Marlin 39A Problem

anfnfalfan · October 16, 2014, 08:21 PM

I just purchased this used Marlin 39a circa 1965 and I'm not happy with the hammer and bolt assembly. When the hammer is released to engage the firing pin, the hammer catches on the right side of the bolt. It looks like it has for some time now due to the wear on the side of the hammer and bolt. Is there a part that needs replaced? Does anyone have suggestions to fix this? Anyone ever had the same issue? The hammer does strike the firing pin, it just hits the rear side of the bolt first. Thanks for the help!

hodaka · October 16, 2014, 08:30 PM

Might be a dumb question but are you sure the take down bolt is tight and the two halves are properly mated?

anfnfalfan · October 16, 2014, 08:39 PM

I should have included that. Yes they are properly meshed together. I used a quarter to tighten the screw.

Snyper · October 17, 2014, 01:54 AM

It's possible something happened to cause the hammer to be bent slightly.

Since it still fires, it's obvious it's only a few thousandths of an inch

If the visible wear is only on the upper half of the hammer, you can probably polish it or the bolt to give it the needed relief

RJay · October 17, 2014, 05:31 PM

I have seen this before on the early Marlins, in fact I had a 1951 Marlin 39A that did the same thing. I simply ( everything was tight as it should be ) smoothed every thing and kept it shooting for another 20 years ( for me, now my son has had it for 10 years )

James K · October 17, 2014, 07:45 PM

Trimming a bit off the bolt will be less obvious than taking some off the hammer. There may be some other problem, but if you can rule out a bent receiver, bent bolt, canted bolt, etc. and that rubbing is the only problem, I see no reason not to just file or stone a bit off the bolt at that point.

Jim

cecILL · October 18, 2014, 07:18 AM

There is a Marlin Owners forum, those guys can help.

Dixie Gunsmithing · October 19, 2014, 07:46 PM

I'm like Jim, about trying to trim the bolt to keep it from rubbing. What has most probably happened, is that one of the parts, most likely the bolt, has been a few thousandths out of spec, but was assembled anyhow. The hammer will be noticeable, unless it is modified, polished, and blued back to the state it was originally. If I remember correctly, the rear of the bolt has an ear that sticks back on the right side that matches the receivers contour, and that is what the hammer would be hitting? If so, then remove the bolt, and the firing pin. Then, use a flat mill file to take away a little of the inside of the ear, on the firing pin side, and cold blue that after the fit is fixed. One would not probably be able to tell it afterwards.

October 16, 2014, 08:21 PM	#1
anfnfalfan Member Join Date: December 30, 2009 Location: South Carolina Posts: 25	Marlin 39A Problem I just purchased this used Marlin 39a circa 1965 and I'm not happy with the hammer and bolt assembly. When the hammer is released to engage the firing pin, the hammer catches on the right side of the bolt. It looks like it has for some time now due to the wear on the side of the hammer and bolt. Is there a part that needs replaced? Does anyone have suggestions to fix this? Anyone ever had the same issue? The hammer does strike the firing pin, it just hits the rear side of the bolt first. Thanks for the help!

October 17, 2014, 01:54 AM	#4
Snyper Senior Member Join Date: December 16, 2013 Location: Eastern NC Posts: 3,047	It's possible something happened to cause the hammer to be bent slightly. Since it still fires, it's obvious it's only a few thousandths of an inch If the visible wear is only on the upper half of the hammer, you can probably polish it or the bolt to give it the needed relief __________________ One shot, one kill

October 17, 2014, 05:31 PM	#5
RJay Senior Member Join Date: November 2, 2005 Location: Arizona Posts: 1,936	I have seen this before on the early Marlins, in fact I had a 1951 Marlin 39A that did the same thing. I simply ( everything was tight as it should be ) smoothed every thing and kept it shooting for another 20 years ( for me, now my son has had it for 10 years ) __________________ Ron James

October 16, 2014, 08:30 PM	#2
hodaka Senior Member Join Date: April 23, 2006 Location: South Texas Posts: 2,010	Might be a dumb question but are you sure the take down bolt is tight and the two halves are properly mated?

October 16, 2014, 08:39 PM	#3
anfnfalfan Member Join Date: December 30, 2009 Location: South Carolina Posts: 25	I should have included that. Yes they are properly meshed together. I used a quarter to tighten the screw.

October 17, 2014, 07:45 PM	#6
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	Trimming a bit off the bolt will be less obvious than taking some off the hammer. There may be some other problem, but if you can rule out a bent receiver, bent bolt, canted bolt, etc. and that rubbing is the only problem, I see no reason not to just file or stone a bit off the bolt at that point. Jim

October 18, 2014, 07:18 AM	#7
cecILL Senior Member Join Date: August 13, 2001 Location: central IL Posts: 769	There is a Marlin Owners forum, those guys can help.

October 19, 2014, 07:46 PM	#8
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	I'm like Jim, about trying to trim the bolt to keep it from rubbing. What has most probably happened, is that one of the parts, most likely the bolt, has been a few thousandths out of spec, but was assembled anyhow. The hammer will be noticeable, unless it is modified, polished, and blued back to the state it was originally. If I remember correctly, the rear of the bolt has an ear that sticks back on the right side that matches the receivers contour, and that is what the hammer would be hitting? If so, then remove the bolt, and the firing pin. Then, use a flat mill file to take away a little of the inside of the ear, on the firing pin side, and cold blue that after the fit is fixed. One would not probably be able to tell it afterwards.