.308 Palma Chamber

C

COBPTR

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Are there specific Palma chamber dies?
My Savage Palma rifle seems to be tighter than SAAMI spec and bumping the shoulder back in off the shelf dies isn't working.
I've tried different shell holders. Savage just told me their chamber dimensions are proprietary and had no suggestions.
Any help would be appreciated.


Robert G.
 
Do you know where it is not fitting ??
Iif it is base, try a small base die.
 
COBPTR said:
Are there specific Palma chamber dies?
My Savage Palma rifle seems to be tighter than SAAMI spec and bumping the shoulder back in off the shelf dies isn't working.
I've tried different shell holders. Savage just told me their chamber dimensions are proprietary and had no suggestions.
Any help would be appreciated.


Robert G.
Click to expand...

Palma Rifles are dimensioned to accept 7.62 NATO or 308 Winchester. But then, so is just about every other 308 Rifle. True Palma Chambers also have a throat that specifically fits the 155 Sierra Match King, but that has nothing to do with your problem.

Are you actually measuring the amount of "bump" on the shoulder, or going by feel?
 
I'm measuring the shoulder on my Hornady comparitor gauge. (I think that's what it's called)
A 1.426 measurement of the shoulder gives me a hard closing bolt. Anything less, the bolt closes fine. My out of the box Lapua brass measures around 1.420-1.421.
Seems my chamber is much shorter than SAAMI min spec. which a little research told me is 1.630.
I'm not even sure I could grind a shell holder down that much, I hate to grind on an expensive die mouth.
Currently I'm using the Redding Type S FLS.

Robert G.
 
Last edited by a moderator:
Fire 3 cases 3x and send em to whidden. He'll make you dies thatll fix your problems. Id bet a small base die will too
 
what does a loaded round, that fits the chamber . measure ?

i have had issues with 308 chambers in the past.

a chamber cast would be a good idea.

do you know it is the length and not the dia, that is causing the issue ?
 
COBPTR said:
I'm measuring the shoulder on my Hornady comparitor gauge. (I think that's what it's called)
A 1.426 measurement of the shoulder gives me a hard closing bolt. Anything less, the bolt closes fine. My out of the box Lapua brass measures around 1.420-1.421.
Seems my chamber is much shorter than SAAMI min spec. which a little research told me is 1.630.
Click to expand...

It's highly doubtful your chamber is .200" shorter than SAAMI. The base to body shoulder on a SAAMI 308 case is 1.5598" and there is no way your shoulder datum is shorter than that. The SAAMI base to datum is 1.634" -.007" and your Lapua brass should be in that window. Something is wrong with your comparator numbers. It'd be hard to help you until you get that figured out.

It is not unusual to have to take a bit off the bottom of a die or a bit off the top of a shelholder to get a case to size properly. Not saying that will solve your issue but it's somewhat common.
 
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So your cases are coming out of the rifle with a base to shoulder measurement of about 1.427, and your dies will not push the shoulder back past 1.426. If that is the case, just grind a little off the base of the die until it gives you about .001/.002 clearance.

I had to do that with my custom 3006 I built a few years back. No big deal.
 
After I got home from work I looked at my notes. Indeed I remembered wrong.
It is 1.620 for unfired cases and 1.624 for FF cases. 1.626 is where it gets sticky in my rifle.
So at least I'm just dealing with just a few thousandths, not 2/10 of an inch.
I will start with the shell holder and grind the die face a little if that is not enough.
I plan on taking the rifle to my gunsmith on Saturday so he can head space it for me so I know exactly what I am dealing with.
I also like the idea of sending some cases off to Whidden to get something made for this chamber.

I appreciate the help everyone. I will report back.

Robert G.
 
If your rifle chambers and fires a factory round safely, and has .004 expansion between base of the case and shoulder, why would you want to modify the chamber.

It appears to be just right.
 
Jackie,

Maybe my terminology was wrong. What I meant was measure my chamber with head space gauges to let me know my min and max specs.
I am a Black Powder Target Rifle competitor, use to only dealing with straight wall cases. Still learning.

Robert G.
 
Follow up....

Had my gunsmith run a go gauge that measured 1.6225 in both our calipers. He did not want to close it all the way for fear of damaging his gauge but said it was REAL close to fitting. He took my shell holder down 12 thousandths.
So my suspicions were right that this Palma chamber is short and now I will have a way to bump my shoulder back to pretty much my factory Lapua brass measurement of 1.620-1.621 for reloading.

Thanks everyone for the ideas.

Robert G.
 
