Gunsmithing Surgeon 1086 7 Mag misfires

ugsly

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Minuteman
May 10, 2005
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Oregon Linn County
I put together a 7 mag on a surgeon 1086 action. I was having some misfires (light primer strikes) I switched from wolf to CCI primers and it helped. I have now started on a NEW batch of brass, and 1 out of 4 may go bang (light primer strikes again) I tried replacing the firing pin spring and it didn't help. So I ran thru some of my loads that the brass has been fired 3 times, everything went bang. The gun head spaces with go/no-go gauges so I don't believe that's the issue. It has a rifle basix trigger, the firing pin protrusion looks good (I will measure it tonight). What can you guys think of or have you ran into?

I'm wondering if it has something to do with new brass head spacing off the belt and once fired brass spacing off the shoulder?

Thanks guys,
Kc
 
I would guess that it may be your trigger causing your issue. Stephan at Surgeon suggested to me to run a Jewell trigger on my build to eliminate any of these issues....................................some of the Smiths on here will have ALOT more knowledge on this than I do though!!

(I too have a 7MM Mag on a Surgeon 1086 action)
 
You may want to contact Jon Addis at Area 419 Firearms.

Home

He just finished a nice 300 Win Mag build on a 1086 and it had the same issues. I'm not sure what the conclusion was, but it looked like the firing pin spring was really short, possibly the wrong one was installed. Again, I do not know all the details, but he was having the same issue, and he put in a Long Action firing pin spring and it fixed the issue.

Mark
 
You may want to contact Jon Addis at Area 419 Firearms.

Home

He just finished a nice 300 Win Mag build on a 1086 and it had the same issues. I'm not sure what the conclusion was, but it looked like the firing pin spring was really short, possibly the wrong one was installed. Again, I do not know all the details, but he was having the same issue, and he put in a Long Action firing pin spring and it fixed the issue.

So I got in touch with Jon, he seemed to think it was the trigger. The problems have been with timney triggers and I had a rifle basix in it. I also called surgeon and he told me to put a jewell trigger in it. I replaced the trigger with a jewell and ran 5 rounds with just a primer in them. Everyone of them went off, I also put a tubbs spring in it. The tubbs spring was about 1" long then the stock spring from surgeon. I will hit the range in the next few days and see how it does now.

Thank you guys,
Kc
 
I put together a 7 mag on a surgeon 1086 action. I was having some misfires (light primer strikes) It has a rifle basix trigger, the firing pin protrusion looks good (I will measure it tonight). What can you guys think of or have you ran into?

I'm wondering if it has something to do with new brass head spacing off the belt and once fired brass spacing off the shoulder?

Thanks guys,
Kc

This is usually caused by the striker / cocking piece to trigger sear bar relationship but not always. Defiance Machine receivers will also do this with a Timney trigger if the wrong sear bar is ordered in the trigger (Remington compliant) Basically, that portion of the sear bar that catches the cocking piece is cut to far forward, just barley. That causes the fire control to be cocked with light FP spring tension. With all of the 591's/XL's & 1086's I've used / built on, a Jewell Trigger was selected. Zero issues across the board.

Also check to see if the bolt handle is closing 100% or if the bolt handle recess in the stock is interfering with it's closure. If your FP tip protrusion is between .055" / .065" your GTG.
 
Here was the biggest reason for my troubles. What came installed in the 1086 from Surgeon in front, stock replacement spring sent from Surgeon in back (appears to be same length as factory Remington spring).

This isn't to say there's still not issues with the Timney in it though because I didn't want to go firing a whole box of ammo through his brand new barrel, but after changing to a factory Remington long action spring five in a row went bang.

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Galaxy S3 on tapatalk
 
Measured firing pin protrusion, .062 with jewell trigger it still didn't go bang on loaded rounds. I did try just empty primed brass with large rifle primers and it popped 5 out of 5. I'm going to pull the loaded rounds that didn't go bang today and see if some of the powder started to burn. It may be the batch of primers don't have enough spark to fully ignite the powder?

Thanks guys,
Kc