MikeRush
-
Posts
967 -
Joined
-
Last visited
Content Type
Forums
Profiles
Events
Store
Posts posted by MikeRush
-
-
I am running converted Uzi mags for now with the thought that I would do a weld up soon.
The irony of all this is I am switching to a Glock pattern lower to prepare for "PCC 10" in California as I have a set of G17 Production mags.
-
21 minutes ago, StealthyBlagga said:
You could cut the bottom off one magazine tube and the top off another, then join the two tubes with an external metal clamp, bonding it to each tube using epoxy resin. If you make the cut square and clean up the junction, then join the two springs using a copper tube and some soft solder, it should give you a workable solution. I have done this with Colt mags (welded the tubes together) and they run pretty well. Just don't go too long because the tapered 9mm case wants to form a curve. I made an 83 round subgun magazine using this approach, but have to give the sign of the cross before every stage if I want it to run 100%
Your Uzi mag weld job looks great! I love the spring idea as well.
I thought about fabricating and tacking in a sleeve to the exterior of the tubes, or maybe just exposing the steel liners and welding then up. It seems like a 31 rd factory tube plus a cut 17 round mag and a +6 pad would get me around my 50 round target. Bonding with epoxy sounds like it might work better. I will take a look and maybe sacrifice a 17 round mag to cut it up and try a few different techniques.
22 minutes ago, Aircooled6racer said:Hello: I think 50 round mags is more than you will ever need for a USPSA match. 38-40 rounds should get you through every stage. So far I have been using 38 round Glock mags and have not had a problem even on a 36 round stage. I will be trying a 32 round Colt mags this coming weekend and will see how that goes. I may end up welding up a Colt big stick that will hold 40 rounds or so. If the mag gets too long it ends up swinging like a pendulum. Thanks, Eric
I know it isn't necessary as 36 rounds has proven to be more than adequate for any USPSA stage. I do shoot a handful of higher round count matches a year and it would be handy for that. I shot the Left Out of Rio match last month and had to reload on almost every stage, and one had a 42 round minimum count. 50 would be sitting pretty.
-
I would really like to see a 50 round stick for the Glocks. That is one reason I started with the Colt pattern lower.
This could be a great option that would come in lighter than a Beta mag. I still wish there was just a really big stick available. I have thought about trying to weld up a couple of Glock sticks, but I don't know how the metal lining would hold up at the joint.
-
In terms of "clean sheet" I am looking forward to the Grand Power Stribog which should be coming to the US next year.
I agree that somebody needs to do a roller or other form of delayed blowback upper for thr AR platform. I don't care if the upper doesn't use standard parts- it would open a superior action type to AR ergos, trigger, etc. I think the availability of mags, lowers, etc would be a huge plus. Also, someone needs to make a lower with a big magwell that will sell individual lowers.
One thing I haven't seen discussed a whole lot is a DI 9mm AR. There are a couple of shops producing them and if anyone really wants to work a comp you have that option. I had a DI upper for a while- recoil is incredibly soft, but runs on slow powder handloads only. I got reliable bolt lock back on empty with a mid range book load of HS6. I think if USPSA were to allow 9mm Major in PCC that would be the dominant choice. The one I had had the barrel nut shaved to install the gas block- the port is that close to the chamber! At the time, I really wanted to get ready for the Red Oktober match and the bump and recoil of a blowback gun seemed beneficial as a trainer. If I were going with the take no prisoners approach that is what I would do. It is like Open for PCC. I am enjoying PCC, but my heart belongs to another division.
-
On 12/2/2016 at 5:13 AM, PHX said:
Mike. When talking about stroke. Are you talking about the length the bolt travels in the receiver? Are you stacking quarters in the back of the buffer tube to reduce travel length? I'm confused how this will help with recoil management/dot flip. Thanks!
I am. Altering the stroke length affects how hard the buffer "bottoms out" in the buffer tube and how long it takes for the bolt mass to change direction.
With the shorter stroke the gun feels (to me) a bit more harsh but there is less overall movement in the dot.
-
2 hours ago, rowdyb said:
or just really lean and keep it strong side shoulder. maybe it's cause i'm thin but i can be behind a barricade and shoot my off hand side, staying in cover, with the gun still on my right shoulder.
.png.b58a4fda545a52217c2ae1adfac54bc4.png)
This. So far I have been able to lean my way out of switching shoulders on barricades. I shot a stage last weekend where I ended up leaning so far the gun was canted almost 90 degrees.
