I know we covered this before on Shooters, but my memory is getting fuzzy. What is that thin aluminium tape made for? Where do you find it? Any brand names? Casting season will be upon me shortly and I want Beagle a mould or two.

I don't have a brand name but most of the big box home improvement stores carry it. It's called AC duct tape.

Mike

I found my roll in a heating/ventilation/air conditioning supply store--none of the big box hardware places had it in my area. The store called it "aluminum tape", and there were three or four thicknesses available.

It's handy stuff, and it's adhesive backing is its most amazing element. I've cast with little bitty pieces of the tape on block faces, and it sticks like crazy without melting out or running at 800 degree casting temps.

The "Beagling" has saved me the cost of having molds made or modified for the fat 30 rifles and fat 38 revolvers. Truly good stuff.

Deputy Al,

Have you used any thickness other than the .003 as first recommended by beagle?

Wondering if flashing shows up with thicker tape.

Regards,

I've beagled way out there on a 12ga mold. I think I went out .020. Once the mold was hot, I cooled a bit and poured slowly from a bit higher and they cast okay. If I cast too fast, then I got big wings, that I had to break off. I ended up drilling and tapping 4 holes in the LEE mold and putting set screws in it for a more permanent shim for my 70cal Howdah. I suppose I could lap it out, but just haven't.

Charles...my supply came from a plumber. They use it for something. It's also used in the aircraft sheet metal industry.

If you can't find any, drop me an e-mail and I'll mail you enough to last a few years./beagle

I had all my air ducts renovated by some in the know guys. That silver tape is all they used, because the so called typical duct/duck tape self destructs in just a few years and is just about worthless. Yes, the heating/cooling capacity of the system just about doubled after all the rotton tape was stripped off. Electrical bills were cut by a third over the summer with no hot spots remaining in the house. Well worth the effort/cost. ... felix

I've had the same results that Lar45 reports using two thicknesses of the .003" tape on block faces. I slowed the flow rate from the bottom pour furnace, and the wings went away.

Any evidence to prove/disprove the resulting out of round condition on the land rider nose and gas check shank has any accuracy effect (either way)?

I sometimes "sweat it" over out of round conditions of a thousandth on my hand-lapped mold jobs. Am I wasting my time sweating this particular little detail?

Veral, did you lead me astray AGAIN?

You guys are intentionally dialing in .003" .006", .010" and a whopping big .020" of pure intentional out of round TIR into the cast bullet form and are saying "because it is dynamically balanced it has no big detrimental effect" when the bullet is fired.

(That gas check shank is oval too, BTW).

You are saying the increase in size (taking out the clearance slop to the bore) totally overpowers the oval form effects of the oval bullet bore rider nose and the oval gas check shank?

A reality check is needed here - somebody's mental paradim about fit-up is going to change a bit over this one, I think.

Who knows? It may be mine.

Oldfeller

Kelly,

The way I've read it when you size the boolit either in a sizer or in the barrel it further minimizes the out of round condition. Am I missing something?

Mike

Just like balancing a wheel with WWs. However, even if it is oval going in, will it still be oval coming out? Especially if it is over groove size...? Boolit deformation can be a good thing as well as detrimental. sundog

JEEZZZ, and I was sweating 2-3 tenths out of round? I sent a sizer back to Lee because it was 4-5 tenths out of round! Maybe too much rubber in my alloy.
Regards Jeff

Oldfeller....I'm like you are, I like things to dimension and rounded when you chamber them. However, saying that, I know there are exceptions in the casting and shooting game. Look at the hexagonal stuff Buckshot's playing with. Look at the internal voids on big 45s for the BPCRs and they're shooting these at 800 and sometimes 1,000 yards.

I'm not sure it makes any difference. When you light off the powder under a cast round, as long as the bore seals, things will usually right themselves. Recovered GCs shot in a MG Marlin into steel plates show distinct MG rifling impressions if recovered....and they're deep. No matter what the base looked like when you fired it.

