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All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Big Bore AirGun Gate => Topic started by: mackeral5 on April 13, 2020, 11:23:02 AM

Title: new to me Extreme .457
Post by: mackeral5 on April 13, 2020, 11:23:02 AM
Over the weekend i worked a trade for an Extreme in .457.  In anticipation of its arrival I have read most everything out there on the topic by members such as Extreme 457, Jeremy 1982, DanH, Shamu25, etc. 

I tend to plink more than anything else so I won't do too much full powered shooting.  Getting a multiple shot bell curve with velocities in the 925-950fps range is more in line with my primary use.  I ordered some 166gr from Hunter Supply as those seemed to be a good choice. 

I've read about spring changes and there being a couple of springs  that are popular to detune a bit.  Century Spring seems to be the preferred vendor but they have a $50 minimum order, at this time I can't think of $50 springs that I need. 

Would anyone happen to have any spare springs that work for detuning the Extreme.  A 3000-3600psi fill is what I would like to target. 

thanks in advance!
Title: Re: new to me Extreme .457
Post by: dyotat100 on April 13, 2020, 12:02:44 PM
Wodering why you choose to shoot such a light bullet?

BC has to be terrible.
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 13, 2020, 12:33:57 PM
Wodering why you choose to shoot such a light bullet?

BC has to be terrible.

Very good question....  I am new to this level of airgun  so part if it is I simply don't know what I'm doing.  I didnt necessarily seek out a .457,  a .357 would have been more ideal for my tastes.  But the deal was for a .457....  perhaps later  it could be rebarreled, I am not certain if the extremes are designed that way?

After reading a bunch of posts it seemed some folks had good accuracy out to 100 yards with this little short 166gr, so I figured that's where I would start for now.... 
Title: Re: new to me Extreme .457
Post by: Wayne52 on April 13, 2020, 03:02:57 PM
Those rifles have been known to take down water buffalo's and there's probably no big game in the US that it wouldn't take down.  I know they're not making them in Michigan anymore, now they building them in Texas.
Title: Re: new to me Extreme .457
Post by: dyotat100 on April 13, 2020, 03:15:18 PM
Yeah and the guy that's building them now is clueless. A machine shop owner that saw a potential to make money. Knows nothing about airguns.

I said 4500 psi isn't practical and you can't tether. He said why can't you tether and gave a answer that had nothing to do with tethering. Was something about how extreme is using 571 psi per shot and Texan probably  is using 4 something. Then posting all these pics and links to $200 Chinese compressors.

Also was telling a guy that his guns only drop 1" from 50 to 100 yds.  Magic bullets I guess. Anything to sell them.

Stay away
Title: Re: new to me Extreme .457
Post by: Wayne52 on April 13, 2020, 03:49:09 PM
The kind of setup that Mr. Hollowpoint has for topping off high pressure guns would be a good setup for those guns. I think his has a big brake cylinder that does the pressurizing from one tank to another.
Title: Re: new to me Extreme .457
Post by: steveoh on April 13, 2020, 03:58:59 PM
The kind of setup that Mr. Hollowpoint has for topping off high pressure guns would be a good setup for those guns. I think his has a big brake cylinder that does the pressurizing from one tank to another.

Not a brake cylinder, but an intensifier or booster pump.

https://ayrtekk.com/
Title: Re: new to me Extreme .457
Post by: ZackUSAF82 on April 13, 2020, 04:10:58 PM
I had a .408 I bought from shamu25, I spent a bunch of time talking with Mr. Hollow Point (awesome dude, actually called me on his lunchbreak at work to chat for 45 minutes), he definitely knows the guns and I'd get with him to get you a sampler of bullets to try.  Nick likely has some ammo that will work as well.  I only kept mine for a couple weeks, was wayyyyy too loud, and heavy.  I was hoping for a more traditional gun to hunt with but in the end it couldn't match my .457 Texan, it's plenty quiet with the RL Shroud (sadly was discountinued).

As far as spings go, Century is definitely the go to, my gun came with everyone made, I played around with them some but again it was so loud I just never felt comfortable shooting it for many shots at a time.  They are super powerful, so as long as you are ok with the noise (or maybe get Neil to build you a shroud) I think you can figure it out.  Definitely can get 3 good shots out of it, just have to find the magic bullet/spring combo.  Good luck my friend!
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 13, 2020, 04:32:59 PM
Yeah and the guy that's building them now is clueless. A machine shop owner that saw a potential to make money. Knows nothing about airguns.

I said 4500 psi isn't practical and you can't tether. He said why can't you tether and gave a answer that had nothing to do with tethering. Was something about how extreme is using 571 psi per shot and Texan probably  is using 4 something. Then posting all these pics and links to $200 Chinese compressors.

Also was telling a guy that his guns only drop 1" from 50 to 100 yds.  Magic bullets I guess. Anything to sell them.

Stay away

As I understand it this gun was built just before the transition, the buyer dealt directly with Brent, took forever and a bunch of phone calls to finally get it and it leaked.   The buyer sent it to an independent shop for repair as he had no confidence with sending it back to the manufacturer.  My understanding is the gun has been resealed and returned to a functioning state.  Other than that  I have no idea as to what I'm actually getting.  Pics look good, but they always do.    I fully expect to have to tune it to get to my preferred state, whatever that ends up being, likely a tune for light to medium weight ammo and 3600psi or so.  It may require more than tuning, I won't know until it gets here.

After a buyjng/trading for a couple of used Flex's that were advertised as "perfect" but required a ton of work to get working at an acceptable level I've learned to somewhat lower my expectations....this is just another adventure in airgunning as far as I'm concerned.


I do appreciate the feedback regarding the current manufacturer and their level of competency along with my poor choice of ammo.   

However what I would really like to do is get this thread on track and hear from actual owners, prior owners, or folks with hands on experience with Extreme .457's.  Especially around de-tuning for lower pressure.and lighter ammo.  Thanks in advance.
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 13, 2020, 04:36:07 PM
I had a .408 I bought from shamu25, I spent a bunch of time talking with Mr. Hollow Point (awesome dude, actually called me on his lunchbreak at work to chat for 45 minutes), he definitely knows the guns and I'd get with him to get you a sampler of bullets to try.  Nick likely has some ammo that will work as well.  I only kept mine for a couple weeks, was wayyyyy too loud, and heavy.  I was hoping for a more traditional gun to hunt with but in the end it couldn't match my .457 Texan, it's plenty quiet with the RL Shroud (sadly was discountinued).

