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17 Mach IV Conversion

wildcatter

Silver $$ Contributor
Finally got the 17 up and running I bought as a 17 Javelina on the old Pence barrel. Ron hasn't built a barrel in over 25 years and to me just to add another to my collection was good enough. But knowing how these 17 javelinas were taken to the dog fields and fried in a couple trips, I wasn't giving iot much hope of making me excited, and was willing to have it just for a keepsake. But wanted to give it a fair shake, and try it in a little smaller more sedate round, especially knowing with the 1-11 twist, it would be only good with the lighter bullets? So I had Fred @ SSS take 1.5" off the chamber and recut it as a .196" NK 17 Mach IV. leaving me a 22.5" barrel. I worried that this might limit my velocity and restrict me from hitting the 4000 fps I wanted to get with the 20 grain V-Max, and 20 grain Varmagedon.
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I threw 18.0 grains of H322 in the Nosler fireball brass after neck turning and running through my FL die, with a 20 grain V-Max and a remington 7 1/2 primer, Then I hit the range last friday just to get it sighted in and after 2 sight in shots, put the las 3 loads I had in a little under 1/2" group, zeroed 1" high.

But today I loaded what I had left of the 322, 25 rounds, and then loaded 3 of the 20 grain Varmagedon with 19.3 grains of XBR 8208, thats .7 tenths less than the max in the Nosler load data for their 17 fireball, and 20 grains is there accuracy load over all other powders? After sending two thru the chrony, I shot the last one at the 12" gong at 300 yard's, and yes, I can go the other .7 if this load doesn't suite me. I held dead on the 300 yard crosshair, and about 2" left for the wind.
300 yard Varmagedon 4177 fps small.JPG 20221026_165437.jpg

But what really pleased me,was that 20 grain V-max load that I had zerod 1" high for a 200 yard dead on for my main crosshair, it made me very happy, I hit 3977 fps with the 18 grains of H322, just 1 grain under max! But best of all, in the 10 to 15 mph wind, with gusts to 25 this afternoon, it proved to give acceptable accuracy. Now I know this only 2 shots, on a 6" 300 yard gong and not the best conditions. I was using the Zeiss Z Varmint reticle in the 6.5-20x50 Conquest scope, set at 16X but holding about 2.5" into the left to right wind, in field conditions with no flags, I gotta say, if this is what it will do day in and out, I am one happy varminter!
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I have a good starting point now for load development with both bullets, and after today my thoughts that this cartridge is just a 250 yard small varmint round has changed. I am now confident that 300 yards is no problem with this little cartridge, and maybe a tad further on smaller varmints. But for sure, to find this old Pence hand cut rifled barrel was a sweet find, and as for having no needs for a 17 caliber, that thought has changed as well. I used to wonder why all them old guy's liked them little bitty cartridges when there were so many other choices,,,,,,,, I guess you just gotta be an old guy to understand,, I do now!

I am in no hurry to work up loads for this rifle now, especially when this V-max load is shooting llike it is with no load development involved. I really just wanted to find a safe starting point to work from and get the rifle sighted in. I am aware that I could have found the magical load right off the bat, and if this is the best this barrel will do,, so be it, I can make it work. But the chances of finding more speed with a load that shoots as well or better, is pretty good. Either way, I can live with it.

Oh ya, and after this, I'm going to have to get a box of 25 grain V-Max just to see if this slow barrel can shoot them, I just gotta see for myself, especially now that I see the velocity it is getting with the 20's. So many projects,, and so little time?
 
Great looking outfit!
The 17 Mach 1V is great for pd’s, enjoy it.Those 20 V-Max’s always shot very well for me,will have to look for some of those Varmagedons too.
Matt
 
I had very similar results with my 17FBa couple of years ago. I run nothing but 20’s through mine. I tried several powders and found it not to be picky to get speed and accuracy. I figure as you mentioned, 250 yards easily. And, if it’s a bit further I am safe as well. I will hold for some wind, but elevation, if I can’t hold center and score an impact on a prairie dog, time to change medicine.
I save the 25’s and 30’s for the 17 Remington.

I am all about splat factor. I see a fair number of folks using heavies in the small cases. I don’t want the worry. One bullet and the same load. As I said when it drops short, time to change.

Lol, don’t ya know the wind blows those little bullets around like a Fall leaf in the wind……….
 
Yep, these little suckers are fast, but they can't outrun the wind! I never had a 17, never thought much of them, but now that I have one I wish I woulda built one decades ago, their fun. But I already see, when I think I'm holding enough off for the wind with this caliber, I need to add a little more, that's for sure!
 
Yep, these little suckers are fast, but they can't outrun the wind! I never had a 17, never thought much of them, but now that I have one I wish I woulda built one decades ago, their fun. But I already see, when I think I'm holding enough off for the wind with this caliber, I need to add a little more, that's for sure!
I had no more hold off, wind issues, than my buddies shooting 20’s and 22’s at similar distances.

Shooting for groups on paper where it is measured yeah probably shows drift.
 
I have not shot a 20 ever, and the last 22 was a 1-9 twist shooting 70grain VLDs, so it will take some adjustment coming from 6mm and up, it is definitely more wind sensitive than my 6BR with 28 grain BT at 3475 fps.

But those 20's and even the22's with the 55 grain and lighter bullets I would imagine are more comparable. Hell in 68 years I have never owned a 17 caliber air rifle, all mine were 22 and one was a 25. I hade to invest in everything from cleaning patches jags brushes to a cleaning rod to shoot this barrel I really have nothing in but a chamber job. It came with the Panda and stock I am building a 222 on on.

This being a Pence barrel is the only way it found it's way in my collection. But now that I've played with it a day, I am glad it did!! I'll get used to it, it is going to be my fall thru spring rifle, then I'll put the 6mm BR Pence barrel back on, It gets me out to about 600 yards for them pesky ground hogs.
 
