Gunsmithing Recoil Lug Bounce?

[Guest]

Talking to an old Gun Smith,...telling him about a stick I have that after taking it out of the stock an reinstalling,...it would shoot 2 different groups, both in the same hole. First shot was a target, second was 1/2moa at 7 Oclock 3 rd was target 4th was back in the 7 Oclock hole, an so on until you could see the two groups connect about the 10th to 12th shot.
He said it was lug bounce an after 10-15 rds it would reseat and shoot good (which it does)if the action an barrel was worth anything. All was good with it (1 year)until, I went to two different mag systems. In fitting both systems it was in an out of the bedding 8-10 times total. Guess now that I have the mag system in place that I'm going to stay with, I should Re-bed it one last time.

Thoughts?

 

[JJones75]

Re: Recoil Lug Bounce?

If its bedded properly it should not do this , it slounds like the bottom of the recoil lug is making contact in the stock.

I personaly like taypered lugs like the Badger and Tubb for this reason , I use 5 mil tape on the bottom and front of the recoil lug (front in the barrel side)none on the back of the sides , this makes for a very tight fit on the side so when the action is snugged down in the stock it gets tight , I tighten the action screw half way then lightly bounce the rifle on its butt , then while standing upright finish torquing them down. I have't seen this make a differance but in my simple little mind its helping to eliminate any "action settleing" in the bedding.

My next rifle I'm going to use a thick recoil lug and taper it from the bottom on the barrel to the bottom of the lug then put 1/16 bevel on the front corners on the lug , this way I can use NO tape (except on the bottom) of the lug for a skin tight fit , their will be no place for the action to settle once its snugged down yet "should: allow for an easy removal

 

[zenbiker]

Re: Recoil Lug Bounce?

I second the lug bounce theory, especially if the stock has a bedding block in it. Bedding the lug as JJones recommends will improve any bedding block stock.

The other problem can be the bottom steel. If one end of the bottom steel raises up when you tighten the other end, it needs to be bedded as well, otherwise it will torque the action and you'll need several shots to settle the action back in.

The only way around this is to drill the stock for pillars and bed the action so the action and the bottom steel sits firmly on the pillars, not on bedding material. Rifles bedded in this manner show little if any impact shift after removing/replacing the action.

 

[Guest]

Re: Recoil Lug Bounce?

It's a Remington LTR stock that is for a DBM. She now has the H/S mag system. It also sports a Tubbs lug and the bedding was done correctly, guess I need to have it re-bedded or just put up with the first 10-15 rd issue.

 

[wnroscoe]

Re: Recoil Lug Bounce?

Is there clearence on the bottom, sides and front of the lug?
Is the back of the recoil lug tight against the bedding?

It's possible that some of the bedding compound may have scraped off and is now under the lug. Make sure there is no debris under the lug. Make sure the DBMs magazine well is not in contact with the receiver. If bedded properly, you should be able to remove the barreled receiver from the bedded stock several times with no change in zero and no POI shift.

 

[Guest]

Re: Recoil Lug Bounce?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">Is there clearence on the bottom, sides and front of the lug?
Is the back of the recoil lug tight against the bedding?

It's possible that some of the bedding compound may have scraped off and is now under the lug. Make sure there is no debris under the lug. Make sure the DBMs magazine well is not in contact with the receiver. If bedded properly, you should be able to remove the barreled receiver from the bedded stock several times with no change in zero and no POI shift. </div></div>

Recoil lug is tight, per P/blue, an shows its touching the bottom, but not the sides or front . Any problem with just removing that?

Mag system not touching reciever, lots of room all around.

 

[wnroscoe]

Re: Recoil Lug Bounce?

You need clearence on the bottom of the lug. Either file the bottom of the lug or dremil the bedding under the lug. Chance are, when you removed the rifle from the bedding the sharp corners/edges of the lug scraped the bedding and debris fell under the lug. If the lug is stainless, dress it's edges with a file so they're rounded.

There's stress under your lug, thats the problem.

 

[Guest]

Re: Recoil Lug Bounce?

Lug is Tapered S/S and sharp, I'll dress the edges up before reinstalling.

Thanks,

Kenneth

 

[wnroscoe]

Re: Recoil Lug Bounce?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gunfighter14e2</div><div class="ubbcode-body">Lug is Tapered S/S and <span style="font-weight: bold">sharp</span>, I'll dress the edges up before reinstalling.

Thanks,

Kenneth </div></div>

Dont forget, the bottom of the lug does'nt need to touch anything except air.

 

[Guest]

Re: Recoil Lug Bounce?

Yep, already removed material that was touching in the bottom, and you were right it was scraping it from the sharp edges on the lugs. They will be round before she goes back in this time.

 

[wnroscoe]

Re: Recoil Lug Bounce?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gunfighter14e2</div><div class="ubbcode-body">Yep, already removed material that was touching in the bottom, and you were right it was scraping it from the sharp edges on the lugs. They will be round before she goes back in this time. </div></div>

I bet she'll be singing a different tune on the next range trip.

 

[Guest]

Re: Recoil Lug Bounce?

Hope so, as in Jan. I've got a match that 1/2 of a .308 hole is a deduction at anything less than 75 yds. I love/hate those 1/4 inch dot, targets.
Fun if you kill them all, a long ride home if your side kick does, an you don't. I've eaten crow, but so has he. This should help alot.

