PCC powder--how slow is too slow?

[funkymonkey1111]

reading up on all the theories--(1)fast powder, heavy bullet; (2) slow powder, light bullet; (3) slow powder, medium bullet (135gr?) or (4) fast powder, light bullets, and have decided to try the slow powder and medium bullet.  

 

In talking to they guy at the local reloading store, he said the slowest powder he'd recommend for PCC would be Alliant 2400, which offers no 9mm load data.   The guy at the store said as much ("you won't find any data for it, but it's worth a try....")   He also suggested trying Longshot and Accurate No. 7.

 

So, the question is--how slow is too slow for PCC loads?   The three powders I've seen show up most commonly in the slow powder PCC realm are Accurate No. 5, Hodgdon HS-6, and Win. AutoComp.  On the Graf's powder speed chart, those are ranked 45, 46, and 47, respectively.  

 

Accurate No. 7, Longshot, and 2400 are ranked 54, 56 and 58 on the Graf's speed chart (and yes, I know these aren't relative speeds, but simply an order they're listed in such that there may be little meaningful difference between a powder from one value to the other).  

 

But, given that No. 7, Longshot and 2400 are at least several values down the speed chart, are these viable powders for PCC or not?   JP has a "developing PCC loads" paper on their site where Longshot powder is used (all the powders are disguised by name).   So, at least it appears they are pushing into the edge of slower shotgun/pistol powders.

 

What say you?

[AHI]

You dont say what gun you are using ..This changes thangs . AR9 is a blow back. Mpx is gas operated

I have AR9 type so     powders much slower than WSF AA5 are in my findings to slow. AA7 for example

has a large flame out the ejection port.Quite simply the bolt moves to soon to take advantage of such a slow powder.

Win auto comp had vertical strings again the bolt is moving open to soon.I had good results with WSF .My best all around

results has been with Bulls Eye and 147 SNS bullets.    

 

[funkymonkey1111]

Sorry--JP GMR-15 14.5"

[Aircooled6racer]

Hello: With that JP use powders in the Tite Group range with 121-135grain bullets at 131-134PF. It will be a nice shooting. Thanks, Eric

[rowdyb]

I have no experience with your gun, but I'm changing my pcc (sig mpx) load up this week as well. Going from a 147 with 3.3 sport pistol to a 124 with 3.6 of win 244.

[Old3GNR]

34 minutes ago, Aircooled6racer said:

Hello: With that JP use powders in the Tite Group range with 121-135grain bullets at 131-134PF. It will be a nice shooting. Thanks, Eric

 

That mirrors my experience.  GMR-13 with 14.5" barrel.  3.6 gr Titegroup,  Precision Delta 124 JHP is a good all around load.  I shoot USPSA as well as KD Steel and occasionally Steel Challenge.  Previously tried 115 and 147 bullets.  

[Aircooled6racer]

Hello: 115's is the best for Sig MPX loads but a little too harsh in a AR9 I think. Thanks, Eric

[pitvpr]

1 hour ago, rowdyb said:

I have no experience with your gun, but I'm changing my pcc (sig mpx) load up this week as well. Going from a 147 with 3.3 sport pistol to a 124 with 3.6 of win 244.

 

I'm curious, why so heavy? Most guys I know, myself included are running 115g bullets in the MPX, it seems to do better with more gas 

[lordnikoncanon]

Hello: 115's is the best for Sig MPX loads but a little too harsh in a AR9 I think. Thanks, Eric

False I run titegroup 3.8 grs and lead cast bullet coated 125 gr


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[sdrr72]

And I have found I like 147g with 3.4 N320.  Best advise we can (and should) offer is to buy a box of 500 of each and try them in two local matches (or range sessions).  I found that the gun jumps around less with 147g, and I am not fast enough to take advantage of whatever speed difference the 124g rounds offer.

 

ETA:  My MPX gas port is opened up to accommodate low PF loads.

Edited December 11, 2018 by sdrr72

[rowdyb]

2 hours ago, pitvpr said:

 

I'm curious, why so heavy? Most guys I know, myself included are running 115g bullets in the MPX, it seems to do better with more gas 

Because I was trying to force the gun to shoot the same ammo as I do in my pistols for uspsa. I shoot pcc rarely so I didn't want to make a load just for it. Nothing about optimizing for the gun but me only have one load for divisions I shoot far more often.

[Aircooled6racer]

1 hour ago, lordnikoncanon said:

False I run titegroup 3.8 grs and lead cast bullet coated 125 gr


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Hello: You run lead cast bullets in your Sig MPX? How is that working out for you? If it is in your AR9 then try 3.1 grains of Tite Group with your 125 grain bullets. Tune the buffer in the AR9 and you will really enjoy shooting that load. Thanks, Eric

Edited December 11, 2018 by Aircooled6racer

[pitvpr]

LOL 

[pitvpr]

30 minutes ago, rowdyb said:

Because I was trying to force the gun to shoot the same ammo as I do in my pistols for uspsa. I shoot pcc rarely so I didn't want to make a load just for it. Nothing about optimizing for the gun but me only have one load for divisions I shoot far more often.

