow]

Here is what was found inside the Handloaded Cartridges Intercooler scored...he sent 5 for investigation.

Cartridge is from Reloaded: 180 grain FMJ
Ballistics Information: 10mm Auto
Muzzle Velocity: 1170 -1180 fps
Muzzle Energy: 556 ft. lbs
Brass Make/Headstamp: Midway & Winchester – Brass
Bullet Make/Weight/Construction/Info; Length 0.6090"/Dia. 0.4000": 180gr FMJ
Actual weight 178.2 / 178.4 / 181.8 / 182.0 / 177.6 grains 
Crimp Diameter 0.3860" - 0.3840"  (looks to have a crimp groove as made or just way over crimped)
Truncated Cone / Meplat 0.2250" / Base is copper covered
C.O.A.L.: 1.2615" / 1.2670" / 1.2645" / 1.2640" / 1.2685"
Primer: Nickel color
Case: Diameter 0.4270" / 0.4275" / 0.4230" / 0.4270" / 0.4300" (they were not "pass-thru" sized and the sizing die did not reach the area above the extractor ring.  4 of the 5 didn't fit the case gauge as seen by the measurements)
Crimp Diameter 0.4135" / 0.4120" / 0.4120" / 0.4120" / 0.4120"  (tight) (bullets look to have a crimp groove but some are crimped way too much)(should be 0.4215" but the crimp groove is why I think they were crimped so much)
Length 0.9795" - 0.9880"  (used cases lengths varied)
Powder Description/Positive ID/Type/Charge Weight: Winchester WSF 7.3 grains

Actual weight 7.0 / 7.2 / 7.4 / 7.4 / 7.2 (Hodgdon shows 180 JHC using 7.1 gr. @ 1150 fps 35,600 PSI)








The inside of the case and the base of the bullet looked like the yellow dust we are seeing. (I think the casing was wet or had corrosion residue inside, it is on the bullet base also.)

I'm not sure if the bullets were made with this crimp groove?

[Intercooler]

  Weird how something unexpected shows something we have seen in the past!

The yellow "dust" we saw in some of the others more than likely is moisture related?

[Intercooler]

The Shadow,


     Now that we are barking up the right tree... let's test it! Can you take one of the good powder reloads and introduce a couple drops of water? Assemble and give a couple shakes? In a month or so pull it down for inspection?