Scoped Rifle Accuracy??

[Mousegun]

I have been a long time pistol shooter and recently purchased a Marlin 39A 22 cal. lever action. I have a scope on it that I am sure was mounted securely at all points on a rail that came with the gun and that too is on tight.

My question is as follows. When the gun is bench rested ( I know this is not a target gun but it does seem to be quite accurate), I can put about 10 shots in a group about the size of a half dollar at 50 yards.

At times with no wind, the group covers a quarter but other times, within minutes, the group seems to open up to silver dollar size. The shots don't fall to any one specific side or form any specific pattern, they just seem to "open uniformly".

What are the main reasons for inaccuracy with this set up? I don't think I am changing the way I am shooting it and I know I am right on the cross hairs when the shot breaks.

I did trigger work on the gun and it is smooth and breaks with very little pressure and no creep so that is not a factor.

Thanks for any ideas.

 

[CDignition]

This is your main reason accuracy isn't obtained...."Marlin 39A 22 cal. lever action".

You're expecting way too much from a platform and caliber that wont deliver.

 

[Dave R]

I agree with CD.

Groups the size of a quarter to half-dollar at 50 yards are very good for a .22. That would be bad for a centerfire varmit rifle, but its good for a .22.

 

[.41Dave]

As has been said, that isn't bad for most .22s, but you might be able to tighten groups up by trying different brands of ammo. Most .22s seem to have a definite preference for one particular load. You just need to discover which one your gun likes.

 

[scrat]

totally agree with .41dave

 

[Squidward]

I agree also. Try here: 22ammo.com

 

[rangerruck]

you could try to maek sure the channel is fully open and free floated with a piece of paper, then once you heat er up, at the range , and the groups start opening, recheck the freefloat and see if you have some new sticking points.

also make sure that if you are support the front of the rifle with a sandbag, make sure the bag, or whatever, is in the EXACT SAME PLACE!!!! this makes a huge diff on some single shots. Also if you have the front of the sling attached, you may be putting some unknown torque on the front of the bbl while shooting. so remove it off the front, just to be sure. It could also just be heat buildup. I would wear a watch, and take a full 30 seconds between shots, before you even start to line up the next shot, and chamber the next round. 30 full seconds. if you are scoped, make sure everything is still tight, after you heat it up!!! Last but not least, if it has a bbl band up front, say for the sling attachment, TAKE IT OFF!!! then retest.
Also something I like to do, just to see if it helps. Take a couple of really nice shot group strings. then I put a little support under the front of the bbl, just above the end tip of the front stock. i use a little round hard rubber thingies, that you put inside of kitchen cabinet drawers to keep them from slamming shut. sort of like a bolt buffer. put it up under the front of the bbl, and shoot some more good strings. then compare, with the old strings, and see which way the rifle is shooting better.

 

[JohnBT]

Try different kinds of ammo and it doesn't hurt to start with the cheap ones. If you clean between brands the barrel might take a box or two to settle down.
Try putting your front bag as far back as you can under the forearm - that's where my old Mountie likes to be supported.
Try loading and shooting one shot at a time. It might not make a difference, but a tube full of ammo starts out heavy and then the gun gets lighter with each shot. It can make a difference by changing the barrel harmonics/vibrations.
I've never shot without a barrel band, but know folks who've had success.

Groups the size of a squirrel's head are good enough.

John

 

[Geno]

Do I understand correctly, the implcation that .22LRs are not accurate, or just the lever action platform? I have never owned a lever action .22LR, but I have owned both Ruger 10/22HBs, Contenders carbines, Contender pistols and others that maintained MOA accuracy out to 225 yards. I have seen this accuracy especially with such rounds as the Remington .22LR subsonic, target rounds.

I have seen many, many .22LR firearms that will place 10 shots though a single hole, that is so tight at 50 yards, that it is nearly impossible to verify that more than 1 round was fired. In fact, many of these .22LRs are so accurate that to properly score them, the shooter has to fire a single round into each target, on the sheet to assure that the shot was actually fired. Again, re: the lever action, I cannot say. But, the "lowly" .22LR is capable of accuracy that bogles the mind.

Doc2005

 

[JohnBT]

It probably has more to do with the relatively loose standard chamber dimensions required to get a lever, autoloader or pump to feed reliably with a wide range of ammo. The majority of guns with tight match chambers tend to be bolt actions. I know my '63 Mountie won't shoot like my Finnfire, 541-S or Cooper and neither would the autoloading Remingtons and Brownings I've been around. There's a reason the rimfire benchresters shoot bolts (other than the fact that it's a bear to crank a lever with the gun sitting on a rest.)

John

 

[Mousegun]

Thanks for all the goood information about my original post. I suspected the lever action format to be the equal of a bolt in that the bullet gets seated and stays there until the next shot unlike an automatic where the shell moves rearward and the ejection port opens. There seems to be a lot going on there and that in itself could and probably does lead to some inaccuracy.

I will try all the things posted just to see what happens. I know it is not a target gun but the fun of it all is to get it to "be all that it can be".

