Contender G2 Carbine barrel bedding

[k9jri]

I am not too happy with the groups from my Thompson Center 21", .22LR Match barrel.  The fit between the barrel and the forearm is horrible to put it mildly.

The groups vary wildly but are in the 1 1/2 to 2" range at 50 yards.  This will be mixed in with an occasional 4 out of 5 in the X ring on a standard NRA 50 yard small bore target.

I have found three basic approaches to solving the bedding problem and while I understand (kinda maybe) the intent of all three I would like to get some input on the one that has been most successful.

1.  Install a hanger bar onto the barrel and inlet the forearm for the hanger bar.

2.  Install some pillars that will provide repeatable contact with the threaded barrel inserts and then sand the stock, where needed, to freely float the barrel.

3.  Epoxy bed the forearm to the barrel removing all float but providing a tight, repeatable fit.

The engineer in me says that number three would be the best fix but I would like input from those that have already solved the problem on their Contenders.

- Mike

[Keith L]

I see no benefit to bedding a Contender barrel.  Bedding is helpful in a one piece stock but even then most of the time these days only the action is bedded and the barrel is floated.  Sometimes and some guns respond well to action bedding and pressure at the front of the forestock. 

What I have done with Contenders is to cut strips of shotgun shells and used them as spacers between the barrel and the forestock.  I have also used o-rings on the forestock screws.  Either seems to work as well, and is lots less work than bedding.  I also make sure that the "ears" on the forestock are not touching the frame of the Contender.

My experience with the Contender is that the low tech fix is often the best.  YMMV

Good luck.

[skb2706]

1. will leave you with two extra holes in your foreend

2. Never tried that.

3. Just finished building a new foreend done this way. Too early to tell if that works. I bought an unfinshed Gunstocks Inc. fore end, di the finish work on it, channeled it for a full bull barrel, hogged out the area between the screws and immediately ahead of the front screw and bedded it in Devcon. Makes an excellent fit.

As far as benefit, bedding allows for consistent assembly and generally removes POI shift when alternating from bipod to bags or no rest at all.

In the past I did hanger bars which work well but only allow for one fore end attachment screw. I like the way they shoot set up with them but I wanted to try something else.

On my sons factory foreend for his G2 I put small orings inside around the screws and a small flat washer over it. Assembled the gun just snug and it works verl well. Definitely low tech.

[k9jri]

What I have done with Contenders is to cut strips of shotgun shells and used them as spacers between the barrel and the forestock.

Good luck.

I am trying your spacer trick.  I don't have any shotgun shells but I cut some small 1" wide gasket strips and punched holes that fit the outer diameter of the dovetailed inserts.  The strips come to within 1/8" of the top of the forearm.  The barrel is centered and a $ bill passes between the barrel and the forearm in front of and behind the front screw.

That looks like it might work well.  The next trip to the range will be the proof.

Thanks - Mike

[Keith L]

There is nothing magic to the shotgun shells.  It was what I had.

Good luck!

[Hopalong7]

    Come on Keith, I love the shot shells too.....let's call'em magic!!!
BTW I have done a full bore glass bedding on a target forend and 16.25" & 21" barrels(they are the very same contour) and it did work great...but so has every other method that I've tried.  Just might be a little advantage to the glass bedding when using an attached bi-pod...don't know for sure.

[Keith L]

Sorry.  O yea.  Me N Hopalong can maybe get you some of the magic shotgun shells if you need them...

[David D.]

I have seen and read several debates on most the above fix's and have tried several of them and more myself.

Shooting pistols and rifles using forearms mounted with H-Bars, pillar bedded, spacers (pc. shotgun shells, hard rubber gasket material, etc.) between barrel and forearm, all the methods have produced the same results for me. They worked!

I can also get the same results using none of the above by making sure the forearm channel is well relieved of stress. By this I mean not touching here and there on the sides of the barrel, or even the bottom. Not over tightening the mounting screws, trying to keep an even pressure between the two. Making sure the ears are not rubbing the frame.

[k9jri]

I applied the suggestion where a spacer (small square of gasket material) is applied under both forearm mounting screws. This did perfectly center the barrel in the forearm barrel channel and allowed a dollar bill to slip between the barrel and forearm in front of the front screw and between the two screws.

During this procedure I did notice that the two screws did not fit smoothly through the holes and into the dovetailed threaded studs. At the time I did not look further into this issue.

The spacers resulted in no real change in the erratic groups shooting from a rest.

While this may or may not be relative the barrel is a Contender (not G2) tapered 21", blue, .22LR Match barrel that was with the rifle when I purchased it used. Both the G2 carbine frame, stock and barrel appeared new and unused I really have no idea of the history. Having said that I then decided to give the barrel a good cleaning. I am not normally an advocate of aggressive cleaning of a .22LR barrel.

Using both Blue Wonder and Hoppe's #9 it took between 17 and 20 patches before they started pulling through cleanly. The first few patches were the expected black sootie color but the remaining patches were a dirty brown in color. A visual inspection of the bore, prior to cleaning, appeared bright, smooth and lead free. No chunks or scales of lead came out, just the brown residue.