As far as spings go, Century is definitely the go to, my gun came with everyone made, I played around with them some but again it was so loud I just never felt comfortable shooting it for many shots at a time.  They are super powerful, so as long as you are ok with the noise (or maybe get Neil to build you a shroud) I think you can figure it out.  Definitely can get 3 good shots out of it, just have to find the magic bullet/spring combo.  Good luck my friend!

Thank you for the feedback.  I will.likely have to get some type of noise reduction, assuming I like it enough to keep it.  I may end up not liking the size/weight, much like you described.
Title: Re: new to me Extreme .457
Post by: Wayne52 on April 13, 2020, 04:42:03 PM
First time I met both Brent and Bob they both had a booth at the Kalamazoo Airgun show back in 2016.  Brent had brought a bunch of guns to show, I could have gotten a good deal on a gun back then but I didn't have anything for filling a gun like that at the time.  Really wasn't something I wanted to spend that much money for only hunting deer basically.  They were all beautiful guns, Bob still makes it to them shows every year but I haven't seen Brent there since.
Title: Re: new to me Extreme .457
Post by: ZackUSAF82 on April 13, 2020, 05:04:47 PM
Sorry, the video I found was not for the Extreme, it was a different rifle with a like name.
Title: Re: new to me Extreme .457
Post by: Jeremy1982 on April 13, 2020, 08:25:32 PM
let me check to see my spring collection.I have some light ones I believe.Im not sure how the 165 will do but I did have luck with the 200 gr REAL round from 3600 psi -2600.I think 5 shot group.200 gr around 880 fps.let me check my stuff.
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 13, 2020, 09:14:06 PM
let me check to see my spring collection.I have some light ones I believe.Im not sure how the 165 will do but I did have luck with the 200 gr REAL round from 3600 psi -2600.I think 5 shot group.200 gr around 880 fps.let me check my stuff.

Thanks Jeremy. 

Does the .457 look as if it could be re-barreled down to say .357 or even .308?  I do like the idea of a bolt gun with a high capacity tube that CAN go up to 4500psi, so the Extreme checks that box.  But I think I would rather have the option to launch a longer 250gr .357 in the 900's or tune down when wanted. 

Either way I'm excited to try out something different/new. 
Title: Re: new to me Extreme .457
Post by: shamu25 on April 14, 2020, 12:00:47 AM
Mike
Here is the link to Extreme springs from Century.   Let me know if I can help in any way.   Hope Jeremy has some to send to you
  I had both the 457 and 408.  Awesome guns
Ray
https://www.gatewaytoairguns.org/GTA/index.php?topic=92225.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=92225.0)
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 14, 2020, 09:53:03 AM
Mike
Here is the link to Extreme springs from Century.   Let me know if I can help in any way.   Hope Jeremy has some to send to you
  I had both the 457 and 408.  Awesome guns
Ray
https://www.gatewaytoairguns.org/GTA/index.php?topic=92225.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=92225.0)

That is an excellent post that I had yet to see, thank you for sharing.
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 17, 2020, 07:07:27 PM
Tracking info show it arriving on time Monday.  I have an assortment of ammo that should arrive Monday as well.  I am very interested to see how Nick's 302gr BTHP's do. 
Also have a couple of springs that should arrive at the same time-  Century 2894 and 72056S were bought through Digikey and Century shipped them almost immediately.

I'm down to 3800psi on my nitrogen tank, may have to go pick swap one out Monday morning....
Title: Re: new to me Extreme .457
Post by: shamu25 on April 17, 2020, 09:34:38 PM
Looking forward to hearing about your first impressions
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 20, 2020, 08:04:10 PM
Today was a soggy day and I knew I had numerous packages, including the Extreme arriving so I texted my postman and told him he could leave my packages at the PO and I would pick them up at lunch.  He gladly obliged as this meant one less trip down my driveway with a half dozen packages from Walmart, Amazon, etc. 

She arrived safe and sound, well packed with the stock separate from the action.  The scope bases appeared to never had been mounted.  The gun is pristine, not a mark on it that I can tell.  No signs of slig swivels, bipod, etc.  Not many rounds have been through this one.

 I connected to my nitrogen tank and she was aired up to 3000psi, so she at least holds air.  I topped her off to 3300psi as that is all i have.  Plan to pick up a fresh tank tomorrow... 

Weight is 9lb bare, 10lb 5oz as pictured below.

A package from Nick arrived today with his 302gr BTHP and 254gr BTHP.  Since I can only fill to 3300 right now I tested with the 254gr and the Hunter Supply 160gr

2 shots of 254gr 818, 737fps
2 shots of 160gr 971, 858fps 

Both of these "strings" ended around 2000psi.

Based on one of Bob Stern's charts, I'm guessing she is ported somewhere around .325.  I believe he based the chart on a lofty goal for 24" barrel and I've found it to be a pretty good reference for me with 28"ish barrels.

My Century order hasn't arrived yet so no testing of the famous 2894 spring yet...  I went through my stash of springs and cobbled together a twin spring setup.  The springs were only 3' so there is a lot of hammer free flight, but i still wanted to try.  3 shots of  160gr went 936, 933, 885fps, ended at 2300psi.  This shows me what others have said, the gun is easily tuned for different fill pressures with different hammer springs. 

I pulled the scope off another gun in the safe and found the lowest set of rings I can find.  I ordered a set of old school weaver rings as the scope needs to be a tad lower.

(https://i.imgur.com/nEaEesh.jpg)

Fit finish, machine work all looks great from what I can see on the outside.  I was surprised to find typical Home Depot looking zinc fasteners securing the trigger guard. 

(https://i.imgur.com/B5OAgOP.jpg)

At some point these will get replaced.

My initial reaction is I think I'll be keeping this one for a while.  it fits right in with my collection of QB based PCP's, albeit a much higher end gun than the QB's. 

Adding a hammer spring adjuster should be pretty straight-forward.

I may look for a lighter hammer for future tuning/testing.  A higher shot count 300ish fpe tune might be interesting. The original hammer is definitely intended for the other end of the tuning spectrum. 

I definitely need a moderator, working on that now. 

Hopefully tomorrow will bring a fresh tank of nitrogen and a shipment of springs. 

So far I really like this gun. 
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 22, 2020, 07:12:26 PM
I was able to swap out a nitrogen cylinder so was also able to do some 4500psi fills.  Results were interesting.

