Free floating barrel question

[mick53]

Hi,

How "free" should a free floating be?

I tried the dollar bill test and the bill slid down fairly easily between the barrel and the stock MOST of the way until it WAS 2-3" away from the end. Then the bill got hung up and I tore it.

The stock is synthetic so some gentle sanding would fix the problem, I believe.

My main question is, just how easily should the bill should slide between the stock and barrel?

I don't want to over sand that synthetic stock. Once the synthetic material is gone, it's gone.

Any tips as to how I should proceed will be very welcomed.

Thank you.

 

[somethingbenign]

I was going to write up a similar question about my long ranger. Only difference is my stock is wood.

 

[GooseGestapo]

Which end? Reciever end or forend?

Most factory rifle stocks, synthetic or wood, are bedded with a pressure point near the forend. Idea is that most sporter weight barrels favorably respond to some foreward pressure.

It’s a crap shoot as to whether it helps or not, to free-float the barrel. In my experience, if the rifle “strings” the shots, free floating likely helps. If groups are random, not likely.

First, try seating bullets to touch rifling with charge weights slightly reduced. If groups improve significantly. Free floating won’t help much. If shots continue to string, free floating is the next best option.

In my experience, free floating isn’t as effective without also glass bedding reciever. I usually do both at same time. I already have action out of stock and dremel in hand...

 

[mick53]

Which end? Reciever end or forend?

Most factory rifle stocks, synthetic or wood, are bedded with a pressure point near the forend. Idea is that most sporter weight barrels favorably respond to some foreward pressure.

It’s a crap shoot as to whether it helps or not, to free-float the barrel. In my experience, if the rifle “strings” the shots, free floating likely helps. If groups are random, not likely.

First, try seating bullets to touch rifling with charge weights slightly reduced. If groups improve significantly. Free floating won’t help much. If shots continue to string, free floating is the next best option.

In my experience, free floating isn’t as effective without also glass bedding reciever. I usually do both at same time. I already have action out of stock and dremel in hand...

I should have beem more specific. Sorry.

The bill got hung up towards the receiver end.

Just how freely should the bill be able to slide between the stock and barrel?

 

[GooseGestapo]

re: long ranger; has a two piece stock. Different animal altogether.

Be sure forestock doesn’t place pressure against reciever and stock attachment point. This will cause stringing as barrel heats. With magazine fed rifles, you are up against allowable length to feed through magazine.

My Browning BLR responded to switching powders. (Much like the LR) It’s a .358win. By switching to H4895, like magic, groups shrank by 1/2.
Ken Waters was right about the .358win and H4895!

 

[Slamfire]

I don't know an exact answer. I use thick card stock, NRA target paper, as a gauge. Recently this action came back from the gunsmith with a new barrel. I had the original featherweight barrel removed and a SAKO Finnbear contour installed. The SAKO barrel is attractive and heavier. Being heavier I had to inlet the stock channel. That required hours by the way, scrape a bit, try to install barreled action, remove barreled action, scrape a bit more, repeat. Towards the end I took 100 grit sandpaper and ran that through the barrel and stock channel. Rough side down against the stock. You know, that worked great, when it was a little tight, I was able to sandpaper out the slight obstruction. So my barrel channel clearance is the thickness of 100/150 grit sandpaper all the way to the receiver front. I don't remember putting bedding material under the chamber, I might have. I often do that, I think it makes the system more rigid.



This 270 Win was bedded in classic late 1940's/1950's fashion:the barrel was fully inletted into the stock. The guy who did it tried to create 100% contact between the barrel and the stock.





The rifle shot like this:







Those wild shots are typical of the flyers you get when the barrel bounces off the forend.

Free floating the barrel, bedding the action, made the groups circular:







greasing the cartridge reduced case stretch and jacket fouling.

 

[GooseGestapo]

I don’t like to be able to squeeze lightly by hand and make the barrel touch the stock.
My Weatherby Vanguard.257wby (synthetic stock) went from 1.5” 3-Shot groups to at/ under 0.5” by further releaving the free-float construction which allowed the forend to touch the barrel. It can be tightly squeezed to touch now, but when firing. It doesn’t vibrate/flex to touch.

 

[243winxb]

My Rem 40x is .025" from the factory. The Rem 600 carbine i did at .020" Both wood stocks measured with a feeler gauge.

When opening up a wood stock, take a little extra out to seal the wood. Polyurethane is thick.

2 business cards, about .020" (at least my cheap ones are)

 

[Art Eatman]

My experience with two "pet" rifles: I free-floated the forearm back to the front of the chamber. Maybe a tad over 1/16" except out at the tip. I then used a strip of wax paper, folded back and forth until it took maybe a four- or five-pound pull to allow this shim to be inserted. After heating from firing sorta melts the wax, I'm guessing that there was maybe a couple of pounds of pressure of the forearm tip against the barrel.

Both rifles were thereafter consistently sub-MOA for many and many a year and bunches of rounds through them.

 

[Varminterror]

The gap should be 60-80 thou, a 16th of an inch is sufficient.

A dollar bill is not nearly thick enough to ensure no contact can happen.

 

[someguy2800]

If this is a hunting rifle I wouldn’t worry about the rearmost 3 or 4 inches of the barrel. Everything forward of that should be floated far enough that light pressure on the forend will not make it touch. I taper the amount of clearance so at the rear it will be about a notecards width, and at the tip about 1/8”.

