.17 Rem Fireball case length ?

[Bad Wolf]

Hi,
I've noticed that AmmoGuide lists the .17 Rem Fireball case as 1.42", whereas my cases, which I have recently received from MidwayUK, are only 1.40".
http://ammoguide.com/cgi-bin/ai.cgi?...IAuW&catid=615

I am just making up some starting loads based on the Hodgdon site data for H322, 25 grain Hornady HP and COL of 1.80". Now, if they were using the longer cases, then maybe my intial loads, with a shorter case, will be too high.

[csterner]

Originally Posted by Bad Wolf

Hi,
I've noticed that AmmoGuide lists the .17 Rem Fireball case as 1.42", whereas my cases, which I have recently received from MidwayUK, are only 1.40".
http://ammoguide.com/cgi-bin/ai.cgi?...IAuW&catid=615

I am just making up some starting loads based on the Hodgdon site data for H322, 25 grain Hornady HP and COL of 1.80". Now, if they were using the longer cases, then maybe my intial loads, with a shorter case, will be too high.

I don't think case length makes any difference in pressures, unless the case is too long for the chamber and pinches the bullet. That's a no-no. Usually you trim under .010", so if they're .020" under, just shoot them a couple times...they'll stretch! LOL

Work up carefully in that small case. A tenth of a grain will raise pressures quickly. I'm using H322 and I think my max was 18.3, but I'm starting to get pressure signs at 18.0.

charlie

[trotterlg]

You will be fine with the shorter cases, they will grow so it just means you will not have to trim much for a while. The last new cases I got had mouths so bad they would not chamber at all, so you will have to work them over a little to get them square I think. I have found that a full case of Winchester 760 does a good job, as I recall you cannnot get too much in a case, something like 20.5gr I think, nothing wrong with a little bit of a compressed load. I use the same powder for my 17 Remington with 30gr bullets, 25.6 gr in it. Good luck. Larry

[LT17]

You guys beat me to it. I don't see the case length being an issue either, and don't worry it wont take long for those necks to grow!

[Bad Wolf]

Thanks for the replies.

I have just checked the body length which is 1.06" - the same as the case dimensions indicated here:
http://www.17remingtonfireball.com-a...casedimensions

So, it looks like my short cases are due to a reduced neck length - which, as you guys have already said, should not affect the pressure, given the same COL.

One last question, at what case length do you guys trim; is it when the case has stretched longer than 1.42" ?

[RareBear]

As far as case length goes, I try to measure every chamber in front of me that I load for. Most often I use a Sinclair International chamber length guage.

http://www.sinclairintl.com/cgi-bin/...TCL&type=store
And for calibers that the Sinclair lineup lacks, I have used Dan C's method of slitting a case neck, then cutting the case neck approximately in half and assembling with a bullet such that the contraption will be longer than the chamber in question, and then chambering and measuring sevearal times.

Since I know the chamber lengths, for full-length sized cases I go with minimum chamber length clearance of .010". For fireformed necksized cases only I have adopted a minimum clearance of .005". And yes, the tight clearances means I have to measure more often and trim more often to avoid ka-booms whereas load manuals, reflecting SAAMI specs, oftentimes recommend clearances of .020" or so.

Can you tell I like the longer case necks?

ETA: For bolts that have spring loaded ejectors in the boltface, I remove the ejectors to get a chamber length measurement.

[Bad Wolf]

RareBear.
Thanks, I'll measure the chamber length.