Doppe skoonskuur / cases and abrasives? - Reloading Methodology https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/ AllGunStuff Discussion Board en-US Fri, 08 May 2026 13:08:36 +0000 wpForo 60 Re: Doppe skoonskuur / cases and abrasives? https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/paged/2/#post-3521 Wed, 27 Dec 2023 08:24:29 +0000                                 Every shot.]]> Reloading Methodology Treeman https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/paged/2/#post-3521 Re: Doppe skoonskuur / cases and abrasives? https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/paged/2/#post-3519 Wed, 27 Dec 2023 05:14:09 +0000 https://gundigest.com/gear-ammo/ammunition/experimenting-with-bolt-thrust

I found this quite interesting in the subject of bolt thrust and case taper.]]> Reloading Methodology Againstthegrains https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/paged/2/#post-3519 Re: Doppe skoonskuur / cases and abrasives? https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/paged/2/#post-3481 Sat, 23 Dec 2023 00:26:51 +0000

The MOD published guidelines on what a lubricated round would do in a smelly and why it was was to be avoided when proofing. The increase in bolt thrust was statistically significant to say the least.


Thanks, I would be surprised, if such an experiment was not done. I wonder of the taper on a case wall would exacerbate the situation, and a modern straight walled case would negate the problem?


Yes, the taper does make the problem worse.

Case taper and pressure are some of the factors that govern ease of extracting a fired case. If there is no taper, cases from mid to high pressure cartridges are difficult to extract. For that reason there are very few straight (parallel) wall cartridges. Those that exist are low pressure with a few exceptions. Most notable is the 5.7 which has a dry lubricant on the case to aid extraction. Cleaning those cases in a tumbler removes the coating and makes them unusable.

Excessive taper causes high bolt thrust and a loss of useable case volume. Also makes it difficult to design high capacity magazines.

Most historical designs have a pronouced taper. That is why PO Ackley could improve cartridges; "Ackley Improved" or AI. He found that reducing the taper and changing shoulder angles not only gave increased powder space, but also allowed a slightly higher chamber pressure.]]> Reloading Methodology janfred https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/paged/2/#post-3481 Re: Doppe skoonskuur / cases and abrasives? https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/paged/2/#post-3475 Fri, 22 Dec 2023 10:34:21 +0000 Thanks, I would be surprised, if such an experiment was not done. I wonder of the taper on a case wall would exacerbate the situation, and a modern straight walled case would negate the problem?


I'll try and dig the document out. It dealt with the procedures for poofing SLMLEs and was really interesting in a number of ways. One was that the Enfield action was up to a fair bit more pressure than legend would suggest. Another was the very strict instructions around chamber and cartridges being completely free of grease or oil due to the enormous increase in bolt thrust invalidating the results if they weren't. ]]> Reloading Methodology oafpatroll https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/paged/2/#post-3475 Re: Doppe skoonskuur / cases and abrasives? https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/paged/2/#post-3472 Fri, 22 Dec 2023 09:43:07 +0000
The MOD published guidelines on what a lubricated round would do in a smelly and why it was was to be avoided when proofing. The increase in bolt thrust was statistically significant to say the least.


Thanks, I would be surprised, if such an experiment was not done. I wonder of the taper on a case wall would exacerbate the situation, and a modern straight walled case would negate the problem?]]> Reloading Methodology Againstthegrains https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/paged/2/#post-3472 Re: Doppe skoonskuur / cases and abrasives? https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/#post-3468 Fri, 22 Dec 2023 01:49:39 +0000
The MOD published guidelines on what a lubricated round would do in a smelly and why it was was to be avoided when proofing. The increase in bolt thrust was statistically significant to say the least.

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Use a fireforming load, not a hunting charge]]> Reloading Methodology Treeman https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/#post-3468 Re: Doppe skoonskuur / cases and abrasives? https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/#post-3463 Thu, 21 Dec 2023 13:27:24 +0000 Reloading Methodology oafpatroll https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/#post-3463 Re: Doppe skoonskuur / cases and abrasives? https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/#post-3458 Thu, 21 Dec 2023 12:35:41 +0000
Has anybody done a study: lets take two identical rifles, and feed 1000 rounds of brass (factory finished with some rough tarnishing) as a control, and then feed the other gun 1000 rounds of the same brass that has been polished  to a gleaming shine, then examine the two rifles for bolt thrust damage. Perhaps add a third group, where the chamber/brass is lubed with something heat proof like molly or HBN. I'm sure in the past, when militaries where doing the early development work, there must be some data on this. Otherwise, this discussion is going nowhere.]]> Reloading Methodology Againstthegrains https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/#post-3458 Re: Doppe skoonskuur / cases and abrasives? https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/#post-3083 Sun, 12 Nov 2023 12:02:48 +0000
Lubing a cartridge is a very bad idea. It increases bolt thrust by at least the tensile strength of brass. Not something you want to do with a World War era rifle built to save steel.

An oiled cartridge is called the "poor man's proof load".

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Use a fireforming load, not a hunting charge]]> Reloading Methodology Treeman https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/#post-3083 Re: Doppe skoonskuur / cases and abrasives? https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/#post-3074 Thu, 09 Nov 2023 12:23:07 +0000
An oiled cartridge is called the "poor man's proof load".]]> Reloading Methodology janfred https://systemz.online/reloading-methodology/doppe-skoonskuur-cases-and-abrasives/#post-3074