I haven't been able to lean my way out of mandatory strong and weak hand shooting though. Do they have that in IDPA?
-
1 hour ago, PHX said:
Thanks for the input. I assumed that a 9mm minor load wouldn't generate nearly enough gas to work a comp. I have found a few cheap comps marketed for 9mm, but I might just do a thread protector. Sounds like you get better recoil management/dot flip by messing with buffer springs. Have you found this to be the case?
In my experience with blowback ARs so far the number one improvement I have seen is a true minor load. In a 16" gun this typically takes a significant powder reduction relative to a minor pistol load. Dropping down to the 130 to 135 PF range dramatically improves the guns behavior.
I have done some experimenting with springs, but the next most significant factor in my experience is the reciprocating mass. If using factory loads, or minor pistol loads I wouldn't go much lighter than a "factory" AR 9mm which is somewhere around 21 to 24 oz combined buffer and bolt weight. I am still experimenting, but I think I will settle somewhere around 17 to 18 oz combined weight with my reduced loads.
In terms of spring weight a GI style trigger/hammer and relatively stiff hammer spring (I use the JP Enhanced Reliability spring kit but mil spec works great as well) will help keep the bolt closed initially and allow you to use a lighter recoil spring than you would otherwise be able to use. I am currently at a Wolff XP AR15 spring, but I think I will go back to a factory carbine spring.
Finally, tuning the stroke can also impact dot movement. I have used quarters for this- when I settle on stroke I will do something more permanent.
-
43 minutes ago, Les Snyder said:
anyone have a source for 1/2-36 thread protectors?
Xtreme precision sells some on Amazon for $8 shipped. I have used 3 of them and found them to br satisfactory for my needs.
I did loctite mine on so I don't have to worry about it backing off.
-
On my 16" I am just using a thread protector. I would rather take the reduced OAL than install a muzzle device that probably won't do a whole lot.
-
The Aussies seemed to do pretty OK at the World Shoot despite using 10 round mags at home.
I am planning on adding a couple of pouches and switching to bullets out. I don't think the rest of the sport should have to change to accommodate our draconian laws.
-
On 11/8/2016 at 7:24 AM, Posvar said:
I'm struggling a bit with my GMR-13. My pistol load with Extreme 147g and 3.1g TG has too much bounce and dot movement. Last night I tried 3.4 and 3.5 and it got worse. For some reason the Stand One Chubby reduced power factor 147g ammo I have has ZERO movement other than a slight push back into the shoulder. It gets the comp going very well too. I am thinking TG is too fast burning of a powder? I'm not looking to change the gun at all or go to a different bullet but may need to go to a different powder. I really want it to get it close to the Stand One feel and still load my own bullets. Any thoughts????
I would reduce the charge. 3.5 grs of TG with a 147 is probably way over the minor PF floor. One of my friends is using a JP barrel and making 130 something with 2.6 grains of TG and 147s. You probably aren't going to be able to feed the comp enough gas to offset the increased recoil from a heavier charge. As far as it being too fast my favorite PCC load is with Promo, which is faster than TG.
On 11/2/2016 at 5:38 AM, StealthyBlagga said:Great discussion, and definitely an area for innovation in this new division. HOWEVER, if folks are new to blowback designs, I suggest they do some research on bolt/buffer/spring combinations and stay within the realm of the "known safe". Unlike locked breach rifles, blowback designs rely entirely on the inertia of the bolt assembly to prevent case head separation/breach explosions - this webpage is an interesting primer. Lighter reciprocating mass may feel flatter, but you could be on the ragged edge of safety and reliability. Be careful guys.
I totally appreciate the concern for safety and I am on board with you in this respect. I have had several friends kaboom cases in the last few weeks (including one where the case head was an independent disk from any of the cartridge walls at the end). I think people aren't using a chrono, and are using heavy charges, long barrels, and light triggers which all work against a safe, reliable blowback gun. We are all trying to have fun and I hate to see anyone get hurt.
That being said, I looked at the Orion site before and the math doesn't seem to add up to me. For a "safe" bolt weight in 9mm he suggests a 27 oz bolt. This is heavier than a standard 9mm AR from CMMG or Rock River, a JP, a Suomi, an Uzi, or ANY 9mm blowback gun I am familiar with.
