223 and Rem 700 Firing Pin Hole

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shimmer

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Hi,

I have a Remington 700 in 223 and have noticed that the firing pin hole is quite large, especially compared to the Kimber rifle that I have. When firing factory ammo there is a bit of cratering/primer flow, whereas there was nothing abnormal about the primers fired from the Kimber rifle. Some google search has talked about bushing the bolt face to create a smaller firing pin hole - so is it worth it and necessary? Or should I just get a Stiller action or similar (by the time you true it, change the bolt knob, bush it........I'm likely getting close to stiller prices). I'm a bit of a velocity whore and will always pick the higher velocity when looking for that magic node for a bullet, so will be running it close to max pressure. I will likely be putting a new 1 in 8" barrel on it for 75-80 gr bullets. For all of those who built custom rifles off of a Rem 700, did you bush the firing pin hole?

Mark
 
Smaller diameter pin tips (.062") and snug holes allow excessive loading without primer failure. I do it for my own .223 and 6mm BR.

bushed700boltface-0.jpg
 
So what is involved in this process? I have the same issue with my 700 in .223. I mean there cant be that much thickness at the boltface to just open up the hole a bit and press a bushing in there, how do you keep it in place? Is there enough clearance on the inside for a shoulder or something?
 
I push a bottomed bushing in and turn the tip down. Make the bushing an almost loose fit and use Loctite. I made a bushing too tight once and are hard as I drove it into place, it did not bottom out... this showed up when it was fired and the primer pressure seated it deeper... had to drill it out and start over.

As mentioned above - smaller pin tip diameters are better for running higher pressures.
 
Spikethedog said:
Could you get away with turning down the pin dia to the .062" mentionned above?
Click to expand...

The factory pins turn easily. But if you turn the pin tip and leave the hole large, every shot would blow a primer and your bolt face would be ruined shortly.
 
I use a top hat style bushing pressed in and make them long so as to capture the firing pin during it's entire travel. Normally they glide into place when fired.
 
guntech said:
The factory pins turn easily. But if you turn the pin tip and leave the hole large, every shot would blow a primer and your bolt face would be ruined shortly.
Click to expand...

Yeah I definatly wouldn't just turn it down and throw it back in the bolt as is. Thanks for the cutout picture that will definatly help, now i just have to figure out how i will make that bushing to stay in there nicely. Would a drill press and reamers be precise enough to open up the hole? I think with the spring loaded center i could locate it quite easily, then it would be a matter of clamping it in there solid enough that it dosent move. I think im going to study this a bit more, it sounds like a nice little project to play with
 
Spikethedog said:
Yeah I definatly wouldn't just turn it down and throw it back in the bolt as is. Thanks for the cutout picture that will definatly help, now i just have to figure out how i will make that bushing to stay in there nicely. Would a drill press and reamers be precise enough to open up the hole? I think with the spring loaded center i could locate it quite easily, then it would be a matter of clamping it in there solid enough that it dosent move. I think im going to study this a bit more, it sounds like a nice little project to play with
Click to expand...

I do mine in a lathe with a steady rest. The bushing is made slightly long and faced back to the bolt face after installation... and of course the lathe is required to turn the pin tip.... and to make the bushing. For me a drill press doesn't fit into it anywhere...
 
I use an endmill and bore in either with the lathe or Bridgeport mill so the hole is square. Bushing/top hat made slightly longer, then machined flat to the bolt face on the lathe. Drilled and reamed for final pin fit.
Drill press isn't accurate enough for this kind of precision. Too much wobble and no true way to dial in dead center to the bolt.
When done correctly the primer hit is dead center on a fired case.
 
Yeah your right lathe would be the way to go for the bolt for sure, my only problem is my bolt has a oversize knob threaded and epoxied in... Im not sure it would allow me to put it in the chuck even on our biggest lathe... Maybe try to set it up in the mill with a V block setup could get me there, we have a nice recent small cnc milltronic, that i think could be able to find center quite accuratly. I would definatly use a lathe to make the bushing and turn down the tip. I will have to bring the bolt in tomorow and see what i can do. Thanks for all the help guys
 
Thread a stub to fit the rear of the bolt, turn it true to the bolt body. Chuck that in the lathe and a steady rest just behind the lugs...
 
This is normal on all remington 700 rifles made within the 7 or 8 years. I hev had about a dozen different reminton 700s in this time period and they all had a chamfer on the firing pin hole which allows your primer to flow into the firing pin hole, making it look like you are using too hot of a load, even when using factory ammo or light hand loads. Rifles built in the early 2000s and late 90s dont have the chamfer on the firing pin hole and they dont have this issue. You dont need to replace your firing pin. You just wont be able tojudge if a load is too hot based on a cratered primer. If you install a larger firing pin you will still get the crater because of the chamfered firing pin hole. If it continuse to bother you, You could always install a firing pin hole bushing.
 
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