266 grain cast bullet, the Dolomite special

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Oldphart
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Re: 266 grain cast bullet, the Dolomite special

Post by Oldphart »

Image

Image

These are the lead ring I was talking about. All the brass used is 2nd fired converted 300 blackout and I've been using bullets cast to .310 before these tests and never have had a lead ring before?

I can't pin point when it happens? I will continue to investigate this and get back to the board.
Oldphart
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Re: 266 grain cast bullet, the Dolomite special

Post by Oldphart »

Test done with Spikes upper, lower, BCG, 8.5 in Noveski barrel and a SilencoCo Omega suppressor.

Target set at 50 yards but had a devil of a time seeing the target. I figured I'd get to the range as early as it is open but alas I forgot in the summer, you look directly at the sun shooting downrange, so the first target leaves a lot to be desired. (it was much better for the second target) The temperature started out about 78 degrees but climbed to about 85 degrees while shooting the 2nd target.

All brass used was R&P(this was the second time this brass was fired as 300 blkout), BOAL 1.356, Winchester small rifle primers, 9.5 grs IMR 4227, one target COAL was 2.110 and the other was 2.120 and I just took the flare out of the case mouth. (no crimp)

Image

The ^^^^ target was shot with a COAL of 2.110 (1st target shot) The 10 shot was off the target, just above in the cardboard.

1. 989.4 6. 1005.2 hi SD 12.1
2. 972.6 lo 7. 1004.3 MAD 9.7
3. 984.6 8. 989.4 AVG 988.6
4. 984.0 9. 1003.5 ES 32.9
5. 979.0 10. 974.3

Image

The ^^^ target shot with a COAL of 2.120 (2nd target shot)

1. 1002.3 6. 998.2 SD 5.5
2. 1001.3 7. 1002.3 MAD 4.1
3. 1001.2 8. 991.2 lo AVG 1006.0
4. 1010.2 hi 9. 1007.4 ES 19.0
5. 992.1 10. 995.7

Any questions or suggestions, appreciate all the feedback


Phil
2manyToys
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Re: 266 grain cast bullet, the Dolomite special

Post by 2manyToys »

Oldphart wrote:Image

Image

These are the lead ring I was talking about. All the brass used is 2nd fired converted 300 blackout and I've been using bullets cast to .310 before these tests and never have had a lead ring before?

I can't pin point when it happens? I will continue to investigate this and get back to the board.
I had this happen before I started sizing PC'd cast bulltets. They were .311 to .312 before sizing, .3105 after sizing. Problem solved.
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Dolomite_Supafly
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Re: 266 grain cast bullet, the Dolomite special

Post by Dolomite_Supafly »

Oldphart wrote:Image

Image

These are the lead ring I was talking about. All the brass used is 2nd fired converted 300 blackout and I've been using bullets cast to .310 before these tests and never have had a lead ring before?

I can't pin point when it happens? I will continue to investigate this and get back to the board.
Do what I suggested and the problems should go away. Your accuracy should improve too.
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Dolomite_Supafly
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Re: 266 grain cast bullet, the Dolomite special

Post by Dolomite_Supafly »

BTW, those rings are not caused by my bullet. They are caused when the bullet is not sized correctly for the chamber. The brass being too short can also contribute to those little lead rings.

On a another not, I will now be offering free palm readings as I have taught myself to become clairvoyant. Or if some of you prefer, rebel, I can just sit and hold your hand.

From a PM sent May 24th to Oldphart----
Dolomite_Supafly wrote:Those bullets are designed to be .309" because that is the throat diameter of a SAAMI spec Blackout chamber. It probably won't be an issue at .310" but in some guns the chamber can have a sharp edge at the transition from case neck to throat. This can strip the coating from the bullet and cause leading. Normally you see little lead rings when this happens.
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rebel
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Re: 266 grain cast bullet, the Dolomite special

Post by rebel »

Dolomite_Supafly wrote:BTW, those rings are not caused by my bullet. They are caused when the bullet is not sized correctly for the chamber. The brass being too short can also contribute to those little lead rings.

On a another not, I will now be offering free palm readings as I have taught myself to become clairvoyant. Or if some of you prefer, rebel, I can just sit and hold your hand.

From a PM sent May 24th to Oldphart----
Dolomite_Supafly wrote:Those bullets are designed to be .309" because that is the throat diameter of a SAAMI spec Blackout chamber. It probably won't be an issue at .310" but in some guns the chamber can have a sharp edge at the transition from case neck to throat. This can strip the coating from the bullet and cause leading. Normally you see little lead rings when this happens.
Yeah I spit 'baccer leaves in your palm and read them. :mrgreen:
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45r
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Re: 266 grain cast bullet, the Dolomite special

Post by 45r »

You can smooth your throat using the Tubb's 30 cal lapping bullets kit but I would think a noveske wouldn't need it.
Noveske barrels use polygonal rifling and might not like cast bullets.
I trim my brass to 1.368 or a little more to lessen the gap between case mouth and throat.
I've gone to 1.378 but that is max according to the sammi spec's.
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Dolomite_Supafly
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Re: 266 grain cast bullet, the Dolomite special

Post by Dolomite_Supafly »

rebel wrote:
Dolomite_Supafly wrote:BTW, those rings are not caused by my bullet. They are caused when the bullet is not sized correctly for the chamber. The brass being too short can also contribute to those little lead rings.

On a another not, I will now be offering free palm readings as I have taught myself to become clairvoyant. Or if some of you prefer, rebel, I can just sit and hold your hand.

From a PM sent May 24th to Oldphart----
Dolomite_Supafly wrote:Those bullets are designed to be .309" because that is the throat diameter of a SAAMI spec Blackout chamber. It probably won't be an issue at .310" but in some guns the chamber can have a sharp edge at the transition from case neck to throat. This can strip the coating from the bullet and cause leading. Normally you see little lead rings when this happens.
Yeah I spit 'baccer leaves in your palm and read them. :mrgreen:
At least it ain't in my eye.
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Brettitt41
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Re: 266 grain cast bullet, the Dolomite special

Post by Brettitt41 »

So any new developments? Have these made it to market yet? I have a CVA Scout and some pistol powders burning a hole on my bench looking for projectiles. :mrgreen:
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Oldphart
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Re: 266 grain cast bullet, the Dolomite special

Post by Oldphart »

45r wrote:You can smooth your throat using the Tubb's 30 cal lapping bullets kit but I would think a noveske wouldn't need it.
Noveske barrels use polygonal rifling and might not like cast bullets.
I trim my brass to 1.368 or a little more to lessen the gap between case mouth and throat.
I've gone to 1.378 but that is max according to the sammi spec's.
I contacted Noveski before I bought their barrel(s). I planned on using cast bullets and knew I didn't want polygonal rifling. They advised me their 5.56 barrels have polygonal rifling but their 300 black out do not.
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