We once intentionally mutilated the noses on about 200 rounds of match 22LR. These were done in 4 different batches in different ways to different degrees. Orienting the defect when chambering in M52 Wincheter target rifles and firing from a prone position at 50 feet indoors produced groups equal to unmutilated match ammo. Random chambering of the mutilated noses produced groups that were round but about twice the size of the normal match ammo. So, as long as things start on an even keel, the bullet stability will take care of some of the problems provided the starting position is consistent.

Imagine a cast bullet as an arrow with the bands being the fins (feathers) If we were able to fire this bullet without any firing distortion at very low speed, the bands would act as feathers on an arrow and more or less guide the bullet to our target. Now, we'll all say that this won't work as the "arrow" is too short and won't stabilize. Correct; but, we induce more spin around the shaft and make it stabilize or nearly so. If the spin is sufficient for the length and diameter, it will. If the spin is too fast, any imperfections in the bullet, base or any intenal voids will be amplified and cause instability and give us larger groups.

This was the thinking back when Pope played with his 32-40s. Don't size, this unbalances the bullet. This was true back then and velocities were sometimes in the 1200 FPS realm and sizing dies were not designed to turn out concentic bullets like they are now. This is where the don't size rule came from. It worked as some of those old records still stand.

Today, we know more about casting and ballistics and equipment is better. Does the out of round make a difference? I don't know but I have shot 1" groups with .25 100 grain bullets that had the noses visibly bent and I didn't bother orienting them either.

In revolvers, I don't think it makes a tad of difference as you're booting that bullet up to chamber diameter, then a jump, then swaging down to barrel diameter in a fraction of a second and they work pretty good even out of round.

So, after saying all this drivel. I don't like it but I don't think it makes any difference. Throw the theories out of the window./beagle

Beagle Tape now has a name. The first air conditioning supply house I called had all sorts. There are three different aluminum tapes sold at such places. The one we want is .003 thick and is Fasson 0802 - Foil Sealant Tape. It is made by Avery Dennison Specialty Tape Division in Paynesville Ohio. a 2 inch by 50 yard roll (which should last a lifetime) cost me $5.50. Happy Beagling to you all!

Outa' round, no problem. Off balance, make them a fishing weight. ... felix

OK, I can see the driver bands surfaces get sized to pretty much back to round (but the lube grooves come and go and some hard lead spring back does play a bit here and there) and I can see upon firing the oval gas check shank probably "upsets" to fill the gas check and becomes effectively nice and round.

I can see this overall ovality thing would not hurt a wall-filling lovern design very much, as on most mil-surps the throat OS will size the entire thing down .003"-.004" more and obliviate even more of the beagling effects.

And it would be well balanced, that oval loverin.

Say 'given' to all of those, then. Heck, I will concede that with a sufficent load the gas check area and all the driver bands can get slugged up to precisely fit the bore wall, even on a bore rider design that is sized to exact bore diameter.

But a land rider nose that is land riding only on two opposing contact patches? One of which hits on the top of a land and the other settles in the groove between a pair of lands (5 groove rifling)?

hmmmmmm .....

It would only affect what, .303 Enfields? Which guns are 5 groove designs?

Oldfeller

[ 09-10-2003, 20:54: Message edited by: Oldfeller ]

Oldfeller, that very well could cause an outa' balance problem, those 5 groovers/landers shootin' land riding nose boolits that actually touch the lands on the boolit nose. But how deep the penetration? A thou, probably not much effect at a hunnert or two. ... felix

The thought on my LEE 12ga mould was to get it to seal the bore. I oriented the wad slot to run from one block to the other so it would be the right size, then the skirt could blow out to fit the bore. ????????????? At this point, I'm happy to make smoke and hit the target. I'd like to be able to reach out to 50-75 yds though.

I did beagle my 54 minnie mold out about 10thou and it shot good, so I lapped it out and it still shoots good.

The thing I wonder about is how much of a lube groove do you actually need? I have a 45 SWC 340gnish with an almost solid shank, just a slight impression where the lube groove should be. I've shot it out of my 454 and got wonderful 50yd accuracy with no leading. I did wipe a little lube on the shank before loading though. ??????????????