While cleaning I also noticed the reason the forearm screws did not engage smoothly. The rear threaded stud appears perfectly centered on the barrel but the front stud was not centered in its dovetail. It was all the way to one side of its dovetail. Using a small brass drift I carefully tapped the stud toward the center of its dovetail. I positioned it so that the forearm could be dropped onto the barrel and both screws threaded into their respective studs with no resistance using only a screwdriver bit held between my thumb and first finger. No screwdriver handle was used. After centering the front stud the barrel now sits perfectly centered on the barrel channel without the aforementioned spacer.

The carbine has been reassembled without any non T/C gadgets and is ready for another range test. If these two "fixes" do not correct the problem it is time for the barrel to go back to Thompson. They suggested that I send the entire weapon but let's hope that this is not necessary.

Anyone have any comments on my findings, procedures or have other suggestions prior to a return to Thompson?

- Mike

[LaOtto222]

I have an older model Contender serial #77XXX. I sent it in to Thompson to be retrofitted with the E-Z open mod. so I could shoot G2 barrels on it. After I got a 23" Factory 221 Fireball barrel, the locking lugs did not engage correctly, so the lock up was solid - there was play in it. I called T/C and they sent me a new set (different) set of locking lugs. It now locks up tight. I still was not getting groups to my satisfaction, so I fully floated the barrel. I did this by relieving the barrel channel and making sure the "ears" would not touch the frame. I put a washer under the screws and epoxied washers between the barrel and the lugs. The only place the fore end touches the barrel is at the lugs. I also found my barrel likes to be dirty. Bottom line - make sure your lock up is good and tight. Do not clean your barrel, very often -I think this is very important especially in a rim fire. If that does not do it, then FULLY float the barrel - there is lots of room around it. It may not look the the best because I have maybe an 1/16" around it; but it shoots very well, about .5 MOA on a good day and .75" with a variety of loads any time for 5 shot groups. Good Luck and Good Shooting

[k9jri]

I went to the range this morning and it appears that the "off center" forearm threaded stud was the culprit.  The cleaning may or may not have also helped.  I should not have done both at the same time  but the results were fantastic.  After shooting about 20 fouling shots I was able to shoot a 50 yard, 5 shot group from a front rest that was easily covered by a dime.  I then mounted the bi-pod and proceeded to shoot two more 50 yard, 5 shot groups that were less than a dime in total spread.  The POI with the bi-pod was slightly different than when shooting from a rest but that was expected.

This was all with SK Standard Plus, .22LR ammo.

It would not shoot anything approaching a group prior to centering the barrel's  dovetailed, threaded stud for the forearm's front mounting screw.

Such a small thing to cause such a large problem and no other "remedies" were required after correcting the error.

- Mike

[rickt300]

My TC carbine in 22 Rimfire has a 23 inch G2 barrel on an early frame and a thumbhole stock.  The factory stock didn't position my trigger finger in the right place so I replaced it (big Hands).  I shot a couple thousand shells thru it and it started to get away from being a .4 grouper at 50 yards to maybe a bit over .5.  I cleaned it with Hoppe's Benchrest and it was pretty dirty and I even got a little lead out of it.  Now it's back to .4 or a bit better with some groups looking like enlarged 22 holes.  Ammunition quality is a huge factor to me.  I shoot a lot of Federal 510 with very good results for cheap ammo but it varies quite a bit among different lots.  Fed 714 usually is so accurate I can't tell it from the match version 711B.  The best shooting bulk ammo to use for hunting has been Winchester Expert and the Dynapoint GT.  I also started hand lubing with Crisco.  Not completely sure if this improves grouping but it does keep fouling soft and reduces the number of fouling shots needed when changing types of ammo.

[Bullseye]

IMO you went down the right road.  I always:

1.  Make sure the stud is where it needs to be.
2.  Sand the ears so that they do not rub the frame.
3.  Sand the channel so that it only hits the studs.

I guess this has worked!  I have great accuracy but have always done it, so not sure if it ever cured a problem or not.

[rickt300]

I have put a layer of black automotive silicon between the studs, covered it with wax paper and put the forearm on the barrel leaving the screws a turn and a half from being tight.  When it hardens, trim the excess wax paper and keep your screw snug, not real tight.

[SD Handgunner]

On the Contenders I have had with Wood or Synthetic Forends I have always just used a piece of PVC the same diameter as the barrel wrapped with sandpaper to sand out the barrel channel in the forend to float it. I sanded to a depth to where the sandpaper wrapped around the PVC had just sanded the saddles enough to even them out. I then used #10 machine screw flat washers in the bottom of the recesses of the forend where the screws pass through to finish the job. This has always worked for me.

Larry

[k9jri]

Larry,  Your process is very similar to many that I have seen but the interesting part was that no modification, add-on or jury rigging was required after the forearm attachment studs were centered on the barrel.  It shoots great as does a new 23", .17HMR barrel again without forearm modifications of any kind.

- Mike
 

[SD Handgunner]

Yep I have had many that shot good without any modifications but the tinkerer in me just had to float them anyway.

Larry