O-give me a chance!

kevin01041961

Well-Known Member
Firstly i have been reloading for over 20yrs and yes i did get some of the terminology wrong sorry for that ! basically i use the Hornady head space guage i want to find out the best space from the O-give the seating depth so yes i got the terminolog and thanks for pointing it ok do i seat 0.010 or do i set deeper ? my thanks for your help
 
Keep it ten thou of the lands see what groups you get if your not happy then back it of a bit more until you get the group you want !
 
My thanks , sometimes you know people ask questions on here and your made to feel foolish .................... so thank you
 
Thank you for the PM. Interesting about the H140 thank you something learned. I wonder when they dropped it as so far I cannot find any references to it at all. The 26th Hodgdons book was printed in 92 and makes no mention of it that I can find.

Now your original post gave me the impression that you were new, as I stated in my reply, the head space tolerance is about 0.004"-0.006" on most modern rimless cases I think you will find.

As for bullet jump I have found that almost all my rifles prefer a good bit of jump. Some due to using light bullets for calibre it's impossible to have the bullets ogive near the leade. An example of this is the 30 cal Hornady 130 Grn SP in my 30-30 bolt action that was throated for the 170 grain bullets by the maker.... another is the 6.5x55 Swedish Mauser which of course was throated for the 156 grn round nose bullet. The 120, 129 and 140 grain spitzers cannot get close to the leade and remain seated in the case neck.

In my 7x57mm BSA I found that the Hornady 139 BTSP needs to be seated so that the canulure of the bullet is just out of the case neck for good grouping which means it has what most it seems would call a massive bullet jump as it's well over 0.040". probably closer to 0.100" but I am unable to check and see what it is .......................... sorry. Seated out close to the leade almost trebles the group size.

On the other hand the 139 grain Hornady Spire Point which has a flat base shoots well with the ogive closer to the leade. Each rifle and barrel has it's own likes and dislikes and it's our job as a hand loader to find out what they are.

Don't get too hung up on being close to the leade/throat of the rifling as from personal experience in a lot of rifles that's not where they shoot their best groups ;).

Using correct terminology cuts out confusion and would get answers quicker as people would know what you mean and not have to guess or assume. Hand loading is no place for guessing or assumption ;).
 
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