4500PSI with OEM spring

302gr NSA
877
779
714fps

254 NSA
933
844
761fps

166gr Hunters Supply
1082
955
877fps

Switched over to the Century 72056S spring and a 4500psi fill

254NSA
645
715
792
832
835
797
746
673fps

166 Hunters Supply
880
935
986
997
966
918
848fps

That was enough for me to see.  I couldn't resist going in and seeing what was up.  Previously I guessed porting was around .325.  I was being generous.  The smallest passage is the valve throat, and it measures approximately .340, with a .157 valve stem going through it.

I have a few raw materials in route.....we are going to open up the valve throat and convert to peek sealing material.  I also have a spare hammer coming from Texas for lower power/lighter weight bullets.  I don't plan on wasting anymore nitrogen and lead until the throat is opened up.

My goal will be to have 2 tunes that are adjusted by changing spring and hammer.  3-4 shots of 250gr over 900 and say 7-10 shots of 166gr around 900 are somewhat optimistic, we will see where it ends up....I had assumed this one had a 28" barrel but measurements show 26.5" from front of barrel port to muzzle.  This is a limitation that I'll just have to live with....
Title: Re: new to me Extreme .457
Post by: dyotat100 on April 23, 2020, 01:18:39 AM
What size is the hole the poppit is covering and what is OD of poppit?

How heavy is the hammer?
Title: Re: new to me Extreme .457
Post by: Wayne52 on April 23, 2020, 01:23:50 AM
Very nice numbers with that beast !!! It's good to see someone actually using one of the older "Extreme Big Bore" guns again.  I never even realized that Brent had thrown in the towel regarding his business with building his big bores but glad to hear and see that someone else has taken over the building of them. ??? 
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 23, 2020, 03:59:57 AM
Very nice numbers with that beast !!! It's good to see someone actually using one of the older "Extreme Big Bore" guns again.  I never even realized that Brent had thrown in the towel regarding his business with building his big bores but glad to hear and see that someone else has taken over the building of them. ???

It is indeed a beast....I hope to he able to somewhat tame it into a little bit less of a beast with a little more refined of a shot string.  A few nice and even shots of 425-450fpe is a lot more attractive to me than 1 shot of 515fpe then a second at 405fpe.

 I do acknowledge that I will be going somewhat backwards from what the design's original intent was.  The manufacturer  is named "Extreme" afterall......I think wherever the tune ends up it will still be possible to put it back into beast mode by  throwing an excess of hammer strike at it and likely build MORE power than it was delivered with.

My intent is for any of my changes to be reversible back to as delivered if necessary....

The gentleman that took over manufacturing seems to have a genuine interest in both maintaining the reputation of the brand and also adding a little innovation along the way.  He was certainly willing to spend some time on the phone with a guy who traded for an second hand gun made by the previous owner, and even sold me some parts in the process.  I wish them nothing but success and look forward to seeing how they do. 
Title: Re: new to me Extreme .457
Post by: Wayne52 on April 23, 2020, 04:05:08 AM
Mike I know if I had one I'd probably be doing the same thing that you're doing, after all I doubt I'll go hunting the big big game, a white tail is fine for my purposes and that big bore would be much nicer than using a slug gun IMO.
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 23, 2020, 11:05:41 AM
What size is the hole the poppit is covering and what is OD of poppit?

How heavy is the hammer?

I included throat and stem diameters already.  Poppet OD is .375.

Hammer is heavier than 100 grams, maxed out my scale.  It is more than 150grams.  Maybe over 200.  Will be able to accurately measure  weight next week....

For now, I am starting very conservative and have increased throat to .375.  Waiting on some stem material to arrive this afternoon, then I will finish the peek poppet.....changes will be reversible, at least that is the intent for now.

The way the valve is constructed does not leave much room for throat increase without impacting the transfer port system. 

My goal is starting to become more clear, a few close shots of 400+fpe at high power, and a half dozen or more close shots above 300fpe for low power.  This is part 2 of why I am increasing throat size in small increments.  Part 1 is the desire to do all of this at a reduced hammer strike than the as delivered gun......
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 23, 2020, 06:33:37 PM
I managed to make some ground on this one. 

I replaced the ugly zinc fasteners.

(https://i.imgur.com/Ufkm4CP.jpg)

I also managed to roughly fabricate a new valve stem with a peek poppet.  This reversed the factory valve setup which was Hatsan-like---steel valve with a plastic seat.
 I removed the factory delrin seat and created a valve seat on the aluminum valve body.  this moved the valve seat roughly .43" towards the transfer port....remember this as it will be come up again.  This method is also 100% reversible. 

I opened up the valve throat from .340ish to .375, which was a decent guesstimate as to where I need to be to achieve my goals.  Transfer is .375 and with the stem going through the throat, the throat is still the choke point. 

I messed up in calculating valve stem length and it ended up .45" too long....I forgot that I moved the seat rearward, decreasing stem length in the process, or at least that's what was supposed to happen.  I decided not to worry as this would simply reduce hammer throw a bit, and of course hammer strike which there is an abundance of already.  Here is a pic of the bolt at rest, those familiar with this gun will notice how far rearward the bolt is.  There is also a little more preload on the spring.  I don't know how all this averages out as compared to the original hammer strike with a .45 longer throw and less preload.  It doesn't really matter at this point anyway.

(https://i.imgur.com/wTDRXif.jpg)

Aired up to 4500psi using the original heavy spring, here are some numbers:

302gr NSA
897
853
768 fps

254 NSA
959
906
833 fps

166 Hunter Supply
1098
1048
982
851 fps

Detuned a bit with a dual spring combo, starting at 4500psi.

254 NSA
860
904
866 fps

166 Hunter Supply
1003
1039
1017
974
917 fps


Shot cycle for the heavy spring became much more snappy until the 3rd shot.  Shot cycle with the dual spring was very snappy for practically every shot. 

I am liking results so far.  A spare hammer is going to arrive tomorrow, I look forward to doing some lighter hammer testing.  A faster moving lighter hammer is my favorite tuning tool, but I don't know how that will translate to a 400-500+fpe setup...

I am debating whether to open the valve throat any more.  There is still an abundance of hammer strike, plus I need to shorten the valve stem which will result in even more hammer strike. 

I have to keep reminding myself I only have 26.5 inches of barrel to work with....

