New .457 Extreme.

[Nutcracker]

Got a chance to mount scope and sight in.

I was using MR HollowPoint's 250 gr.

I only shot 14 shots, I can only imagine how well this baby is going to perform with more psi and more shooting.

The top target was sight in shots, the bottom were the last 5 shots.( target was 25 yards & I did not chrony any of my shots)
I was pleasantly surprised that I did not have to wait to receive this rifle, I ordered it & had it in less than a week.

[uncle paulie]

Sweet! I want one!

pv

[Airgun.Sniper]

Looks good

 Cheers

Jay

[wwonka]

That's a beautiful rifle. Congratulations. Look forward also to some chrony, shot strings without the external tank.

[shamu25]

Way to go Nutcracker......beautiful gun.  I have had mine for almost 2 years and have lots of experience with it so let me know if you need any input.

[bnowlin]

Great, almost as big as the target.
Bob

[Nutcracker]

Way to go Nutcracker......beautiful gun.  I have had mine for almost 2 years and have lots of experience with it so let me know if you need any input.

Have you chronied it and if so what kind of results are you getting? Is there anything I need to be on the look out for?
Thanks

[shamu25]

Here are some tests that I have done in the past.  The first set was done with the 2 different springs provided by Extreme:

EXTREME HUNTER BIG BORE AIR RIFLE TEST .45 CAL
All shots with 280 gr Mr HollowPoint hollowpoint bullets
All shots at 40’ with chrony at 38’
 
Test 1  Light Spring
1.864 fps 4100 psi fill
2. 814 fps 3400 psi
3. 758 fps 2700 psi
 
Test 2 Heavy Spring
1.858 fps 4050 psi fill
2. 800 fps 3300
3. 756 fps 2700
 
Test 3 Light Spring
1.820fps 3500 psi fill
2. 766fps 2700
3. 720fps 2250
 
Test 4 Heavy Spring
1.826fps 3500 psi fill
2.768fps 2800 psi fill
3.717fps 2300 psi fill


The following test was done with a Century Spring which is a lighter spring than both of the above that I received with my gun.  With this spring you can get a nice bell curve at a much lower pressure. Notice the peak of the bell is at 3100 psi fill.


Here are some new numbers that I shot this am with a new spring. Brent has the .45 cal set up for 4200 psi and he said the bell curve is found with a 4500psi fill. She's a total powerhouse with fills above 4000psi. I am aiming to tune this thing down a bit for plinking and yotes etc. I received a box of springs from Century Spring in LA yesterday (thanks Marvin for the lead on Century Spring) and ran the following numbers with their Spring #2894 which is 4.5"long, .718" O.D., .072 wire dia, 20.5 coils, 7.7 #/in. spring rate, spring steel zinc plated. This spring is much lighter than the stock Extreme spring and is very easy to cock. The numbers are still quite impressive. I have not shot for accuracy yet with this lighter spring. These strings were shot in my basement. May be a few days before I can get to the range. Cold here in MI.

166 gr
3500 psi 882 fps 286 fpe
3300 psi 926 fps 316 fpe
3100 psi 928 fps 317 fpe
2800 psi 911 fps 305 fpe
2500 psi 878 fps 284 fpe

350 gr
3500 psi 667 fps 345 fpe
3300 psi 724 fps 407 fpe
3100 psi 750 fps 437 fpe
2800 psi 728 fps 411 fpe
2400 psi 699 fps 379 fpe

With the stock spring the pressure drops about 600 psi per shot. With this spring the pressure drops only 200 to 300 psi per shot. She's performing way beyond a stock 909s and similar to a tuned 909 with air to spare. I could only get 2 shots from my tuned 909s with one follow up.

[rsterne]

Interesting that the two springs supplied with the gun show virtually no difference in velocity, even at 4100 psi.... That tells me that the heavy spring is wayyyyyyy too much for that pressure.... It might be OK at 4500, and the lighter stock spring might then be showing a curve.... or it might not.... Too much spring only makes a PCP waste air and be even louder, without giving any extra power.... but it SOUNDS more powerful.... My DAQ .308 Exile was the same, it only got 3 shots in a declining string, with the stock setup.... By decreasing the spring tension, I doubled the shot count, used less air, and got 4 shots within a few fps of the original fastest shot.... and my 6th shot was faster than the 2nd shot stock.... In other words, I went from 2 usable shots to 6....

Bob

[shamu25]

Yes, Bob, I think that these guns are intended to shoot around 4500psi.  I have been very pleased with the performance with the lighter spring provided by Extreme and even more happy with the lighter Century spring.  Accuracy seems good no matter what fill pressure.  Would be nice to add a spring tension adjuster to this gun.  Some one had done it I think but it is beyond my capabilities. 

[rsterne]

I always wonder why so many custom big-bores don't have a preload adjuster.... seems strange to me....

Bob

[Nutcracker]

Question, how are you checking your remaining air in your Extreme, since it has no gauge? Are using the gauge on your regulator?

