17 HMR NECK SPLITTING

WinMag4me

Well-Known Member
Joined
Aug 29, 2018
Messages
169
Location
GA
Not long range,but looking for experience with.17HMR
Removed this Marlin 917?…from my safe and have split necks on factory ammo
Posting pics although I am not good at photos
Any explanation for this would be helpful
 
Not long range,but looking for experience with.17HMR
Removed this Marlin 917?…from my safe and have split necks on factory ammo
Posting pics although I am not good at photos
Any explanation for this would be helpful
I've seen that happen with 17 HMR and 243 WSSM and the only thing I can sum up is just flat out bad brass and the WSSM brass was almost grainy looking
 
What type ammo and how old is it?

Have been more than a few batches over the years with this defect, it's probably kicked off a half dozen recalls over the years from at least half the flavors. Those shoulders are thin. Hm2 and wsm will on occasion do it as well.

Last recall batch was winchester... I shot my brick before the recall kicked off... messy but never any problems other than chamber grit.
 
17 hmr split necks
 

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over size chamber

metallurgy on the brass too brittle to expand

undersize brass

You maybe forced to keep the chamber clean and use the ammo up.
Thanks VINCEMULE
I am still enjoying the knives you sent me
Thanks again
 
On the clean chamber front that's worth keeping an eye on. Wife gets these q tips with a long stick, I push them up in the chamber and get a good soak then get in nice and clean. 17s all have chamber sensitivity issues. Was home today and checked zeros on all of mine, one 17hm2 was filthy as was a hmr, my 17 wsm was looking like a stove pipe less than 100 rounds since last cleaning. Kinds goes with the territory, but ocd chamber cleaning definitely helps.

I'd hate to give bad advice so will frame it this way, some folks have lower risk aversion than others. If you double masked in the car by yourself I'd say don't shoot them. If you ride a road motorcycle without a helmet and eat food past the expiration date... you will be just fine shooting them.


During covid a buddy found out he had bought a case of recalled 17hmr ammo, being in Alaska they sent him money in lieu of shipping the recalled ammo back for like exchange. He wasn't sure the best way to dispose of it, and my services were volunteered. They shot great with the occasional one going bang with a decent flier and the use of a decent little pry bar to remove the offending brass. Different risk aversion different response, personally I'd throw on a set of saftey glasses and let it ride.
 
I had a pest on top of a power pole today
I got the 17 hmr and tried to load a round (bolt action)
I could not get it to chamber
On inspection I found a fired brass in chamber
The round I unsuccessfully tried to load was pressing into the stuck chamber brass
I stopped and cleared the chamber and noticed the round I attempted to load pressed the bullet completely inside the shell
I could see the bullet tip(barely) and powder in the cartridge
Out of curiosity I orientated the barrel up and hand fed the cartridge into the barrel
I fired at my pest about 65 yards away and it dropped as it always does
So this makes me question all the time I spend on bullet seating depth
I realize this is a 17 hmr but I could barely see the bullet as I had jammed the bullet inside the shell
Any explanation?
 
So this makes me question all the time I spend on bullet seating depth
I realize this is a 17 hmr but I could barely see the bullet as I had jammed the bullet inside the shell
Any explanation?

Bullet seating depth will absolutely have an effect on accuracy, however at 65yds you're talking accuracy differences in the tenths of an inch, not inches. No surprise you still hit the pest.

The more important issue might be the pressure spike created when you have a bullet pushed that far back into the case...you lost a lot of volume and increased the pressure substantially, no doubt.
I know I'm 9mm 0.030" too deep can double the pressure with some powders.

As for HMR neck splitting, it's well documented all over the Internet usually stemming from brittle brass after the forming process. Don't worry much about it, just keep the chamber clean. I've had hundreds of split necks in my marlin 917 and never had an issue. More often than not, I don't even see a flier on the paper.
 
Just tension on the neck, Caused by case neck to tight, When bullet is inserted into the case will harden the brass and necks will split.
That is why most commercial rounds have little neck pressure, And bullets are crimped. So the ammo can be stored and lay on store shelves. No one would want to buy shells if 1 case in the box had a split neck
Military ammo is crimped and sealer placed at the case mouth/bullet junction for long storage.
 
Picked up Tikka 17HMR this Spring, researching the ammo found out that CCI makes all of the 17 HMR ammo for everybody.
T.P.
Well this interesting mine shoots federal and Remington the best hates cci and Hornady! They all are the same tipped 17 grain bullets strange?
 
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