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how much bullet tension do you need in a semi auto rifle

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10 June 2020, 17:40
canuck4570
how much bullet tension do you need in a semi auto rifle
I have a Benelli 338 Winchester Magnum rifle
what tension should there be on the bullet
I am asking because my bullet creep forward by .0010 when it chambers my cartridge
so usually the say .0002 so should I put more 3. 4. 5. 6 thousand
thank you

Canuck
10 June 2020, 18:11
Rapidrob
60 pounds of pulling force.


Gulf of Tonkin Yacht Club
NRA Endowment Member
President NM MILSURPS
10 June 2020, 18:19
canuck4570
I don't understand you answer
10 June 2020, 18:31
tsturm
quote:
Originally posted by canuck4570:
I have a Benelli 338 Winchester Magnum rifle
what tension should there be on the bullet
I am asking because my bullet creep forward by .0010 when it chambers my cartridge
so usually the say .0002 so should I put more 3. 4. 5. 6 thousand
thank you

Canuck


I crimp every thing I load with Lee Factory Crimp Die they don't move. & 1 or 2 ten thousandths wont make any diff.


10 June 2020, 18:40
dpcd
This has to be a joke; you say your bullets move TWO TEN thousandths forward when chambering?? that is .0002.
How do you measure that? Bullet ogives are not that uniform anyway.
And neither is brass trimming.
10 June 2020, 19:20
canuck4570
read I say up to 10 thousand
and how I found out is when I loaded the round and did not fire it and took it out the OAL had grown by 10 thousand
I had one that jam in the rifling after doing it twice
the quick forward motion of the action must act like a kinectic bullet remover
10 June 2020, 19:59
dpcd
No, you said it creeps up to One thousandth and you also said "so usually the say .0002" (which is two ten thousandths), which is like a gnat's eye lash. I don't know of any reloader who can measure in ten thousandths.)
So, you have your numbers wrong; however, your words are now decipherable; ten thousandths is too much. Get or make, a smaller expander plug and that will solve your problem.
10 June 2020, 20:23
Terry Blauwkamp
Or... take the expander plug off...and try that.


Remember, forgivness is easier to get than permission.
10 June 2020, 20:48
canuck4570
one zero to many
I just took off the expander and to my surprise the die only neck it down to .337
guess its a defective die
tried same thing on a 30-06 die and its .008 smaller
will check with RCBS about it

thanks .....
11 June 2020, 10:45
crbutler
If the neck is taken down to .001 under bullet size (on the outside by micrometer) you have way more neck tension there from brass neck thickness than you can possibly seat the bullet with.

0.001-0.002 tension has been more than enough for me most of the time. If I want more, I crimp the case for autoloaders, automatics, or lever guns.

I also crimp on my big bore guns with a lot of recoil.

So if you are having bullets move when they cycle through the action, and you have a couple thousandths tension, crimp them.
11 June 2020, 15:59
canuck4570
will be trying all the above this morning and will give result

thanks
11 June 2020, 17:02
Saeed
This might be of interest to you


www.accuratereloading.com
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12 June 2020, 01:32
Atkinson
Crimp your reloads in any automatic rifle larger rimfires..I like the taper crimp die, but not concerned with a factory crimp that comes with most dies, just don't over due it.

On a double rifle or single shot, I tend to turn about a thousand or two off the expander ball use a powder that fills the case and ever so light a crimp..Never have had a problem with that approach..


Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120

rayatkinsonhunting@gmail.com
12 June 2020, 08:50
F. Guffey
quote:
read I say up to 10 thousandand how I found out is when I loaded the round and did not fire it and took it out the OAL had grown by 10 thousand I had one that jam in the rifling after doing it twicethe quick forward motion of the action must act like a kinectic bullet remover


You need to move from tensions to bullet hold. The bullet that slid out was caused by the sudden stop.

F. Guffey
12 June 2020, 15:56
canuck4570
I bought a new Redding die
result still creep out after 3 to 4 cycling
I did with a Lyman M die at 336 ID neck
tried it with the expander plug 334. ID neck
tried it with no expander at 331. ID neck
and the bullet did the same on all of them. 2 to 3 thousand creep
and this is after cleaning the cases with ultrasonic
so the mystery remains.....
12 June 2020, 19:53
dpcd
Why are you cycling them 3 or 4 times??? When shooting them, don't they just go in once? I think you might be inducing a non existent problem into the system. How much do they creep with One cycle? I might not be a mystery at all. They are not asphalt sealed, heavily crimped, military ammo.
12 June 2020, 22:23
crbutler
I think I’ve caught on with what you are describing...

As an aside if the OAL is increasing, you are not entering an unsafe situation (which can be the case if your OAL is shortening.

With a heavy spring, you are in effect trying to pull the bullet with an impact bullet puller every time you cycle it through the rifle.

Repeated load/unload will do this. I don’t know of any round that you cannot pull the bullet with an impact bullet puller given repeat strikes.

Your test is the problem. If it moves 1-2 thousandths with one cycle, it’s not a problem. That is the nature of self loading guns.

The answer is “don’t do that” - meaning repeat load/unload cycles with the same round.

Handgun bullets do this over time in police weapons- it’s why you are supposed to not use the same round all the time and switch ammo.
13 June 2020, 02:12
canuck4570
Like you said it a self loader prblem
I will live with it