Diagnose my failures to fire - Rem700 *SOLVED*

[drh2687]

Howdy fellas,

I have a Remington 700 short action in .308 that has been re-barreled (by a non-clownshoes smith) with a Bartlein blank. I've converted it detachable mags with Badger bottom metal.

That re-barrel was relatively recent and I have about 50 rounds through it - all surplus M118LR.

My last range trip, I experienced a bunch of failures to fire with the M118LR. In all cases, I had a dimpled primer that just by visually comparing did not appear to be any lighter than normal. I've used several hundred rounds of that specific batch of surplus M118LR with zero issues previously (in both this rifle and others). During this range trip, I had 4x FTFs out of 19 or 20 rounds before I called it quits.

Is it THEORETICALLY POSSIBLE that I just so happened to have the 4 bad rounds from my batch of hundreds of rounds of M118LR all show up in the same 20 round string? ...sure, I suppose. But highly unlikely bordering on impossible. This leads me to believe there is something going on in the gun that needs to be addressed.

My armorer knowledge is limited mostly to AR stuff. Tip of the firing pin seems fine. Can the Remington 700 experts chime in here? What do I need to check out that might be causing this?

 

[just browsing]

Did you try different ammo? Can the issue be replicated with anything other than M118LR?

It should be very easy to isolate rifle or ammo as the culprit… start there.

 

[OREGUN]

Switch ammo and see if the problem follows.
If it does, take It back to clown shoes and make him figure it out.
May be a weak firing pin spring, a damaged firing pin, or the most out of spec chamber ever produced.

 

[hlee]

Any issues before the rebarrel? Were any firing components changed during the rebarrel? How many rounds on the firing mechanism?

 

[thebolt]

Change your ammo

 

[Supersubes]

Easiest solution would be to take the striker out of your bolt and check for issues. If you ever pierce a primer, that little blank you punched out likely ended up in the bolt, and is now affecting travel or pin energy. Perhaps there’s oil or grease in the striker assembly causing drag. Maybe your pin spring took a shit. One of the members here recently had an issue with the cocking piece retaining pin under the bolt shroud. The pin shimmied out and was rubbing on the inside of the shroud.

 

[DownhillFromHere]

I'd check headspace by putting a piece of painter's tape on the case head. If the bolt will close and lock... even close and not lock... that would be a big red flag to me.

 

[OREGUN]

Here’s a quick and dirty method for taking your bolt apart, since you aren’t a bolt gun guy. This will allow you to clean and inspect the firing pin assembly and the bolt body. Which likely where your problem lies. John McQuay won’t steer you wrong.

 

[ShtrRdy]

Lots of good advice here.

If the trigger is known to work fine prior to the rebarrel, I would take the firing pin assembly out of the bolt and look it over closely. You might have a broken spring. If the spring looks okay, give the firing pin assembly a good cleaning as well as the inside of the bolt body.
if the Rem 700 action has had a lot of dry fire and live fire cycles the firing pin spring should be replaced.

If the bolt assembly looks okay then I would suspect ammo or headspace as others have mentioned.

 

[rustyinbend]

Buy a box of factory ammo and shoot it. If you get 20 "BANG's" ... then it's the rifle. That answers question #1. Then you can move on to question #2.

 

[DownhillFromHere]

Buy a box of factory ammo and shoot it. If you get 20 "BANG's" ... then it's the rifle.

Not necessarily. I had a Tikka T3X Varmint that shipped with a "bad" firing pin - there was no radius on its business end; it was cylindrical, not rounded. This shape spread out the imparted energy over a wider area of the primer. So soft-primered ammo (think CCI 400) would work ok. But loads with harder primers (CCI 450 or even Winchester SRPs) would have a 10-20% misfire rate, showing shallow primer indentations.

Beretta kept that rifle five weeks and declared it fixed. Misfired within the first ten rounds. Local gunsmith found the problem in five minutes and fixed it in 15.

 

[drh2687]

Thanks all for the input. My hunch was something going on in the bolt/firing pin assembly or channel (fouled/gunked up/etc) like several of you mentioned.

I finally got around to pulling the firing pin out and having a look. There did not appear to be anything obviously wrong. Wiped down and reinstalled. Will have to wait for a range day to test and see if the issue continues.

For what its worth, I purchased this action (with OEM barrel) pre-owned with an unknown round count or maintenance schedule prior. It appeared to be good shape at the time of purchase. Had my smith re-barrel with the Bartlein and since then it has functioned fine with the ammo in question (prior to the incident described in the OP).

if the Rem 700 action has had a lot of dry fire and live fire cycles the firing pin spring should be replaced.

I've done a several hundred dry cycles on this rifle (in addition to the ~50rds live). Not knowing the prior owner's usage, this could very possibly be a factor.

I'll try some other ammo on my next range trip just to be sure, but the cartridges that the FTFs happened with are a known quantity. As I stated in the OP, I've used them for many hundreds of rounds on this and other rifles without issue. They are factory produced surplus, not handloads.

If the problem persists after my next try, I think the gun will go back to the smith for inspection.

Edit to add: I forgot to check headspace with the tape test that Downhill recommended! I'll have to carve out a few minutes to try it out.

