1/20 and nose slump ...

Hi

FWIW...

Last spring, I recovered bullets that I shot in the snow in January 2018.

- Fire line at 600 yards
- Shiloh Sharps 45-90
- Bullet: Creedmoor 45001, 539 grains. casted tin-lead 1-20 (5%)
- Powder Old Eynsford 1 1/2 , 81 grains
- Starline brass: fireformed.
- Lube: SPG. Newspaper wad, LDPE 0.60 wad


I recovered 24 bullets of which 2 had their newspaper wad stuck at the base. Some had still the lube in the grooves. ( I am not an expert eith the cam ...). Just a few were shorter by no more than 0.015 inch. Most were longer.


Still worth to think to cast 1-16 ? …


https://i.imgur.com/YI00BQO.jpg

Wish you had some 16/1 to compare. Is there any nose damage on the short ones?

There was an interesting article on boolit deformation and it’s effect on accuracy where noses were intentionally deformed. According to the article noses deformed more dramatically than we would see still shot accurately. A minor deformation to the base of the boolit significantly affected accuracy. We wipe the lube off the base of the boolit to prevent wads from sticking to the base of a boolit and hampering accuracy.

So, how was the accuracy?
As you know, that is a good measure.
Also as pointed out, trying the harder alloy and comparing groups under fair conditions may tell the whole story.

In my experience, the strength of 20-1 or its alloy hardness equivalent, is enough to hold bullet noses like the 45001.
The high Bc, long nosed bullets require harder alloys to hold up to the inertia.

Dan Theodore did substantial testing of 1:16 alloy including an extensive article in the BPCR News and several detail posts on the Shiloh Rifle Forum. That's the only alloy I use for BPCR reloads

Quote:

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Originally Posted by kokomokid

Wish you had some 16/1 to compare. Is there any nose damage on the short ones?

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I recovered the 20-1 ones shot in the last winter to see if I need to cast 16-1 bullets, so I do not have any 16-1


Here are the photos of two of the shot ones: no 2 and no 16: I do not see any nose damage...


https://i.imgur.com/UXG6hOe.jpg

https://i.imgur.com/Rvbj1z2.jpg

Quote:

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Originally Posted by Chill Wills

So, how was the accuracy?
As you know, that is a good measure.
Also as pointed out, trying the harder alloy and comparing groups under fair conditions may tell the whole story.

In my experience, the strength of 20-1 or its alloy hardness equivalent, is enough to hold bullet noses like the 45001.
The high Bc, long nosed bullets require harder alloys to hold up to the inertia.

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I will do some tests, but I will wait after the annual Canadian Championships, as all my elevation numbers are with the 45001 bullet.

The accuracy I get with the 20-1 45001 bullet are around 1 1/4 MOA when I do my part...

Quote:

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Originally Posted by John Boy

Dan Theodore did substantial testing of 1:16 alloy including an extensive article in the BPCR News and several detail posts on the Shiloh Rifle Forum. That's the only alloy I use for BPCR reloads

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I would love to read this article. Where may I find it ??

Quote:

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Originally Posted by Etienne Brule

I will do some tests, but I will wait after the annual Canadian Championships, as all my elevation numbers are with the 45001 bullet.

The accuracy I get with the 20-1 45001 bullet are around 1 1/4 MOA when I do my part...

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This is just my opinion; if you are regularly able to put all your shots into 1.25 MOA, especially at the longer distances, your bullet and alloy are doing well together. I am not sure a change into a harder alloy will get you anything. Certainly try it and see!

I don't think the creed moor nose shape would benefit much from 16-1, but it might. I would suggest you wait until after your big match to make and changes if you're getting that sort of groups, and then after the match do some testing with different alloy.

Can you tell me what your lead was, pure? recycled from the scrap yard? or the lead containers the radiation medicine is shipped in ?

Quote:

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Originally Posted by Lead pot

Can you tell me what your lead was, pure? recycled from the scrap yard? or the lead containers the radiation medicine is shipped in ?

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It was pure lead.

Very good.
The reason I asked is I don't see results like you have posted. but I don't shoot greasers to often. Here is a sample of some 1/20 alloy I got from Rotometals but this bullet was the mini grooved money bullet that took a hard setback with 1/20 supposedly pure from Rotometals.

I have some PJ 45001 records from back around 2005 I shot with very hard monotype to soft I can dig out that might have some 1/20 used for comparison.
Attachment 224361

The Bullets Flight - Franklin W Mann has extensive information on how accuracy is affected by bullet damage - nose, base, much more - old but still relevent.