Is there such a thing as too much bump?

[BLR81]

Got my press set up over the weekend (LockNLoad single stage). I've been practicing making dummy rounds and checking with the LockNLoad Headspace guage and the Bullet Comparator against some factory loads.

The directions for the Headspace tool only says to leave a 'Little headspace'. I've found that the rifle doesn't go into battery if the shoulder isn't exactly set to the length called for in the Hornady Data Book or less. They can be longer then what's called out as the max cartridge length and still chamber and eject properly, but the shoulder has to be exactly the dimension cal1ed for or less.

I should have said that I'm resizing Winchester factory cases that were shot from this rifle. The rifle is a lever action Browning, so I'm using the full length resizing die.

Anyways, I've set the die to .001" less then the size called for, but the cases vary after resizing from 1.624" to 1.621 at the shoulder. So my questions are " Is .001 below enough headspace and is the .004" variance in the shoulder length after resizing too much? Can putting too much lube on the case cause them to compress too much?

[CEDaytonaRydr]

Anyways, I've set the die to .001" less then the size called for, but the cases vary after resizing from 1.624" to 1.621 at the shoulder. So my questions are " Is .001 below enough headspace and is the .004" variance in the shoulder length after resizing too much? Can putting too much lube on the case cause them to compress too much?

No, it will fire form to the chamber dimensions. Too much lube in your die will cause oil dents, but even those will blow out, once fired.

I wouldn't worry about it...

[gau17]

1. Is this for a bolt action?
2. You generally do not want to bump the shoulder too much when sizing. This can cause head separations. On my bolt action I only bump the shoulders back .001.

Take 10 cases fired from your rifle and measure the headspace. Use the biggest measurement and set your die to bump .001 (bolt action0) or .002-.003 (semi). Make sure this case will chamber. TEST IT. If it does, you are set. The shorter ones will grow the next firing. Going forward they will all end up getting the same amount of bump. I hope this makes sense.

[Bill Steele]

You shouldn't be getting .004" variance if everything is locked down. Perhaps you just are getting a measuring error. Are you turning the case in the gauge to get consistent measurements?

[BLR81]

1. Is this for a bolt action?
2. You generally do not want to bump the shoulder too much when sizing. This can cause head separations. On my bolt action I only bump the shoulders back .001.

Take 10 cases fired from your rifle and measure the headspace. Use the biggest measurement and set your die to bump .001 (bolt action0) or .002-.003 (semi). Make sure this case will chamber. TEST IT. If it does, you are set. The shorter ones will grow the next firing. Going forward they will all end up getting the same amount of bump. I hope this makes sense.

As I said in the original post "It's a lever action Browning". So, I guess I should be using your .002-.003 (semi) target. But, what is the starting point?

I've ordered some additional books, but right now I only have the Hornady book that came with the press. It calls for "a little bump" but starting where? The shoulder spec called for in the book is 1.625 and that seems to be exactly where my rifle starts to go into battery easily. So, is that the starting point? Because if I set the shoulder there, I've been able to load shells whose neck is at least .005 over the max length.

Thanks for the feedback by the way.

[BLR81]

You shouldn't be getting .004" variance if everything is locked down. Perhaps you just are getting a measuring error. Are you turning the case in the gauge to get consistent measurements?

I don't believe it's a measuring problem, because most of the 50 cases I resized are coming in at the same 1.622. The ones I'm reading as longer, I've gone and chamfered just to be sure there weren't any burrs. And, I'm using the Hornady LockNLoad Headspace Gauge so they should all be seating the same.

Your comment about being "locked down", makes me think the press might have a little fudge factor in it's design. The lock nut on the die has an allen screw which is tightened down. But, the LockNLoad uses collars with 1/8th turn twist to lock into place, and a rubber o-ring between the press and the twist collar to keep it from backing out. I don't think it did back out because most of the last ones resized were the same size as the first ones.

The new RCBS lube pad called for loading up with a tablespoon of lube-2. It ended up looking like a thick glaze of goop on the top of the pad. So, rather than roll the cartridges in it and put too much on, I chose to tap my finger on the pad and lube the cases with my finger and thumb. I didn't do the neck, but I did get some inside the neck when the expander ball started to make it tough to extract the case. So, I was wondering if too much lube was keeping the cases from seating completely.

No case measured longer then 1.625, and only one measured less than 1.622 and that one was 1.6205. What I haven't tried was going back and resizing the ones longer than 1.622 to see if they will resize correctly.

[Bill Steele]

On the lube pad, I used the RCBS lube pad for decades and was probably the last person I know to switch to spray lube (I still don't have a smartphone... ), but I have to say if you decide to go with a Lanolin spray lube like Dillon (or RCBS) sells your life will be easier. I use a pump style spray lube when I am loading bulk and Imperial Sizing Wax when loading smaller quantities.

On the measuring variance, I was speaking specifically about the Hornaday Headspace Gauge. I use the same gauge and I have found I need to spin the case in the gauge to get reliable measurments, but as you noted, that still might not be what is going on. The press may have enough slop to be causing the variance. I bought a cheap Lee Breech Lock a while back as I wanted a second single stage press. It uses a similar bushing system to the Hornaday (although I think the Hornaday might be a little more stout), in any case, it will not hold close enough tolerance for my needs on things like shoulder bumps or seating depth when I am loading for great precision. It is a demon for my universal sizing die, collet neck sizer and collet bullet pullers though, can beat the quick change but I guess everything has a price.