Why do you have your chrony 38 feet away from the muzzle?  I have been setting mine about 10 feet on the big bore , & 3 feet on my .22 PCPs?

I am  relative new to these PCP rifles and may be doing a few things wrong.

[PakProtector]

Spring preload is a *MOST* useful adjustment. I would not consider a Marauder w/o one, let alone something as nice as an Extreme. Looks like a Bob's Boat Tail is going to be just the ticket. The rifle has the range to make it useful.
cheers,
Douglas

[shamu25]

Nutcracker....I am monitoring the pressure by keeping the fill hose from my tank connected with the  tank valve off.  Gauge shows what's left in the gun.
Douglas.....any idea who can make a spring tensioner for these guns?

[Jeremy1982]

Looks just like mine ;DYour gonna love that gun!Its a power house and very accurate.You just gotta play with it on ammo.I use a 280 hollow point (a lyman 292 gr that was converted by Erik) for hunting.Does the trick out to 100 yards.Dropped a doe in her tracks at 96 yards last season.The Lee REAL 45 shoot great too as does a few others. have fun

[crosman999]

    OOOOOH would love to WHALLOP some jacks with that mean machine

[Nutcracker]

Nutcracker....I am monitoring the pressure by keeping the fill hose from my tank connected with the  tank valve off.  Gauge shows what's left in the gun.
Douglas.....any idea who can make a spring tensioner for these guns?

Thanks, that is what I will do.....

[Fur-n-dirt]

Extreme are great!

[bluethunder]

Sorry no pics. I too received my .457 Extreme about 8 weeks ago. My goal was to have an air rifle version of a black powder Sharps. So I had Brent install the 1 in 20" twist barrel so that I could stabilize the long bullets required to have high ballistic coefficients. I'm shooting a NOE 392 gr. round nose and the SAECO 380 gr. spitzer mould # 023. Since I'm trying for long range my closest targets are at 100 yds. The gun as it came from Extreme would only group at around 4.5" after averaging 5 consecutive 5 shot groups. I was disappointed.   I tether the gun to one of Joe Bracato's tanks and I purchased a regulator from him as well. I regulate the rifle to 3200 PSI. This gives me about 40 shots per bottle. I'm shooting the stock hammer spring.
   What I immediately noticed was how thin the rifle's barrel walls are. You can flex the barrel with a small amount of thumb pressure if you press right in the middle. So my first experiment was to tape the barrel in a couple of places to tame the harmonic torque that the bullets are doing to the thin barrel. Groups dropped to just under 4" for 5 shot groups at 100 yds. with this modification. Feeling that I was on the right track. I found some spacers to place between the air tube and the barrel and tightly taped the barrel over the spacers. Groups dropped again. Pleased with this success I took two pieces of leather and a couple of worm screw clamps and really bound the barrel tight against the spacers/air tube/barrel. Groups tightened again.
    I noticed that the SAECO 380 gr. Spitzer mould had a little slop in it when the blocks were closed. I miked the pin and punched it .008" deeper. This cured the mould's looseness. Now the bullets were sizing more evenly around the circumference of the bullet. I also started weighing the bullets and sorting them into groups with a maximum weight variance of plus or minus .25 grains. With the barrel bands and bullet quality improvements my 5 consecutive 5 shot group average had dropped to 2.73" at 100 yds. with the 380 SAECO spitzer. The 392 NOE round nose is close with a 2.92"  5 shot average. I'm using Roto Metals lead that has 2% tin added.
     I have also installed a Cold Shot 300 MOA scope base to the rifle. I'll let you know how it works out when I take the rifle to Thunder Valley Precision. There I can air the rifle out to all 300 minutes of angle. I'll have to see how far it will shoot. By the way the 380 gr. Spitzer is going 707 fps. at 3200 psi. According to JBM Ballistics software the rifle should be able to shoot 900 yds. holding dead on with the 300 MOA scope base. This is a very unique air rifle and there is still a lot to learn.

[bluethunder]

One more thing that I forgot to mention about the .457 Extreme, when the gun arrived the bolt had a handle with a cocking knob. The problem that I had was that I had chambered a bullet and closed the bolt. I then turned the bolt handle/knob down like you're supposed to. Then I cocked the hammer. Apparently while pulling the hammer knob back I partially pushed the bolt knob up, so much so that when I fired the rifle the bolt blew open with such a blast that it sheared the bolt handle right off of the bolt. My ears rang for an hour -- it was that loud. The bullet did clear the barrel but I never found the handle. The handle's sheared off stem had been red locktighted  into the bolt. I called Brent at Extreme and he told me how to take the rifle apart and I shipped the bolt back to him. He modified the bolt in two important ways: 1. The bolt no longer has a knob on the end of it. It is much shorter now. And much less likely to inadvertently be pushed up while cocking the hammer.  2. Brent relocated where the handle attaches to the bolt. If the bolt gets blown open again it will not be sheared off by the action. Live and learn.