There is a book, the "Submachine Gun Designer's Handbook" by George Dmitrieff that goes into great detail on designing a safe blowback gun. It includes formulas for barrel time, extraction rate, bolt speed, etc and also lists barrel lengths, bolt weights, and other characteristics of common subguns. His perspective (not mine) is that a 500 gram (just under 18 oz) bolt is sufficient for a 9x19 from a safety point of view. That is about where I am at with my CMMG now, at 17.x oz combined bolt/buffer weight. I stress that this is what I am comfortable with, and I am not making a recommendation that anyone follows suit. I am putting together a second upper with an 11" barrel and permanently attached 5.5" flash suppressor which will mean pressure is dropping sooner than with a 16" barrel. Using some of the math in this book, I am planning experimenting down to around 15 oz with MY reduced handloads only. This is with an extra power recoil spring, a fast powder, light bullet, minimal charge and relatively heavy hammer spring. I probably will settle around 17-18 oz total weight just to have a "safety factor" built in should someone use factory ammo in it.
I think anyone who wants to experiment blowback guns should get the load set first, and then work on tuning via bolt mass if they feel compelled to do so AND understand the safety implications. Honestly I wouldn't shoot WWB out of my gun as it sits, and the gun shot reduced loads pretty well at 21.x combined bolt/buffer weight.
-
I am finding the SIG Romeo 3 doesn't wash out for me and makes precision shot placement easy. I used it to skip a position last weekend when a sliver of a popper was exposed behind a barrel. I don't know that I would have been able to make the shot with a bigger dot.
For what it is worth, I am using it mounted on the first slot of the upper, right where the upper and rail meet with a collapsible stock 2 clicks out.
-
1 hour ago, jwalter said:
Does anyone have any experience with the barrels being made by Ballistic Advantage? I would to be able run XTreme bullets.
I have one on the way. I don't think I have any extremes left, but in my experience they will typically chamber if coated lead will. I should be testing it next week.
-
Just as an update- after the first stage of yesterdays match I removed the central mass from my CMMG bolt using loads that were slightly above minor PF. The difference was night and day! Recoil was slightly more harsh, but I felt like the bolt was finally moving and I can drive the gun and split the way I want to.
The question for me now is if it is better to remove the weight from the bolt, or the buffer. Initially I was thinking it would be best to keep as much mass in the buffer as possible (a la JP) but swapping buffers is faster and easier. It would be nice to be able to choose heavy for factory ammo or light for USPSA ammo.
-
I have a dedicated Colt pattern lower, and am purchasing a dedicated Glock mag lower.
I think that Colt pattern has more reliable BHO, straight magazine insertion and a mag cost advantage as well as better very hi cap mag options.
I think the Glock single feed mag design is more reliable and less picky about OAL. The feed cycle doesn't involve smashing into a ramp and being funneled toward the barrel, and if you already have Glock mags then you probably only need to invest in extensions.
Colt mags may have better durability because mag catch is metal on metal. Glock mags are less susceptible to rust.
Both work when dialed in. I probably would stick with only the Colt pattern if I didn't live in CA, but since next year we will be shooting PCC 10 being able to use production mags will keep me from having to purchase and block a bunch of metalforms.
-
On 11/20/2016 at 8:28 AM, Flatland Shooter said:
Will you also experiment with different power factors on the way down?
I am targeting 130-135 pf with 125s, so I am looking for the lightest reciprocating mass/spring combo to support that safely and reliably. I have been close to 150 pf with my Prod loads, so dropping the powder charge is beneficial.
If I pull that weight and go to a carbine buffer that would be about a 25% reduction in reciprocating mass.
-
The central mass and roll pin in my CMMG bolt is 3.45 oz. I am going to pull it, and start with a 5.4 oz buffer and work my way down.
-
2 hours ago, Aircooled6racer said:
Hello: The lower kinda looks like a Matrix one? Thanks, Eric
I always thought the Matrix looked like the QC10! I think QC10 (previously DDLES) has at least a 5 year headstart on Glock mag AR lowers.
Agree that drill/tap is probably best solution. Is this for a lower you already have, or are you in the planning stages?
If you haven't purchased lower yet, the Angstadt appears to have a larger button at a similar price point.
-
I like the way my gun cycles with a standard carbine 3 oz buffer compared to the 5.4 oz 9mm buffer. This is with 148 PF reloads, with a very fast powder and a relatively heavy hammer spring.