 

[LRI]

I did not read through the comments so if this is redundant, apologies.

I'm assuming you've had this action for a while and this problem is just now presenting itself. One thing to note is the change in weather. If you are up north, you might take a look at your fire control assembly. Some oils/grease get pretty gummy in cold weather. This will put a lag on your striker assembly and create lethargic ignition.

Good luck.

 

[Chris1972]

Headspace, while possible, would have to be really bad to misfire.

 

[DownhillFromHere]

Headspace, while possible, would have to be really bad to misfire.

Yes. And it's also a really easy thing to check.

Many years ago, I watched a colleague struggle with a computer network problem. After poking at the server software for twenty minutes, he calls his team lead. Puts the phone down, grumbles, goes around to the back of the server rack, [expletive], comes back, picks up the phone, tells team lead, ok, yeah, the cable was unplugged. Hangs up, still no connection, picks up phone, calls lead, puts phone down, grumbles, goes back around rack, [expletive], comes back, picks up phone, tells team lead, ok yeah the other end was unplugged too. Everything worked fine with both ends of the cable plugged in.

I watched talented infrastructure engineers go through that same exercise many times in my career... and I made similar assumptions myself early on.

Check the simple things, especially when time required is measured in seconds.

 

[drh2687]

I'm assuming you've had this action for a while and this problem is just now presenting itself. One thing to note is the change in weather. If you are up north, you might take a look at your fire control assembly. Some oils/grease get pretty gummy in cold weather. This will put a lag on your striker assembly and create lethargic ignition.

It did briefly cross my mind that weather might have been a factor. It was 60* and raining at the time of the failures. Almost certainly not cold enough to cause lubricants to gum up, and the gun obviously SHOULD work in the rain. That said, I've never had it in rain or at 60* before - all prior firing has been on a climate controlled indoor range.

I'll pull the trigger assembly and have a look per your advice.

 

[FuhQ]

Howdy fellas,

I have a Remington 700 short action in .308 that has been re-barreled (by a non-clownshoes smith) with a Bartlein blank. I've converted it detachable mags with Badger bottom metal.

That re-barrel was relatively recent and I have about 50 rounds through it - all surplus M118LR.

My last range trip, I experienced a bunch of failures to fire with the M118LR. In all cases, I had a dimpled primer that just by visually comparing did not appear to be any lighter than normal. I've used several hundred rounds of that specific batch of surplus M118LR with zero issues previously (in both this rifle and others). During this range trip, I had 4x FTFs out of 19 or 20 rounds before I called it quits.

Is it THEORETICALLY POSSIBLE that I just so happened to have the 4 bad rounds from my batch of hundreds of rounds of M118LR all show up in the same 20 round string? ...sure, I suppose. But highly unlikely bordering on impossible. This leads me to believe there is something going on in the gun that needs to be addressed.

My armorer knowledge is limited mostly to AR stuff. Tip of the firing pin seems fine. Can the Remington 700 experts chime in here? What do I need to check out that might be causing this?

My guess is either a weak striker spring, or shit in the bolt blocking travel. Buy one of these, and keep your bolt clean. It makes taking it apart and reassembly an absolute breeze.

Kleinendorst Bolt Disassembly Tool Remington 700

The Kleinendorst Bolt Disassembly Tool enables the operator to easily disassemble a firearm bolt for routine cleaning and other maintenance. The tool...

www.midwayusa.com

 

[bunsen27]

Something else to consider along the potential list of potential fire control issues is that M118LR uses a harder primer (CCI#34) than most commercial ammo. I ran into this with a factory Rem700 action and a Timney trigger when swapping from WSR to CCI41 primers. A stronger firing pin spring fixed the issue. There is also potential for fire control drag issues. This is how to check for that issue and what you should see if there is no drag:

 

[drh2687]

OP here: as a follow up and thank you to all the assistance provided here, I figured I'd circle back to this and share what I found.

I 3D printed a firing pin disassembly tool to further inspect and clean the bolt components. After removing the cross pin and cocking piece (both of which were a bear) from the firing pin assembly, I had to BEAT the firing pin out of the shroud with a straight punch and HAMMER. As I stated originally, my armorer knowledge on the 700 is limited, but that didn't seem quite right...

Once I got it out, I tried to put it back in to sort of test fit it. Couldn't get in back in at all. I went looking around inside the firing pin shroud and lo' and behold there was a big-ass burr - a lip/ledge, really - on the inside channel where the firing pin should slide back and forth. It was big enough that it made the channel in the shroud so tight that there was no way to even re-assemble everything. I cannot imagine how much ignition force it was stealing from the firing sequence. It's a wonder the gun ever worked at all. The firing pin spring must've been just barely overcoming the drag being created.

I had to (CAREFULLY) grind the offending lip down to match the inner diameter of the firing pin shroud. Firing pin now slides freely through the shroud. And as a added bonus, my bolt lift was also dramatically improved - Score!

I have not yet confirmed with live fire at the range, but there's no question in my mind that this was the source of my issue and I'll be good to go. Thanks to all for the help!

 

[smoooth1]

Thanks for the update, glad you found the problem! Too often these posts go without resolution.