I am looking at a very clean black pad No. 1 RSI in 7x57. I had a red pad 7x57 RSI several years ago, and I could never get it to shoot satisfactorily. A couple of acquaintances surmised that it might have been chamber with the old original long-throated chamber. However, I never got around to measuring it before I had a chance to trade it.

Does anyone know for sure how the black pad RSIs are throated? Thanks!

I had a 1A black pad rifle 7x57. It shot 139 interlocks and 140 partitions around an 1.5". I never really went any further than that, and Im not that great a shot. Im sure someone else will chime in. I think ruger started using their own hammer forged barrels in the early 90's. So anything with a 133-134 serial number should have a reasonable throat.

Heres a good read on # 1 throats in 7 X 57

https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/9625806/Re:_Do_all_red_pad_7x57_#1a's_#Post9625806

Thanks, KK. Sounds like I need to do a little more homework.

Theres another thread buried where we measured throat length on 7 X 57,s in # 1,s and other rifles, we seated bullets backwards and measured shank of bullet. Both my LH Zastava and Red recoil pad Ruger # 1 have long throats and both shoot well.

My Ruger #1A 7x57 was a red pad gun that would not shoot anything that resembled a group. My gunsmith did a chamber cast and determined the throat was almost 2.5" long. Contacted Ruger and they said send it in. They declared it accurate and sent it back. There was a deep scratch on the barrel and that was conspicuous by it's absence so I figure Ruger just put another barrel on the without admitting doing it. It's quite accurate now. My favorite #1.
Paul B.