More heavy gun questions

[gmitchell]

OK, you guys convinced me to use a barrel block, now I need more answers. Is there any advantage to using a longer block? Im thinking of 8" is there an advantage to say a 10'' block? I'm planning on doing a glue in, using two pieces, we will bore hole with the two bolted together. How much clearance do I need between barrel and block? What type of glue should I use? How do I keep barrel centered in block? How do I pump glue into block? I know its hard to get answers on HG questions, any info will be appreciated.

 

[4Mesh]

Note, all responses are my opinion only...

Is there any advantage to using a longer block?

Yes. I used blocks in the range of 10-12" and preferred that to a shorter block. Imo, 6" blocks on light guns back when that was a rule in pa, were a waste of time.

Im thinking of 8" is there an advantage to say a 10'' block?

The physics of this tend to say a longer block 'could' help. Then, you'll probably be beat by guys with shorter blocks. Who knows. My opinion is, the longer block is a good thing. Just like, hanging on to an axe is easier with two hands than it is with one. Is this measurable on a target? Probably not... I wouldn't sweat it if 8" is the material you have. But if you are doing the work, and 10" or greater is the same money, I'd do it. My best HG has a 14 or 15" block. Was a B**** to make!

I'm planning on doing a glue in, using two pieces, we will bore hole with the two bolted together. How much clearance do I need between barrel and block?

Assuming you bore it resonably straight, I like to use at least .030 per side. I can only guess but some I've taken apart have had on the order of .050 or so. Remember, you have to be able to get the glue in there, so you can't go too tight. You'd be surprised how much pressure it takes to stick the glue in that itty bitty hole.

What type of glue should I use?

Brownells has kits with the glue in double tubes with mixers, and a gun that squeezes it in the block. That's the easiest way to go. Once you have the gun (like a caulking gun), all you need is the glue gizmo and you're ready for a block job.

How do I keep barrel centered in block?

O-Rings at each end.

How do I pump glue into block?

Again, Brownells has the caulking gun gizmos in a kit.

I know its hard to get answers on HG questions, any info will be appreciated.

Getting answers for HG's is no trouble at all. Getting answers that agree with one another is what is difficult!

 

[Lynn]

Is there any advantage to using a longer block?
No


Im thinking of 8" is there an advantage to say a 10'' block?
No

How much clearance do I need between barrel and block?
0.050 - 0.125


What type of glue should I use?

J-B Weld

How do I keep barrel centered in block?
O-rings keep the glue in place and masking tape wrapped around the barrel keeps everything in alignment front to rear.


How do I pump glue into block?
You don't pump the glue into the block.Put your barrel block in the stock like your going to shoot the gun with the top off of it.Wrap masking tape around the barrel without the action installed so it sits centered up in the block.This means you'll have one width of tape between your barrel and the action threads and you'll probaly have two sections out in front.One at the end of the forend and one right next to the O-ring.You then coat the barrel with Kiwi natural shoe polish so the barrel isn't welded into place.You then mix up your J-B weld and apply it to the top of your barrel block the bottom of your barrel block and your barrel that has the O-rings showing you the correct location.Lower the barrel into the block and rotate it slowly.The J-B Weld will puddle up on one side of the barrel block and the excess can be removed with a paper towel.Put the top of your barrel block on and finger tighten the four corner screws and leave it sit for atleast one day.
I like to use O-rings on the inside of the barrel block for the 4 bolts that will hold the top in place so you don't over tighten the top or make it touch the bottom of ther block.If the two halves of your barrel block will touch each other follow 4Mesh's advise.I don't like those type of barrel blocks on my guns.
Edit== The 4 O-rings go on the threads of the capscrews to keep the block up off the bottom.If your top is made out of stainless you need them to keep all the epoxy from squeezing out due to the extra weight.Also don't twist the barrel once you put the top on it.If you do the epoxy will fill in the gap and the clean-up will take longer.

The first two pictures show a gap between the top and bottom of the barrel block.The red stock has had the J-B weld milled out of it and is waiting on delrin sleeves instead of the J-B Weld and that is why it has the top touching the bottom.