Hardest Thing We do!

Proper brass resizing. :rolleyes:

On page 99 of his book "Extreme Rifle Accuracy" Mike Ratigan states in the first sentence,

"Proper full length resizing is the single hardest mechanical thing we do."

And I agree wholeheartedly! In teaching and coaching BR shooters in the tunnel, I find this to be THE most misunderstood and problematic part of loading benchrest quality ammunition. In his chapter 11, Mike covers the subject thoroughly.

In this thread the OP said nothing about the diameters of a fired case at the pressure ring right in front of the extractor groove and the shoulder diameter, both of which are very important. How much sizing is going on at these two points with the die you're using? :confused: Ideally, the FL die should reduce these diameters by .001 to .002 when the die is adjusted to bump the shoulders no more than .002. It sounds as if you are putting too much emphasis on the virgin cases as they come from the box. Until they are fireformed, you have no way of knowing what they will measure after being fired in YOUR rifle's chamber. You sure don't want to push your shoulders back to match an unfired case out of the box. That will result in greatly reduced case life and eventually case head separation.

I wish I could work with you one on one with YOUR equipment. You would be surprised what there is to learn about care of your cases, proper fitting dies, proper adjustment to control headspacing, etc. Properly prepared, sized and cared for, Lapua cases last almost forever. The door of the tunnel is always open if you need help.

Gene Beggs
 
Thanks for your response Gene

First off, I am definitely learning this game from scratch. BPTR is my only reloading experience as far as competition reloading.
I only mentioned my factory dimension brass measurements as a baseline compared to my FF cases which come out to the listed 1.624 above.
With my newly ground shell holder I managed to set it so my FF cases are being bumped back to 1.623.
I certainly haven't measured any other part of the case besides the shoulder, OAL and mouth.
To achieve the 1.623 shoulder my FLS die is ALMOST touching the ram so whatever the Redding FL Type S die is supposed to be doing is happening close to 100%.

My plan for now is to anneal, FL size with decapper pin out
Neck size with the Type S Neck Sizer (whole neck to .306)
Seat with my Arbor and Wilson Seater .002-.003 off the lands

Shooting Palma, the sling and position will be my initial issues and loading techniques second.

Shouldn't have offered, now I will be bugging you.

Robert G.
 
COBPTR said:
Thanks for your response Gene

First off, I am definitely learning this game from scratch. BPTR is my only reloading experience as far as competition reloading.
I only mentioned my factory dimension brass measurements as a baseline compared to my FF cases which come out to the listed 1.624 above.
With my newly ground shell holder I managed to set it so my FF cases are being bumped back to 1.623.
I certainly haven't measured any other part of the case besides the shoulder, OAL and mouth.
To achieve the 1.623 shoulder my FLS die is ALMOST touching the ram so whatever the Redding FL Type S die is supposed to be doing is happening close to 100%.

My plan for now is to anneal, FL size with decapper pin out
Neck size with the Type S Neck Sizer (whole neck to .306)
Seat with my Arbor and Wilson Seater .002-.003 off the lands

Shooting Palma, the sling and position will be my initial issues and loading techniques second.

Shouldn't have offered, now I will be bugging you.

Robert G.
Click to expand...




Robert, sounds like a plan. If I were you I would skip the annealing step. I never anneal and have no issues with my Lapua cases which I use for several months firing them almost daily. The only reason I ever toss a set of cases is if the primer pockets become loose. I'm a benchrest group shooter using the Lapua 220 Russian case for my 22 and 6mm Beggs cartridges. The same procedures used with them also apply to your 308.

I don't know your location but I'm out in the wilds of West Texas, Midland/Odessa to be exact. Southwest Airlines serves the area and the airport is about a twenty minute drive from the front gate of the tunnel.

You didn't mention the type of rifle you are using. I'm not familiar with Palma but I believe the bolt action is used and not a semi-automatic. I have no experience loading for the semi-automatics but am told they require a little more sizing and shoulder bump than a bolt action.

Let me know if I can help you. :)

Gene Beggs
 
I am from Austin, TX but live in Denver, CO now. When I drive home next time there might be a stop, as that is on the way.
My rifle is the Savage 12 Palma. Single shot, solid box.

Thanks again

Robert G.
 
COBPTR said:
I am from Austin, TX but live in Denver, CO now. When I drive home next time there might be a stop, as that is on the way.
My rifle is the Savage 12 Palma. Single shot, solid box.

Thanks again

Robert G.
Click to expand...


Sounds good. I'll be here.

Gene Beggs
 
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