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That's good shooting and a good looking rifle. If you can find some 20 grain Nagels, they shine in a FB so they should too in your rifle. Good luck with the PDs.
 

[hogpatrol]​

No prairie dogs where I am at, but crows, fox without destroying pelts, ground squirrels, and other small pest will get to see this little gun in action. But I would sure love to play on the prairies with it if that was to develop for me.

But I hope I am not showing to many teeth and blinding anyone!! But after going to the range this afternoon, I am dam sure grin'n ear to ear! For more reasons than one!!

See I bought a new Benchrest rifle this summer and along with it I bought 2 8# cans of N-133, but being out of the 6PPC game for over a decade, I was out of the loop on some of the known components that are less than desirable!! One of them being (2015) N-133, it seems this is a fluffier batch that just doesn't play as well as other lots of this powder, especially in the 6mm PPC with the 62 to 68 grain BR bullets!

Well I read a few were happy with 133 in the 17 Mach IV so I decided to try it. By the way I gave up on the XBR 8208 with these light 20 grain pills. But seeing I had nothing to lose since I have no other use for this, and was ready to peddle it, I gave it a try! Since I had little reliable data to go by, I started with 18.0 grains, and dam am I glad I did!
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I did walk my sights in and set them about 1" higher than that first 3 shots before shooting the 18.3 load, that is why the difference in POI between the two loads.


It was a tad slower than the 322 loads which I am very short on and read a lot about temp sensativity in this caliber. The first load was plenty good enough for me, even though it had a 37fps ES for inside 250 to 300 yards, that will work for me.

But being the first 3 shots with this powder, I thought it may be a fluke, then I shot the three I had loaded with 18.3 grains, and it was obvious, being in the 3's it still works! But for the first time dropping the pin on this powder, and .3 of a grain difference still producing this kind of results,,,, and mind you, no bullet seating experiments yet, I have found a use for my so so batch of 133, at least the open jug.

Which brings another thought to the table. Since this powder is showing such good results with this cartridge, what might it do with the new 222 Bench gun I'm building with 52 grain pills??? I might just have use for both jugs, time will tell.

But I am pretty sure I should be able to come up with a load that will keep these in the low to mid 2's and if I have to settle for the mid to low .3's, I can live with that, at over 4000 fps. I think I should order some more of these V-Max and leave well enough alone,,,,, at least till find some Lapua 221 fireball brass?
 
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I have noticed with the H-322 and XBR-8208, the further you venture past about 4050 to 4100 fps, the bigger the groups get, and the more erratic the Standard Deviations and Extreme Spreads get! The 18.3 load of 133 had a 17 fps extreme spread, but 18.6, which about all I can get in this case, was over 80 fps Extreme Spread!

Now I am doing all this whill fireforming the Nosler 17 Fireball cases, that are neck turned to give me a loaded .193" dia. for the .196" NK chamber. I also know some of these cases are over 1 grain difference from one to the next, nd I am not sorting any yet, but after all are fired the first time, then trimmed to length, I will.

That is when the real load development will begin. But right now, for my first ever 17 caliber, and acquiring another Pence barrel at that, I am quite pleased!
 
N133 is my main powder in the 17 FB and it works up to 30 grain bullets in a 9 twist. A heads up on Nosler brass, it's capacity is a couple grains less than Remington brass. I tried it once and the results were not as good with Remington. FYI, there's a guy on Saubier selling a large amount of once fired and new 17FB R-P brass.
 
N133 is my main powder in the 17 FB and it works up to 30 grain bullets in a 9 twist. A heads up on Nosler brass, it's capacity is a couple grains less than Remington brass. I tried it once and the results were not as good with Remington. FYI, there's a guy on Saubier selling a large amount of once fired and new 17FB R-P brass.
I'm going to stick with this for now, but as soon as Lapua makes it's next run of 221 Fireball cases I'll grab a hundred and have all I need to wear this barrel out. It has been the best cases to date for a couple buddies of mine. Lapua can't tell me when that will be, but has confirmed that it is still on there production list.

Don't know how much this barrel has been shot when it was a 17 Javelina? but I've cleaned it twice now with over 30 shots both times and it's not copper fouling yet? I am done looking for a powder and as you said, the 133 will be my go to powder in this gun, with the 22.5" barrel the 4033 fps is enough to satisfy me.

As long as I can prove the accuracy of this load and confirm it to agg under 1/4" for 5 shot groups, it will exceed not only my hopes. but my needs! That .192" three shot would be nice to see it hold as a true agg giver, and I'll never need more than three shots on an outing for what and where I will use it around here. Time will tell?
 
I did some brass inspection a little bit ago from my test loads Friday. Seems all three rounds from that 18.0 grain load of 133 had brass that all weigh within .3 of a grain overall, the 18.3 load used brass that had 1.2 grains overall difference.

Like hogpatrol said this Nosler brass aint the most consistent, I found over , but we'll see how it goes from here with weight matched fireformed brass from here out. I will use those three cases for my target weight Keeping all my test brass within 3ths of a grain of each other and sort all cases out of this 100 round lot to 5 tenths of a grain of each other.

But make no mistake if that 18.0 grain holds a .250 or less 5 shot group when I reshoot it, this load development is over.
 
The 8208 gave faltering velocity, 4179 fps, but in this barrel accuracy suffered, 3/4" was about as good as it got.

I reshot the 18.0 grains of 133 and the 20 grain V-Max gave the same results so far the best I used. 5 shots were a bit bigger group, this time, and a bit more wind, but gave me a solid .338" group. Only 4037 fps, but that works for me.

The 133 was the best with the fbhp 20 grain Varmagedons as well, about .5" was the best I got with them.
 

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