17 cal bullet jump experiences

[Frankm]

I ve got a 17 Hornady Hornet that has to jump 20 gr bullets .100 to lands. That gives me .150 of bullet in the case neck and what I consider minimal 'grip'. Gun shoots 3/4 - 1" groups but it took lots of messing around to get there. 11.1 grs of AA1680.

I ve got a fair supply of 25 gr VMaxes that I can actually touch the lands with and still maintain .170+ of bullet in the case.

What's some of your guys experiences with 17 caliber bullets and if getting close to the lands gets you better accuracy??

Gun has been bedded, 2# trigger, etc. I believe it's capable of more.
Thx

 

[Mark M.]

I'm interested as well, good question

 

[AckleymanII]

In the custom 17 Mach 4's and 17 Remingtons, best accuracy is touching the lands.

Your rifle will tell you what it likes the best, trail and error.

 

[dstoenner]

I found that I had to jump a mile also but when I loaded my handloads to the same COAL as Hornandy factory ammo, they started shooting MUCH better. If my gun doesn't mind the jump I don't mind the jump.

CZ527

David

 

[germanlongbow]

My Mach IV likes light jam no jumping, at least with Vmax bullets. My 20's like to me jumped 5-10 thousandths.

 

[Frankm]

I think I ll lightly touch lands, then shorten them up in .020-.030 lengths down to factory OAL and see what groups best. I know that's how I approach larger calibers... kind of Berger recommendation, but didn't know if 17 s had any issues since I only have the one and darn those things are tiny!

Thx for responses and I d welcome others input also.

 

[B23]

My experience with most bullets has been they shoot their best either really close to touching or jumping them a long way off and with off the shelf factory chambered guns you generally run out of case before they touch so in those guns they usually have a lot of jump.

 

[Frankm]

B23..... that's the exact issue with this Ruger 77/17... can't get close with 20 trainers but can get there with 25 s.

So we ll see if those 25 s will group better than the .800-.850 I m getting with the 20 VNE s. If so that ll be the good news, bad news will be that I have 5000 or so 20 s and only 1500 25 s.

Yes, I do shoot a lot of grd squirrels !

 

[kgsmith1]

With the 17 hornet I have wondered if the primer detonation is enough to start the bullet and have had success with pistol primers and either increased neck tension or a mild crimp. It’s possible that those finding success with jamming are accomplishing the same thing.

 

[searcher]

The small bullets tend to favor jumping more often than not. What I found to be more important than bullet seating depth with these small bullets is that the neck tension be relatively light and uniform, that the neck is sized to result in concentric necks, with shoulders pushed back no more than .001". To obtain fantastic accuracy in these "micro" calibers, these details will usually result in better groups - no matter the depth adjustment. I think you will find that these little bullets do better seated well into the necks and be "fully supported" as called for in the manuals. It is also a bit safer as these little rounds elevate pressure quite quickly with the fast powder they burn. Mine will shoot most bullets into 1/4" MOA 5-shot groups with the right powder after I have turned the necks, pay special attention to shoulder setback, carefully trim and chamfer cases and fairly light neck tension, acquired with neck bushing die. Using a "non-bushing" regular sizing die is probably the biggest enemy. I use a Redding bushing die. The reason for turning necks is that because the neck is so small, that the deviation of brass thickness in an unturned neck creates much larger differences in neck tension than with larger cartridges. Turning the necks gets bigger accuracy payback with this cartridge than my PPC's or BR's. The .17 Hornet is also much more intolerant of inconsistent bullet jump distance differences. While most seating dies will usually give you decent repeatability in seating depth - if you have more than .001" shoulder setback - you create jump deviation there by making things too sloppy. I know this goes beyond what you asked - but some of this might save you a bit of work. Good luck.

 

[charlesasmith]

Searcher:

Not sure what light neck tension would be. I plan on using a K&M expander to get .003 neck tension. Is that light enough? I also plan on turning necks, which is a pinta as I have 1,000 cases per gun. I found out that annealing hornet cases is a must for brass life.

Chuck

 

[Paddyd]

Beware of jamming those tiny bullets and fast powder. If the 17 is anything like the 204R that long jump is engineered into the equation (or so I've been told) to allow them to be loaded hot enough to get desired velocities and not over pressure the case.

 

[B23]

You'll find, if you don't already know, 17 Hornady Hornet brass has neck thickness that's all over the place. Neck thickness in my 17HH brass ranges from 9-11.5 thou depending on the Lot #. I despise neck turning so to keep my neck tension as consistent as I can, I keep my brass segregated by neck thickness and use a bushing die. I always dip the necks in Imperial dry neck lube after sizing and run 1-1.5 thou neck tension

 

[searcher]

I use .002" neck tension with moly coated bullets and turned necks. Normally, one would use at least another .001' for spring-back but that is evidently not needed to that degree with such a small neck. B23 is right about the neck thickness - and is reason I turn. Same tricks as applied to .20 practical.