Thanks

 

[wnroscoe]

Re: Recoil Lug Bounce?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gunfighter14e2</div><div class="ubbcode-body">I've eaten crow, but so has he. </div></div>

Hot Sauce helps

 

[Guest]

Re: Recoil Lug Bounce?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">
Hot Sauce helps

</div></div>

Hear say, or experience?

 

[wnroscoe]

Re: Recoil Lug Bounce?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gunfighter14e2</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">
Hot Sauce helps

</div></div>

Hear say, or experience?

</div></div>

We'll, I am from Louisiana

 

[Guest]

Re: Recoil Lug Bounce?

Justin Wilson, style?

Wait, he was all about cayenne pepper.

 

[RADcustom]

Re: Recoil Lug Bounce?

That Roscoe is one fart smeller I mean smart feller.

 

[wnroscoe]

Re: Recoil Lug Bounce?

I'm speechless

 

[Guest]

Re: Recoil Lug Bounce?

Well,...she was a shotgun (1.5-2 IPHY)until about the 25-26 rd then went to 1/4 moa, most likely me but I've never shot that bad before with this stick. Had to come up 1.5 IPHY and left 1/2 IPHY. Don't have a clue why it would do this. Hope it's just me, as I would have called all but 2 targets. Taking the 300wm an .308 both tomorrow, to see whats up, if the 300 won't shoot,... it's me.

 

[wnroscoe]

Re: Recoil Lug Bounce?

There was bedding under the lug pushing up when the front screw was torqued. When you removed the bedding it let the pressure off and would have changed the POI. Is there a barrel pad by chance?

Loosen the front guard screw and see if the barrel moves up, out of the stock slightly. When you remove the rifle from the stock and put it back in, do you push the rifle to the rear to make sure the lug seats firmly or is the lug still bedded tight?

It's like it has to settle down for some weird reason prior to shooting. If it shoots .25moa the rifle is fine, I'd say a bedding issue, stress.

If it continues in this manner I'd re-bed it stress free and tape the lug off on the bottom, sides and front. No barrel pad.

 

[JJones75]

Re: Recoil Lug Bounce?

I've seen one have similar problems , the lug shaved some of the bedding out from its recess , when the recoil would push the action back it was causing the front action screw to contact the pillar , the screw hole was drilled out about and extra .050" and it solved the problem.
(NOTE,this lug had paralell sides)

I can't see the lug shaving off more than several thousands off of the bedding but is some cases that all it takes.

Like roscoe said , dress the edges of the lug and rebed it if for nothing loese for a piece of mind.

And quit taking the action out of the stock

 

[Guest]

Re: Recoil Lug Bounce?

Action does not move when either screw is removed first, tried that. Barrel pad yes about 1.25" worth. When I reinstall the action I drop it straight into the stock install the screws a thread or two, then stand it on the butt and tighten to 65" lb's.
I'd love to quit taking it out, but it took me this long to get the H/S mag system, too not raddle and drop free.

 

[wnroscoe]

Re: Recoil Lug Bounce?

I've never had any luck with barrel pads and dont use them. With a stres free bedding job and free floated barrel the rifle should shoot good from shot #1

 

[Guest]

Re: Recoil Lug Bounce?

If I can't get her to shoot an the 300 shoots fine today I'll remove/float the pad an see what happens. Worst case is just to have it rebedded, I guess. Never had this problem until installing the mag system. If she shoots 1/2 or better from the gate this morning I'll just leave it were it's at, as now it won't come out again unless something breaks. The trigger is a Jewell so it just gets flushed with lighter fluid from the top, anyway. No other reason to remove her again.

It's been a learning exp. either way. LOL

 

[Guest]

Re: Recoil Lug Bounce?

The 300wm printed 3, 3/8" groups. Sent first .308 win down range, punched the 1/4" dot perfect at 100yds, sent 2nd one, same thing, sent 3rd, same again. Setting there wondering WTF is going on, took it out of the stock and looked everything over, found nothing put her back in. Punched 5 more dots w/o issue, now really thinking I was going nuts I left the 100yd to recheck the mech. off set at 25-100 Everything same an working great. Pleased, I return to the 200 an shot a 3/4" group would have been a 1/2" hole except I threw one out.

My best guess is it was me, after removing the bedding from under the lug, or something had to reseat, either way now if it comes out of the stock,(only if something breaks, now) when reinstalled it's back on target as it should.

Thanks Guy's,.....

Now looking for my sidekick,... OSOK,...or as some call him "Roland",
time that JarHead/Cop'er tastes, the Hot sauce.

 

[wnroscoe]

Re: Recoil Lug Bounce?

Did you remove the pad prior to shooting these groups?

Glad it's working now.

 

[wnroscoe]

Re: Recoil Lug Bounce?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gunfighter14e2</div><div class="ubbcode-body">Now looking for my sidekick,... OSOK,...or as some call him "Roland", time that JarHead/Cop'er tastes, the Hot sauce.

</div></div>

Ahhhh, crow..........it's what's for dinner

 

[Guest]

Re: Recoil Lug Bounce?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">Did you remove the pad prior to shooting these groups?
</div></div>

Yes. Only removed enough to float the barrel from the lug forward, the bulk is still there, but not touching the barrel at all. A folded dollar bill will pass between them now.

 

[wnroscoe]

Re: Recoil Lug Bounce?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gunfighter14e2</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">Did you remove the pad prior to shooting these groups?
</div></div>

Yes. Only removed enough to float the barrel from the lug forward, the bulk is still there, but not touching the barrel at all. A folded dollar bill will pass between them now. </div></div>

Tada.......that was part of the problem if the rifle now shoots great from shot #1