Why not load hotter?

[Honkeymcgee]

This is something I have been curious about since I saw people start using PCCs. 

 

I don't own one and have only shot one once on a classifier to try it out. 

 

I realize you can't be scored major but my question is why not load a slower powder in the 140-150 or so PF range with a light bullet?

It would seem to me that this with a comp would make for a nice shooting platform. 

Please explain to me if this isn't the case. 

 

The PCC I tried once was one of those 5" barrels with a long shroud over it and it sure seemed bouncy. 

[Patrick Scott]

I chronoed 141pf at Area 7 with a 124. Its the load I like for my gun(14.5" w/comp). 

[HoMiE]

5 hours ago, Patrick Scott said:

I chronoed 141pf at Area 7 with a 124. Its the load I like for my gun(14.5" w/comp). 

What powder are you using?

[Patrick Scott]

2 minutes ago, HoMiE said:

What powder are you using?

124gr Precision Delta JHP, 4.5gr WSF, 1.125" OAL,  new Starline brass, Federal SPP 

[HoMiE]

1 minute ago, Patrick Scott said:

124gr Precision Delta JHP, 4.5gr WSF, 1.125" OAL,  new Starline brass, Federal SPP 

WSF is what I’m using, 4.5gr with 115 MG out of 16” barrel, getting 138-140pf. 

[JAFO]

Personally, I wanted to stick with Titegroup since I have a lot of it.  When I tried my regular pistol load using coated bullets, I was getting 149 PF but leaving a ton of lead in the comp.  Backed it off to where I'm getting 131 PF and I only get a very small amount of lead left behind.  The gun also seems to jump less with the lighter load. 

 

A lot of people are reporting very little benefit to the comp on a 9mm with a 16" barrel.  I see gas blowing out of mine, but in retrospect I got the wrong type of comp.  Most of the gas goes out of the side ports on mine, as opposed to a design like the MBX that only has upward facing ports.  Some people that are putting mid-barrel comps in their builds (a pistol-length barrel with an upward directing comp and permanently attached extension tube) seem to be getting more benefit out of them.  Gotta watch that support hand position with those, though.

[Honkeymcgee]

2 hours ago, JAFO said:

 

A lot of people are reporting very little benefit to the comp on a 9mm with a 16" barrel.

 

Yea I realize this but I always wonder how much of that is people using a load that's just 4-5 grs of powder. 

Versus something like 6-8grs of a slow powder like 3n38 and a 115 jhp. 

 

I've almost been tempting to make one of these USPSA abominations just to try it. 

[JAFO]

Doing a quick Enos search, it looks like you'd be in the Open gun 9mm Major ballpark with that load.  But those loads are working comps in pistols with 5" barrels.  When you more than triple the barrel length (and volume), there's a lot less available pressure for the comp in the PCC barrel.

[Honkeymcgee]

2 minutes ago, JAFO said:

Doing a quick Enos search, it looks like you'd be in the Open gun 9mm Major ballpark with that load.  But those loads are working comps in pistols with 5" barrels.  When you more than triple the barrel length (and volume), there's a lot less available pressure for the comp in the PCC barrel.

Yea, I could see it being less for sure. 

If I was going to try it I'd definitely be going with 14.5" pinned and welded for the most gas without going SBR

 

[jtrump]

I tend to like the gun around no less than a 137-142pf,   It feels better to me anyway.   I think I would like a light projectile "95g" running 1400+fps,  but going to tinker with that later.   I've finally got a load that the dot barely moves and it actually tracks straight up and down go figure.

 

I've been through TG, WSF, n320, autocomp, hs6.  

[ClangClang]

I'm not a PCC shooter, nor a reloader, so I'm WAY out of my lane here, but I was under the impression that the majority of PCC recoil and dot movement was attributable to the violent blowback action and heavy bolt slamming backward. Not due to the recoil of the round itself, cause 9mm is pretty mild out of a 14-16" barrel.

 

 

[Patrick Scott]

I have run about a half dozen muzzle devices on 9mm PCC guns, fast and medium speed powders. Comps don't do much, but they do something. Its not like on an open gun. Think more along the lines of the cherry on top of a cake instead of the cake itself. 

[L9X25]

One thing to remember is that a comp, any comp, only takes a percentage of the recoil out.  Adding more power will increase the recoil, even if the comp/brake becomes more effective at the higher power factor.  IMO the best way to achieve both goals is to load the lightest projectile you can find, with a slower powder, and aim for the usual 130pf with that.  It will produce more gas to operate the comp more efficiently without creating additional recoil for the comp to have to offset.  

[Flatland Shooter]

All last year I shot PCC with around 134 PF loads.  I'm using a 16" lightweight barrel with a Miculek style comp, 15.2 oz bolt, 5.2 oz buffer and stock M-4 spring.

 

The bullet was147 gr RN plated over 2.9 gr N-320 (OAL = 1.085").

 

After some comments on the forum about hotter loads giving less dot movement, I started playing around with it.  Thanks to Black Friday sales, I stockpiled enough of the 147 gr bullets for the 2018 season, so I stuck with that.

 

I found that with my guns, bumping the powder up to 3.3 gr N-320 gave me a 145 PF and much less dot movement.

 

In the future I may experiment with lighter bullets but for now, I'm happy with the results.

 

 

Edited July 4, 2018 by Flatland Shooter

[joelpend]

PCC 9mm with 16" barrel, blowback bolt is very dirty so I like a faster burning powder which seems to run cleaner for me.