While she was in pieces, I saw some striking similarities to tube/thread size.  check this out.  I do NOT plan to proceed any further than the mock-up you see below, but did want to share.  This is a Mrod tube extension and a WAR bottle adapter.  I can't recall if that is a 17 or 22ci bottle though.  The extreme tube is much thicker walled, but the ends match an Mrod.  There is a step just past the oring which tube ID gets smaller due to the thicker walls. 

(https://i.imgur.com/nESTjNQ.jpg)

Again, this is simply a mock-up that I do not plan to put together again.  This was for demonstration purposes only.

Looking forward to seeing any thoughts on throat diameter.....
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 23, 2020, 07:11:46 PM
here's some 3500psi data.  peek poppet, .375 throat.  Lighter twin spring setup, hammer barely preloaded.

166gr Hunter Supply
966
974
953
910

254 HSA
794
824
803
Title: Re: new to me Extreme .457
Post by: Rizen 1 on April 24, 2020, 01:05:31 AM
Great job! You may want to try this for fine tuning..https://www.gatewaytoairguns.org/GTA/index.php?topic=85527.msg821213#msg821213 (https://www.gatewaytoairguns.org/GTA/index.php?topic=85527.msg821213#msg821213)
Title: Re: new to me Extreme .457
Post by: Rizen 1 on April 24, 2020, 01:20:11 AM
This may also help...even though it was 40 cal testing, springs fit all calibers...
Title: Re: new to me Extreme .457
Post by: Rizen 1 on April 24, 2020, 01:53:57 AM
The rva "rear velocity adjustment" should be an easy upgrade. Hope this helps...
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 24, 2020, 12:08:29 PM
Mike--thank you for joining the discussion.  Much of my research has included your Extreme posts.

I underestimated the effect of reducing hammer travel.  Last night I disassembled and did 2 things.  1, I cleaned up and radiused where I drilled out the throat.  I didnt do this before as I may have decided to go bigger in throat size.  At this time since I have a goal of 2 tunes, I dont plan to go any larger as I think that will negatively affect ES on low power tunes.  2, I trimmed the valve stem to a .55 stem protrusion, which is closer to OEM.  This restored hammer stroke to OEM.

Here are some initial results.  Heavy spring 4500psi start.

302 NSA
920
851
807

254 NSA
976
906
864

166 Hunters Supply
1128
1066
1018
984
940

I did some other testing but wont enter all of that data. 

I will be working on some type of RVA.....I think I have the porting in a good compromise between flow and restriction.  If high energy was my only goal I would go straight to .4125 throat, which is 10% over transfer size, something Bob S generally suggests and has worked well for me in other builds.

Time to work on hammer strike...
Title: Re: new to me Extreme .457
Post by: rsterne on April 24, 2020, 01:02:03 PM
Looks like you are closing in on it, Mike....

Bob
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 24, 2020, 01:57:10 PM
Looks like you are closing in on it, Mike....

Bob

Getting closer.  Have a couple more inner/outer springs coming so I can fine tune the combination.   Then I need to home in in a tune below max pressure, maybe in the 3800psi range.  Something I can shoot 3 shots, the top off with a guppie and repeat a time or two.  9 full power shots should satisfy any full day hunting scenario I can imagine.  I'm envisioning a full day of slaying nuisance swine somewhere nearby.
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 24, 2020, 11:03:34 PM
a Few pics...for anyone intimidated by making their own poppets, this should show you it isn't as hard as you think.  And you only have to be precise in certain areas.  This was carved from a piece of 1/2" peek rod and a m4 cap screw....

(https://i.imgur.com/jNbkDO9.jpg)

(https://i.imgur.com/GpotO4h.jpg)

(https://i.imgur.com/dID7SxL.jpg)

(https://i.imgur.com/msBY3fj.jpg)
Title: Re: new to me Extreme .457
Post by: rsterne on April 25, 2020, 02:21:40 AM
Nice job!....

Bob
Title: Re: new to me Extreme .457
Post by: Wayne52 on April 25, 2020, 02:33:33 AM
That PEEK is ideal using as a pcp poppet, I've never personally worked with it however I've got two that I bought from duy and the finish is mirror finish.  I have worked with delrin for transfer ports but haven't attempted making a poppet on the drill press yet.  I poked my thumbnail on one of the Peek poppet's and no give at all . . . it's hard stuff but sure makes a nice sealing surface.
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 25, 2020, 10:53:48 PM
Nice job!....

Bob

Thanks Bob.  Once I get 100% settled on porting I'll make a permanent poppet that is threaded on the striker end so the factory retainer will screw on.  This poppet  will fall out of the valve into the tune should it be pointed muzzle down and not pressurized. 

There is a side of me that wants to see if it can crack 600fpe by increasing throat to .4125.......but I'm pretty sure that will negatively impact having a second tune in the 300 range.

Can you share your thoughts on the matter?

This afternoon I cracked off a 166gr as the first shot of a 4500 fill.  This was the first time shooting it WFO  outside.  All previous full power shots were indoors over the chrony, wearing muffs.   It was LOUD.  I mean like PB loud.  I didnt shoot it anymore this afternoon, I wasnt quite prepared for that....
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 25, 2020, 10:59:24 PM
That PEEK is ideal using as a pcp poppet, I've never personally worked with it however I've got two that I bought from duy and the finish is mirror finish.  I have worked with delrin for transfer ports but haven't attempted making a poppet on the drill press yet.  I poked my thumbnail on one of the Peek poppet's and no give at all . . . it's hard stuff but sure makes a nice sealing surface.

Wayne, a good sharp file and as much RPM as you can get.  A fine hacksaw blade works for parting and for cutting oring grooves.  500, 800, 1200 W/D sandpaper to slick it up. 

For me the key is pressing/beating in the stem as the first operation.  A fairly tight interference fit.  You can add some loctite 638/680 before you press it in if it makes you feel better.  Then use the stem as an arbor.....
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 27, 2020, 08:10:26 PM
Working on the lower pressure, high power tune.  One of my optional inner springs arrived, it was a bust--coil bind right at barely cocking.  I may loose a coil or two and that will help.  Another size of outer springs will arrive tomorrow.

My current scale doesn't go beyond 100 grams so I can't get an exact hammer weight.  But with a not so precise fishing scale both hammers weigh at roughly 5oz.  I removed weight from one until it started reading in the 4oz range.  Soon I will have a more precise scale so that I can measure exact hammer weights.  I am thinking that  a 3500-3800psi tune is roughly 75-80% of 4500psi, so I plan to initially reduce hammer weight by 20-30%.

