Umarex RP5 pre-review

[oldskoolzzz]

Ok, have done some testing this morning using my trusty Combro. For consistency I used RWS Hobby, 11.9gr. I did three sessions, first with a Webley QGS silencer fitted, second with a Swift Stumpy silencer and then with no silencer at all. Temperature indoors a pleasant 18 degrees.

With each of the silencers fitted I was getting a (disappointing) average of 5.5 ft/lb. Moving to chrono with no silencer, I used the standard practice of inserting a small square of paper between the muzzle and the Combro, which negates false readings from gas on CO2 guns. Oh my...output up to 8.5 ft/lb!

Just been chatting with my mate about this, and we reckon the RP5 system with choke does not like silencers, possibly due to the physics of what happens when the pellet emerges from the choke. I couldn’t see any clipping on the silencers and testing two seems to rule out a silencer problem.

I’d be very interested to see test results from Umarex with a silencer/moderator fitted!

So, in summary, the RP5 Carbine meets or exceeds its stated output...as long as you have not fitted a moderator!
Any views welcome!

Interesting findings and thanks for taking the time testing 👍🏻

Have you tried other brands of pellets without the silencer fitted?

Curious to know if say a bigger sized 5.52 Pellet fairs with the choke etc

[gingernut]

Good to know.

But most shooters would want to use a silencer on the carbine?

I need to do a chrono test on my pistol with and without silencer.

[short-carabine]

Good to know.

But most shooters would want to use a silencer on the carbine?

I need to do a chrono test on my pistol with and without silencer.

This is an issue I want to use a silencer but it is clear the RP5 doesn’t like them. Some chrono figures with and without would be good. Is the pistol rifled or choked? The choke appears to be the issue.

[oldskoolzzz]

Cheers. This was a baseline test with a known quantity. I plan to try Superdomes, Accupell and maybe some Crosman HP without a mod fitted to get some comparison.

Ok cool 👍🏻 Keep us updated.

This is an issue I want to use a silencer but it is clear the RP5 doesn’t like them. Some chrono figures with and without would be good. Is the pistol rifled or choked? The choke appears to be the issue.

Does seem a strange one how a silencer is not only reducing muzzle report but also seriously reducing the power 🤔

[short-carabine]

Ok cool 👍🏻 Keep us updated.



Does seem a strange one how a silencer is not only reducing muzzle report but also seriously reducing the power 🤔

The choke slows the pellet momentarily and then instead of exiting free, it pushes pressure into a restricted vessel. Physics is not my strong point but I think I sort of understand why this is happening. I plan to try it out with a muzzle brake to see what sort of effect that has.

[gingernut]

Pistol has the same TG choked barrel.

I see JSR do a single shot tray as well as the 5 shot mags.

[short-carabine]

Pistol has the same TG choked barrel.

I see JSR do a single shot tray as well as the 5 shot mags.

Ah, then possibly the same effect will apply with mod/non mod setup

[oldskoolzzz]

The choke slows the pellet momentarily and then instead of exiting free, it pushes pressure into a restricted vessel. Physics is not my strong point but I think I sort of understand why this is happening. I plan to try it out with a muzzle brake to see what sort of effect that has.

I get the theory but slightly confused with how the silencer would cause ‘more’ choke effect to slow the Pellet down further

I would have thought soon as the Pellet exits the barrel regardless of silencer fitted or not it’s at x power as it leaves with the blast behind the Pellet being muted by the silencer.

Physics isn’t my strong point either but it’s certainly interesting.

[short-carabine]

I get the theory but slightly confused with how the silencer would cause ‘more’ choke effect to slow the Pellet down further

I would have thought soon as the Pellet exits the barrel regardless of silencer fitted or not it’s at x power as it leaves with the blast behind the Pellet being muted by the silencer.

Physics isn’t my strong point either but it’s certainly interesting.

Confusing, isn’t it?
All I know is that you lose about 3 ft/lb when you put a mod on. Never experienced this on any other gun, so am guessing this is down to the choke

[cozzamec]

There is a German site that sells an full shroud with no cut outs for these for 40 euro, I'm not sure if I'm allowed to post link, if not pm me.
Maybe this would dampen noise enough not to worry about adding an extra silencer?

[short-carabine]

Interesting findings and thanks for taking the time testing 👍🏻

Have you tried other brands of pellets without the silencer fitted?

Curious to know if say a bigger sized 5.52 Pellet fairs with the choke etc

Cheers. This was a baseline test with a known quantity. I plan to try Superdomes, Accupell and maybe some Crosman HP without a mod fitted to get some comparison.