I think I am going to remove the center mass of my CMMG bolt, go to a 3.8 oz A5 buffer, and drop 15 pf. I also am going to a shorter barrel with a long, welded muzzle device so that the barrel depressurizes sooner.
Winchester white box is pretty nasty in my gun- I wouldn't run factory without the bolt mass in and full weight buffer. Even then I have seen some flame out of the ejection port.
-
Just a follow up- the match was excellent! The gun ran great although I did have some issues with reset. With a bit of wear the ALG was down to 1 lb, 6 oz and sometimes took jiggling the bolt to get it to reset. I added the auxiliary spring after I got back and now it is 2 lbs with very positive reset.
This will go on my must shoot match list for next year. The night stage prompted me to order a PWS FSC47 Mod 2 for some flash suppression and I am going to play with white light mounting.
-
Something to keep in mind with these is the nitride. Faxon and Kaw Valley (both made by Faxon) in my experience do not like the coated projectiles I use loaded any longer than 1.10 which is not ideal for feeding. I don't know that a regular throating reamer will cut a nitrided chamber very well.
-
24 minutes ago, CHA-LEE said:
I figured it would make sense for the Nationals stages to test a wide range of shooters skills based on what stage design is like at most other major matches. But I guess the masses would rather spend a crap ton of money and time to attend a "Run-Stop-Shoot" repetitive grind with shooting challenges that are over the top for the average competitor. I was going to continue trying to explain my stance on this but I am evidently totally off base from what the USPSA customer base wants to see and experience at the Nationals.
I, for one, voted no on the nationals should be harder than other majors question. Perhaps more difficult than the Master Blaster Hosefest, but comparable to say, A2 would be appropriate in my eyes. I agree that you can test the shooters skill without stomping and restomping the groin.
Where I think you are losing people (or maybe it's just me?) is by calling it unfair.
I can agree that stage was harder than it needs to be. I can even agree that I would rather not see virginia count SHO 25 yard partials at Nationals as I do not think it is a "practical" challenge. I can't agree with your suggestion that we need to redistribute the "real champ" title because a stage was hard.
In the fecal sandwich analogy- you can be against fecal sandwich consumption at matches AND awknowledge that the winner put in the work to choke down that sandwich better than others.
-
2 hours ago, CHA-LEE said:
Just because you like getting your nuts crushed in a vise for the only reason of "THE NATIONALS HAS TO BE HARD" doesn't make it the right thing to do for everyone.
I can understand the frustration here. If I had shot that stage I would be happy to walk away from it with a non zero score (because I suck at strong and weak hand shooting). I get it, and I agree that I don't think it is in line with what we are used to seeing. That being said, if everybody gets their nuts crushed in a vice we wouldn't call that "luck". It is a shooting challenge that was equally difficult for all involved. It isn't like it was a non-shooting challenge, or inconsistent target presentations, or getting your nuts crushed in a vice.
1 hour ago, teros135 said:Bad stages, obviously. Throw 'em all out! (kidding, kidding!
)
If you throw away stages 1 through 19, 21 and 22 from 2013 Nats I would have been in the top 16. Those were clearly bad stages.
In 2014 I would have repeated a top 16 performance if we just threw out stages 1-17, and 19-27. Same thing- just a lot of bad luck and stages.
-
11 minutes ago, ATLDave said:
No, Bobby B. Class merely managed to get 7th.
You are right. You found the smoking gun. A B class guy shoots the stage slow and clean, for a maximum of 66% of the HHF. Sounds suspicious to me. Especially since he place ahead of very good shooters who shot the stage 50% faster with lots of penalties.
.png.b58a4fda545a52217c2ae1adfac54bc4.png)
)
PCC Build
in Pistol Caliber Carbine
Posted
Ron Williams at RMW Xtreme builds these. They won't cycle factory ammo reliably, but will work with slow powders like HS6. The biggest concern is fouling.
The .223 bolt just needs to be opened slightly. I tested mine with a full weight carrier and carbine buffer, but I think a super light bolt carrier and tac com buffer would probably only increase reliability.
I think the problem with a piston is clearance between mechanism and barrel nut. The MPX gas port is approximately where the barrel nut is on an AR.
The lower needs a few mods to work with the DI upper, but overall it is pretty doable. You can send him your lower and he will mod it and send it back. Very light recoil.