I found a combination of springs and the lightened hammer that gives a decent 3700psi tune.  With NSA 254gr, 3 shots goes 887, 887, 850.  Not quite my goal, but a decent tune nonetheless.  Fairly easy to cock, easier than the oem spring by far. 

I haven't been able to find the right combination of springs and pressure for a 220gr tune yet. 
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 28, 2020, 05:54:24 PM
Working on the lower pressure, high power tune.  One of my optional inner springs arrived, it was a bust--coil bind right at barely cocking.  I may loose a coil or two and that will help.  Another size of outer springs will arrive tomorrow.

My current scale doesn't go beyond 100 grams so I can't get an exact hammer weight.  But with a not so precise fishing scale both hammers weigh at roughly 5oz.  I removed weight from one until it started reading in the 4oz range.  Soon I will have a more precise scale so that I can measure exact hammer weights.  I am thinking that  a 3500-3800psi tune is roughly 75-80% of 4500psi, so I plan to initially reduce hammer weight by 20-30%.

I found a combination of springs and the lightened hammer that gives a decent 3700psi tune.  With NSA 254gr, 3 shots goes 887, 887, 850.  Not quite my goal, but a decent tune nonetheless.  Fairly easy to cock, easier than the oem spring by far. 

I haven't been able to find the right combination of springs and pressure for a 220gr tune yet.

I was able to weigh the hammers.

OEM hammer with cocking lever installed 182.6 grams

Lightened hammer/cocking lever in above 254gr tune 152.7 grams.  I think bullets 250ish and up I will run the full weight hammer and run the lightened hammer for 220gr and below. 

I've since trimmed it down to 145grams.   

Edging closer to the desired 220gr tune.  I stumbled across this tune starting at 3700psi 934, 936, 911
Title: Re: new to me Extreme .457
Post by: steveoh on April 28, 2020, 06:08:55 PM
This is an interesting thread. I have a .458 Quackenbush LA Outlaw I shot this past Sunday. With a 3400 psi fill and 220 grain home cast bullet I was hitting 956 fps for 446.57 FPE. It was singing. I will say I get two shots and that's it. A third shot might/will empty out the gun completely.  The smack on steel at 100yards is pretty substantial. I shot out to 250 yards and it's happy rifle and shooter too.

The bullet comes from a AirHog / Noe mold. I used the flat nose pins, but have hollow point and cup point. Going to powder coat the next batch so barrel cleaning is minimal.

Title: Re: new to me Extreme .457
Post by: mackeral5 on April 28, 2020, 06:40:01 PM
I remember reading up on the legendary Quackenbush guns throughout the years. The maker was a trailblazer in the big bore market.  Some day I may pick up one of those pistols that pop up every once in a while.  Any other tunes that you've run with the Outlaw?

Brent definitely designed this gun to run on 4500psi.  I think he sized the throat a little small which contributed to excessive ES and less peak power.  He was also known to run helium, so maybe helium consumption was the reason for the small throat.. 

By trying to tune it more conservatively,  I think I'm going to be able to find a fairly economical hunting tune at 3500-3800psi and still have 3 shots above 400fpe.  Then with a simple spring/hammer change go back to slinging 302gr at 920fps on a 4500psi fill.  Somewhere along the way I'd like to find a 5+ shot 300fpe plinking tune with relatively flat ES.
Title: Re: new to me Extreme .457
Post by: steveoh on April 28, 2020, 07:08:52 PM
Early on the DAQ was dumping on the second shot. Talked to Dennis and he said up the fill pressure from 3000 psi to 3300 psi and maybe a little more to see if that doesn't fix the dump. He said he tests the guns at much higher pressures, and didn't bat an eye at increasing it over specified pressure.

I think I could take a little off the hammer spring and get three decent shots, and have air left over. This is why your thread is interesting to me. You are doing what I should probably do. I have varied the pressure from 3k to 3700 psi. I've had extended conversations with Mr. Hollowpoint, and Eric Henderson. Both have owned many Quackenbush's, and both told me the same thing, that the gun is built heavy duty and most of the rifles seem to have a sweet spot of 3300-3700 psi. That's 10-19% increase over what Dennis says on his website. The kick is more substantial at those higher pressures. But as Dennis says, gauges tend to not agree with each other and each gun is unique, and that's why he's okay with upping to the 10% while suggesting that a little more is ok. BB Pelletier said his .308 Outlaw liked 3200-3500 psi.

I giggled with almost every shot I made on Sunday. :)



I remember reading up on the legendary Quackenbush guns throughout the years. The maker was a trailblazer in the big bore market.  Some day I may pick up one of those pistols that pop up every once in a while.  Any other tunes that you've run with the Outlaw?

Brent definitely designed this gun to run on 4500psi.  I think he sized the throat a little small which contributed to excessive ES and less peak power.  He was also known to run helium, so maybe helium consumption was the reason for the small throat.. 

By trying to tune it more conservatively,  I think I'm going to be able to find a fairly economical hunting tune at 3500-3800psi and still have 3 shots above 400fpe.  Then with a simple spring/hammer change go back to slinging 302gr at 920fps on a 4500psi fill.  Somewhere along the way I'd like to find a 5+ shot 300fpe plinking tune with relatively flat ES.
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 28, 2020, 07:09:25 PM
The low rings arrived as did a piece of 1mm wall CF tubing.  I've read a few posts where other owners report the barrel being a little on the whippy side and accuracy improving with some extra barrel reinforcement.  I have not glued it in place yet, this was more of a test fit so see if it detracts from looks any.  So far I think it blends in pretty well.  it doesn't quite fill the gap between barrel and tube, but unfortunately the gap was just a hair too small to go with 2mm wall. 

(https://i.imgur.com/iSEckUs.jpg)
Title: Re: new to me Extreme .457
Post by: rsterne on April 28, 2020, 07:22:41 PM
I asked Dennis about overfilling my Exile, and all he would say is that the recommended fill pressure was 3000 psi, as it states in the owner's manual....  ::)

Bob
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 28, 2020, 07:35:07 PM
Early on the DAQ was dumping on the second shot. Talked to Dennis and he said up the fill pressure from 3000 psi to 3300 psi and maybe a little more to see if that doesn't fix the dump. He said he tests the guns at much higher pressures, and didn't bat an eye at increasing it over specified pressure.

