#of ports on a comp?

[hcore44]

HOw much difference is there between carver 3 and 4 port compensators?  Other than one more set of baffles and a little length will there be much difference performance wise?  IM looking at the carver 3 vs 4 port comp.  Thanks for any help.

Use will be ipsc/uspsa both major and minor as I get comfortable with the platform.

[kneelingatlas]

The comps are aluminum right?  Go for the four port, the only downside would be the additional weight, but with aluminum it's negligible.

[teros135]

47 minutes ago, kneelingatlas said:

The comps are aluminum right?  Go for the four port, the only downside would be the additional weight, but with aluminum it's negligible.

Atlas - Do you mean 2 vertical ports and 2 sideways (toward the front)?  How about a 3-port comp with 2 additional horizontal ports at the front? 

Doesn't port design also play into the gun's performance?

Is it different for 9mm vs 38SC?  Does it change if you have popple holes in the barrel?

Inform us, Obi-Wan!

[hcore44]

Yes it is aluminum.  The carver comp is 4 ports on the top and 3 on the side (or 3 on the top and 2 on the side for the smaller one).  

Edited October 22, 2016 by hcore44

[zzt]

teros, the correct description of the Carve comp would be 4-chamber, 10-port.  Another way to describe it would be 4-port with 3 bleeders each side.

The four "chambers" means you have four baffles for the gas to push against.  That reduces felt recoil.  The up ports vent gas upwards and reduce muzzle lift.  The side ports bleed off excess gas that would otherwise jet out the front and increase felt recoil.

Popple holes do change the equation.  If you add poppels you reduce muzzle rise, but rob the comp of gas it needs to operate.  So if you had a perfect load before you added the poppels, it will not be slower and harder on the hands.

You could combat this by using more powder, moving to a slower powder, a lighter bullet, or a combination of these.  You fine tune your load to maximize performance of the poppels and ports while making sure that almost no gasses go out the front.  The more poppels you add, the louder the gun and the flatter it shoots.  Also, the more powder you must add to make up for the lost velocity.  They do little to reduce felt recoil.  For comps, as long as you generate enough gas to use them, more ports are better.  When you have both, it's a compromise.

You can go too far.  I recently saw a picture of a Open gun designed for steel challenge.  You don't even have to make Minor for that game, but the gun had at least four poppels and load of ports on the comp.  There is no way you could develop a Minor load to use all those holes and ports.

Edited October 22, 2016 by zzt

[teros135]

And that's part of the fun with Open guns.  So many varables, that interact in multiple ways.  I know GMs with 38SC guns that have no holes and others that have V8s and V6s, and they all shoot flat, for each owner.  Go figure. You just have to experiment and find out what works.  

[kneelingatlas]

I was talking specifically of the OP's choice between

and

Surely a comp with a better port design would be more effective, but given the choice above, I'll take the extra baffle.

[igolfat8]

I have a G34 & G35, both have Carver 4 port comps. I shoot mid minor from both guns and both guns shoot VERY flat.

[hcore44]

Can you share what load you use for the mid minor 9mm load?

[igolfat8]

132-138 power factor in 9. 150-155 PF in .40.

In 9 I usually load 120 grain cast / powder coated pills over WSF. I've used AC and HS6 but prefer the softer impulse of WSF. 

[staudacher]

Port design makes a big difference. Here is my 3rd prototype major comp compared against a Carver 4 port major comp. Video was shot at 600fps. It is amazing how with the carver comp the recoil was so harsh it made my whole hand half numb for a bit. With my comp the recoil didn't feel any worse than shooting minor PF non-comp'd gun.

 

[teros135]

Nice work!