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300 Whisper Rem700 Misfiring

CUTRIGHT

Sergeant of the Hide
Full Member
Minuteman
Feb 20, 2011
109
16
54
ILLINOIS
I have a Rem 700 rebarreled to 300 Whisper the Hornady 208gr ammo shoots without fail but the Remington220gr misfires with only a.light dent on the primer.
Anyone had trouble like this?
 
Re: 300 Whisper Rem700 Misfiring

I had this issue with my 223 AI.
Like an idiot I replaced the firing pin/spring and then realized the Lapua brass I was using was slightly undersized.
Seating the bullet out to engage the lands and keep the casehead where it ought to be solved the issue.
You can't do this with factory ammo and shouldn't with subsonics anyway.
 
Re: 300 Whisper Rem700 Misfiring

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MLC</div><div class="ubbcode-body">Difference in headspace.
The Remington load is likely shorter as it's Blackout not Whisper spec.
</div></div>


This!!!
 
Re: 300 Whisper Rem700 Misfiring

The 220gr 300 Blackout ammo has a couple thou clearance, I shoot reloads with less clearance. Im thinkin I got a weak firing pin spring, new from Remington. The Remington ammo must have a harder primer cup.
BTW: the Hornady ammo has .007 headspace clearance. Im measuring with a depth mic (barrel in the lathe) took out the Go gauge and shoved in a loaded round just to see how far off the factory ammo is.
 
Re: 300 Whisper Rem700 Misfiring

The misfired case measures .025 shorter than the fired case. The shoulder is evidently getting bumped under the pressure of the firing pin hitting the primer.
I dont know if Remington has a batch of really hard primers or some over annealed brass???
 
Re: 300 Whisper Rem700 Misfiring

I dont know if anyones still following this but I thought I might as well keep it updated az I go.
I thought if the firing pin had less surface diameter and faster/harder lock time that it might be able to punch a hard primer cup without pushing the round forward in the chamber.
I turned and bushed the firing pin down to .062 thinking that it might help, it didnt.
I then replaced the firing pin spring with a speedlock chrome silicone spring and that didnt help either.
I did a little research on the ammo and found there is some Remington ammo out there that has a problem so I'm awaiting a reply from Remington.