Tuning FX Impact slug - retract adjustable pin

[bigHUN]

I may be wrong with this my idea, but what I am looking for I don't see it listed anywhere.

These pellet and slug pins went through a hell of a evolution during this past year or two, there were several variations and currently what is available on the market - people are mostly happy with.

I am just stating using slugs and seeing some shortcomings.

If you already know what weight and length slugs (or pellets for example) you want to use there are several options from Nielsen adjustable probe to Huma or FX.

But I am just starting with slugs, some are shorter some are longer, some are skirted and some are boat tails. Adjusting/pushing the seating depth is different concept.

I don't want to retract the pin probe like the Nielsen (the edge will come too come close to the port oring), but I want to retract the pin only.

Who is making this pin currently? Looks like exactly what I want - theoretically.

If none available on the shelfs I would need a machinist to make me some.

I am talking .25 cal

 

[M0ist0ne]

Looks like the one made by HP Performance from the interwebs searching I did. The FX pin probe is similar, the screw only changes the pin length.

 

[bigHUN]

......The FX pin probe is similar, the screw only changes the pin length.

Yes the HPP is/was .22 cal only and they selling it somewhere in S Africa.

The FX online pictures are oriented in the way I could not see if the pin length is adjustable. I don't like that loose .25 sleeve I would prefer an integral piece but given as a only option I would give it a try if any available on shelf. Also I don't need the entire kit I have my own handpicked parts already installed.

 

[Eddy1840]

That’s a fx slug probe I have one installed on my impact 

 

[biohazardman]

NSA and FX both make an adjustable pin probe. 

The main body of the probe is adjusted on the NSA.

Just the pin is adjusted on the FX. I am not sure that all calibers are all available in the adjustable flavor or not.

I was disappointed with my FX pin probe when I learned that it can not be adjusted to seat things any deeper than the stock probe unless you loaded single shot. As the probe will interfere with the magazine when adjusted any amount forward of the stock unit. So I sold mine.

https://nielsenspecialtyammo.com/search?q=Fx*+Impact*+Probe*

https://www.pyramydair.com/product/fx-impact-slug-power-kit?a=9604

 

[Centercut]

The pin probe from the FX slug power kit is fragile and will bend. Not recommended. I use the one from NSA, which is much more robust. Huma makes one also but I’m not familiar with that one. 

 

[bigHUN]

............Just the pin is adjusted on the FX. .........I was disappointed with my FX pin probe when I learned that it can not be adjusted to seat things any deeper than the stock probe unless you loaded single shot. As the probe will interfere with the magazine when adjusted any amount forward of the stock unit........

Just looking at the online pictures I am speculating the same problem exist with both FX and Nielsen probe - to have a rear clearance to the mag but to adjust the seating depth deep. I assume it is working only one way, one or the other?

I have collected a variety of slug weights, the 37 and 41 gr are some standard shape and most likely just any pellet or pin probe would work.

Bbut ones I step up to 44 or 46 gr these already have boat tails, the length difference is significant, and the 46 gr is a definite single load slug.

 

[bigHUN]

I made this pin last year (picture dated Apr.2020) to (at that time) existing Huma brass piece.

I was shooting pellets until now so I never used that pin.

In mean time they changed the design around and the orings got new dimensions and now turns out that this my pin is undersized = may leak with worn out oring.

 

[bigHUN]

Just for educational purposes only I collected these numbers:

37 gr - length 9.1 mm

41 gr - length 9.7 mm

44 gr - length 10.9 mm

46 gr - length 12.2 mm

So how would you do this? Lets assume I am searching for a best POI and shooting in sequence let say each slug weight/length per day.

a) - Pushing all the different slug nose to the same depth, meaning adjusting the pin probe length for each weight? there is a 3mm length difference and with the longest slug the pin edge may be sitting right on the oring.

b) - Or you don't touch the pin probe and each of these slugs nose will be pushed to a different depth?

 

[Hobbyman2007]

BigHun, 

This is where it gets complicated. The leade has to be cut for one projectile length or better yet profile. You may get lucky and have a couple slugs that will engage the lands and groves but to get the absolute best accuracy . Pick one and run with it. As for the pin length and seating depth , as long as the base of the projectile is clear of the transfer port , you should be ok. For engagement , I tend to use 1/4 to 1/3 of bullet length. You can cheat a little bit with the probe length but it’s not a substitute for a properly cut leade. That’s my opinion anyway. 

 

[bigHUN]

Do you have the heating working in your shop? I can send you my drawing.

The adjustable pin length to be made from ejector pin.

 

[Hobbyman2007]

Hun, I do have some hardened drill steel in 2mm OD . That should be good for a .25 and not dent the back of your slugs. I’ve run as small as 1mm but that’s only good for pellets. And yes my shop is heated. It’s actually in my basement better known as “ The Gungeon”.