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DarylS
.700 member


Reged: 10/08/05
Posts: 26535
Loc: Beautiful British Columbia, Ca...
Re: Foam Filler = Ruined barrels ? [Re: 9.3x57]
      #103799 - 29/04/08 01:30 AM

My bro didn't enjoy shooting 122gr. of 2f with a 500gr. to 560gr. bullets in his 3-1/4" .45 cal. Sharps, so he developed a load of 95gr. 2F, with something like 8 to 10 .1" card wads to slightly compress the charge underneath the bullet. Accuracy was MOA and it didn't pound him quite as hard.
: There is a place for fillers, but they must be used correctly. Some fillers are not useable for some jobs, while others work for most jobs.
; Good poke, 9.3. I found a 275gr. cast bullet from my H&H would also kill a gopher - if you hit him right. Nice Columbia Ground Squirrel. About 1/2 size of a PD. Wish we had those, but alas, only Columbia's.

--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V


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Bill_Cooley
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Reged: 14/12/06
Posts: 197
Loc: Fort Worth, Texas
Re: Foam Filler = Ruined barrels ? [Re: DarylS]
      #103826 - 29/04/08 01:19 PM

I posted this on Accuratereloading.com on the same post on using filler and blowing up his Krieghoff barrels. I don’t think he used enough filler to take up all the space and got the results G Wright talked about the base of the bullet acted like a secondary obstruction in the chamber/ barrel.
Hear is my other post.

I have read this thread and found it quite interesting. I read up on this phenomena back when I was starting to reload as I was using a filler over the powder in my old 45-70 trapdoor and was afraid of damaging it. Charlie Dell’s work was helpful in understanding the problem. A problem I didn’t know existed until a friend cautioned me about it.
I think the problem is caused by the pressure front caused by the rapidly expanding gasses of the burning powder. With a over powder wad this becomes a part of the pressure wave hitting the back of the seated bullet resulting in the barrel obstruction syndrome. This is why filling ALL THE SPACE is important. This retards the pressure wave enough that you don’t have a problem. Uniform ignition is just a happy by product of doing this.
“Federal factory 470 ammo sometimes has large variation in velocity due to the position of powder in the case when the trigger is pulled.”
I wonder what would happen if you pulled some of these and used a foam filler as Kynoch does and see if it helps.
Bill[


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Ripp
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Reged: 19/02/07
Posts: 16072
Loc: Montana, USA
Re: Foam Filler = Ruined barrels ? [Re: Bill_Cooley]
      #103847 - 29/04/08 10:51 PM

Bill
its ironic that you mention the variation on Federal Factory ammo as I have chronographed it with the same results--sd is as much as 75 fps .... I have not experienced this with using filler on my reloads with RL-15...

Ripp

--------------------
ALL MEN DIE, BUT FEW MEN TRULY LIVE..


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DarylS
.700 member


Reged: 10/08/05
Posts: 26535
Loc: Beautiful British Columbia, Ca...
Re: Foam Filler = Ruined barrels ? [Re: Ripp]
      #103865 - 30/04/08 01:18 AM

SFD's of 75fps doesn't sound like much (as a number), but that represents spreads of velocities up to the 200fps range, shot to shot. Of course, this is totally unaceptable.
: Ripp has a solution, but as all solutions, just be used correctly as he is doing.
: Old loading manuals and articles by 'gun writers' can be misleading to downright dangerous in not used EXACTLY as shown. A certain picture from a manual or article comes to mind of one such occurance, in that it shows a sectioned .45/70 case, with a very small charge of dfast burning powder in the bottom of the case, held there with a tiny tuft of dacron. It is a long way from the bullet. Now, such a light, small tuft of dacron will never ring the barrel, but if you double the amount of dacron, still a long way from the bullet, or change the material to a heavier density filler, and have it off the bullet's base, problems can become real.

--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V


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Bill_Cooley
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Reged: 14/12/06
Posts: 197
Loc: Fort Worth, Texas
Re: Foam Filler = Ruined barrels ? [Re: DarylS]
      #103900 - 30/04/08 12:47 PM

Daryl,
I was doing exactly what you described in your post “that it shows a sectioned .45/70 case, with a very small charge of fast burning powder in the bottom of the case, held there with a tiny tuft of Dacron.” The load I was using was about 10 gr of Unique with a ¼ sheet of single ply tissue holding the powder over the primer. I never had a problem but I was only using a 300 gr bullet. Where the problem of ringed chambers became most evident was with the long range shootsen shooters who seated the bullet into the rifling then loaded a charge of powder in the case. They often used a fast powder with a card wad to hold the powder in place. Charlie Dell did a bunch of experimenting to determine the cause of the chamber ringing. He found he could ring a chamber with out using a over powder wad.
I noticed you were using cardboard wads in your BP loads. Just be sure to add the weight of the wads to that of the bullet when deciding on what charge to use. You have it right in you MUST fill the case and compress the powder.
Bill


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Ripp
.577 member


Reged: 19/02/07
Posts: 16072
Loc: Montana, USA
Re: Foam Filler = Ruined barrels ? [Re: Bill_Cooley]
      #103923 - 30/04/08 09:39 PM

Just an FYI---but the gentleman I got my info from that I am currently using and have for some time stated to use 5 to 6 grains of dacron --which is actually quite a bit and really does a pretty good job of filling in all the space in a .470 case.

Ripp

--------------------
ALL MEN DIE, BUT FEW MEN TRULY LIVE..


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450_366
.400 member


Reged: 17/01/07
Posts: 1068
Loc: Sweden, west-coast.
Re: Foam Filler = Ruined barrels ? [Re: Ripp]
      #103928 - 30/04/08 10:21 PM

Hi!

Is the mentioned powder fast or slow? A reduced load with a slow powder could blowup when the pressure doesent build up. Thats what I have been told anyway. If so perhaps the wadding wouldnt make a differense.

--------------------
Andreas

"Yeas it kicks like a mule he said, but always remember that its much worse standing on the other end"


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REN3
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Reged: 30/04/08
Posts: 31
Loc: Colorado, USA
Re: Foam Filler = Ruined barrels ? [Re: 450_366]
      #103937 - 01/05/08 12:17 AM

Look at Trail Boss powder from IMR. It is designed for low velocity heavy bullet loads for cowboy shooting. The powder has twice the bulk per ounce as other powders so you do not, and must not, use fillers. Great solution for practice loads. Bob.

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DarylS
.700 member


Reged: 10/08/05
Posts: 26535
Loc: Beautiful British Columbia, Ca...
Re: Foam Filler = Ruined barrels ? [Re: REN3]
      #103953 - 01/05/08 03:06 AM

Bill - with black powder loads, in order for the powder to burn correctly and give consistant results, the charge must alwasy be compressed. If not by the bullet, then by whatever wad you use. Soft wads cause spread standard deviations and are normally innacurate with BP.
: As noted in my post on the reduced charge in the BP case- my bro used 8 or 10 card wads of 1/10" thickness to 'compress' the powder charge.
: Yes - the weight of the cards adds to the weight of the other ejecta, which also includes roughly 57% of the powder charge's weight as solid waste. So- if you ware shooting 100gr. of black powder, with a 500gr. bullet, loaded with 30gr. of wads, you are actually shooting - 500gr. bullet + 57gr. solid powder waste + 30 gr. wads = 587gr. of ejecta.

--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V


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