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View Full Version : Mosin 91/30 Some More Questions



Eddie2002
05-22-2015, 10:38 AM
I know a lot has been posted on the 91/30 but I'm havin some accuracy problems with a 1942 Mosin and can't figure out the problem.
I had it at the range this week and couldn't hit paper at 50 yds no matter what ammo I used. Even had one shot hit almost 3 feet to the left of the target, yikes!! So far I've tried a 100 grain .311 plinker over 5-6 grains of Bullseye or Greendot which is my go to load for both 30-06 and 7.7 Jap, Military light ball which is steel cased, and two different hand reloads both using a .311 150 grain spitzer over either IMR 4350 or H4895. The IMR4350 load and H4895 load are from midrange 7.7 Jap loads taken from Speer #9 reloading book and work in both my Arisakas. After shooting about 5-6 rounds of each type of I decided not to waste any more ammo and put the 91/30 back in it's case.
The bore is a little rough and slugged out to .311 with no fat spots and has been counter bored at the muzzle and from what I can see it should be a decent shooter. So far I've scrubbed the bore with a bronze brush and given the rifle a good cleaning. Yesterday I clamped the rifle on a bench and bore sighted it, it was off just a little but not enough to be off paper at 50 yds.
The only thing that I could think that might be wrong is that when they did the counterbore the crown of the muzzle wasn't done properly and is affecting the slug as it leaves the barrel. Has anybody ever heard of a bad crown with a counterbore?
I know it is only a Mosin but it is starting to get on my last nerve, any ideas as what to do next?
Thanks
Ed

Tackleberry41
05-22-2015, 11:41 AM
I have been going around with some mosins. Some just don't shoot very good. I had 3 at one point, a very nice 1933 hex gun, beautiful stock and finish. Shoots very good, cast or jacketed. I picked up 2 more in a deal, project guns. Both war time round receivers. One was garbage, bore didn't look bad once I cleaned it up. But you would be lucky to hit a barn from the inside, it key holed at 10ft. The other did seem to shoot good, pretty roughly made, alot of wobble in the lathe, way out of concentric. I cut the barrel back a little, now its terrible, just poorly made barrel. Probably going to get a 308 barrel for it. But going to go look at a Fin M27 this weekend, its barrel is trashed. So might fix it and put the other to the side for conversion to 45-70 or something.

Brett Ross
05-22-2015, 12:25 PM
Look at the stock bedding. Mine was so loose the rear tang bolt ran out of threads before it was tight. I made up some shims an that was a major help in grouping.

leebuilder
05-22-2015, 02:14 PM
Look at bedding as mentioned and the crown. Seen many with just loose screws. Is the bore rough? Boil and oil up the bore. Some shoot good and can be fixed up to shoot much better.
be safe

Patrick56
05-22-2015, 04:39 PM
Check the bedding and make sure that the stock and handguard does not touch the barrel. Start with the recoil lug and fill the rear area behind the bolt at the rear screw when the barrel is clear. Freefloating the barrel usually makes the Mosins shoot better.

Eddie2002
05-22-2015, 10:34 PM
Checked all the hardware and found that most of the screws could be tightened a full turn or better. Pulled the action and found a section of the stock in front of the recoil lug pressing on the barrel, didn't mess with it yet but might float the barrel in the future.
Had a small round Dremel stone that would fit down the counterbore so I spun it gently by hand till it wasn't grabbing and then used a pencil eraser wrapped with 400 grit w/d paper to finish smoothing the crown, from what I can see with a bright light looking down the muzzle it looks a lot better. Not sure if what I did has helped but had to try something to make it more shootable. Won't be able to get to the range for a while to test out the changes.

leebuilder
05-23-2015, 07:29 AM
Mosins are poison at times, neat piece of history. One of the few rifles that against its self and won every time. If you feel good about your mods you should see your grouping decrese. I have a few i fixed up, mostly bedding and crowns plus cleaning the barrel, and they shoot much better. My cousin has a tack driver, he only shimed the action with bits of beer cans and cleaned the barrel.
be safe

GhostHawk
05-23-2015, 08:07 AM
A Tried it with the Bayonet on?
Most of these Mosin's were sighted in with it on, and it can have an effect.

B Mine started out shooting a foot high without the bayonet.

C Lower powered loads (25-30 grains of 4895 is what I use)

I have in the year since I bought my pair done a few things. Worked on the triggers, used pieces of plastic cutting board to bed the action where the back screw is and at that big front recoil lug. Then wrapped a piece of coke can around the barrel in 2 places and fixed it into place with a small piece of tape.

With the Mosin's, it is all cumulative. Every little thing you do adds up over time and builds the effect.

Mine are not Minute of Angle shooters, yet. But I think they would hit a 1 pound coffee can at 50 5 out of 5.

Last, keep shooting that girl, and clean it after. Your slowly polishing that barrel back up. Mine was quite dark when I got it and it mirror shines now.

leebuilder
05-23-2015, 08:50 AM
Plus one on foot high with out bayonets. Most shoot like that and a bit to the right, easy fix by raising the front sight and sight in.

