New guy, may be a dumb question

[Hampton]

I have a new to me .22 R5M that I am sighting in. It is pretty much hole on hole with JSB 25‘s at 10 yards. If I shoot NSA .217, slugs of the same weight the poi moves to the right 2” with no elevation change. Is this to be expected? The NSA 17’s and 20’s are all over the place. Is this just because they are not going fast enough? Would it even matter at 10 yards? Thank you for your time.

 

[SoulSniper]

maybe something related to the spin they gain depending on how they're behaving with the barrel lands and grooves... e.g. their metallurgy/physical properties (hardness/weight/internal ballistics) provided the push everytime is consistent.
Still, at 10m difficult to conclude...

Welcome to the AGN, @Hampton

 

[hawkeye69]

They may be the same weight, but the shape and ballistic coefficient will be different, so you should expect them to have a different POI.

 

[Ezana4CE]

@Hampton Is your R5M standard length or the long version? Either way, I wouldn’t waste airgun slugs shooting them at 10 yards. This is coming from someone who has shot pellets and slugs from a .25 Edgun Lelya 2.0 (R5M platform) out to 60 yards.

I suggest that you begin testing and tuning around 50 yards with slugs out of that gun. As Hawkeye stated just because the projectiles are a similar weight doesn’t mean they’re going to perform similarly, particularly when you’re comparing slugs to diabolo pellets. That is unless the JSBs you’re referring to are JSB KO slugs. Even still, don’t expect them to perform the same as NSAs. Also be mindful of the stated slug diameters (which can vary by thousadths of an inch affecting performance from your barrel).

 

[beerthief]

Very old saying "the only dumb question is the one not asked"

 

[Hampton]

I was just getting the scope on paper in my garage and seeing weather any of those slugs would group. I’m not too impressed at this point. Most of my shooting will be 50 and in. I also have a puff of air hitting my face when I fire a shot. Just waiting on Amazon to deliver my 12 mm allen wrench so I can replace those two barrel o-rings. Then I’ll get more serious. It‘s my first PCP and I’ve got lots learning to do. Thanks for your input.

 

[Ezana4CE]

@Hampton I see. When testing different ammo all sorts of things happen. You’ll need to get that breech o-ring reseated. When testing various ammo, it’s good to be able to make adjustments to your regulator and hammer spring. To get to the reg you have to get into the gun. With this particular platform some sort of vise is good to have for tuning so you can clamp the chasis and shoot with the stock removed from a rest in order still have access to the hammer spring to make adjustments between shots. A Caldwell Shooting Turret placed on a table works great. I suspect that you can get away with using a clamping head like a Pig/Hog Saddle or a BOG Death Grip. Just be sure to have a solid and level tripod for a base. I prefer the Caldwell Turret on a table to a tripod. You also need a chronograph to measure velocities after making adjustments.

Considering that it’s your first PCP check out the videos online. It’s a pretty easy gun to learn. Plenty of info in it in the forums and on YouTube. I’d focus on finding a good pellet that it shoots well first. Get that established then try others.

 

[Hampton]

Here are a couple slugs I was able to find in my trap. You can definitely see the rifling on them.

 

[Feinwerk]

Hello @Hampton
Great rifle! The R5m is easy to work on and nicely designed for maintenance. If you are getting air in your face when you shoot you may have lost your breech o-ring. The bolt block slides backwards and away with just a single 4mm hex socket screw in the rear. You may need a block of wood and some gentle tapping in the magazine well if it is tight. And then you have to separate the puzzle piece connection in the cocking link rod on the left side by moving the bolt block sideways and wiggling it. You will see a counterbore in the breech where an O-ring should be.

According to the schematics I have, the O-ring size for the r5m 22 caliber breech should be 5.3x2.4mm (0.208" ID x 0.094" CS). this is mighty close in dimension to a standard dash size -207 o-ring which is specified to be 0.206" inside diameter and 0.103" cross section diameter. Standard 70 durometer buna n type compound is good.

Sounds like a used gun, don't be surprised if you need to replace another o-ring or two here and there. Although the air reservoir may be rated for 300 bar, it's better not to fill past about 230 bar or so to avoid over stressing the O-rings in the air reservoir and regulator assembly.

You can search for maintenance videos from Edgun West and others on YouTube that show these procedures. Edgun West has schematics on their website.

Regards,
Feinwerk

 

[Gmon]

I have a new to me .22 R5M that I am sighting in. It is pretty much hole on hole with JSB 25‘s at 10 yards. If I shoot NSA .217, slugs of the same weight the poi moves to the right 2” with no elevation change. Is this to be expected? The NSA 17’s and 20’s are all over the place. Is this just because they are not going fast enough? Would it even matter at 10 yards? Thank you for your time.

It probably does not like slugs because it is a choked barrel which is not designed for slugs some guns can shoot slugs but they shoot better at higher speeds some choked barrels like slugs

 

[Hampton]

Hello @Hampton
Great rifle! The R5m is easy to work on and nicely designed for maintenance. If you are getting air in your face when you shoot you may have lost your breech o-ring. The bolt block slides backwards and away with just a single 4mm hex socket screw in the rear. You may need a block of wood and some gentle tapping in the magazine well if it is tight. And then you have to separate the puzzle piece connection in the cocking link rod on the left side by moving the bolt block sideways and wiggling it. You will see a counterbore in the breech where an O-ring should be.

According to the schematics I have, the O-ring size for the r5m 22 caliber breech should be 5.3x2.4mm (0.208" ID x 0.094" CS). this is mighty close in dimension to a standard dash size -207 o-ring which is specified to be 0.206" inside diameter and 0.103" cross section diameter. Standard 70 durometer buna n type compound is good.

Sounds like a used gun, don't be surprised if you need to replace another o-ring or two here and there. Although the air reservoir may be rated for 300 bar, it's better not to fill past about 230 bar or so to avoid over stressing the O-rings in the air reservoir and regulator assembly.

You can search for maintenance videos from Edgun West and others on YouTube that show these procedures. Edgun West has schematics on their website.

Regards,
Feinwerk

Thanks for the reply’s. I replaced the transfer port o-rings and got rid of the puff of air in my face. It is now shooting JSB 25‘s and hades minute of acorn at 25 yards. I’m pretty pumped. I can wait to get out and shoot at longer distance. Slugs are still in the future. But I need all the tuning gear first. @Feinwerk, I really like reading all your post about R5M. Below is a five shot group at 25 yards. I did pull one to the left a little.