Nielsen .177 caliber slugs for a Brocock Compatto Sniper XR

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Blackpaw

Blackpaw

Member
Apr 23, 2020
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Idaho, United States
Hi Everyone: I am slowly assembling my shooting kit and part of that is to try out different ammo. Does anyone have experience shooting Nielsen slugs in a .177 rifle? My rifle is a .177 Brocock Compatto Sniper XR (2020) and I at 24 joules / 18.5 foot lbs, so in theory I think the rifle can shoot slugs. So i bought a box of Nielsen Slugs in 15.5 / 6 grain for my .177 Brocock Compatto. 

Nielsen said they worked with Daystate to make / design the slugs so I figure Brocock uses a lot of the same technology so its logical to assume the Neilsen slugs preform well in Brocock barrels as they do Daystate. Or am I wrong?

Thanks for the info everyone.
 
I have noticed slugs in general need a gun that can produce a higher feet per second for them to be more effective in the smaller calibers. I have a 22 cal which would not shoot the 17.5 gr .216 slugs well at less than 880 fps. Once I was able to reach 880 to 910 fps they started to group well. I am sure others will chime in with their experiences as well.
 
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I have noticed slugs in general need a gun that can produce a higher feet per second for them to be more effective in the smaller calibers. I have a 22 cal which would not shoot the 17.5 gr .216 slugs well at less than 880 fps. Once I was able to reach 880 to 910 fps they started to group well. I am sure others will chime in with their experiences as well.
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Agreed. Slugs, aka bullets are spin stabilized and with the slower twist pellet guns they require more velocity to get that spin. Generally, you want to go with the lightest slugs you can. The combination of short length and higher velocity helps get to the length to spin speed requirement. 
 
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Just to give an update....The NSA .177 slugs / bullets 14ish grain arrived today, so I did a quick test using a small pumpkin. I compared the expansion of the slug vs a h&N barracuda hunter 9.6 and I looked at expansion. Gun was set to 18 ft lbs / 24 joules for both projectiles. Distance from pumpkin around 5 yards. When I can I will go a longer distance shot, but the slugs’ performance was disappointing to say the least especially considering the slugs are far more expensive than the pellet. The exist is of the pellet. Comparison of slug vs pellet in same pumpkin at same power setting and distance.





considering the extra cost. See photos. The
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 exi
 
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750 fps is a little slow for a slug to be effective. General rule is +800. I try to get them leaving the barrel plus 900 fps. Find the smaller diameter slugs, with their smaller hollowpoints, need even more velocity. 

Also, did you Chrony the slug? I find they usually have less velocity than an equivalent weight pellet because the extra bearing surface causes more friction.

Smaller diameter slugs work better in choked barrels in my experience. The choke of a pellet barrel can deform slugs that fit tighter.

Here is a NSA 17.5 gr. .22 leaving the barrel around 900 fps retrieved from a squirrel.

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Well, I have the newest version of Compatto, the Sniper XR, and Brocock CLAIMS on their website the gun is “self-regulating” as do some some of the reviewers for the newer / newest versions. Also, I have the FAC version and Brocock claims at 12 ft/lbs you get up to 75 shots and up to 25 shots at 18 ft/lbs, which seems true. This is all from the Brocock website. Thus, I thinking the Compatto is regulated, just not using like a Huma regulator. Also, shot wise consistency using the FX chronograph, but “not formal” monitoring, it seem pretty consistent per pellet type, plus or minus an average of 7 feet per second, but I will a full 20-30 shot string and post the data.
 
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Self regulates is just a way of saying unregulated. The valve, hammer and spring design is such that the shots will vary a slight amount over a wide pressure range. Typically the velocity will start low, progress up and then back down, in an arc. The lower the power the flatter the arc.

There isn't anything inherently wrong with an unregulated PCP. Regulators are a relatively new phenomenon in airguns. They do add pressure consistency over a fill, but at a cost and with their own reliability and service issues. Unregulated designs have gotten better and better at eliminating bounce and delivering a wider range of consistent shots.

Having said that you want to take that new Chrony of yours, fill the gun up and shoot it down to determine the ideal range based on the velocity deviation you are willing to live with.

Here is an example of a curve I shot with my AEA Backpacker.

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Okay here is the quick and dirty info with a JSB exact 8.44 grain shot at 12 ft lbsish setting for 50 shots, I thought that was enough to tell the basic story, and this was from 200 bar full fill. I didn’t run it out, but again 50 shots gives a pretty good story. I was using the FX chronograph attached to the barrel to do the readings and linked to my iPhone 10XR, for full disclosure. Over 50 shots the average speed was 763 FPS with a standard deviation of 2.7 FPS. Officially regulated or not it acts like it, so i am happy.

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That is good over that range and power setting. The low power and high power settings will act differently. The high power setting will have a "curvier" distribution.

It is a good idea to find the proper fill and refill points even if it takes a lot of pellets to do it. I try to combine accuracy and target practice with the process so I'm not just wasting pellets.
 
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Daniel, I 100% agree with you on the power setting vs consistency and etc and variation, but at least I have a general idea of what to expect. I have created a sort of indoor range, and want to keep the gun on the low power setting. I haven’t even had a chance to get a proper range to really sight in the scope (which came yesterday) maybe next weekend I can get to a range for a 20-25m sighting in. Damn covid19 is playing hell with our fun. :p. But like I said, you are 100% correct with variation, power setting, accuracy and I still need to find the Compatto’s favorite pellet.

As I progress I will give updates and thank you for your advice and input, it is helpful.
 
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Okay upon further investigation, and meaning Brocock needs to update their website, I found the Brocock Compatto Sniper XR IS regulated based off their own literature. However, their website’s description still says “self-regulating”, so someone must have had a lazy day and just copied and pasted specs from the standard to Sniper versions. See below, but the Compatto Sniper XR weighs a TENTH of a pound more than the Compatto XR!!! Now I am wondering if having a regulated gun is worth the extra weight. Hhhmmm.

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Not sure if this has been addressed yet on this thread, but....Don’t forget that slugs shoot best out of specific twist rate barrels (I’m ignorant to the specifics) It’s really the draw of luck that they will perform well in Pellet barrels. When I try them, I consider myself fortunate if I get good accuracy out of them. 

I have had more success with the FX Hybrids, and even those like some Ummph behind them. 
 
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