How to figure muzzle pressure with diff barrel lengths (.22)

[Sid Post]

I have an all Stainless Steel AAC Scarab suppressor and 22 Hornet rifle inbound. Since I need to have the barrel threaded, I'm thinking I want to have the 24 inch bull barrel cut back. However, I don't want to cut it back so much I blow out the guts of my suppressor. 24 inches plus suppressor is pretty long and unwieldy. How short can I get before the muzzle pressure increases too much for this 22LR suppressor?

If it matters, I have a 22 Magnum I could thread too. I also have a suppressed 5.56 option (too big and heavy) but, I want to find something in between 22LR and 5.56. The 22 Hornet seems like a good fit between those two and staying with a centerfire option gives me handloading options I don't have with a 22Magnum.

What barrel length should I go with? What is too short and too much pressure for the suppressor?

[BigDave@SMDW,LLC]

You might want to contact AAC and verify that all the baffles in your Scarab are in fact stainless, we retrofitted one a while back and it had some aluminium k baffles in it..... Just wanted you to know before you kill your can thinking it was all stainless.

Dave
Liberty Suppressors

[Conqueror]

I think QuickLoad can calculate muzzle pressures, maybe someone who owns the program will compare 5" .22LR, 16" .22WMR, and 20" .22 Hornet muzzle pressures for you.

[JohnInNH]

I don't think Quick Load has 22 LR data ... I'll have to check


ETA: it has .22 Experiment.. but I could not find any bullets but could use a .22 cal 29 gr pellet. But what powder?

Some how you would have to get the factory equivalent into the program .. THEN you can get Muzzle Pressures.

[Sid Post]

You might want to contact AAC and verify that all the baffles in your Scarab are in fact stainless, we retrofitted one a while back and it had some aluminium k baffles in it..... Just wanted you to know before you kill your can thinking it was all stainless.

Dave
Liberty Suppressors

Thanks Dave! Yes, mine has all stainless baffles. I can tell by the weight alone. This was special ordered by my local dealer after I called AAC and got one from "dead stock". I think they had two all stainless models left when I got mine. I would consider having it upgraded if needed but, it is such a niece work of art and craftsmanship that I don't alter it. I did call AAC a couple of years back and got confirmation that it would work on a 24" barrel so, I know that is a good option except for the overall length issue.

Best Regards,
Sid

[Sid Post]

I don't think Quick Load has 22 LR data ... I'll have to check

John,

Can you use a factory load with a 24" barrel and run some samples with it cut back to shorter lengths? THANKS!

Best Regards,
Sid

[garry]

Does anybody happen to know the weight of a all s/s scarab?
Thanks in advance

[JohnInNH]

I don't think Quick Load has 22 LR data ... I'll have to check

John,

Can you use a factory load with a 24" barrel and run some samples with it cut back to shorter lengths? THANKS!

Best Regards,
Sid

Sid Quick Load does not have "Factory" .22 LR data. (That I can find.) If I did I would be more than happy to run some data.

[silencertalk]

Scarab was available with either aluminum or stainless baffles.

[Sid Post]

Sid Quick Load does not have "Factory" .22 LR data. (That I can find.) If I did I would be more than happy to run some data.

John, sorry about the previous post which was unclear. Do you have access to any 22 Hornet load data? I'm wondering for example:
Is pressure from a 16" 22H versus 20" versus 24" factory 22 Hornet load significantly different?

THANKS!
Sid

[JohnInNH]

Sid Quick Load does not have "Factory" .22 LR data. (That I can find.) If I did I would be more than happy to run some data.

John, sorry about the previous post which was unclear. Do you have access to any 22 Hornet load data? I'm wondering for example:
Is pressure from a 16" 22H versus 20" versus 24" factory 22 Hornet load significantly different?

THANKS!
Sid

The .22 hornet barrel is it a .224 custom groove or a .222 groove SAAMI barrel? What weight bullet?

Funny the data in QL for my Lyman cast 158 gr GC bullet I shoot in my 357 Mag which is listed as SAFE of 8 gr Unique in the Lyman Book (and has been for years) is in QL as WAY over pressure! Soooo I don't trust the data in QL It is OK for suggestions and comparisons.. but does NOT replace loading manuals and real range time.

[Sid Post]

The rifle is a Ruger Model 77 in 22 Hornet, stainless heavy barrel which I think uses the .222 SAAMI barrel. I plan on shooting 45 grain bullets.

[Twinsen]

I never even thought of getting a Spectre and using it for .22 Hornet. I have a Ruger No.3 with a 22" barrel in .22 Hornet that I'd love to silence. My father would never forgive me, but I'd shoot the gun a lot.

[JohnInNH]

The rifle is a Ruger Model 77 in 22 Hornet, stainless heavy barrel which I think uses the .222 SAAMI barrel. I plan on shooting 45 grain bullets.

http://forums.cabelas.com/archive/index.php/t-752.html <--worth reading this page

from one of the posts. re the Rugar 77: "On the Ruger M77, you can take out the pin that holds the two piece bolt together. Then get some .005" shim stock and cut a washer, (a pair of fly-tying sissors works great), to place between the two bolt halves and reassemble the bolt.

When you replace the bolt in the rifle, you will notice a great difference in the pressure required to close the bolt. This simple fix can turn a bad shooter into a real tack driver!

Ruger needs to address this problem with tighter tolerances."

The Ruger will have a 1:14 twist.
more good reading: http://forums.gunbroker.com/topic.asp?TOPIC_ID=82154

I woudl NOT try to shoot the M77 Hornet subsonic with that twist!

It may even cause baffle strikes with some supersonic loads biased on the reading above... Make sure your ammo is not all over the paper before you shoot it with your can.

Seems to be a problem with it. Long throat and a short magazine. For some reason the Winchester 46 gr hp will shoot OK in it .. I will see if that is listed in QL and run the numbers with it. But it's late... Maybe tomorrow.

The CZ seems to be the one to get.. I would build a hornet with a fast twist barrel. a 1:9 or even a 1:7 since I would be loading subsonics for it....

Shorter barrel will reduce the RPM as the Vel goes down... you might exacerbate the issue of wobbling bullets.

[Sid Post]

Interesting read in those old threads. The rifle is coming from Davidson's so, if it is a total lemon they might offer a solution. And, no I don't plan on shooting ~35gr loads which seems to be part of the problem in those two threads.

Another good read on the Ruger: http://www.gun-tests.com/performance/dec96hornet.html