This Rifle won't Shoot! Diagnosing the issue(s).

[TheCZKid]

Really hope you haven't taken the dremel to it yet...

No, have not messed with that yet. I would only do that after taking the rifle to my local gunsmith, and talk to him about what's going on with the rifle first.

I'm going to get some factory 17 Fireball ammo, mount my scope and go see if it likes 20 grain factory ammo. That should tell me some interesting feedback.

 

[urbanrifleman]

These four clearly hit the target sideways. Can you get any lighter or shorter bullets?

View attachment 1679604

There you go.

 

[dfrosch]

If you already have some loaded, a quick test would be to pull the plastic tips.

 

[lawman29]

I've run all your numbers with the various bullet you used through the JBM stability program. I suggest you do the same.

Al has been trying to tell you about your stability problem....see post 55...

The Nosler Varmageddon 20 grain FBHP (not tipped!) is shorter than everything you've tested.

Your testing should be a max of .2 grains between loads given the case capacity of your cartridge.
You only need to shoot two per load - at the end it will tell you where to go back and test in .1 grain increments.

 

[dfrosch]

... this gun was made about 20+ years ago.

If shorter bullets don't work for you, I would have to guess that the barrel needs flying lessons.

 

[LCazador]

I think you should try flatbase bullets before you do anything else. Twist is too slow for boat tail bullets. Reloader 7 and H322 should be the best powders for 17 Mach 1V. Like Dave Tooley says try putting a bullet into the fired case neck. It should freely enter the neck.

 

[TheCZKid]

Al has been trying to tell you about your stability problem....see post 55...

The Nosler Varmageddon 20 grain FBHP (not tipped!) is shorter than everything you've tested.

Your testing should be a max of .2 grains between loads given the case capacity of your cartridge.
You only need to shoot two per load - at the end it will tell you where to go back and test in .1 grain increments.

I hear ya, definitely see the likelihood of stability being a huge issue. So, no more testing with 25 grain bullets for now. I'll try to get ahold of the 20 grain Nosler Varmageddon bullets.

As for the tests and load variances, yes I normally would not do .5 grain spreads, but in this case, I wanted to span a fuller range of loads and opted for larger spans. When I get a range that shows promise, then I'd go smaller increments. I didn't want to shoot 10 loads for one powder, 5 seemed to be a better test, I could be wrong in my thinking.

In this rifle, I've found that two rounds might be close, and a third to be a flier, so I opted for 3 round minimum per load. Appreciate the input!

 

[TheCZKid]

I think you should try flatbase bullets before you do anything else. Twist is too slow for boat tail bullets. Reloader 7 and H322 should be the best powders for 17 Mach 1V. Like Dave Tooley says try putting a bullet into the fired case neck. It should freely enter the neck.

So far, all the bullets I've tested have been flat base.
And yes, when I've put a bullet to a fired case neck, it had clearance and wanted to fall in. I'll be testing some brass with slightly thinner necks as well, but at about .0125" it appears that's a usable thickness.

 

[SBS]

While there were variations of the Mach IV, they were generally shorter than the .17 FB. Is it possible that the barrel was rechambered to .17 FB and not so marked? Any signs of excessive headspace with the rounds you made up for it? Since it accepts factory .17 FB rounds, might be another reason to do a chamber cast as AL suggested.

 

[pavementends]

In your post #19 you state that the rear action screw cannot be tightened too much. If the action is bedded so there is no strain you should be able to tighten both actions screws to pretty much what ever value you want. Particularly with a single shot action with a solid bottom. Cleaning the barrel is a good first step. Insuring the front action screw is not contacting
the bolt and the front base screw is not touching the barrel is always a good step. After insuring there is no binding when the action screws are tightened, and the bolt handle is not touching the stock and of course you have a known good scope you are looking at the barrel and bullets. You can measure the neck diameter of a fired case vs. the neck diameter of a loaded case and be reasonably sure there is enough neck clearance. Since a fired case will allow a bullet to drop in you are probably ok. Since the bullets do not appear to be stable I would try a shorted bullet. The barrel may indeed be shot out.

 

[drewh]

I got a really good suggestion from someone, buy a box of factory 17 Fireball ammo, and shoot some. See how they shoot. I have tired to chamber some factory 17 FB ammo, and it chambers fine in this action. So I'm definitely going to go to LGS and get some ammo. My loads are all made from my own converted brass, and most have been once shot, might be an issue with my brass, compared to what it "should be" and hopefully shooting factory ammo will give me a reference point.

Remington purposely made the Fireball brass/chamber longer than the wildcat M4. It may not chamber in your rifle.

