RAW HM1000x external plenum

I got the last inline plenum from a friend of a friend. Apparently Mubhaur now has the information he needed to have his machinist manufacture some of the plenums. Mubhaur, you can take over from here!;)
Stoti
Screenshot_20231016_191924.jpg


After finding a Huma regulator of newer HM1000X, my machinist has made male and female matching threads sample for future reference.

I hope it will work.

Bhaur
 
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Morning all. You would be surprised that my RAW is actually almost stock, and is shooting Altaros Smooth ATP .22 cal 32.5gr slugs at 915fps. They are incredibly accurate at this speed all the way out to 250 yards so far. See 1 MOA (2”) group at 200yds below. View attachment 385316View attachment 385314

I have the regulator set at 145bar and it has a dual hammer spring. The only non-stock part is a small plenum extension that screws into the valve return spring plug hole above the regulator. With this gun setup, I am able to achieve a max of 920 with these 32.5gr slugs, and Altaros says they shoot best at this speed. I tried slower and they weren’t as accurate, but haven’t tried faster yet.View attachment 385319

I plan to start working on some improvements so I can shoot the 32.5gr slugs faster (980fps) and also shoot the Altaros Smooth .22cal 40gr slugs at 910-920fps when it cools off this fall. One upgrade will be a larger plenum.

I am actually very happy with the way the gun shoots now. It doesn’t have much kick, I get about 25 shots per fill, it is super consistent and very accurate, and the Altaros slugs have a very predictable but small wind drift due to their high BC. I am only curious what I can do shooting faster or with a heavier slug, and my goal is to end up shooting 40gr slugs at 1040fps like rimfire rifles do.
Jeff, I agree with you on the Altaros, and I'm surprised more shooters don't use them. The 32.3 in .22 are very good, and really don't benefit from going any faster than 910-915 fps. You COULD go faster or shift to the 40-grain version, but your shot count would go down quickly.
One reason I think they aren't as popular is that shooters that are used to fast-faster-fastest have that speed fetish, and when trying out the Altaros shoot them too fast and decide they aren't accurate - when it's really operator error, not the slugs.
The 32.3 in .22 cal. with a BC of 0.18, the 40 grain at 0.21, and the .25 caliber at 0.21 are almost double the BC of current standard offerings. They are somewhat expensive, but no more than slugs from boutique shops like VK, AVI or Griffin.
I shoot the .25 Altaros ATP Smooth at about 890 fps and a confirmed BC of 0.21 G1 or 0.111 G7. Wind drift is less than .22 RF rounds. They'll easily put ten rounds on a 3-inch spinner at 200 yards...
 
Hey mubhaur,
I would gladly buy 3 in-line plenums made by your machinist.
He’s very good😎.
I wouldn’t need anything fancy, just 15, 20 and 25 cc plenums made from SS.

once we get the specs figured out, let me know what it would cost.

If 3 are made at once, it should be pretty fast/easy to do😎.
I hope that I can provide you inline plenums in near future.

Here is my 1st inkine plenum for RAW.

Screenshot_20231112_222223.jpg
 
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Mubhaur,
I was thinking of a plain, (polished) stainless steel (round stock), threaded to go into the RAW receiver w/o-ring; which then would accept the RAW regulator on the other end. This hollowed/threaded piece would give and additional 25/30cc's of plenum space between the regulator/receiver.

A one piece part and no knurling required. Unfortunately, my lathe is not ridged enough to thread SS accurately or I would do this myself.
I'm looking for one very similar to your picture above; the hex sides would allow a wrench to fit it.

FYI, my 20 gram Co2 cartridge works great as a plenum on my Green RAW, but forced me to carve out the stock - which I'm reluctant to do again with my Red/Blue RAWs.

Thanks for your time,
Kirk
 
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Mubhaur,
I was thinking of a plain, (polished) stainless steel (round stock), threaded to go into the RAW receiver w/o-ring; which then would accept the RAW regulator on the other end. This hollowed/threaded piece would give and additional 25/30cc's of plenum space between the regulator/receiver.

A one piece part and no knurling required. Unfortunately, my lathe is not ridged enough to thread SS accurately or I would do this myself.
I'm looking for one very similar to your picture above; the hex sides would allow a wrench to fit it.

FYI, my 20 gram Co2 cartridge works great as a plenum on my Green RAW, but forced me to carve out the stock - which I'm reluctant to do again with my Red/Blue RAWs.

Thanks for your time,
Kirk
I hope I saw this message too late.

I understand that in order to add an SS hollow pipe between the block and the regulator, the filling point and gauge point would need to be moved a bit towards forward position.

Apparently it is not possible without modifying the stock.

I have old style stock in my mind.
 
Thanks, I can get one from my friend or from Martin in a week or two, I’m just in a crunch for time, so I’m trying to get one asap. If necessary, I can just use my current tune and multiple BC’s for the upcoming NRL22 match and then deal with the plenum when I can. I appreciate the response though.
Have a good one. Stoti
Does Martin make external plenums?
 
Thanks. The gains were between 30-45fps depending on the slug. The VK 32.8 and Zan 33 grain were the two standouts, as they were before the upgrade. The Wildman 30gr also shot pretty well. Not sure if we’re going to go with the Zan or VK, both were so accurate, it was hard to tell which was better. It was pretty windy but I think the edge goes to the Zan 33gr at 980fps. Cooper was shooting some tiny groups at 50, 100 and 175yds.
Have a good one.
Stoti

View attachment 391539

Thanks. The gains were between 30-45fps depending on the slug. The VK 32.8 and Zan 33 grain were the two standouts, as they were before the upgrade. The Wildman 30gr also shot pretty well. Not sure if we’re going to go with the Zan or VK, both were so accurate, it was hard to tell which was better. It was pretty windy but I think the edge goes to the Zan 33gr at 980fps. Cooper was shooting some tiny groups at 50, 100 and 175yds.
Have a good one.
Stoti

View attachment 391539
Other than the inline plenum what mods do you have done to reach 980 fps with the 33 grain slugs? And what's your regulator at ? I have a .25 caliber hm1000x and would love to sling some slugs at that speed !
 
Morning all. You would be surprised that my RAW is actually almost stock, and is shooting Altaros Smooth ATP .22 cal 32.5gr slugs at 915fps. They are incredibly accurate at this speed all the way out to 250 yards so far. See 1 MOA (2”) group at 200yds below. View attachment 385316View attachment 385314

I have the regulator set at 145bar and it has a dual hammer spring. The only non-stock part is a small plenum extension that screws into the valve return spring plug hole above the regulator. With this gun setup, I am able to achieve a max of 920 with these 32.5gr slugs, and Altaros says they shoot best at this speed. I tried slower and they weren’t as accurate, but haven’t tried faster yet.View attachment 385319

I plan to start working on some improvements so I can shoot the 32.5gr slugs faster (980fps) and also shoot the Altaros Smooth .22cal 40gr slugs at 910-920fps when it cools off this fall. One upgrade will be a larger plenum.

I am actually very happy with the way the gun shoots now. It doesn’t have much kick, I get about 25 shots per fill, it is super consistent and very accurate, and the Altaros slugs have a very predictable but small wind drift due to their high BC. I am only curious what I can do shooting faster or with a heavier slug, and my goal is to end up shooting 40gr slugs at 1040fps like rimfire rifles do.
Are you using the 5.50 or 5.52 on the ATP smooth altaros slugs ?