17 fireball problem

DEEREHART

Hey guys I have a problem with a 17 fireball. when chambering a live round the bolt is sometimes stiff to close, I have measured all dimensions and everything is within spec. i have also chambered sized cases and have the same issue. What I find the most frustrating is that this does not happen all the time. I tried a different size die,same problem. Tried a different rifle no help.Any suggestions would be appreciated. DH

bait dunker

does this happen with factory loaded ammo? Perhaps the bullet seating die is set to deep/too hard of a crimp and making the shoulder buldge slightly?

perry shooter

If these are reloaded cases have you trimmed the necks. I bet the OAL is too long.

336marlin

Since this happens with an unloaded case that has been sized you may not be getting the size die down far enough to contact the shell holder. Strain occurs in the press and die under load and unless you have preloaded the process with a little "cam-over" pressure when setting up the sizing die it could be swaging all the slack brass towards the base and leaving a slightly oversize and unsized ring that makes for difficult chambering.

DEEREHART

factory ammo does not have this issue. OAL is 1.410 1.420 is max. Size die is all of the way down. still confused, DH

Odawgp

quote:Originally posted by DEEREHART
factory ammo does not have this issue. OAL is 1.410 1.420 is max. Size die is all of the way down. still confused, DH


trim length is listed at 1.400 making 1.410 max
data from hodgdons load data site, hit print to see trim legth
you are 10 thousandths over at 1.420

Ambrose

I think you need to "bump" the case shoulder a little more. As 336marlin says, there's a little spring in most presses and you have to screw the die in so it touches the shell holder and then a little more. You will notice it requires a SMALL amount of effort to raise the press ram against the die without a case in the shell holder. To be sure the die is touching the case shoulder, you might try smoking the shoulder with an ordinary paper match before running the case in the die. You might also try a neck sizing die on cases fired once in your rifle and see if the problem goes away.

Personally, I like to feel a little resistence when I close a rifle bolt. It insures there is no "slop" between cartridge and chamber. This is, of course, provided case length is OK and bullet is not jammed into the rifling.

Odawgp

quote:Originally posted by Ambrose
This is, of course, provided case length is OK and bullet is not jammed into the rifling.


Which is exactly what I think is happening

If it does it on a freshly re-sized case then I think the above is not the problem

then it could be the bullet seating die belling the shoulder

http://forums.gunbroker.com/topic.asp?TOPIC_ID=353385

zimmden

Are you using Mach IV cases or 17 Fireball. There is slight difference. I use Hornady headspace gages to check my new once fired brass and record reading. All cartridges fired in this chamber should measure the same after firing. Resizing should set the shoulder back ( headspace ) slightly. I do not full length resize any of my fired brass in any of my 7 different calibers. I only neck size and have no hard closing of bolt. I also neck turn my brass for perfect fit. Since the 17 Fireball is a necked down 221 Fireball, the necks can end up too thick and too tight in some chambers. Bob

Ambrose

Take one of your re-sized cases that is giving you trouble, smoke the shoulder/neck/case mouth with a paper match, carefully insert it into the rifle chamber with you fingers, and close the bolt. When you remove the case from the chamber, you will be able to tell where it is binding--case mouth, oversize neck, or shoulder. If it appears that none of these areas is the problem, then take a magic marker and color the circumference of the case ahead of the extraction groove, re-insert the case, and close the bolt. That will tell you whether the O.D. of the case is not being sized enough near the base (unlikely).

DEEREHART

hey guys, here is what i have found out so far; the cartridge specs that I had gave a max case length of 1.420 most of my once fired brass was 1.409-1.412 figured that this was ok, not so. Sorted the brass by length and found that 1.409 did not bind but the closer I get to 1.411 the harder the bolt closes. Factory unfired brass is 1.40 no binding,so I guess I trim everything once its fired never had to do this before. On my way out to find a 17 cal cutter for my trimmer. DH