 

[TheCZKid]

In your post #19 you state that the rear action screw cannot be tightened too much. If the action is bedded so there is no strain you should be able to tighten both actions screws to pretty much what ever value you want. Particularly with a single shot action with a solid bottom. Cleaning the barrel is a good first step. Insuring the front action screw is not contacting
the bolt and the front base screw is not touching the barrel is always a good step. After insuring there is no binding when the action screws are tightened, and the bolt handle is not touching the stock and of course you have a known good scope you are looking at the barrel and bullets. You can measure the neck diameter of a fired case vs. the neck diameter of a loaded case and be reasonably sure there is enough neck clearance. Since a fired case will allow a bullet to drop in you are probably ok. Since the bullets do not appear to be stable I would try a shorted bullet. The barrel may indeed be shot out.

The reason the I don't want to tighten the rear action screw too much is it's very thin and can break if tightened very much. I'm not sure if there's a recommended torque spec for that top screw, so I'm just making it tight for now.

The bolt handle does lightly touch, not sure when I'll try to fix that, as it appears to be a minor deal. I'd need to modify the stock and repaint it, and I'll fix other stuff first.

And, the Remington ammo does fit, appears to not be jamming the front of the neck into the chamber, but don't know for sure. From what I know, the difference in length of 17M4 brass and 17FB brass is 1.400" vs 1.410" respectively. I got ahold of some Remington 17FB ammo, and just measured the cases on loaded ammo, they measure 1.403 and 1.404 average. So, seems to be okay.

The ammo I'm going to try is Remington Premier AccuTip-V 20 grain, flat base tipped bullet.

 

[gunsandgunsmithing]

As for the tests and load variances, yes I normally would not do .5 grain spreads, but in this case, I wanted to span a fuller range of loads and opted for larger spans. When I get a range that shows promise, then I'd go smaller increments. I didn't want to shoot 10 loads for one powder, 5 seemed to be a better test, I could be wrong in my thinking.

Definitely, rid yourself of that logic. Until you know node spacing, you really can't possibly know proper intervals. So, why would one look for any kind of repeatability from pretty much completely unknown variable values? Seriously, IME, .5 is a pretty huge increment to change at a time in a case that size. I'd do .2 or .3 at most.

Ultimately, after following this thread some...I'm guessing either a crown or twist issue with the bullets you've tried. Either is a stability issue and both are still possible, regardless of how the crown looks with your magnifying glass. I've been there more than a few times..fwiw.

 

[dfrosch]

I hear ya, definitely see the likelihood of stability being a huge issue. So, no more testing with 25 grain bullets for now. I'll try to get ahold of the 20 grain Nosler Varmageddon bullets.

There's the possibility of your 20 year old barrel being shot out. Unless you have something else in 17 caliber, you might not want to stock up on other bullets. Pulling the plastic tips from the 25 gr VMax should shorten them enough that they stabilize.

 

[dhagerty40]

that is a H&S precision stock and they do have an aluminum bedding block. AT least on their xp100 handgun stocks we Normally torque the front bolt between 25-30 in-lbs and just tighten the rear screw snug but not tight.

But what has me concerned is what is making that mark (marked with arrow on pic)? The only thing in that area is the front pin holding the trigger in the action. if the pin is too long or stuck, it could cause the action to not sit correctly in the bedding.

 

[Coyotefurharvester]

The fired case in post 1 looks distorted ? Is it from your phone position?

 

[TheCZKid]

that is a H&S precision stock and they do have an aluminum bedding block. AT least on their xp100 handgun stocks we Normally torque the front bolt between 25-30 in-lbs and just tighten the rear screw snug but not tight.

But what has me concerned is what is making that mark (marked with arrow on pic)? The only thing in that area is the front pin holding the trigger in the action. if the pin is too long or stuck, it could cause the action to not sit correctly in the bedding.View attachment 1679696

That area seems to have been carved out for some reason, I don't see a correlating protrusion on the bottom of the action that would require that space. It's unusual and not sure why it's there.

 

[TheCZKid]

The fired case in post 1 looks distorted ? Is it from your phone position?

In person it's not distorted, but it's a photo, so not sure what you're seeing.

 

[Coyotefurharvester]

The body and the sizing die marks look different ?

 

[rickiesrevenge]

I shoot a lot of xp-100s in their original pistol configuration. Torque the front action screw as normal. The rear screw being an 8-32 you just make snug. It doesnt need torqued to 1/4-28 specs! The mark on the right side kinda looks like it corresponds to where the trigger pin is, is there any depth like it was relieved with a mill?

I bet the 10.5 twist is gonna hold you back from any of the plastic tipped bullets. I agree with an earlier poster that said get some 20gr noslers without the plastic tips. the 15.5gr ntx is lighter because of being lead free but it isn't shorter than the 20vmax.