I suspected heating up the barrel may have an effect but how much I did and do not know. This is way more an exact science than pistol shooting especially at the longer distances.

Rangerruck, please remember I have little rifle experience and although I have heard of the the following:
>>>>>>>>>> you could try to maek sure the channel is fully open and free floated with a piece of paper, then once you heat er up, at the range , and the groups start opening, recheck the freefloat and see if you have some new sticking points.<<<<<<<<<<
I need a bit of further explaination if you would please.

Thanks

 

[1911 guy]

Lever vs. Bolt action and barrel channel.

The lever action doesn't lock up anywhere close to what a bolt action does. Better than an autoloader, but not as good as a bolt. However, the groups you're getting aren't bad at all, especially since you say you don't have a lot of experience.

As for the barrel channel, here's what he's talking about. The barrel lays inside the stock in a groove called the barrel channel. If this contacts the barrel, it can ever so slightly push one way or the other. When the barrel heats up or vibrates at the shot, it can increase pressure to one side or the other. To check this, take a dollar bill or other similar sized piece of paper and try to slide it between the barrel and the stock all the way up to the reciever. If it goes, you're golden. If not, here's how to fix it. Place the rifle in a padded vise with the stock screws removed so you can lift the barreled action out at will. Coat the barrel with carpenters chalk (the blue stuff in a chalk line) and lay it in the stock carefully. Tighten the screws evenly, then remove them again. Lift out the action and look for chalk in the stock. Lightly sand these areas. If it's a wood stock, be prepared to refinish the upper edges on the barrel channel after sanding.

 

[JohnBT]

Free floated barrel:

A free floated barrel allows the barrel to move/vibrate the same way every shot. Sort of hard to do on a rifle with a two-piece stock.

John

 

[Geno]

1911 guy:

Excellent idea! I had never heard of that technique for free floating the barrel before. Thanks!

Doc2005

 

[Sniper X]

Hey John, can I borrow 20 bucks?

 

[JohnBT]

Sure, but that's not my twenty, gun, scope or hand in that pic, so will this do?

 

[rugerdude]

I had the problem of groups opening up all of a sudden too. Even after I free-floated my barrel. I found that it was due to heat build up.

I suggest waiting a set amount of time between shots and see how that works out. You may have to increase the wait time towards the last shots to compensate for the heat build-up of the previous rounds.

 

[Mousegun]

I found that the way the gun was held made all the difference in the world. I knew that it effected air gun accuracy immensely but didn't think it would do the same on ballistically faster rifles like a 22 or above.

I rested the gun in a home made deal and adjusted the scope accordingly. It shot a very small hole at 50 yards. Then when I held it while resting on a bench the point of impact was considerably different.

I readjusted the scope for that point of impact and was able to shoot a nice small group now that I knew to hold it the same each time.

Thanks for all the helpful comments, you guys are tops.

 

[rangerruck]

thanks for backing me on the freefloat expain, John, and 1911 guy. Also I like to check this out, after the bbl is getting hot, as when cool, it may be fine, but once the bbl starts to expand, you find new problems... i once had one that I thought was perfect, but still messing up. I took my time with a bill out on the range, and realized, i was hitting a very teeneh, tineh snag, once the bbl was getting hot, a front action screw was barely , and I mean barely , touching the bbl, once it started expanding.
Oh yeah, that reminds me. also once you start shooting, the action / receiver, may heat up, and expand a bit , then expanding your wood a bit, and be getting a tiny bit sloppy, inside your stock, in the action area. Go get some aluminum tape from home Despot, and shim it up a bit, on both sides, of the receiver, to keep it real still.
For groups that are real random , and totally unpredictable, yet showing no pattern, or stringing in any direction, nor leaning to any direction left or right, then this is maybe the most common problem. action/receiver, moving a bit , up , down left right, inside your stock. also try to keep the same amount of torque used, when tightening down the action screws.
And since a lever action, especially a take down, is similar in hinge/bbl stress, and gravitational pull , to a single shot break open, I would try to put my front support, right up against the front of the trigger guard, and make sure it is in the same place , every time!!!! This makes a macro quantum( is that a mathematical possibility?) in shooting break opens.

 

[rangerruck]

oh yeah, go here, and here
http://www.rimfirecentral.com/forums/
http://www.marlinowners.com/board/

to check for all your 39 accuracy tweeks. Good luck to you, by the way, never sell that, it is a fine rifle, Allways months behind on backorder, and allways goes up in value, it is allready worth more , than whatever you bought it for!!!

 

[rangerruck]

as far as ammo goes, if you know anything about 22's, they can be so diff, in what they like and don't like. but there are some out there, that all rimfires seem to do good with, Eley, which is also Aguila, Golden Eagle(mex. and Am. made, respectively) wolf match, lapua, smk, Rem/eley orange and yellow box. Also , for a cheapy, the American Eagle redbox, made by Federal, seems to be able to shoot quite well, out of a lot of dudes stuff, even high dollar rifles seem to shoot them well.
But your 39 has a high accuracy potential, as you will read from those other sites, so don't be afraid to go out and buy about 50 diff types of ammo, and give them all a try.