45/70 ideal OAL

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bearboy1066

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I read many places that the ideal oal for a sharps 45/70 is just touching the rifling. Having had some success with the 535 gr postell. I tried to establish the length by inserting a bullet into a sized case. All mine are Starline and measure 2.099 .By gradually pushing the case into the chamber the bullet was finally seated touching the rifling,I assume. This gives me aol of 3.161 with the forward lube groove completely exposed. Lyman manual for Springfield shows a oal of 2.930. Different rifle but nothing shown in manual for Sharps.
Does the method described above constitute an accurate method for establishing an accurate oal for a Sharps? What about the exposed lube groove.
I have reloaded fo 40 yrs but this cast bullet Sharps thing has me buffaloed. Makes we wish i had never seen Quigley Down under.
 
You have to be careful the bullet doesn't stick in the lands and get partially pulled back out when you extract the case. You can do this by pushing the cartridge in, as you did, until it is stopped by whatever surface the cartridge is designed to headspace on (the rim recess for this cartridge) and then I push the cartridge out from the bullet end with a cleaning rod or a dowel, so you overcome any pinched bullet friction first. But don't let an extractor or ejector act on it.

The other method you can use, and one that will ensure true maximum COL, is to get the bullet in place as you describe, insert a wood dowel to kiss the nose of the bullet, and mark it at the muzzle. A single-edge razor blade puts a clean mark on it. Remove the cartridge and close the breech and then get a second mark made with the dowel touching the breech. The distance between these two marks on the dowel will be a maximum COL for the cartridge fitting snug in the chamber (not even against the rim recess) with that particular bullet, and you can tweak it from there.

Having a long throat will put the bullet out further than a SAAMI standard .45-70 would have, but maximized in your chamber. This will increase case powder capacity.

But all that begs the question, what will work best in your gun? Only you can determine that. It might like the bullet jammed into the lands. It might like it further back and jumping to the throat. You just have to test to see.
 
I own, and have owned a good number of 45-70's over the last several years. I've also been reloading for around fifty years. There are so many bullet designs for this cartridge that OAL sort of becomes a moot point. If you can gently close the lever (you mentioned Sharps) without having to cam the round into the chamber, you're OK. What I've done in the past is make up dummy rounds for different bullets. I keep trying to gently close the lever as I decrease the OAL. When I can no longer feel any resistance when closing the lever I know I'm just off the lands. For most loads, even just touching the lands won't cause a problem as long as you're not at or above the high end of a listed book load. Some of my most accurate loads were actually well off the lands...contrary to standard belief that the closer the better.
 
Many, even most BPCR silhouette and target shooters load long. Grease grooves are often exposed. This does not matter because we are shooting out of a clean cartridge box and the long load is more accurate and leaves more powder space.

For hunting, I would bury the grease groove, that buffalo will never know the difference in absolute accuracy.
 
I want to thank you all for your advice. I will try all methods. Secondly my search for .460 Postells has proven fruitless so far. The sagebrush is out of production for the holidays and i haven't found any others. If I settle on a bullet I may break down and do some casting,something I haven't done in 50 yrs.
 
I have reloaded fo 40 yrs but this cast bullet Sharps thing has me buffaloed. Makes we wish i had never seen Quigley Down under.
Click to expand...

That's funny.


I too am working on some 45-70 loads. Mine are hunting loads though, not moon taker long range loads. I have also delved into the cast bullet realm and what came easy with jacketed bullets like OAL measurements, seating depths and even load data are a bit more elusive.

Furthermore, even my quickload software is mostly useless as it struggles with straight walled cases.

But good luck. The Quigley rifle is one iconic piece of machinery.
 
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