I’ve seen a few examples of guns that grouped well and were consistent with bedded barrels, but every rifle I’ve ever done it on has shot better with a floated barrel. Not just in group size but consistency as well, meaning they take little or no scope adjustment from season to season.

 

[jmr40]

Generally speaking free floated barrels shoot more consistently. Some shoot more accurately with some pressure, but they can also be erratic and change POI. Heavier barrels respond to free floating more than pencil thin barrels. For example some Mountain Rifle type barrels may shoot 1" groups with some pressure, and 1 1/2" groups free floated. But when floated they will always shoot to the same spot. With pressure on the barrel that 1" group could impact today quite some distance from where it did yesterday.

How much stock you remove depends. My Tikka CTR is extremely accurate with a very generous free float. About 1/8" up to 1/4". Guns with very flexible fore ends can shoot extremely well as long as the stock is quite some distance from the barrel to avoid contact. The stiffer the stock the less material that needs to come off the stock.

 

[MEHavey]

How far ? Free to within 1 - 1½" from receiver.
How free? Dollar bill ($5 if you want more clearance)
( )

 

[taliv]

barrels don't touch the stock on any of my bolt guns ever. some people have luck bedding the first inch or two of barrel.
as was stated above, i believe the clearance should depend on how flexible your stock is. if it's flexible and sling or hand pressure might cause it to get closer to the barrel, it will need more clearance than if it's a very rigid material.

 

[Slamfire]

I don’t like to be able to squeeze lightly by hand and make the barrel touch the stock.

I agree, light hand pressure should not allow the barrel to contact the stock. This is based on the assumption that the barrel vibration will not be equal to or greater than the deflection by a human hand.

I cannot see how the barrel bedding on something, like a pressure point, cannot cause strange vibrational patterns when the energy input changes. I have a 6.5 X 55 M70 and I did bed the action and leave the pressure point in the barrel channel alone. It shot exceptionally well with one low velocity load. Everything else it sprayed. Then I free floated the barrel, the rifle shot more consistently with different ammunition, really well with a couple of loads.



You know a Benchrest National Champion just pissed over my targets on another forum. Those guys had a 17 lb lightweight category, up to huge rifles that must weigh up to 100 lbs.He never showed me his 200 offhand groups with his benchrest rifle. I don't think those guys hold their rifles. I think this is pretty good for a lightweight hunting rifle at 300 yards:



This was not terrible:



Pretty good


Five shots in 4.5" at 300 yards is not shabby



Sometimes there are things that cannot be corrected by bedding or free floating the barrel. This rifle tube hates Remington Core Lokts.



This rifle was bedded and the barrel free floated, it did not like Rem Core Lokts





As much as the SMK

 

[Varminterror]

Barrels should float clear to the recoil lug - meaning the barrel should touch NOTHING but the receiver threads and recoil lug (for a pancake lug set up).

Chamber pads are popular, but that doesn’t mean they make sense. The chamber area will be the hottest part of the rifle, meaning greatest thermal expansion - so a chamber pad is a pressure point under the greatest expansion point in the barrel.

Forend pressure pads and chamber pads are bandaid fixes for bad inletting or bad receiver/barrel machine work. I made my living for a few years doing stock work for a group of local gunshop “smiths” (mechanics, really) and kept busy doing block and bed jobs. I have never seen a rifle which shot its best with any barrel pressure. When guys claimed such, 10min with a mag base indicator to check their inletting/action bedding revealed why it helped - as their bedding was wonky.

 

[jmorris]

i believe the clearance should depend on how flexible your stock is.

I agree with this.

I always shoot them first so I know if I did any good or if it’s even worth messing with.

 

[Picher]

I never shoot a new rifle of mine until after pillar and/or epoxy bedding and free-floating the barrel at least 1/16" everywhere exept about 1" up the barrel channel (to provide epoxy to lengthen the bedded area).

 

[Bfh_auto]

I don’t like to be able to squeeze lightly by hand and make the barrel touch the stock.
My Weatherby Vanguard.257wby (synthetic stock) went from 1.5” 3-Shot groups to at/ under 0.5” by further releaving the free-float construction which allowed the forend to touch the barrel. It can be tightly squeezed to touch now, but when firing. It doesn’t vibrate/flex to touch.

This is what I found to work best also. If you use a sling, make sure it doesn't touch under sling pressure.

 

[Captcurt]

Back in the good old days a floated barrel, if done correctly, was made with about 1/48-1/32" on the sides of the barrel. There was usually more clearance under the barrel, but it was hard to tell that the gun was floated by looking at it. That was a sign of precision stock work. Some smiths would glass bed the barrel channel to keep it from swelling or warping. They would hog out the wood, wrap the barrel with several layers plastic tape and slather it with release agent. Then ease it into the bedding material. After it set up they disassembled it and stripped the tape off leaving a reinforced forearm with a floated barrel. I once bedded a rifle and couldn't get the action out of the stock. One of my gunsmith books said to put it in a freezer overnight. It worked swell.

When the mass market started floating them they found it easier and cheaper to hog out the stock with many stocks having enough room to run corrugated cardboard under the barrel. It is unsightly and is a great place for weeds, grass, leaves and trash to accumulate. Many good stockmakers will glass bed the action and about 3 inches of the barrel channel. I had to do this when a Ruger 77 went soar on me. I floated the barrel, bedded the action, and also had to put a pressure pad about 3" from the forearm tip. My groups went from about 2 1/2" down to 1" -1 1/4".

 

[sugarmaker]

I float enough that a sharp palm whack upwards or downwards on the barrel does not cause any sound from some part of stock banging into any metal.