One thing is the measured bump for a given die setup will change slightly from headstamp to headstamp depending on the hardness of the brass. Harder brass has more spring, softer brass, less.

[BLR81]

On the lube pad, I used the RCBS lube pad for decades and was probably the last person I know to switch to spray lube (I still don't have a smartphone... ), but I have to say if you decide to go with a Lanolin spray lube like Dillon (or RCBS) sells your life will be easier. I use a pump style spray lube when I am loading bulk and Imperial Sizing Wax when loading smaller quantities.

The kit I bought came with some Hornady's aerosol case lube. The can feels light so I'm guessing it's just a sample size, but I can try using some of that.

One thing is the measured bump for a given die setup will change slightly from headstamp to headstamp depending on the hardness of the brass. Harder brass has more spring, softer brass, less.

All the cases were Winchester, but they weren't all from the same lot. I do have another 100 pieces of Remington and Federal brass so I can go back and try some of those.

[Bill Steele]

The kit I bought came with some Hornady's aerosol case lube. The can feels light so I'm guessing it's just a sample size, but I can try using some of that..

I use the Hornaday One Shot aerosol lube with my progressive press when loading pistol, but won't use it for bottle necked rifle cases. Some experienced guys swear by One Shot for their rifle loading needs, but many also swear at it.

The Lanolin based pump sprays work much more reliably for me. You can even make you own with one part liquid lanolin and 8-9 parts 99% isopropyl alcohol, basically what Dillon and others sell commercially.

[russt]

When in doubt keep it simple. Raise the ram and screw sizing die in until it touches she'll holder then lower ram and screw it in 1/3 turn more and lock it down. The press should slightly cam over. Size 10 rounds load em up and see if they chamber well. they should chamber flawlessly.

[gau17]

If the rifle feels smooth with 1.625, then give that a try. Compare the figures after firing. I would probably only do a small batch.

Do the longer ones chamber?

Try to put the same amount of force when resizing your brass.

[BLR81]

When in doubt keep it simple. Raise the ram and screw sizing die in until it touches she'll holder then lower ram and screw it in 1/3 turn more and lock it down. The press should slightly cam over. Size 10 rounds load em up and see if they chamber well. they should chamber flawlessly.

The LockNLoad classic press is a cam over press. If you raise the arm fully you will overwork the brass because it touches before reaching the full length of the arm stroke. I tried the 1/4 turn more when I started and the shoulder and neck were pushed back so far the neck was almost twice as long as a new case, and the shoulder was half as long. And, none would chamber and allow full battery.

I'm getting the minimum bump that I wanted which was .001" less than the Hornady Reloading Book calls out for the shoulder length. It's that when I set the press to give me a .003" bump, it's not consistent. It's 1.622 + or - .001 when 1.625 is minimum to allow chambering with full battery.

So, my concern is that this is a lever action rifle, so is .002" back from the spec called out in the book TOO Little bump, and is the .005" back TOO much bump.

The variance isn't all that often but it did happen in 20% of the first 50 cartridges I resized.

[fguffey]

[FLIGHT762]

The new RCBS lube pad called for loading up with a tablespoon of lube-2. It ended up looking like a thick glaze of goop on the top of the pad. So, rather than roll the cartridges in it and put too much on, I chose to tap my finger on the pad and lube the cases with my finger and thumb. I didn't do the neck, but I did get some inside the neck when the expander ball started to make it tough to extract the case. So, I was wondering if too much lube was keeping the cases from seating completely.

The type of lube and the amount of lube you use can change the amount of shoulder bump you're getting and can cause variations in the readings. I would try another lube. I found this out several years ago when I first bought the Hornady gauge.

When you get to it, order some Imperial sizing wax, but in the meantime, there are a couple of locally available lubes that will work very well for you. "Kiwi" brand "Mink oil" in the metal tin works very well as a case lube, you can find it at any department store. Chap stick will also work. I'd toss the RCBS lube, I tried it decades ago and found I didn't like it.

To remove the Kiwi, chapstick or Imperial lube, I use a small piece (2"X2") of cotton T-shirt with some 91% rubbing alcohol on it. This is good for making up small batches of ammo or when I'm testing like you are.

When using the Hornady gauge you do need to deprime (using a universal depriming die or tool) your fired cases before measuring. The fired primers can give you false readings from cratering.

Since you're using a lever gun, if you bump back -.003" you should be fine. Just don't bump more than -.005". Some dies will allow you to bump more than that. Don't get hung up trying to get the cases within .001". I would be comfortable with a bump measurement of -.003"-.005". And yes, I reload for a Browning BLR 81 in .358 Winchester.

The other thing that will vary your shoulder bump reading is when dragging the expander ball back through the neck on the upstroke. Depending on the cartridge case, an unlubed neck can gall badly and pull the shoulder forward if galling badly enough. On my 270 Winchester cases, I have to lube the inside of the necks and I get better readings. On other calibers, not so much.

I lube the inside of the necks using a RCBS nylon neck brush with a little CLP on it. These are for cases that will be tumbled clean and removing the lube. There are dry lubes that are used like motor mica.

I would first try a different lube and re-do your measurement tests on fired cases from your rifle.

It does take a bit of experimenting to find out what techniques work.

[nothing4u]

There might just be too much play in linkage, lube type, lube build up and/or too much lube on shoulder, expander ball stretching the shoulder longer because of friction, threads on die/press too much slop. Just remember a 5 degree turn on the die is about .001" for your 14 tpi dies. IMO 3-5 less than the chamber is acceptable for a semi-auto.