Patrick Scott

Jade, I gotta say. Using one given load(130pf), I have also seen differences in dot movement by changing up buffer weights. I see more dot "pull off" with the system bottoms out in the tube and more muzzle dip when it closes with the heaviest buffer I have on hand(7oz) The energy built up through momentum of the bolt and buffer has to go somewhere when the system bottoms out and closes up. While I am not a fan of going super light for safety reasons, but I think the conventional wisdom of going heavy in these guns is wrong for our application.

Physics 101. The heavier the mass the harder is is to get it moving and stop it. By definition mass is the the property of matter that measures resistance to acceleration.

It has to be so heavy to keep the system closed until bore/chamber pressure dissipates to the point where extraction is safe. If the system opens too soon it will blow out cases.

Pistol matches were kind enough to let us into their house, lets not try to rearrange their furniture. Being provided a warm blanket(start positions, ect), was pretty gracious as it is.

The sport is supposed to be a challenge(of shooting ability). Choosing to shoot a rifle in the sport brings with it its own set of challenges that need to be accounted for and overcome.

People seem a little more mindful of where their bullets are going if there is a NS penalty involved. My observation is that shooters will take a little extra time to make sure they clear it.

Ive seen this done a lot for no other reason than to protect the prop.

^ this is what we(I shoot PCC) asked for.

I dont think changing courses to support one division is a good idea. This problem is totally on the shooter. I see open guys do it as well.

I was wonder about sweeping while the gun is carted or being carried so I sent this off to Troy and dropped it on the USPSA forum close to a month ago and have not heard anything back. I have a question about rule 10.5.2 "10.5.2 If at any time during the course of fire, a competitor allows the muzzle of his handgun to point rearwards, that is further than 90 degrees from the median intercept of the backstop, or in the case of no backstop, allows the muzzle to point up range, whether the handgun is loaded or not (limited exceptions: 10.5.6)." Am I to read this as the stated actions are only DQ'able under 10.5 during the COF? ie between "make ready" and "range is clear"? The reason I ask is that I am wondering if PCC rule 10.5.2, being subset of rule 10.5.2, is only applicable during the same time frame(COF)? "PCC 10.5.2.1 Failing to point the muzzle at a side berm or back stop during casing or uncasing, or sweeping any person with the muzzle of a PCC, whether loaded or not, even if a chamber flag is inserted." More specifically, If a PCC gun sweeps the shooter or another competitor while it is slung/carried "reasonably vertical, and flagged, outside of the COF, is that grounds for DQ per 10.5 or its subset? Example: 1) Shooter approaches start position while PCC is slung or carried "reasonably vertical) and flagged, and muzzle sweeps shooter or other competitors on the way to the position. Is shooter DQed? 2)After "range is clear" command is given, shooter wants to follow RO to check hits. PCC while slung or carried "reasonably vertical" and flagged sweeps his/her feet or the RO's feet. Is shooter DQed? I know we all want to avoid sweeping and being swept at all times, but it seems that it is more difficult(for some situations) for it to be avoided. I just want it to be clear at matches what constitutes a PCC sweeping DQ. I would imagine the worst case scenario of a PCC shooter sweeping someone while not holding the gun "reasonably vertical" ie straight up pointing it at someone would be a DQ because the gun is no longer "reasonably vertical", but what rule # would that fall under?

Maybe, but I and others run a JP bolts with no issue. Im wondering if that build just got bit by the tolerance stacking bug. The lower, upper, bolt, and barrel can all have an effect on the situation. It wouldnt be the first AR build I have seen with the same issue.

http://www.shootersconnectionstore.com/Taylor-Freelance-Glock-41-1-Mag-Kit-P4271.aspx

147gr Black Bullets International, 2.8gr VV N320, 1.110"oal 130pf out of my 16" barrel Milspec carbine buffer tube

Thats strange, an AR buffer should not contact the retainer pin when the gun is assembled when using "in spec" buffers and bolts.

My starting mag is a 31rd tube with the big Taylor Freelance kit on it. The mags(2) on my belt are 17rd tubes with Taran Tactical +5/6 pads on them I even have a G26 10rd tube with a Taran Tactical +3/4 in case I ever have to go really low prone.

Yup, you can ream. I reamed my Colt barrel(chrome lining and all) because when using my Production loads( minus .2gr of powder) I found that the bullets were getting driven into the rifling making unloading the chamber a chore. I already owned the reamer, because of the same issue with my CZ Production guns.

Id venture a guess that the reasoning is With a handgun uprange start the firearm is never in the shooters hands, clear of the holster, trigger exposed while facing uprange. If those things happen you are DQed for a safety violation.

pfcchambers, This may be a strange request, but maybe you can help me out. If you were to run a normal carbine buffer and buffer spring with no spacer in the buffer tube would the fake gas key contact the "trap door" in that matrix upper? I have heard some conflicting info on that. Thanks

I have had a USPSA PCC gun since before it was a thing. I built it for fun and the ability to have an AR that could run my Production reloads. Its a 16" gun. I shot some USPSA practice setups with it, shot a few USPSA stages post match before the division came to be and now that the division is real I have shot 3 matches with it. I have never felt that the 16" barrel is a hindrance (even on a shoot house stage). I have the ATF forms in hand, but I am hesitant to go the SBR route. $200 bones for the stamp, engraving fees, filling out paperwork for interstate travel, SBR unfriendly states, ATF notification if I move, selling the gun,blah blah blah. If you have run PCC with a 16" gun and a SBR, did you find that the SBR was that much of an advantage? Or this may be an excuse to build another one, one SBR, one not.

In my testing heavy buffers and heavy springs did contribute to muzzle dip.

I agree with all of this

I have done the heavy(7oz) buffer and heavy(308) buffer spring while shooting 130-196pf(yes 196pf, I went there) ammo. Gun felt sluggish up until about 145pf and had tons of dot "pull off" when the system bottomed out in the tube. Now I run 130pf ammo, 4.6oz buffer(H2) and a .223 spring. Less dot "pull off" and the gun cycles fairly fast(Id like to try a reduced power .223 spring). More gooder First time shooting this lighter stuff in a match was today. I'm definitely a fan of going lighter for the operating system as long as you are loading for the gun. If you are going to shoot factory or hotter stuff, I think you will beat the piss out of the gun with a light system and dot bounce will be worse.

I plan on building another gun, just not quite yet. I think I may go ahead and pick up a spare bolt, that would cover a few parts all at once and I can just put it in a spare gun once built. I know some of the other parts are overkill, but I already have them and they really wont affect the amount of stuff I already bring. Thanks

Practice the processes of making ready and showing clear/flagging. Practice the process of bagging/unbagging(if that is how you are rolling)

Quarter Circle 10 Yes, metal I don't know