Cartridge length question

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fraser2

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This is probably a dumb question but anyway I have to ask. I hand load a 243cartridge and the OAL is about 1/8" short of what it's supposed to be...........is the cartridge OK to shoot?
I'm new at handloading so please excuse my ignorance. Any help would be very much appreciated.
 
Fire away. But next time seat your bullets out to the proper OAL. Better for feeding in some rifles, and better for accuracy.
It's true that a deep seated bullet will raise pressures somewhat, but unless you are at or above max loads, it's unlikely to be a problem.
 
Couple of questions.
First, what did you use to determine OAL?
Second, Did your manual give an OAL for each bullet weight and shape or just a maximim COL?
There is quite a range in lengths. For instance the Min OAL listed in Modern Reloading for a 55 gr bullet is 2.540". That same book lists a 107 gr bullet Min OAL as 2.850". That's a difference of .310" of almost 5/16". So there may not be a problem.
Sierra says ALL subject cartridges have an OAL of 2.600"
Barnes says to seat the bullet .050" off the lands and cycle through the magazine. If it works, then increase length for accuracy .005-.010 at a time.
IMR states all cartridges are 2.640", but they only give data for 80 and 100 gr loads.
Hodgdon doesn't give any length in their data.

I wouldn't load less than the min OAL if I was close to max. Pressures would be too high. If you have a short (55-60 gr bullet loaded) don't worry about firing it. All the spec drawings I have for the cartridge is 2.700, even in Modern Reloading (so I guess that you are loading that 107 gr round off the lands) so if you are only an eighth of an inch off from that, then you are golden. That'd make it 2.575 (not far off of the 2.6) or 2.475 if you started with 2.600". Either would be sufficient.
I currently load 100 gr short jacket rounds for gophers in my .30-06. They are NO WHERE CLOSE to the specified max OAL and they shoot fine (I have to crimp them).
Relax. Don't load to max until you get more experience. Pay more attention to min OAL, that's where the pressure surprises can creep up.
 
Many thanks guys. I was loading 75 gr HP Sierra Varminter bullets for my .243 Winchester M70. The loading chart said the OAL should be 2.625". I used about 34 gr of H4895 which is quite a bit less than what Hodgdon recommended as a starting load.
 
fraser2 said:
Many thanks guys. I was loading 75 gr HP Sierra Varminter bullets for my .243 Winchester M70. The loading chart said the OAL should be 2.625". I used about 34 gr of H4895 which is quite a bit less than what Hodgdon recommended as a starting load.
Click to expand...

I was told to NEVER use a starting load below book minimum. FS
 
fraser2 said:
Many thanks guys. I was loading 75 gr HP Sierra Varminter bullets for my .243 Winchester M70. The loading chart said the OAL should be 2.625". I used about 34 gr of H4895 which is quite a bit less than what Hodgdon recommended as a starting load.
Click to expand...

Hopefully you don't get a squib,if loading below book minimums pay particular attention when shooting. One stuck bullet is bad enough but not noticing and firing a second:eek:
 
The issue of higher pressures caused by seating bullets deeper really only applies to straight walled cases, such as most pistol cases, and rounds such as the .45-70. The difference in case volume in a .243 if it is seated a bit deeper than specification is minuscule. The effect on the pressure is probably less than the normal variation of different rounds.
 
"...quite a bit less than what Hodgdon recommended as a starting load..." Don't do that. Under minimum loads can be as dangerous as over max loads. They can create weird pressures from the powder detonating as opposed to burning. However, like John Y Cannuck says, 34 grains of H4895 is the starting load. OAL should be 2.640".
 
Hey fraser - I'm not preachin' at ya, but a reminder to all new reloaders - attentively reading a reloading manual will answer all these questions and prevent an unsafe situation...

OK, maybe I am preaching......
 
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