I have some 117 grain Hornady BTSP's, and can't find a length stat anywhere for this bullet. Any help?

First of all what make of rifle do you have?
If it is a short bolt action, OAL 2.75
If it is a long action, and has been throated for a longer length, then possibly 3.00

Ruger 77 Hawkeye

Hornady calls for a COAL of 2.78. If you can’t fit that length in your rifle’s magazine then you’ll need to shorten them up until they fit and reliably feed into the chamber.

I load 100 grain Nosler Partitions for my M-77 Ruger, with a OAL of 2.950"

In my m77 tang safety The 117gr interlock at 2.92" was too long and the bullet was engraved by the rifling. I now load to 2.779" in my 257 Roberts, with the 117grn Hornady interlock. Win brass, CCI, RL19-43grns. Loaded to that length the ogive is about at the case mouth, and the crimp groove is well down into the neck of the cartridge.

The Hornady book says you can go to 47.2grns of RL19 in that cartridge, but I had ejector marks on the case head until I dropped it below 44grns of RL19.

Good luck, my Roberts has always shot the 117grn Hornady well, even in factory loads.


Also MickinColo is right about max OAL for the Roberts. Just about every bit of book info is 2.78" or shorter OAL.

Yup, I just got an e-mail from Hornady saying 2.780

There is no magic to the 2.780 length.
The Ruger has a longer magazine fit the round to the magazine or to the rifling.
Who cares what Hornady says?

I was thinking I should let the rifle determine the length, and deduct a bit for staying off the lands a few thousands, but how many?

try 5 then 10 and then 20.
you'll know right quick which way to go.
you'll only need 5 of each.
i had an old mossberg 270 that liked them .0050 off.
and my 25-06 likes them at .0010
most are somewhere in the 5 to 20 range, and some don't care.
once you find it however you can swap brands or weights of bullets and set the ogive to the same place and they will usually be good right off.

quote:

Originally posted by wymple:
I was thinking I should let the rifle determine the length, and deduct a bit for staying off the lands a few thousands, but how many?

If you are going to work up loads you can start right against the rifling then you can always back off.
If you are going to start with a middle or higher load, which I don't recommend, back off of the rifling between .025 and .050.

Just check any length you use to make sure it feeds. Some combinations of case shapes, bullets and magazines are particular about length.

My M77 MKII gives a length of 2.5 to contact of the ogive of a Hornady 100 sp using Stony Point tools. I get better accuracy with this combination at 2.455 with the Stony Point which translates to 2.95 overall length. Not sure what the difference would be between the 100 and 117s

I loaded 6 rounds at 2.779, and shot 2 groups just under 2 inches. Being rusty from shoulder surgery, that's probably as good as I was gonna get anyway. I'll let a better shooter try it out. I closed the bolt on a long one and it came out 2.781.

Hey Wymple, You might have a bit more accuracy using the Cleaning Rod Method found in that link. It is easy to do, repeatable and accurate.

Then convert the OCL to ODL and you can Seat the Bullets at any depth Off-the-Lands you desire, just as if it was a $$$HIGH$$$ Precision Micrometer Style Seating Die.