348 Crimp

[tribex]

Hello,

I'm new to the forum and this is my first post. I have a model 71 winchester shooter. I'm having a hard time with the crimp on the .348 cartridge. I've purchased a Lee crimp die but still am experiencing a little bullet slippage with heavy loads. Any tips or advice would be appreciated. Thanks.

[1886]

Welcome to the forum. You did not mention bullet type, brand, size, etc. Die manufacturer, age, etc. Forgive me I do not want to be a smart a-- but this is a little like "the engine will not start well does it have gas in the tank"? You came here for help and that is perfectly acceptable and understandable. We have all been there. More specifics would certainly help. Assuming everything matches and assuming you are not somehow leaving lubricant on the inside of the case neck, I would check the size of the expander first. Next I would remove the expander assembly and size a case. How much is the neck being reduced? You will need to measure the outside diameter of the neck before and after sizing. Do not think of the crimping operation as the final word in neck tension. It is only the icing on the cake. Too much crimp can actually decrease neck tension. I prefer a sizer .004"- .005" smaller than bullet diameter when loading jacketed and hard cast projectiles. Best to measure with micrometer of known accuracy. Good place to start. Is your brass new or old? Your brass is not work hardened to the point of very little elasticity? Brass that has been sized repeatedly without proper annealing will eventually work harden to that point. Use newer brass of known origin and history. Many variables to consider but hopefully you have some direction. Please advise, 1886.

[mod71alaska]

Tribex,

I haven't been a reloader for quite a while now so I can't help you with your question, but I want to compliment you on your choice of levergun and caliber. You have to love the .348 Winchester (and Browning) Model 71!

Welcome to the Leverguns Forum. I hope you'll stay around and contribute. There's a lot of expertise here. Yeah, there's some idiocy, too, but you'll figure it out. Most of all, there are great guys who will become your friends!

Welcome to the Forum!

[tribex]

1886 & mod71alaska, thank you for your replies. I apologize for not being more specific on the loading data. First, the brass is new winchester purchased from Midwayusa. No lubricant is left in the case mouth. Bullets are 200 gr. Hornady jacketed. I was not aware that too much crimp could actually decrease neck tension. That is good to know. I am using RSBS dies. I will take 1886's advice and measure the outside diameter of the case before and after sizing. I'll show my ignorance by stating that I didn't know I could actually change the expander size. Will RCBS be able to supply an expander a thousandth or two smaller or larger if needed?

This gun is just too much fun to shoot and if anyone has checked the price of factory .348 ammo lately you'll know why I'm loading my own!

Thanks guys for your help and for making me feel welcome.

[1886]

Chuck the expander assembly in a drill. Get a starting measurement. Polish the expander ball, ball only, with crocus paper until it measures about .343-344". This will suffice. Any smaller and it could/ probably will be counter productive. If you like to experiment you could develop data with the expander at .344" and then at .343". See what happens. Go slowly as you can always take metal off but it is tough to put it back on! Crimp firmly but not excessively. You will get the feel when it is correct. Buffalo Arms produces custom expanders and will make any size you want but it is easy enough to size it yourself. An additional benefit to polishing the expander ball is easy of sizing. You will find the cases size much more smoothly after polishing. They will be worked less. Please advise, 1886.

[salvo]

Welcome tribex, you have some great info now to track down the problem. I know Hornandy normaly ships out a great bullet, the 200 gr is what I shoot mostly. Just to be sure while you are measuring check a few bullets too, stranger things have happened.

[flatnose]

tribex, hello and welcome.
Someone here recently had the same situation as you. If the brass crimp is staying within the cannelure of the bullet, then you should not worry. The cannelure is in the bullet for that very reason. I just use the standard die set for the 348, with a light crimp. Nothing fancy.
It is possible that the bullet can move back and forward in recoil, but the bullet isn't going anywhere. If you are still concerned, take a loaded round and try to remove the bullet with an inertia puller if you have one, and I will bet it will take a few swipes to dislodge it.
As a side note, look after your brass as it is expensive. It may be prone to early splitting if it becomes work hardened. I anneal after every second usage with full power loads. i also neck size whenever possible. Compare a fired cartridge to a freshly sized case, and you will see why. The fired case may visually seem a lot larger in the body area. It probably is.