Eddie2002
05-23-2015, 09:01 AM
I'll give bedding the recoil lug a try next b y wrapping the action with teflon tape and setting it into some quickset epoxy. got the Volusia County Gun Show to go to today, don't need any more projects but it sure is fun to look!!!

nagantguy
05-23-2015, 09:31 AM
Check the bedding and make sure that the stock and handguard does not touch the barrel. Start with the recoil lug and fill the rear area behind the bolt at the rear screw when the barrel is clear. Freefloating the barrel usually makes the Mosins shoot better.I've found this to be the best place to start, it never hurts and always help, this gets done now as a matter course when ever one or two of these old natashas follow me home which actually hasn't happened in a spell.

nagantguy
05-23-2015, 09:35 AM
And if you can't make her shoot to your satisfaction or if that "last nerve" breaks pm me if make you a serious offer, not that I know any magic tricks or am a better smithy or trouble shooter that you but if she's just a "junker" I can always use parts, my one time large parts pile has depleted itself some how.

Eddie2002
05-23-2015, 04:33 PM
I don't think she's a junker an I will make her shoot to my satification. Gotta run.

LAGS
05-23-2015, 05:15 PM
If you have a rough bore, then slugging the barrel may be giving you a false reading.
I have one that slugs all the way thru the bore at .311 every time.
But when I cast the bore with Cerosafe it is .315
And at the chamber end it too is .315.
But the roughness in the mid part of the barrel is shaving the lead off and the slug only represents the narrowest POINT of the barrel or the result of hitting a rough spot.
Try some .314 or even .315 sized boolits and see if it improves.
Mine did greatly, and with the scope, can hit a gallon can at 100 5 out of 5 all day long.
A harder lead boolit will also help if you have a rough bore if sized properly.

1911cherry
05-23-2015, 08:29 PM
Wartime production guns are known to shoot all over usually due to rushed machining and assembly, try to float the barrel and cork the front of the stock to see if it improves. Josh Smith has a good video and instructions on his site for accurizing ;I think he's a member here too, he knows the mosin well.

jugulater
05-26-2015, 08:23 AM
it is my experience that mosins shoot best with a .314-316 boolit. a big 200 grn boolit like the lyman 314299 is what my 1936 Tula and my 1939 Izzy shoot best with.

my 1939 Izzy has a sparkly clean barrel, but is slugs out at .313 with a massive throat.

Motor
05-26-2015, 06:48 PM
Do your cleaning patches come out clean after brushing? Dried and polished cosmoline can look very much like clean steel when looking through a barrel. I learned this from my first MN.

I know others have mentioned it but screw the action screws into the action without the wood and count how many turns it takes for each to bottom out. Then make sure when tightening in the stock they actually get tight before bottoming out.

There are lots of good shim materials. I use bulk auto gasket. I personally don't think fully floating a 91-30 is a good thing. The barrels are long and thin and tend to whip. Float it, but then shim it out near the end of the forearm.

Motor

Eddie2002
05-26-2015, 08:54 PM
Haven't had a chance to work on the old girl yet, brought home from the show a scope for my Marlin 60 and spent some time sighting it in. Also picked up a second set of RCBS 30-06 dies for $15.00.

leadman
05-27-2015, 01:53 AM
My experience with the MN bores is there are layers of fouling consisting of bullet jacket and powder fouling. What I have found works good for me is plugging the bore and filling it with Purple Power alkyli soap. This gets the powder fouling loosened, then brush the bore, plug it and fill with Hoppe's #9. this gets the next layer of bullet jacket material out or at least softened. Repeat as needed. Then use some 600 grit lapping compound or JB Bore Paste to smooth out the bore.
I usually see an increase in the size of the bore slug after this is done. Had one MN that gained almost .002"! It does shoot very well now with .315" Lyman 314299, 200 gr boolits.

I also have one that was counterbored that had a burr on the end of the rifling. I found a drill that fit tight and turned it by hand to remove the burr and all was good.

Good luck with your project.

Eddie2002
05-27-2015, 09:28 AM
Leadman, Thanks for the tip, I've been running patch soaked in Hoppes #9 down the bore and then let it sit overnight before brushing it. Haven't seen any fouling the last time I tried it. I'll try corking the barrel and soaking it next. Starting to think I need to go for a bigger diameter boolit for the old girl to make up for all the wear in the barrel.

dogmower
05-27-2015, 09:18 PM
ive had good luck with birchwood casey bore scrubber. In my mn, I shoot the lyman 311299 over 25 gr. of h4895. shoots grapefruit sized groups at 200 meters if I do my part.
good luck, milsurps with cast boolits is definitely a sickness.

goofyoldfart
06-06-2015, 01:24 PM
yea, that they are---a sickness, but my o my, what a wonderful way to be sick!!!!! Beats the **** out of Pancreatic Cancer;-). Now that that is over (I hope a hope a hope, thank you Lord) I can play with the 3 that I have. YEA, what a beautiful way to be a sicko!!!:lol: God Bless to all and to theirs.

Goofy aka Godfrey:lovebooli