I think I could take a little off the hammer spring and get three decent shots, and have air left over. This is why your thread is interesting to me. You are doing what I should probably do. I have varied the pressure from 3k to 3700 psi. I've had extended conversations with Mr. Hollowpoint, and Eric Henderson. Both have owned many Quackenbush's, and both told me the same thing, that the gun is built heavy duty and most of the rifles seem to have a sweet spot of 3300-3700 psi. That's 10-19% increase over what Dennis says on his website. The kick is more substantial at those higher pressures. But as Dennis says, gauges tend to not agree with each other and each gun is unique, and that's why he's okay with upping to the 10% while suggesting that a little more is ok. BB Pelletier said his .308 Outlaw liked 3200-3500 psi.

I giggled with almost every shot I made on Sunday. :)



I remember reading up on the legendary Quackenbush guns throughout the years. The maker was a trailblazer in the big bore market.  Some day I may pick up one of those pistols that pop up every once in a while.  Any other tunes that you've run with the Outlaw?

Brent definitely designed this gun to run on 4500psi.  I think he sized the throat a little small which contributed to excessive ES and less peak power.  He was also known to run helium, so maybe helium consumption was the reason for the small throat.. 

By trying to tune it more conservatively,  I think I'm going to be able to find a fairly economical hunting tune at 3500-3800psi and still have 3 shots above 400fpe.  Then with a simple spring/hammer change go back to slinging 302gr at 920fps on a 4500psi fill.  Somewhere along the way I'd like to find a 5+ shot 300fpe plinking tune with relatively flat ES.


I've yet to have experience the giggles associated with smacking steel with 400+fpe.  I look forward to it.  Once I get the tunes finished I'll give it a good cleaning and bore polishing then it will be time to sling some lead a ways.

What size is the Quackenbush spring?  I may have a few springs I could share with you depending on what size you need.  The normal tuning principles seem to apply to these big bores.  dual stiff springs with little if any preload result in very snappy, efficient shot cycles without much loss in FPE. 
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 28, 2020, 10:50:28 PM
Just before closing up shop for the evening I decided to try something.  I still have a little over 5k in my nitrogen tank so any full power testing needs to be done soon as I won't be able to do 4500psi fills in a week or so.  I ran a 4500psi string using my 145gram hammer and NSA 254gr.  I didn't think the results were anything special until I compared it with previous 4500psi, heavy spring 254gr data.

With the OEM 182gram hammer, heavy spring, 4500psi fill NSA 254gr

961
920
878

With the 145 gram hammer, heavy spring, 4500psi and NSA 254gr

969
946
896

35grams less hammer tightened things up a bit with this weight slug.  2 shots over 500fpe then a finisher over 450fpe aint too shabby.  out of a 26.5" barrel, had to remind us all of that as I normally think 28" barrel or greater when thinking .457 guns. 
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 29, 2020, 10:34:03 AM
while testing various spring lengths and weights I discovered a problem with consistency.  I believe this is a problem I created, not anything to do with the gun's design.  I do not believe it was ever intended to be ran without some bit of preload on the hammer spring. 

Due to the hammer spring sitting in a shallow cup, when running no preload and when running hammer free-flight, or gap, the spring just floats around.  There is no form of spring guide.  This was causing inconsistent velocity, depending on where the spring landed during that initial bounce off the valve stem. 

Here you can see the end cap/spring cup.

(https://i.imgur.com/561HEjy.jpg)

I fashioned a quick spring guide for testing purposes.  A short piece of 1/2 delrin screwed to a 1" fender washer fits perfectly.  This shortens the required spring length by 1/4" but there is an abundance of hammer energy so that's not going to be a problem.

(https://i.imgur.com/HlajvWv.jpg)

Here is a picture of the OEM heavy spring, a McMaster Car spring that is almost identical, just about 1/4 inch shorter and a touch stiffer.  Then you see where I have been cutting down the McMaster spring 1/4 coil at a time chasing that elusive 3800psi 220gr tune. 

(https://i.imgur.com/A8NjGTj.jpg)

I did find a pretty good 254gr 3800psi tune using the short spring/guide pictured above.  3 shots went 901-903-860. I think I'm going to label that spring and save it for future use.   The only downside is this required excessive gap----almost 1/2".   

Lock time keeps increasing as I lighten the hammer and shot cycle is nice and snappy.  I don't think I want to give that up going to a lighter spring.   I may reduce hammer weight a bit more.

The Mcmaster Car spring part number is 9657K462.  This would be a great spring for a stock Extreme as it still produces full power, but with almost no preload, resulting in a tighter string. 
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 29, 2020, 03:58:42 PM
Finally decided to give the barrel a good cleaning and the lapping treatment with JB's bore paste and Mother's.  This required removing the breech/barrel as they are one unit then removing the bolt, being careful not to lose its detent ball and spring, so that the work can be done from the breech end. 

Upon completing the job, I found a little surprise at the muzzle.....

I've mentioned a few times on here when we find a deal that may be too good to be true, or we are wondering why someone is dead set on getting rid of a perfectly good looking gun.  I just figured out one reason this one found itself on the used market. 

A couple of times I had sighted in at 75 yards but resulted in 5" or so groups.  I wrote it off to a dirty barrel which would get cleaned once I was close to the end of tuning....

Check out the crown.

(https://i.imgur.com/UgpxvoT.jpg)

(https://i.imgur.com/Rcj61JN.jpg)

(https://i.imgur.com/K5v9Gwm.jpg)

(https://i.imgur.com/9NCcBKR.jpg)

There was a long story about the original owner waiting 18 months for this gun, it was supposedly ordered prior to production moving to TX and was likely one of the last produced in Michigan.  Previously I had a nice discussion with the current manufacturer in TX, which confirmed this one was made in Michigan, so this should not in any way be viewed as an indicator of the current manufacturers processes.

The gun has changed hands once or twice, there could be more to the story than I'm aware of.  So it is hard to determine when and where this occurred....