[Lefty Dude]

As a new reloader, I am sure you do not know that you must resize new brass before you load it.
New brass must be brought to proper specifications before the loading process is started. All new brass should be sized and the proper length checked before you go any further. Also check for primer pocket & flash hole size.

The neck is sized smaller than the actual bullet diameter, as the bullet is seated an expansion occurs and this helps to keep the bullet in the neck. The crimp keeps the bullet from pushing back as it is in the mag. tube of the lever gun.
When you reload for a bolt action, crimping is optional. Many do not crimp rounds that are used for the non tube magazine guns.

Resize your brass, I think your problem will be resolved.

[WinM71]

I load the .348 fairly stout, & haven't had any trouble at all as long as I use the Lee Factory Crimp die and, most importantly, get the crimp exactly into the bullet's cannelure on the Hornady 200 FP.

[tribex]

Thanks a lot for all the help guys. I am full length resizing so that is not the problem. I am using the Lee crimp die as stated earlier and crimping in the cannelure. The slippage is detected because the cannelure is no longer visible after a chambered round is fired and subsequent cartridges are fed from the magazine. I've measured my expander ball as 1886 advised and found it to be only .001" smaller than bullet diameter. I'm going to hone it down .002" more and try again.

Because I don't have the luxury of a shooting range close to home and all kinds of holiday plans it may be a couple of weeks before I'm able to analyze the results.

Thanks again for the tips and suggestions. Cool website.

[1886]

Thanks a lot for all the help guys. I am full length resizing so that is not the problem. I am using the Lee crimp die as stated earlier and crimping in the cannelure. The slippage is detected because the cannelure is no longer visible after a chambered round is fired and subsequent cartridges are fed from the magazine. I've measured my expander ball as 1886 advised and found it to be only .001" smaller than bullet diameter. I'm going to hone it down .002" more and try again.

Because I don't have the luxury of a shooting range close to home and all kinds of holiday plans it may be a couple of weeks before I'm able to analyze the results.

Thanks again for the tips and suggestions. Cool website.

Given the elasticity of new brass and an expander ball that measures .347 ", chances are very good the inside of the case mouths measure .3475"-348" after sizing. Hardly enough for adequate neck tension. In addition to increased reliability of your ammo you will find increased ballistic consistency/grouping ability of your ammo. When you get back to us we can discuss this. Regards, 1886.

[flatnose]

tribex,
Measure the inside diameter of the case neck first. Even new brass will have some memory, and it will try and return to its last diameter. I would hedge a bet that the case neck is around 3 thou smaller than the bullet diameter.
Some cartridges like more tension, some like less. It is possible that on the second resizing of a fired case you will have a smaller inside neck diameter. 1 thou of neck tension should be enough, but most of my reloads come out at 3 to 4 thou.

[tribex]

Hi guys,

You probably thought I'd flaked out after receiving info on crimping the .348. I know it's been a long time since replying but between work and raising a three year old I have not had time to try things out until recently. I took 1886's advice and reduced the expander ball a couple thousandths to .344. This took care of the problem. With 52.0 grains of IMR 4320 behind the 200 gr. Hornady there is absolutely NO slippage from recoil.

As a side benefit, I have never experienced accuracy like this from a model 71. After making a few adjustments on the Redfield receiver sight I fired four groups of three shots each. All four groups were under 2" with the smallest measuring 1.38". It wasn't until the barrel heated up later in the shooting session that groups opened up to two and a half inches or so. I've owned scoped bolt actions that wouldn't shoot that good.

Thank you for your help guys. Much appreciated.

Tribex

[1886]

Wow, I forgot about this post. Glad it worked for you. It is not uncommon to see an increase in accuracy and consistency(they do tend to go hand in hand) when one experiments with expander size. Did you see that Victor is selling neck dies for the .348? Great tool to have. Maybe he still has some. Welcome back. 1886.