7.7 jap reloading data help in Reloading and Ammunition Forum

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7.7 jap reloading data help

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LJG	7.7 jap reloading data help	Lead	[-]
Posts: 3 Dec 30 11 5:29 PM Reply Quote More My Recent Posts	Tags : None I have a couple of 7.7 type 99 rifles I am trying to reload for. I purchased brass and bullets from Graf and Sons. My problem is, I can't find case overall length for the Hornady .311 fmjbt bullets. They are 174 gr. and I only have the Sierra loading manual and no one I know has the data. I'm using IMR 4895 42 gr. but if I use the Sierra loading manual for the Sierra 180 bullet hpbt data, I would only have about .140" of bullet full dia. in the case at 3.150" If I seat the bullets to the bottom of the Hornady 174 gr. fmjbt canular ie; all of the canular showing, I get a case overall of 3.05" Does anyone have data to help? I've heard a rule of thumb is case mouth depth = bullet dia. is that a good starting point? Any of this make any sense to anyone?
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jeeper1		#1	[-]
Posts: 5945 Dec 30 11 7:30 PM MODERATOR Reply Quote More My Recent Posts	My Hornady 7th edition shows the cartridge maximum overall length is 3.100 inches. Just crimp it in the cannelure and it should be fine.
LJG		#2	[-]
Posts: 3 Dec 30 11 7:40 PM Reply Quote More My Recent Posts	if I seat the bullet at the bottom edge of the cannelure, it's oal is 3.030 with the case trimmed to 2.270". If I seated approx. mid point of the cannelure, the oal would be about 3.010". If I seat to 3.100" oal, the bottom edge of the cannelure is approx. .070" out of the case neck. I guess I'll try it at 3.030" just at the edge of the cannelure, I was told these bullets are really meant for the .303 and the cannelure may not mean much. My only concern was that the bullet was not seated deep enough into the case. Thanks, for the info. LJG
jeeper1		#3	[-]
Posts: 5945 Dec 30 11 9:15 PM MODERATOR Reply Quote More My Recent Posts	The key word is maximum. That means you can go shorter if you want to. All it has to do is cycle through the magazine without hanging up. When I loaded the 7.7 jap I used 8x57 cases and crimped in the cannelure. It doesn't matter as long as your load is safe pressure-wise. You are right about the bullets being better in a 303. A .312 bullet will work better in the 7.7 jap but unless you trying for the smallest group possible the .311 bullets will be fine.
LJG		#4	[-]
Posts: 3 Jan 5 12 9:09 PM Reply Quote More My Recent Posts	Reloaded 7.7 Jap with 174 gr. FMJBT Hornady and 42 gr. 4895. Some seated at 3.08 some at 3.05 both worked great. Too windy and cold to do any zeroing. Thanks for the info. LJG
gandog56		#5	[-]
Posts: 67 Jun 4 12 12:59 PM Reply Quote More My Recent Posts	LJG wrote: Reloaded 7.7 Jap with 174 gr. FMJBT Hornady and 42 gr. 4895. Some seated at 3.08 some at 3.05 both worked great. Too windy and cold to do any zeroing. Thanks for the info. LJG Which 4895? IMR or Hodgdon "H" ? By the way, my Hornady 174 gr.'s are .312" Hornady #3130G and they have no cannelure at all Neith do my Hornady #30501's 168 gr. BTHP's I'll be using for my Swiss K31. People say I'm paranoid because I have so many guns. If I have so many guns, what do I need to be paranoid about? Last Edited By: gandog56 Jun 4 12 1:03 PM. Edited 1 times.

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