I think I'll need to find someone to cut/recrown. 
Title: Re: new to me Extreme .457
Post by: Airgun-hobbyist on April 29, 2020, 06:37:50 PM
By the looks of those marks, someone could have tried polishing the barrel with a power tool, resulting in over-sizing the bore some. After the cut and re-crown to fix the barrel, you may experiment with a larger diameter, tighter fitting slug.  I experimented with a smaller slug recently and got a bigger group size with a looser slug.   With that spring running the first two shots being within a few fps it will make a great hunting rig when you get that barrel sorted out.
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 29, 2020, 07:46:11 PM
By the looks of those marks, someone could have tried polishing the barrel with a power tool, resulting in over-sizing the bore some. After the cut and re-crown to fix the barrel, you may experiment with a larger diameter, tighter fitting slug.  I experimented with a smaller slug recently and got a bigger group size with a looser slug.   With that spring running the first two shots being within a few fps it will make a great hunting rig when you get that barrel sorted out.

Virtually impossible to say who what when, but somebody obviously messed up.  It was disappointing when that didn't clean up.  But I'm sure they guy on the other end of the trade found things he didn't like about the gun I traded.  However while that gun will shoot less than MOA at 100 yards and I have targets to prove it, this one won't.  The gun I traded wasn't cosmetically perfect, this one is.....  at the end of the day I am still happy with the trade....

I found a local gunsmith that I plan to visit tomorrow to see about cutting and recrowning.  Assuming we both pass the interview process I'll be leaving the barrel/breech with him for a couple of days.  On my other guns I would have done this myself, but having the barrel/breech permanently attached prevents me from using my normal set of operations....

I measured the damage stopping right at .300 past the muzzle.  Hopefully it loses 1/2 inch or less length...
Title: Re: new to me Extreme .457
Post by: mackeral5 on April 30, 2020, 05:48:09 PM
The local gunsmith I found was able to cut and recrown for me today, I'm glad something finally pushed me to finding this resource.  They are less than 10 miles from my house.... 

I only lost about 3/8" of barrel.  Here's the scrap and the new crown.

(https://i.imgur.com/OW2d4Xf.jpg)

(https://i.imgur.com/gAHEeV5.jpg)

That's the good news.

The bad news is we still have major barrel problems.  Slugging the barrel still shows nasty smearing on one side of the slug.  Looking into the barrel with a light shows that the lead is in similar shape, if not worse than the muzzle was.  I pushed an NSA 302gr a few inches into the barrel and then pushed it back out and the same smearing exists, so it appears the problem is at the lead. 

Here are 2 pics taken 180 degrees of each other, a  302gr NSA I pushed through.

(https://i.imgur.com/bBvFnBQ.jpg)

(https://i.imgur.com/viVUAGQ.jpg)

I've pushed multiple slugs through and they all look the same.  Whatever tool was used to cut the chamber and lead was off center by a tiny amount.  Since the barrel/breech are one assembly it's hard to see and impossible to get a pic of without a borescope (which will arrive next week.) Looking from the breech end I can see a nice tapered lead from about 9 o'clock to 4 o'clock.  between 4 and 9 o'clock there is a pronounced edge where the cutter was too far to that side of the bore. 

I think this is the rest of the story.....when this gun was built in Michigan, the builder was obviously under some level of duress and put a substandard product out on the market........

I won't touch the lead until the borescope arrives, then I'll share pics.....
Title: Re: new to me Extreme .457
Post by: dyotat100 on April 30, 2020, 10:26:28 PM
Hate to say it but  that's the way he did stuff.

Blue Thunder on here had his barrel redone a few times. Seem Brent doesn't have chamber reamers. His barrel was chambered .310+. Had Brent redo and it was still .3094" for a .308 barrel.

Most likely your leade is to big and bullet is not centered when entering the rifling

The breech and barrel are not one piece. It is green loctite and set screws. Heat it up and it will come apart
Title: Re: new to me Extreme .457
Post by: mackeral5 on May 01, 2020, 06:29:59 AM
Doug---I really appreciate your help here. 

It is very sad that this was the one corner I can find that was cut.  All other machine work/tolerances/fitment is spot-on.  I mean, of all things to screw up, the muzzle, chamber and lead??  I'm an at home hack and I've fit a few TJ's blanks that shoot MOA or less at 100 yards.....

What continues to surprise me is the cult like following some of these guns and manufacturers get.  For example, I have owned 2 Flexes.  You would be hard-pressed to find much negative information about them.  However both that I had showed various signs of loose tolerances/practices in manufacturing.  On one--Barrel/breech fitment was very loose.  untension the barrel and good luck finding anything close to optical zero again.  Overtighten the barrel nut, pop the snap ring.  Knock the gun hard, pop the snap ring...  Breech machined a little tight in the bolt screw area---hard to operate with a tight bolt handle.... Nothing but posts about how great the guns are....  Once it was together and running, a sub-moa gun.   Picatinny and dovetail rails were machined just under specs, requiring scope ring modifications to clamp down tight.  Add a Cobra reg to an early gun---better by a die to bring the reg to tube threads to spec, then better buy a bottoming tap to bring the bottle adapter threads to spec.  On the second one, it had a cheap AR stock with a lot of play.  So I replaced it with a Magpul.  then I discovered the play was also in the stock adapter/tube plug.  Had to be shimmed to make tight....

Meanwhile, the guys at JSAR have their challenges, but in recent history nobody has done more to try to bring innovative products to such a broad audience in the airgun tuning community.  They get SKEWERED at every turn....the community basically turned on and ran Travis out of the business.  I know there were other reasons some easy to connect the dots on, others we all will never know, but the mob mentality cancel culture certainly didn't help.......Meanwhile, you will have to look long and hard to find any negative posts about Extreme when it was out of Michigan or WAR. 

I'm slowly learning, don't believe the hype.
Title: Re: new to me Extreme .457
Post by: mackeral5 on May 04, 2020, 07:18:16 PM
A couple of items arrived today. Now I am able to share a pic of the off-center chamber/lead.

(https://i.imgur.com/fK0DNg4.jpg)

A key component of the resolution plan arrived, too.

(https://i.imgur.com/Z4SyHdo.jpg)

Title: Re: new to me Extreme .457
Post by: Extreme .457 on May 04, 2020, 11:49:15 PM
     Hey my Brother, congratulations on getting an awesome Big Bore Air Rifle. I haven't read the thread yet but wanted to answer to your post. My gun was the one Brent made on the video Helium Hogs and Airguns. My gun shot awesome and very very accurate, this TJ barrels and Timny triggers are wonderful. My gun was used strictly for hunting. I used Mr. Hollow Point 280 and his new 255 that he designed especially for this gun. The purpose of the 255 is to insure complete pass thru. The 280 open up huge and usually is lodged on the opposed side of the animal stuck in the hide. My gun preformed best at 4300psi getting 980-990fps with the 280 for the first shot. Accurate out to 175 easy but kept all my kill shots under 125. I did take a few longer shots but for me the hunt is the spot and stalk!! That gun took Fallow, Axis, whitetail, mule deer, Pronghorn and several other animals. I had a very nice offer and wound up selling her. My next gun is the Extreme .408 Carbine.

