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Double Rifles, Single Shots & Combinations >> Double Rifles
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Palmer
.224 member


Reged: 06/07/04
Posts: 15
Loc: Missouri
COL make a difference?
      #34283 - 04/07/05 04:35 AM

I've heard it said that cartridge overall length does not make much difference in a double rifle as long as you can still crimp the bullet.

Why does it not make much difference?

--------------------
ALLEN W. JOHNSON

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NE450No2
.375 member


Reged: 10/01/03
Posts: 942
Re: COL make a difference? [Re: Palmer]
      #34289 - 04/07/05 06:01 AM

Anything that changes the barrel vibrations and/or the barrel time can effect how a rifle shoots.

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500Nitro
.450 member


Reged: 06/01/03
Posts: 7244
Loc: Victoria, Australia
Re: COL make a difference? [Re: Palmer]
      #34290 - 04/07/05 06:10 AM

Palmer

I tend to disagree - I have a couple of Double rifles that shot well withn acceptable
expectations. Once I had them shooting, I decided to play around with the Bullet seating
depth that of course affects the COL.

I found that I could improve the accuracy even more of some of the Double Rifles.

I think from talking to others that it has to do with BARREL TIME, the amount of time
the bullet spends in the barrel which with a double rifle has a direct bearing on the regulation
and therefore accuracy.

Also, re crimping, I generally DON'T Crimp ammo, I just make sure that when I resize
the necks of cases that it does so in a way that leaves the bullets tight enough to hold well
without crimping.

Only very occasionaly have I had the bullet push into the case and it often tunred out
to be a case on the verge of throwing out due to too many reloads and thin neck brass.

Hope this helps. What I have found is not necessarily gospel and varies from person
to person.

500 Nitro

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Palmer
.224 member


Reged: 06/07/04
Posts: 15
Loc: Missouri
Re: COL make a difference? [Re: 500Nitro]
      #34294 - 04/07/05 07:00 AM

So I take it from both your replies that COL might make a difference in accuracy after all. That makes sense to me but it brings up another bit of confusion on my part.

I have been seating the bullet so that I could crimp into the cannelure. That distance could be varied a little by the trim length of the case -- but not much.

If one is to crimp into the cannelure it doesn't seem that cartridge overall length can be varied significantly.

I also have been under the impression that unless the bullet is crimped, the recoil from the firing of one barrel could possibly dislodge the bullet from the case in the other (unfired) barrel.

Can one rely on uncrimped bullets in a 470 in a dangerous game situation?

--------------------
ALLEN W. JOHNSON

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500Nitro
.450 member


Reged: 06/01/03
Posts: 7244
Loc: Victoria, Australia
Re: COL make a difference? [Re: Palmer]
      #34296 - 04/07/05 07:19 AM

Palmer

I answer to your question

"I also have been under the impression that unless the bullet is crimped, the recoil from the firing of one
barrel could possibly dislodge the bullet from the case in the other (unfired) barrel."
Can one rely on uncrimped bullets in a 470 in a dangerous game situation? "

As I said in previous post, I generally DON'T Crimp ammo an that includes 465, 470 and 500
Nitro's in doubles.

HOWEVER, to reiterate, you do need to make sure that when you resize the case and / or necks of cases
that it does so in a way that it is tight enough to hold the bullets tight enough under recoil and running
around after game.

I don't recommend this for everyone but it works for me and I hunt with large calibres in DR's
and Bolt guns on a regular / yearly basis.

Hope this answers your question. Ask away if you have any more.

500 Nitro

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André
.333 member


Reged: 28/06/04
Posts: 254
Loc: Brussels (Belgium)
Re: COL make a difference? [Re: 500Nitro]
      #34316 - 04/07/05 06:14 PM

500Nitro,
No doubt that COL may improve the accuracy of the individual bbls., like with single-barreled rifles. However I seriously doubt it can substantially improve barrel regulation, which is a matter of muzzle convergence. The latter is adjusted by trial and fire after pulling out (shooting apart) or pushing in (crossing) the bbl. wedge. Does your experience invalidate my thinking ?


--------------------
André
---------------------------------
3 shots do not make a group, they show a point of aim or impact.
5 shots are a group.

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500Nitro
.450 member


Reged: 06/01/03
Posts: 7244
Loc: Victoria, Australia
Re: COL make a difference? [Re: André]
      #34318 - 04/07/05 07:30 PM

André

Does your experience invalidate my thinking ? No and Yes !!!

I fully understand how doubles are regulated (ie made and then barrels regulated by
the methos you say).

I wouldn't say that it can "substantially improve barrel regulation".

Wha I would say (and did in my previous post) is reposted below:-

"I have a couple of Double rifles that shot WELL WITHIN ACCEPTABLE EXPECTATIONS
Once I had them shooting, I DECIDED TO PLAY with the Bullet seating depth that of course affects the COL.

I found that I could improve the accuracy even more of some of the Double Rifles."

What this meant is that instead of 1.5 - 2" apart, I found that some of the rifles came together
really close - 1". Nothing else changed.

I will comment however that I am NOT talking about 1 - 2 thou difference in bullet seating depth
but more like 4 - 6 thou - it partly depended on where the rifling started.

It obviously affected barrel time but I just found the "sweet spot" !!!

On the other hand, I hav other double rifles that shoot the same with 4 - 6 grains of powder
difference (500 Nitro's being a good example).

Hope this answers your question.

500 Nitro

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Palmer
.224 member


Reged: 06/07/04
Posts: 15
Loc: Missouri
Re: COL make a difference? [Re: 500Nitro]
      #34320 - 04/07/05 10:31 PM

500Nitro,
Thanks for the report of your findings. I will experiment with mine and see if it makes a difference.

What I find fascinating about double rifles is that each seems to have its own personality and temprement.

