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I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 3:43 pm
by intercooler
ok, i got one of the mosin snipers from AIM a few months ago. i have not shot it and did not try until a week or so ago. i picked up some good surplus ammo that works fine in my m44 and other mosin. My problem is that the sniper seems to have short headspace. The bolt is hard to close and requires a good slap (yes i know mosins are famous for that) to close. it is so hard that it is unuseable in my opinion. I looked online and saw numerous references to the ectractor so polished, deburred etc...same deal. I then got another bolt head and extractor, same problem. I got a new extractor, installed it, same thing.
Frustrated,I took the sniper bolt and tried with with some dummy rounds in my m44 and it is perfect, feeds perfect...smoth as it should be. I took the bolts from the m44 and other mosin i have and they are all the same as the original sniper bolt...too hard to close with out a hard slap
The chamber is clean (i steam cleaned it and its not the problem)
i ordered some okie headspace gauges, but i suspect that the gun is short headspaced. who or where can i send it? i looked and found no mosin gunsmiths...anywhere.
Re: I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 4:25 pm
by Junk Yard Dog
There will be no Mosin gunsmiths outside of the fiftys Soviet military, a regular gunsmith should be able to take a look at it. Ask at your local gunshop were to find a gunsmith, or look online for one in your area.
Re: I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 4:27 pm
by Jumperwire
I'm not really sure on the problem. I'm going to move your post to the main forum, for the time being. This way, more eyes will see it and maybe get you some help.
Re: I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 5:09 pm
by Three_Dogs
Keep us posted to what you find out.
Re: I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 5:18 pm
by desdem12
Well i would like to ask if there is any marks on the cases after putting them in the chamber and extracting? Another area i would look at is the extractor channel on the chamber face. Sometimes it is hard to clean that area and stuff piles up in the bottom of it and the bolt will have trouble closing on junk in the channel. Also i would compare the channel to another mosin and see if it is timed right.

Re: I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 6:10 pm
by intercooler
i notice that if i close the bolt slow, when it hits the hard stop, if i push against the spring pressure forward while rotating the laver down, it closes with a click.
i worked the extractor with 1200 grit and bent it out a good bit and it helped, still doesn't close when worked without a slap
it is perfect without a cartidge...
Re: I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 6:31 pm
by BuckeyeSgt
Sounds like the problem Jaime was having. He had something in the chamber if I remember right.
Re: I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 6:40 pm
by Greasemonkey
Are the any obstructions in the chamber? Sounds like a broken case mouth, the thin ring of jacket metal from a bullet that separated during firing. I had a Finn M91 with the same bolt issue, took me a while to find it. It was a very thin, way less than 1/16 of an inch thick, but just enough the bolt would not shut and it was black colored, blending in with the rest of the chamber.
Re: I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 6:44 pm
by WeldonHunter
intercooler wrote:i notice that if i close the bolt slow, when it hits the hard stop, if i push against the spring pressure forward while rotating the laver down, it closes with a click.
i worked the extractor with 1200 grit and bent it out a good bit and it helped, still doesn't close when worked without a slap
it is perfect without a cartidge...
If you suspect to little headspace you might try measuring a round (tip to base) with dial calipers then chamber it, extract it and see what measures. If the bullet (projectile) is hitting the bore at the end of the chamber it might show up as a now shorter round. If the shoulder of the case is what's hitting there might be marks on that part of the case. Have you tried to put a round into the bolt with the rim already under the extractor and see how it chambers. That might eliminate the extractor as the problem if it goes away. One other thing to consider. I know you said you cleaned the chamber good but is it possible there's still some dried cosmoline in the area where the lugs on the bolt head ride? It's the area right in front of the end of the barrel.
Some pictures of the bolt face as well as a round that's been chambered might help here to start with.
Re: I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 8:24 pm
by intercooler
it seems to be much better if you click a round onto the bolt/extracter then put the bolt back in the rifle. I am gonna scrub the thing more tomorrow. The rifle is as it came from AIM, I have not fired it. I have noticed that the rim of the cartridge that i have used are getting ragged from the extractor
Re: I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 9:21 pm
by Simo
Cheaper to buy another 91/30 and swap the optics over.
Re: I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 9:53 pm
by bunkysdad
Eddystone06 wrote:Cheaper to buy another 91/30 and swap the optics over.
Someone is being mean. I think you have decades old dried stuff plastered in the extractor channel. One steam cleaning just might not have done it. I would start with a soak of Hoppes #9 for a few days to hopefully soften things up. This could be missed even with headspace guages.
Re: I have a problem with my Mosin sniper
Posted: Sat Oct 20, 2012 10:45 pm
by Ironnewt
There is a product available that can be used to make a casting of your chamber (Cherrosafe maybe???) it's available from Brownell's. Could make a casting of your sniper and one of your M44 and then compare them? that is what I'm going to do with my 42 Izhevsk that has rings in the chamber
Re: I have a problem with my Mosin sniper
Posted: Sun Oct 21, 2012 11:42 am
by Starshina
There is a tool that lets you scope the chamber and bore, Hawkeye. It's very expensive. A lot of benchrest shooters have that tool. It is also used by aviation mechanics. Seeing is better then guessing.
Re: I have a problem with my Mosin sniper
Posted: Sun Oct 21, 2012 1:13 pm
by bunkysdad
I have a Snap On color screen digital bore scope and can check the chamber, but the flexible camera shaft is 8mm, just too snug for the 30 cal bore. I can get a 5.5mm flex shaft but it is 225.00. I don't want it that bad. Besides, looking that closely to the bore of a rifle you love can make you not like it too much any more.
Re: I have a problem with my Mosin sniper
Posted: Sun Oct 21, 2012 1:27 pm
by Longcolt44
Something i have done to check for obstructions in the chamber, before I got an electronic scope, is to color a round completely with a felt pen. Carefully insert the round in to the chamber, close the bolt and extract the round. Look to see if there are any scratches in the ink on the case or bullet. Have you talked to AIM?
Re: I have a problem with my Mosin sniper
Posted: Sun Oct 21, 2012 1:48 pm
by Starshina
bunkysdad wrote:I have a Snap On color screen digital bore scope and can check the chamber, but the flexible camera shaft is 8mm, just too snug for the 30 cal bore. I can get a 5.5mm flex shaft but it is 225.00. I don't want it that bad. Besides, looking that closely to the bore of a rifle you love can make you not like it too much any more.
Hawkeye is around $700. It's direct optical light transmission. Much bettet view then digital camera / screen kind.
Re: I have a problem with my Mosin sniper
Posted: Mon Oct 22, 2012 6:12 am
by Darryl
Eddystone06 wrote:Cheaper to buy another 91/30 and swap the optics over.
You're not advocating bubbaing another M91/30 up on this forum are you?
I hope not.
Dolk
Re: I have a problem with my Mosin sniper
Posted: Mon Oct 22, 2012 6:20 am
by Junk Yard Dog
Hold on a sec, gelding knife..gelding knife...what the hell did I do with it..Ah, there it is

Re: I have a problem with my Mosin sniper
Posted: Mon Oct 22, 2012 2:00 pm
by andrewd41
Longcolt44 wrote:Something i have done to check for obstructions in the chamber, before I got an electronic scope, is to color a round completely with a felt pen. Carefully insert the round in to the chamber, close the bolt and extract the round. Look to see if there are any scratches in the ink on the case or bullet. Have you talked to AIM?
Great idea. Simple and will tell where the problem is located. Put a cross on the base of the round so you can tell the orientation of the marks