9mm loads in a pcc

[gpidaho]

Hello all. Anyone else notice a big pressure gain in loads fired in a pistol caliber carbine over those fired in a regular handgun? Here's the story. Using Berry's double coated 9mm 124gr. hollow base bullets As to Berry's web sight it says to load these bullets to the powder companies data for jacketed or cast bullets of the same weight. The VihtaVuori Reloading Guide 2017 listed bullets, both jacketed and cast. The lowest listed bullet was 5.4gr min. to 5.9max for a 124SWC the highest listed was a FMJ 124grRN at 5.2 to 6.2 this with 3N37. I loaded some test rounds, 5.7gr 3N37 under the 124gr Berry's to be fired first in my Rem. R51 my test platform for new loads as I really dislike this little slide biter and would not grieve it's loss. Anyway the loads seemed fine in the R51 with normal recoil and primers that looked no different than my other 9mm loads. Now to the Brigade 9mm AR pistol. Six rounds all had flat primers with two pierced. Now, I know a couple things. One being VV load data is known to be somewhat warm. Another is there is a velocity gain with a longer barrel (in this case 4" to 9") I just didn't expect the pressure signs to be this dramatic. Thoughts? Gp

[poppy42]

Well if the Velocity goes up in a longer barrel so must pressure. Now I don’t use Vihtavuori, but I do have there reloading guide. I also have Lyman AR reloading handbook. I tried to do some cross checking but the Lyman handbook and Vihtavuori book doesn’t list pressures. I’m sure someplace there’s a program or a mathematical formula that will determine how much pressure is increased when you double the length of the barrel. Way Beyond my math skills.

[onelight]

All else being equal , I would think the peak pressure would be the same but in the longer barrel but the pressure has more time to act on the bullet .
But chamber and bore dimension differences can certainly can change pressures in different barrels.

[rintinglen]

All else being equal , I would think the peak pressure would be the same but in the longer barrel but the pressure has more time to act on the bullet .
But chamber and bore dimension differences can certainly can change pressures in different barrels.

The Brigade is a blowback operated fire arm, while the R51 is a hesitation locked breech. Sometimes a blowback cartridge will let the pressure start the bolt back before the pressure has fallen, allowing the primer to be partially ejected, then driven back into the case as the pressure drops and permits the cartridge case to fully release the chamber walls. The primer will look a little funky in this case. Have you noticed this before with other components?

[gpidaho]

rintinglen. The Brigade AR pistol is pretty new to me but this is the first time I've seen this much of a change in pressure signs. That said, I'll be dropping the powder charge of 3N37 down to the lowest recommended by VV and give that a try before abandoning that powder. The Brigade manual lists several brands of factory ammo that MAY cause feeding problems. I'm happy to report that fairly lite charges and TC and WFN bullets seem to feed just fine with my handloads as do Winchester 115gr factory rounds. The folks at Brigade seem to build a very nice AR in it's price range. I had a FosTech EchoII triger installed on this pistol and while the Echo mode does nothing for accuracy it's a hoot to do short bursts. Gp

[onelight]

I have used 3n37 in 9mm in a variety of pistols and also a sub-2000 and a Beretta storm both blow back.
I found loads that worked great for my use , but I was not looking for max velocity just loads that functioned in all the guns with enough accuracy to be entertaining for 7 to 25 yard shooting.
I like the powder but have less expensive powders that work well so have only shot 1lb of it.
As rintinglen pointed out it may not be over pressure that you are seeing but just a different fingerprint on the case/primer , if you have some factory loads it might be interesting to see how they look after shooting .

[Tokarev]

Back when I still had Beretta CX4, I wondered about the possible loads for it and inquired with Stoeger as to whether it can handle +P. They said yes. I went on to use 6.0, 6.2, and finally 6.4 gr of HS6. The last one became my favorite load with little recoil and muzzle jump and quite accurate.

[gpidaho]

Tokarev: Thanks for the reply. What bullet were you using? I'm pretty fond of 124gr but have moulds from 95gr to 137gr for the 9s. Gp

[slughammer]

Press 10 of your loaded rounds against the edge of your reloading bench and see if you can push the boolits deeper in the case. You could possibly be getting set back in the PCC.

Sent from my SM-G970U using Tapatalk

[Tokarev]

Tokarev: Thanks for the reply. What bullet were you using? I'm pretty fond of 124gr but have moulds from 95gr to 137gr for the 9s. Gp
Used mostly Frontier plated 124 or 125gr and some Hornady RN and HP 124gr.
Never used cast in Beretta, only in my Chicom 9mm TT.

[gpidaho]

Press 10 of your loaded rounds against the edge of your reloading bench and see if you can push the boolits deeper in the case. You could possibly be getting set back in the PCC.

Sent from my SM-G970U using Tapatalk Thanks to all that replied. While I can't seem to get any movement pressing the bullets against the bench, slughammers thoughts on this are just about the best explanation I can think of. I do use the Lee taper crimp die and crimp enough to remove the belling plus a thousandth or so more but a 9mm AR does slam the rounds home with some force. The AR seems to feed well and had no problems even with wide flat point cast bullets and round nose hollow points. These showed no signs of high pressure loaded with AA#5 and HP38 respectively. Thanks again. Gp

[1006]

You can also chamber the same round several times and measure it for setback.

[armoredman]

When I still had my CZ Scorpion I shot many loads in it, and it was almost universal that whatever load I fired in it would be 100-120 FPS faster than the same load in a handgun. Longer barrel helps there.

[Tokarev]

Best I can remember the velocity out of the custom 18 1/2" barrel that I had on the CX4 was slightly over 1 1/2 times that of the TT that has 4 1/2" barrel. The same load and bullet.