Are they all female?

--------------------
ALLEN W. JOHNSON

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500Nitro
.450 member


Reged: 06/01/03
Posts: 7244
Loc: Victoria, Australia
Re: COL make a difference? [Re: Palmer]
      #34321 - 04/07/05 10:57 PM

Palmer

What I find fascinating about double rifles is that each
seems to have its own personality and temprement."

You can say that again - tenfold !!!

When I get a new double, after getting it checked out by the gunsmith
I do the usual standard reloads and head off down the range. In the majority
of cases all well and good, guns shoot OK and I go on from here.

However some of my doubles are (or were) tempremental / sensitive and it took a couple
of tries to find the right load / formula etc ... you know what I mean.

I am NOT one who does unlimited experimentation once I have a gun shooting, however
from memory it was partly by accident / partly by trial that I found that the seating depth
affected the accuracy of certain doubles - I think the intial one was a 450/400.

"Are they all female?"

I called all mine "old girls" so I would tend to agree with you.
On the basis of temperment - definately !!!

One thing I have found is that the larger the calibre the easier they are to get to shoot.
500 Nitro's being the easiest - only had to reload for one 600 Nitro and that was a breeze.

Any comments from your experiences ?

Hope this helps.

500 Nitro

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1885
.275 member


Reged: 27/12/04
Posts: 92
Loc: Edmond, OK, USA
Re: COL make a difference? [Re: Palmer]
      #34325 - 05/07/05 12:28 AM

One other thing to remember...and I'd think it would be quite important. Bullet seating depth also causes increases/decreases in pressure. A bullet seated deeper in the case causes an increase in overall pressure...not necessarily a good idea in nice old rifles.

Consequently, .500's recommendation about neck tension is important. If you fire one barrel that might cause the bullet, for some strange reason, to seat deeper into the case, the result is a potentially significant increase in pressure in the second shot.

By the way, does anyone have the factory OAL for the .450/.400 3-1/4" NE?

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Palmer
.224 member


Reged: 06/07/04
Posts: 15
Loc: Missouri
Re: COL make a difference? [Re: 1885]
      #34330 - 05/07/05 01:23 AM

500

"the larger the calibre the easier they are to get to shoot.
Any comments from your experiences ?"

Are we talking about women or double rifles now?

What little experience I have has indicated that owning more than one at the same time can lead to confusion and complication.

Both seem to have limited use but when you want one logic does not prevail - at least that has been my experience.





--------------------
ALLEN W. JOHNSON

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500Nitro
.450 member


Reged: 06/01/03
Posts: 7244
Loc: Victoria, Australia
Re: COL make a difference? [Re: Palmer]
      #34337 - 05/07/05 06:05 AM

Palmer,

Are we talking about women or double rifles now?
Very funny - it made me have a good laugh this morning anyway.

Firstly, as 1888 says, seating the bullet deeper can / DOES cause
an increase in pressure so to those who reload - beware !

Re confusion and complication - I had the same problem once when
trying to get a gun to shoot when I was new to all this - I changed more
than one thing / component and eneded up over 2 weekends totally confusing myself
as I didn't know which change had caused the improvement !!!
It was a 450/400.

I ended up going back to the starting load and bingo, got it very quickly.

I THINK the gun I have been talking about is a 450/400 3 1/4" Lancaster Sidelock
Ejector that now belongs to a friend in the US who then went to Africa and shot an
Elephant, Buffalo and Lion. Obviously the loads I gave him were correct !!!
He was happy.

500 Nitro

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Palmer
.224 member


Reged: 06/07/04
Posts: 15
Loc: Missouri
Re: COL make a difference? [Re: 500Nitro]
      #34338 - 05/07/05 07:22 AM

500
I also have a Jeffrey 450/400 but thankfully it is shooting fine so that does not add to the confusion.

I am currently preparing for an elephant safari to Tanzania in 6 weeks so am limited in the time to experiment with the 470.

I do want to try some different seating depths for it but I will probably stay with a light crimp for the time being because I would not have enough time to become confident of the neck sizing required to go without crimping.

I appreciate your information.

--------------------
ALLEN W. JOHNSON

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unspellable
.300 member


Reged: 06/03/04
Posts: 187
Loc: Iowa
Re: COL make a difference? [Re: Palmer]
      #34391 - 06/07/05 10:47 PM

Elmer Keith claimed that bullet seating depth had an effect on regulation and it was a trick he sometimes used to bring a stubborn case into regulation. I forget all the details but I seem to remember he usually seated the bullet further out than normal in such cases.

Edited by unspellable (06/07/05 10:48 PM)

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Marrakai
.416 member


Reged: 09/01/03
Posts: 3591
Loc: Darwin, Top End of Australia
Re: COL make a difference? [Re: 1885]
      #34618 - 12/07/05 07:39 PM

1885:
In reply to:

By the way, does anyone have the factory OAL for the .450/.400 3-1/4" NE?


Bill Fleming probably measured more than anyone, and lists the OAL of the NE cartridge as 3.857 min, 3.875 max.
He lists the BPE cartridge as 3.783 min, 3.800 max.
The non-express BP cartridge he measured was 3.685.

George Hoyem, on the other hand, is a 'lumper', and gives the range for all variants of .450/.400 3 1/4 as 3.57 to 3.87 inches.

Hope this helps.

--------------------
Marrakai
When the bull drops, the bullshit stops!
--------------------------------
www.marrakai-adventure.com.au

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1885
.275 member


Reged: 27/12/04
Posts: 92
Loc: Edmond, OK, USA
Re: COL make a difference? [Re: Marrakai]
      #34641 - 13/07/05 09:45 AM

Thanks, Marrakai, that helps. I'll be loading up some NE loads soon and will keep the info in mind.

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