Makes sense, I have a friend who shoots production, he also wants to shoot PCC every so often and wanted to have one load for both, 

not much luck there, but I’m sure it’s possible if you really work at it.

 

Luckily I shoot Open 9major, so no chance 

[gerritm]

I played with some HS6 loads with 124gr & 115gr plated bullets in my JP 14.5 pinned barrel/Taccom SS buffer and found no real difference in dot movement or recoil than my standard 3.5grs Titegroup/115 plated RN that we use for all our minor pistol/pcc loads for 3-gun, USPSA, & steel. Did not quite go to major loads, but went pretty hot. Much more smokey, though. 

 

I think some of this will depend on how your buffer is set up. The Taccom SS buffer seems to run anything with the same dot movement. Can feel a little change in the recoil push, but dot is the same. 

 

gerritm

[echotango]

I run a MG 121 w/3.9 TG. 139pf thru 14.5" pcc and 130pf thru my SS and CO. 

[LowSpeedHighDrag]

I've run both VV N320 and N350 with 115 gr. Hornady HAP bullets in my GMR-13.  Seems to like both powders, but I'm staying with the N350 so I can get the pf up to around 135.   N320 seemed to plateau at around 125.

[GregJ]

13 hours ago, rowdyb said:

Because I was trying to force the gun to shoot the same ammo as I do in my pistols for uspsa. I shoot pcc rarely so I didn't want to make a load just for it. Nothing about optimizing for the gun but me only have one load for divisions I shoot far more often.

 

I'm with you.  My CO load is 124gr Zero 1.100 OAL 4.1gr W231 130PF out of my CZC 75, runs about 140-145PF out of my MPX carbine, and it runs like a scalded ape. 

[rowdyb]

yeah, the 147 option just wasn't ideal for both the mpx occasionally and my pistols all the time. the 125 for both will be a better compromise.

 

[MemphisMechanic]

I prefer the feel of the quicker cycling 115s and 124s to the sluggish feel of something 147+ grains anyway.

 

That’s true of handgun and PCC both. I don’t think bullet weight has an impact on how fast you can shoot; that all comes down to having the gun properly spring, and your stance/grip/recoil control.

 

Edited December 11, 2018 by MemphisMechanic

[dgreen]

100 grn bullet with 4.4 of AutoComp. 7.5 oz buffer with 308 recoil spring.

[Flatland Shooter]

2 hours ago, STIboy said:

I've run both VV N320 and N350 with 115 gr. Hornady HAP bullets in my GMR-13.  Seems to like both powders, but I'm staying with the N350 so I can get the pf up to around 135. 

 

To get to your target power factor (135) are you loading around 5.4 gr N350?   Almost out of N320 but have plenty of N350 on the shelf.

 

Thanks.

[Mike H]

I struggled with developing a load for my JP PCC 16".  I use E3 powder for .40 and 9mm pistol and it was way too fast a powder for the PCC.  After spending too much time and effort on the process, I ended up settling on HP38 which is a mid to slower range powder.  I load a 124gr JHP with 4.7 grains of HP38, 1.135 OAL for a PF of 140.  The rifle cycles great at that PF. for my preference.  HP38 is easy for me to obtain, doesn't seem to to be temperature sensitive, incredibly accurate, meters well and the price is right.  Now, I prefer HP38 over  E3 for 9mm pistol, as I find it has better recoil, not as hot and meters more consistently.  I haven't had time to mess with a .40 load with HP38.

 

I also had a few pounds of VVN340 left over and loaded a 124JHP with 4.9 grains for a PF 138.  That load worked very well, but due to lack of local supply and no measurable performance issues between the VVN340 and HP38, I'm sticking with HP.

 

JP PCC's are typically slower than other barrels.  Your 14.5" will not present the same issues I faced, but I'd steer towards a mid range to slower powder.  The IMR chart shows VVN320 at #24, HP38 at #28 and VVN340 at #37.  A lot depends on what you personally like in terms of cycling, recoil and dot movement.

[Steve RA]

Out of curiosity, what were the bad results with E3??  Velocity too low ?  Or something else ?

[LowSpeedHighDrag]

4 hours ago, Flatland Shooter said:

 

To get to your target power factor (135) are you loading around 5.4 gr N350?   Almost out of N320 but have plenty of N350 on the shelf.

 

Thanks.

Spot on.  I just checked, and 5.4 gr. gives me 130.4 pf in my JP GMR-13 (14.5" barrel), and 5.7 goes 141.3.  I plan to try 5.5 and 5.6 once it warms up a bit here.

I'd actually recommend N320 for PCCs with shorter barrels, and N350 for ones with longer barrels.

As always, YMMV.

Edited December 11, 2018 by STIboy