7x57 Lead SP Touching Rifling

[DHall_37]

New reloader here with probably a simple question. Started reloading some 7x57 with Remingtons old 175gr RNSP bullets. Lyman 45th manual says to seat at 3.065 seating there causes the lead SP to engage the rifling (but not the jacket) making the bolt a little harder to close. This made me nervous as I didn’t want to spike pressures even with a starting charge. I backed off 0.015 and it’s still engaging the rifling, cannelure is almost not visible anymore.

I gave the Lyman manual a second look over and they used the same bullets as I, my bullets model number matches theirs.

I’m thinking that since the soft lead is engaging the rifling and not the harder jacket I’m probably fine as this is what I assume cast bullets do. Thanks for any help!

 

[Adam in WI]

Pictures would help. How wide is the lead nose if rifling is able to be seen in it? Sounds like there could be other issues afoot. What model rifle? Does any other ammo do this?

 

[Dusty Stevens]

You sure you have the correct rifle? That sounds like a very small bore if its touching the lead

 

[DHall_37]

Pictures would help. How wide is the lead nose if rifling is able to be seen in it? Sounds like there could be other issues afoot. What model rifle? Does any other ammo do this?

Thanks for your response. I gave the bullets a second look over and noticed they there are no rifling marks it’s actually a mark from going up the feed ramp and into the chamber. I seated a test bullet long, 3.115 and it chambered. Bolt was still stiff to close and no apparent rifling marks.

could a stiff bolt close be from me partial resizing my brass. I use a penny to separate the shell holder from the die. I doesn’t size the case all the way like a FL die. It’s like a half and half of a neck sizing die and FL die, I believe that it increases case life.

I reloaded some of these bullets and even a pulled surplus bullet a year or so ago with my mentor and they still gave a stiff close.

Pictures would help. How wide is the lead nose if rifling is able to be seen in it? Sounds like there could be other issues afoot. What model rifle? Does any other ammo do this?

 

[DHall_37]

You sure you have the correct rifle? That sounds like a very small bore if its touching the lead

It’s a Spanish 1916 Mauser in 7x57. I think I was worried about nothing it wasn’t touching the lead on a second inspection.

 

[DHall_37]

Bullet tip is around .200 inches wide, impossible to be rifling marks. Ogive is way down the bullet body. I think I was worried about nothing. My newbie is really showing right now, face palm.

 

[Adam in WI]

View attachment 1299659
could a stiff bolt close be from me partial resizing my brass. I use a penny to separate the shell holder from the die. I doesn’t size the case all the way like a FL die. It’s like a half and half of a neck sizing die and FL die, I believe that it increases case life.

Yes. Neck sizing in that fashion has a tenancy to squeeze the shoulder forward and cause hard closing. You need to set the die so it just starts pushing the shoulder back. A headspace comparator is helpful here. A cheap and dirty way to see how long you can seat that bullet would be to take a case fired in that rifle, and lightly press the case mouth opening against your bench at an angle to just ever so slightly dent the mouth. Just enough that you can still wiggle a bullet into it and be held in place. Then chamber the round and let the rifling finish seating it, extract and measure the overall length. Trying this with a full length sized case usually results in the rifling gripping the bullet and pulling it back out when the case is extracted.

I'm going to guess with an old Mauser, you're not going to get very close and still have much bullet in the neck.

 

[DHall_37]

Yes. Neck sizing in that fashion has a tenancy to squeeze the shoulder forward and cause hard closing. You need to set the die so it just starts pushing the shoulder back. A headspace comparator is helpful here. A cheap and dirty way to see how long you can seat that bullet would be to take a case fired in that rifle, and lightly press the case mouth opening against your bench at an angle to just ever so slightly dent the mouth. Just enough that you can still wiggle a bullet into it and be held in place. Then chamber the round and let the rifling finish seating it, extract and measure the overall length. Trying this with a full length sized case usually results in the rifling gripping the bullet and pulling it back out when the case is extracted.

I'm going to guess with an old Mauser, you're not going to get very close and still have much bullet in the neck.

Thanks for that tip, I also have a Hornady OAL gauge on they way with proper modified cases.

would doing a regular FL size every few firings on that brass help keep the shoulder with in tolerance? I don’t feel super comfortable with a FL size at the moment because a lot of the rifles I have are older and might have excessive head space and keeping the brass as fire formed to the chamber seems like the safest option for me.

 

[Adam in WI]

If that's the case, you really should get yourself a headspace comparator and learn how to set your dies to just move your shoulder back a little. We're only talking moving it .002" or .003". That amount of minimal sizing is going to provide easy chambering without putting undue stress on your brass.

 

[Adam in WI]

Another thought if you're dead set on neck sizing is to get the Lee collet sizer. Doesn't move the shoulder forward like partial full length sizer does. You'd still eventually have to bump the shoulder back though

 

[DHall_37]

If that's the case, you really should get yourself a headspace comparator and learn how to set your dies to just move your shoulder back a little. We're only talking moving it .002" or .003". That amount of minimal sizing is going to provide easy chambering without putting undue stress on your brass.

Thanks I’ll give those a look into. As for now I’m going to sling those reloads tomorrow and read up on FL resizing.

 

[Dusty Stevens]

Will the bolt close on an empty case before you seat the bullet?

 

[DHall_37]

Will the bolt close on an empty case before you seat the bullet?

It will close on a partially resized case which is what I usually do. Just FL resized a case and it closes much easier on it.