Marlin/Glenfield 25 grouping problems

[BradZ]

Got an old rifle that I came into that I'd like to turn into a little shooter. Got it all together and took it to the range for a test fire day. At first I was pretty happy, managed to walk the scope over and all was good till I got it around where I wanted and started putting more ammo through it.

Grouping is inconsistent, first group maybe 1/4" low, next group 1/4" left and so on and so on. Most consistant thing is there is always a single flyer round out of each mag. Two separate targets and 2 separate shooters same thing happens with sub sonics. 5 rounds, 4 touching and 1 flyer, but groups moved. Remington bulk pack was similar but a bigger group.

I've also never been a rimfire guy so I don't know if its normal but sub sonics shoot a lot better than high velocity rounds. That make any sense?

And what can I do, I'm not sure if I should try bedding a rimfire stock. I've read these things are supposed to have great accuracy but mine doesn't and I'm a decent shot.

 

[justin amateur]

Shim that puppy and see if eliminating play between the stock and receiver helps improve accuracy.
Can't expect accuracy from a rifle, if each time you pull the trigger the alignment changes.
Try shimming the barrel too. There are those who believe free floated is the only way to go,
but I'm not one of 'em. Cheap ammo will not produce decent results, not enough quality control.

 

[TOP PREDATOR]

if i recall, that's a single mounting bolt for the receiver to stock, with the front of the receiver just sitting on wood.

as above, shim that with something or a seat it (bed) at least the front with some JB weld, a metal like stick epoxy or other bedding material just to hold it in place.

also make sure your scope is ok, and that the rings aren't slipping on those damn grooves. sort of sounds like the group walking around could be due to that.

count your flier shot - is it the first or last one through the mag? that single bullet may be getting "shaved" or deformed going into the chamber causing the consistent 1 flier

yes, generally the sub sonic will do better - advanced search sub sonic ammo vs hv, sub sonic match ammo more accurate, etc. mostly comes down to transonic barrier, stability, and barrel harmonics.

you'll be surprised how well that 25 will shoot once some of those simple thing are gone over, and even a bubba trigger job:

http://www.snipershide.com/shooting...37-marlin-882-925-25-etc-trigger-mod-job.html

http://www.snipershide.com/shooting...vs-marlin-25-925-sporter-barrel-part-1-a.html

http://www.snipershide.com/shooting...vs-marlin-25-925-sporter-barrel-part-2-a.html

http://www.snipershide.com/shooting...vs-marlin-25-925-sporter-barrel-part-3-a.html

 

[TOP PREDATOR]

check out the crown too, you'll get some crusting at the muzzle, you may have to clean that up a little.

a simple touching up ever so slightly with a chamfer tool, ligt sandpaper on the tip of a small funnel, etc can get some of that caked on crap off.

heck, while at it scrub the shit out of the barrel using copper and lead remover, and start from scratch. you'll probably have to run 100rounds through it to "reseason" the barrel to your go to ammo, whatever that may be.

 

[BradZ]

Never tried to shim a gun before, I've done regular bedding and pillar bedding before. How does shimming work?

I'm gonna yank it all apart and clean the hell out of it to start, trigger isn't bad for a cheap .22

 

[justin amateur]

Shimming is an easily removable fix for slop between the receiver/barrel and stock.
It's a way to fix the imperfections created during the manufacturing process.
It's all about ensuring that the relationship between the receiver and stock stays constant.
by using a flexible but solid filler material in the areas where the receiver should be making
contact but isn't. I use FelPro automotive gasket material as it is temperature and oil resistant.
Easy to cut with scissors and can be layered to fill larger gaps. Comes in handy for
testing changes to determine if a shim will result in an improvement in accuracy
without all the work of epoxy bedding. I've also used business cards, aluminum foil,
duct tape, electrical tape, friction tape, end flaps from ammo boxes, silicon cooking sheets,
strips of rubber cut from radiator hoses and sorbothane. Whatever works to fill the gap.

Even chunks of cardboard pulled from a target backing...whatever it takes to stop unwanted movement.

 

[z71rat]

For shimming purposes, I have always used, and will ONLY use aluminum foil. It is readily available, cheap enough to use, very user friendly to build up to a specific thickness, and easily removeable with no traces. Cheap way to experiment to get your rifle to perform to it's fullest potential.

DK

 

[BradZ]

I've gonna give the shimming a shot on my weekend here (mon/tue) and see how it comes out

 

[z71rat]

How did the results turn out?? Range report and pictures are mandatory you know!! LOL

DK

 

[BradZ]

Sorry for the delay guys, I went and tore my rotator cuff at work so I haven't been able to get anything done. Actually forgot about this thread but when I saw it I wanted to update it

 

[JoeMartin]

The only Marlin's I've not had to shim are the vintage (Pre 1950) Model 80's. The 1964 Sears & Roebuck Mod. 80 (which surprised me), and the 925, both needed shimmed. There really is no comparison between the quality of workmanship from most vintage rifles as compared to today's manufacturing process.