caspian guy

+1 regardless of timer/RO the competitor is responsible for making sure his score /time is accurate.

From what I understand from some reading around rocket nozzle physics, the angle of the of the cone shape that the port makes (15 degree included angle) and the area of the exit port matters. The rib lets you do that. My understanding is that the guy who originally designed this barrel setup used to work in aerospace. I think that's a consideration as well. http://www.braeunig.us/space/propuls.htm is interesting (but a little dense)

Yea... Not the best installment.

I think as time goes by the brass will get more expensive but unavailable, no... The FBI dropped 10mm years ago and yes 10mm brass costs more than it did when I could get 1x fired but I can still get it from several sources to feed my single stack gun. Too many 40 pistols have been sold for it to disappear.

So I was curious enough to look it up... The current world Open record for the main match is 74.84 shot by Max (2016). Max also held the previous CO record at 81.38 (2018). So this year in the main match BJ set a new CO record at 75.37. (Max was at 81.21 in CO and 82.60 in Open ) So short of doing hard core data analytics what I can say is the world record time for CO dropped by about 8% and it is less than 1% slower than the open record.

Be curious to see the open world record times (maybe held by Max/Bj?) against their CO times this year? To see what the comparison is between Max's max CO effort and max open effort. (trying to find a common yard stick to judge the OP's conjecture against.)

They could cut the entire back of it past the dot module off and put modern electronics in it probably increase the battery life by 100x... But that would require new injection molds and design work that would have to be paid for in cost savings or increased price. Betting they have decided its not worth it.

Dpp 7moa triangle. I like the dpp with the small dot but having had and tried both sizes, the bigger dot works better for me on the clock (easier to track) That is a similar conclusion I had come to for optics on my open guns as well. Started out with like a 4moa cmore dot module. After a number of years I settled on 8moa dot modules.

You could always measure them to make sure some thing isn't really off. But, when I am fortunate enough to get a fit that tight I heat the receiver gently and cool the barrel and tap them together exactly as you describe. I usually only bother with bearing retaining compound (green loctite) when the fit is loose.

Curious about the basepad on your mag?

Cool i guess that's what I'd have expected.. the 308 ptr I have has been a good gun. Yea hks rifles aren't notorious for wonderful triggers are they? I keep hoping with more clones on the market someone will offer a better after market trigger for them. It's not as if it can't be done, I have a PSG1 trigger pack I picked up that I use in my PTR and my Hk94 which is really good. Shame no one reproduces those.

Cool, let us know what you think of the ptr, I have one of their 308s but haven't had a chance to handle one of their mp5 clones.

The meopta is eotech/aim point bright with a fresh battery.

Yep James was faster than me... If you look carefully it looks like the front sight is mounted on a block attached to the barrel instead of the slide (like an old sti tru sight). That would make the sights almost non-reciprocating which would make them easier to track as well as the gun cycled. Same sort of effect as an old highstandard target pistol I have.

I'd assume it's to get more sight radius and still fit in the box for Ipsc standard division.

Being 6'4" with long arms an 11.5" or so gun is about as short as I can drive aggressively.

Very cool. Corporate memos sure don't look like that any more.

I vote you start with what you have and spend some time learning your hold overs. While it's not optimal with some practice a decent optic and trigger you can make it work. If you want to buy something by all means get a JP15 or a CTR. If you asked me who built a better rifle I'd be at a loss to tell you. Plus if you decide to sell it later you won't take much of a loss on a factory JP gun.

For me I'd say the MP5 is a lot softer/smoother than a normal blowback AR. I never bothered to shoot mine back to back with a really well tuned blowback AR (JP or something like that) or an MPX, so not much help there. If I think about it maybe after a match I'll see what I can borrow.

I ran my hk94 for a while in pcc. I had a B&T style rail adapter that clamps to the top of the receiver with a cmore on it. That plus a psg1 type trigger pack I had in the HK parts box and a choat stock with a 3d printed cheek piece seemed to work pretty well. For a lower scope mount (should work with normal stock height) you might look at: https://www.hkparts.net/shop/pc/HK-MP5-MP5K-Low-Profile-Mount-RMR-p18234.htm It replaces the rear sight drum. The triggers aren't good unless you happen to have to have a Psg1 pack hanging around in your parts box like I did. You might consider getting one from HK Parts that Bill Springfield has tune. The mag changes do take some practice (particularly since my gun has a button mag release instead of a paddle) and I never got around to designing a magwell for it but they aren't impossible. I have some of the short mags ( I think they are 15 rounds) I need to try one of these day to see if that makes the reload better. All in all if you are comfortable running one there's no reason you can't be competitive with it.

If that turns out to be true, and it's durable and bright, I'll be replacing a couple of delta point pro dots late this year.

Maybe try contacting him and offer to pay for a license to print one based on his design. That's not unheard of in the 3d print world.

There's some other costs to think about there... Insurance, Healthcare, taxes,costs of keeping a shop open, wear and tear on tooling and equipment. Plus the occasionally taking time off for vacation and being sick plus the normal risks of small business ownership.

Yep pretty much an adjustable parallel.

When i firat started loading 9mm major i experimented a bit with it, and waw able to loaded the same cases that started out as once fired 5+ times with no real problems I did start to see some splits after that. Now I shoot them once in practice and load them back up and shoot them at a match and leave them on the ground.