Bushing a firing pin

[DANNY-L]

Glad I spotted this, going through the same problem with a model 7 7mm08

 

[AlNyhus]

I am experiencing primer flow and pierced primers on a Rem700 footprint custom action with a .068 pin diameter. The manufacturer checked the bolt this week and everything is in spec. Firing pin diameter, firing pin hole diameter, firing pin protrusion, firing pin shape, etc.


I am think would be nice to have the pin diameter reduced for peace of mind. I called Gretan And they are not interested in taking this work.


1. Is there any reason why I should not reduce the firing pin diameter? Any disadvantages to doing this?

2. Any recommendations for a machinist that is qualified to do this?

-Trevor

Trevor, I would verify the pin hole diameter. A .068 pin tip shouldn't be a problem, provided the pin hole is correct and isn't jagged. -Al

 

[Jeff Porter]

Try some harder thick cup primers.

 

[AlNyhus]

Try some harder thick cup primers.

You're right...the OP didn't say what primers he was using. It could be as simple as that.

 

[J.d. Popkes]

Sent it to Longrifles Inc. Fast turn-around and great quality. I had mine done because my 223AI kept piercing primers when it shouldn't. They did a great job on it and no more pierced primers.

Chad and the gang are the best

 

[ELR LVR]

I never had a problem with any of my Remmy's
I just don't understand all these Rem 700 horror stories
I mean statistically speaking sure
When we have 2.2 Millions members on here
and maybe 1/10,000 remmys got a little wack
We're going to hear over 200 horror stories instantly come out of the woodwork once 1 of them pops up
I've read even custom actions can have a bad day, new out of the box occasionally.
---
If I drive pressures up to where we see presure signs sure, I can get some cratering goin on
Thats just basic physics - there has got to be SOME clearance in the bolt for the pin to go through
And once pressures go high enough, the brass flow will take path of least resistance.
Into that clearance...
But - ??? I don't see why some people think every single bolt in existence needs to be bushed
Wondering if some people are not understanding why cratering happens
(IE: tune the load down a notch, its a pressure sign)

 

[AlNyhus]

Having had several 700's with this issue, I can vouch for it being a real deal on some actions.

The stock 700 bolts don't provide any guidance for the pin tip when it's in the cocked position. Because of this, there has to be enough pin hole clearance to let the pin tip find it way through the hole. That clearance lets the primer flow into it...thus, the 'crater' or ridge around the pin indent in the primer. If the pin hole is jagged and sharp, this gives a punch effect that can shear little bits off the primer cup.

 

[DaveTooley]

I've seen an intentional chamfer on the firing pin hole on Remington 223 bolts by a parts supplier . A Remington engineer said QC missed seeing it.

 

[JPB3]

I've seen pin holes chamfered too, Dave..

 

[Coyotefurharvester]

I had one M700(22-250) that really had a raised ring spent primer at mid range book loads. I tried sizing too close with tension but it is a hunting rifle. I sent to Carlsbad, now primers are all normal up to book max with Varget. I wish I had saved more chrono/group data before bushing, it seems to shoot better now with a wider powder charge weight range(??).

 

[Tommie]

But - ??? I don't see why some people think every single bolt in existence needs to be bushed

I’ve never heard anyone say that. But I will say that bushing the pin did solve primer flow issues on one of my rifles with loads well below max using CCI 450’s. Stacking tolerances can and does happen. Throw in human error and worn tooling for icing on the cake.

 

[pavementends]

This seems to be mostly an issue with 223 bolt face. The CCI 400 primer cups are thinner than the 450's and many times changing primers cures the issue. I have not seen the same issue with large rifle primers