Lynn

On my computer you can enlarge the pictures and believe me there is a gap on the polished stock.Those are old pictures

 

[gmitchell]

Lynn, I just want to understand your system. Do I take back apart and clamp solid, Is your system like bedding the barrel in the block? Do I need to turn down the barrel to make a shoulder? My barrel is a 1.450. Thank you for such a detailed answer to you and 4mesh. Gordy

 

[Lynn]

Do I take back apart and clamp solid?
Yes when the J-B Weld dries take everything back apart remove the O-rings in the epoxy with a razor blade and cut all the tape off.You will get some J-B weld on the block because it tends to sag while its drying.You can use a razor blade or dremel tool on that.

Is your system like bedding the barrel in the block?
That is exactly what I am doing.I don't want anything metal or conductive pulling heat off of the barrel at only one point along its length.I seem to get more vertical stringing with the blocks that have some metal to metal contact and it could be my method of clamping but with the epoxy I don't see it.

Do I need to turn down the barrel to make a shoulder?
NO!!! Never do that as the bedding alone will hold everything in place and allow you to make quick barreled action swaps.Out here if you get on a early relay you can shoot your 6Dasher heavygun and if you get a later relay you swap out to a 300 Ackley in a couple minutes time

My barrel is a 1.450

Everytime you buy a new barrel the outside dimensions will change even on the 1.450 barrels.The bedding material can be sanded with 80 grit sandpaper on top of a woden dowel wrapped with tape.You can then add more J-B weld for your next barrel for perfect bedding each time.

I will try and get someone to take some pictures of the inside of my blocks and post them.I have a 50BMG unlimited gun with a clamped style 9 inch aluminum barrel block on a 36 inch long 2 inch in diameter barrel without bedding and it has never slipped on me.
Lynn

Edit---The two halves of my split type barrel blocks never touch each other with the barrel installed.

 

[sdean]

Lynn do you prefer aluminum? Thanks for the info so far.

 

[Lynn]

If weight isn't a problem stainless works just as well but your out $100 just for the metal.I can get round aluminum real cheap and it makes boring it out much easier.You can then slab it any way you like on a mill.
I put a tapered stainless HV barrel into a straight 1.250 barrel block one time and must have gotten some cleaning fluid in it somehow.It was a slit clamped style block and you could shoot it without the cross bolts in place and nothing would move.We ended pounding on it with a hammer to remove it.The inside had what looked like dried toothpaste in it and the seal was incredible.
Lynn

 

[gmitchell]

Lynn, you mentioned change from dasher to 300 ackley, do you think there is a weight limit for a smaller caliber to shoot? I've heard of guys talking that 40 lbs is about limit for a dasher, cause it needs to recoil, What is you opinion on that? Is anybody having any luck using a 6 mm in a HG? And what is the weight if the answers yes?

 

[Lynn]

If the gun doesn't recoil atleast 3/4 of an inch it won't shoot for beans.My 6 Dasher weighs in at 59 pounds and has two 1 inch wide tracking rails on the front.I use teflon tape on the rails and carnuba powder on the leather bag.I soak my bag in laundry starch and put the gun in the rest and let it dry.This makes the bag fit perfectly.Next I strap the stock into my rest system and leave it in the bed of my truck for atleast a month.The motion of the truck has the stock sliding back and forth in the bag and with carnuba added regularly it slides like its on ball bearings.
Cordura seems to slide easier but with the rules the way they are my cordura bags seem to move too much on me during recoil.I like my bags as captured as is legal so I don't get any movement front to rear.I also don't like people pinching my bags.You can spend alot of time settling the sand and getting everything just right and some turkey will come up and pinch your work.
If you ever get the chanec to look at the late Clifford "Skip" Talbots gun called "Cyborg" you can better see how he set it up for adding and removing weight.
Here is a link for a 6mm heavygun and you can see it recoiling into the shooters shoulder.4Mesh can probaly tell you what kind of a year the shooter is having as they both shoot at the same club.
http://www.youtube.com/watch?v=MfHqzlCPgS8

Lynn

 

[gmitchell]

Has anybody hogged out stock and built front plate shapped like a T, and mounted barrel block to front plate?

 

[4Mesh]

I've heard of guys talking that 40 lbs is about limit for a dasher, cause it needs to recoil, What is you opinion on that? Is anybody having any luck using a 6 mm in a HG? And what is the weight if the answers yes?

40 is definitely not the limit. The one shown in the video above is a good bit over that. It was the winningest HG at PA last year. I don't think it was an agg winner, partially due to missed matches. But it was sure close. Won the most shootoffs by a good bit.

That is one of a group of very dedicated shooters, so, don't expect to see the sort of results they get without putting in a lot of time. They're serious.