Best of luck and enjoy that GREAT GUN!!
Title: Re: new to me Extreme .457
Post by: mackeral5 on May 05, 2020, 08:32:51 AM
     Hey my Brother, congratulations on getting an awesome Big Bore Air Rifle. I haven't read the thread yet but wanted to answer to your post. My gun was the one Brent made on the video Helium Hogs and Airguns. My gun shot awesome and very very accurate, this TJ barrels and Timny triggers are wonderful. My gun was used strictly for hunting. I used Mr. Hollow Point 280 and his new 255 that he designed especially for this gun. The purpose of the 255 is to insure complete pass thru. The 280 open up huge and usually is lodged on the opposed side of the animal stuck in the hide. My gun preformed best at 4300psi getting 980-990fps with the 280 for the first shot. Accurate out to 175 easy but kept all my kill shots under 125. I did take a few longer shots but for me the hunt is the spot and stalk!! That gun took Fallow, Axis, whitetail, mule deer, Pronghorn and several other animals. I had a very nice offer and wound up selling her. My next gun is the Extreme .408 Carbine.

Best of luck and enjoy that GREAT GUN!!

Valente, thanks for adding to the discussion.   I've read good bit of the posts chronicling your Extreme journey.  Very informative and made for great reading too.   

I don't recall, but what was your barrel length?  I'm curious to see what changes to expect when I go from the current 26.5" to 32".

Everything on this gun was perfectly made, except the fairly simple operations of cutting a crown and cutting the chamber/lead.  Both were cut well off-center as shown in the above pics.  I guess the manufacturer was just over and done with the airgun  business when this one was sent out the door....
Title: Re: new to me Extreme .457
Post by: mackeral5 on July 01, 2020, 11:05:44 AM
It's been a couple months since I updated this one.... I ended up picking up my parts from the local guy, I came to the realization that the work I was asking him to do was too far outside of his comfort zone.  Specifically, creating the chamber/lead reamer and cutting the chamber/lead were things he was not familiar with and this had him sortof vapor-locked.  This was somewhat disappointing, however this was much better than him making a mess of things and me ending up with much less than 32" of usable barrel blank...

So I ended up modifying my taper pin reamer to use in cutting the chamber/lead.  Now I have reamers for .257, .300, .357, and .457 barrels... They are all made from ~$25 used ebay taper pin reamers.  This one started life as a #8.

(https://i.imgur.com/3gp2PHz.jpg)

This one cut very well, obviously it was in pretty good used condition when I bought it. 

I'm having difficulty getting a good pic of the lead, but let me assure you it is a nice gradual taper,, centered in the bore with no ridges/steps. 

(https://i.imgur.com/IjIpkCy.jpg)

Now I will take the barrel/breech back to the local guy and he will fit the barrel to breech.  Perhaps I can get him to match the barrel port to transfer port, but if not I'll do that myself as well...

Title: Re: new to me Extreme .457
Post by: mackeral5 on September 19, 2023, 10:58:53 PM
Well...  Over 3 years later and here we are.  Removing the old barrel was not uneventful.  I was able to "phone a friend" to repair the breech and fit the new barrel.  No significant testing yet, it will take a while to reacclimate with this one. 

Pics and more test/tuning to follow, but this time with 31.5" between barrel port and crown. 
Title: Re: new to me Extreme .457
Post by: mackeral5 on September 20, 2023, 06:45:47 PM
It had been so long since I touched this one as an assembled gun I really didn't know where to start.  Low on nitrogen, so no max energy testing, so let's perhaps let's see how that 31.5, let's just call it 32" barrel can be leveraged for "low pressure" 3000psi fills.

Amazingly enough, I was able to find the shorter spring and delrin spring guide mentioned in previous posts, from like 3 years ago,  and started there.  It is a relatively heavy spring, and it requires over .5" of free flight just to be somewhat reasonable at 3000psi.

Ebay 220gr BBT hollowpoints  960, 901, 850, 790fps. 

NSA 254gr 915, 850, 801fps

NSA 302gr 854, 775fps

I stopped there, getting a pretty good blast from the probe oring, will have to replace it before further testing. 

I will say I forgot that I actually liked this gun, it feels like the powder burners I grew up with.  Darn thing kicks pretty good for an airgun!

More testing to come.  for now here is a pic of a true long gun

(https://i.imgur.com/Ukyayp7.jpg)
Title: Re: new to me Extreme .457
Post by: mackeral5 on September 22, 2023, 05:52:31 PM
A bit of progress was made with the 3000psi tune.  After whittling a spare hammer down to <120grams, reducing hammer travel by .75", and reducing hammer-induced valve lift by .25" I finally have a decent string.  4 shots of 220gr BBT hollow points go 925, 950, 920, 880fps.  I really have nothing to compare that to but it seems to be a decent 3000psi .457 tune. 

The 3000psi tune mods are totally reversible as I have an unmolested spare hammer and the OEM heavy spring.  Some time soon I will put the heavy hammer and spring back in to see what the 32" barrel will do with 4500psi.
Title: Re: new to me Extreme .457
Post by: mackeral5 on September 22, 2023, 07:59:11 PM
I couldn't resist the urge to find out what a 4500psi fill and the 32" barrel would do. 

NSA 302gr 3 shots 980, 921, 846fps

I have a 390 gr mold, perhaps I will cast some over the weekend and see how it does when lugged down a bit.
Title: Re: new to me Extreme .457
Post by: mackeral5 on September 23, 2023, 05:42:12 AM
I casted up around 50 or so of an NOE mold 460-396-RF-AE2.  Using the hollowpoint pins these are dropping around 368-370gr.

3 shots at 4500psi using the OEM hammer and spring.  I can tighten this up through tweaking hammer travel and limiting valve lift, but this is at least a baseline. 

913, 851,735fps
Title: Re: new to me Extreme .457
Post by: Back_Roads on September 23, 2023, 08:56:05 AM
 That is keeping up with my Piledriver .510 with similar weight slugs.  8)