.17 Fireball Trim Length

Str8 Shooter

Str8 Shooter

New member
I had posted a couple of weeks ago about having some difficulty closing the bolt on my Rem. model 7 Predator in .17 FB... yesterday I had the chance to shoot a few reloads (20) that I had trimmed down to 1.39" instead of the listed 1.40" I noticed that I didn't have any trouble closing the bolt on any of the rounds. Has anyone heard of any discrepancies in the listed trim lengths on the .17FB? or is this just an exampled of a rifle with a short chamber?
 
Factory chambers are very generous. I seriously doubt your brass was too long or that it'll ever needed trimming. But it's easy to find out. Just get a Sinclair chamber length plug and it'll show exactly how long the chamber is. My guess is that you pushed the shoulder back a little when sizing.
 
I didn't run into any trouble until after 4 firings. My cases stretched to 1.420. Cases were slightly hard to chamber. After firing a couple, you could see a shiny ring around the case mouth and pressures were a lot higher with previous safe loads, as evidenced by tight bolt lift and extractor marks on the casehead.

I trimmed back to 1.400 and the pressures went away. After trimming and firing once, the cases were stretched to 1.405 already. All cases FL sized every time. I have read, and now experienced it too, that that the 17 FB is a case stretcher in factory guns. Keep an eye on it, for sure. I'm gonna partial resize from now on, or at least until I have to bump the shoulder back. That might help a little.

I agree with Ackman partly, it is doubtful you have a chamber that short, but it is possible. No matter how sloppy your chamber really is or isn't, eventually you will have to trim your cases. A chamber length plug will give you the exact measurement you need to trim to.

bownut
 
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Quote:
My guess is that you pushed the shoulder back a little when sizing.



One "OLD SCHOOL" way to avoid the above...

[*]take one of your once fired reloads (It as to have been fired in your chamber not someone else's once fired)
[*]hold the case mouth and neck just above a lite cigarette lighter or match roll the case in your fingers until the case neck is black with soot
[*]then screw your die out 3-4 turns then run the case into the die
[*]visually note were the die has pushed the soot down the case neck
[*]adjust your die and repeat until it removes the soot down to the bottom of the case neck @ were the shoulder comes into the neck. Once you have done this make sure the case will chamber (from the magazine) in your rifle. You may have to help the case into the chamber but you want it behind the extractor so that you can tell weather or not the case easily chambers
[*]once you have it were you want it, run the case back into the die set the lock ring and your set.
[*]trim the case to 1.4 and reloaded it as normal [/list]

the way above will resize the case mouth as needed and will leave the rest of the case fitted to your chamber. And will insure that you aren't setting the shoulder back too far

Eventually you will have to bump the shoulder back a bit

I have some 20-30 17rfb cases that I have resized this way 4 or 5 times and have yet to see any pressure signs or case head separation signs.

there are better ways to do this. before all these ex$pen$ive gauges and measuring tools were available to everyone not a gunsmith this was the way great grandpa did it.

WARNING!!!! If you go with the above resizing method don't mix match reloads with another gun chambered in 17rfb They may or may not fit and could cause head space problems in the other chamber
 
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I had the same experience with my model 7 CDL, once fired factory shells measured 1.415, I trimmed to 1.40 as per the hodgdens manual and the second firing stretched to 1.405 and had the bright ring you spoke of. My thought is that 1.390 would be the proper trim to length, the 1.40 would be the length when you need to trim.
 
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I had the same experience with my model 7 CDL, once fired factory shells measured 1.415, I trimmed to 1.40 as per the hodgdens manual and the second firing stretched to 1.405 and had the bright ring you spoke of. My thought is that 1.390 would be the proper trim to length, the 1.40 would be the length when you need to trim.




I have not had that problem with my 700cdl /ubbthreads/images/graemlins/confused1.gif

I have reloaded the same 20-30 pieces now 3 or 4 times and haven't noticed the bright ring which you speak of

I do have to trim them every reloading but that is it
 
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