jasent
Well-Known Member
Some where I once read about a guy using kerosene as a brass lube while fire forming to reduce brass growth. Any once else heard of this or tried it?
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Forming 375 Ruger brass from 8x68s cases
- Thread starter yorke-1
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It's not kerosene, but it's what I stumbled into and use for cream of wheat fire forming. Only for C-O-W. It helps ensure cases are fully formed to the chamber with a lower pressure powder charge.
jasent
Well-Known Member
yes that's what I meant.
Wild Monkey
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Here's the results from the forming I got done today. All cases were trimmed to 2.600" and formed using a false shoulder sized for a crush fit in the chamber. Everything was fired from a 338/375 Ruger Savage Striker.
Brass dimensions are an average of 10 samples of each brand. Norma and RWS case are capacities after a single fireform load.
Hornady 375 Ruger brass
Empty case weight: 262.2gr
H20 capactiy: 100.1
Norma 8x68s
Load: 22.8gr Trailboss, 277gr MTAC, CCI BR2
Empty case weight: 282.6gr
H20 capacity: 95.5
Length after forming: 2.585"
RWS 8x68s
Load: 21.8gr Trailboss, 307gr Hammer Hunter, CCI BR2
Empty case weight: 274.6gr
H20 capacity: 96.4gr
Length after forming 2.582"
I love the fact that I recovered a couple of the bullets in the dirt bank. Muzzle velocities are around 1900 fps and the bullets obviously didn't stabilize. The interesting part was that they grouped fairly well considering they're un-stable and the group was shot by my 16 year old daughter at 100 yards.
Are those the case H2O capacities after fire-forming them to 338-375R?
I don't see much difference in case head strength between the Norma and RWS 8x68S brass I recently tested. I measured and monitored case rim expansion during load development while working up to, and past, maximum pressure loads. Was measuring MV while firing the identical bullets in both brands of cases. So I knew I had equivalent chamber pressures based on equivalent MVs.
Case rims begin to expand at very similar MVs. The RWS is very slightly stronger at the case head and primer pocket, based on my testing. I expected the RWS to be clearly tougher. But had to conclude it was only slightly stronger.
Case rims begin to expand at very similar MVs. The RWS is very slightly stronger at the case head and primer pocket, based on my testing. I expected the RWS to be clearly tougher. But had to conclude it was only slightly stronger.
Those are after fire forming. They'll gain a little more capacity after a full power load, but not much.
That's the right way to do it!
Wild Monkey
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Evidently Norma 8x68S brass is being sold on the retail market in different grades when it comes to dimensional tolerances. Which was somewhat surprising for me. I didn't know Norma was marketing unprimed casings in different quality control batches. Here's what I determined as well as how I determined it:
I purchased 20 Norma cases from Huntington Die Specialties around 4 months ago. They came in a 20Ct plain-Jane white cardboard container without any separation within the box. All cases were in direct contact with one another.
I purchased 50 casings from Midway USA about 1 1/2 months ago. They came in 25Ct fancy norma USA cardboard boxes, each case separated by individual cardboard slots and covered with a piece of foam to keep them from rattling and banging against one another during storage and shipment.
The Hungtington cases looked a bit rough to me. Additionally one of the 20 casings came with an oversized primer pocket which was so large that one could see the flaw with the naked eye. It was about 0.015" over-sized, which meant a primer would rattle around loose in the primer pocket. A defective primer pocket straight from the Norma factory. Huntington replaced that case sight unseen, so good on them.
The Midway USA cases looked highly uniform and polished in comparison. So I set about weighing all of the cases, both from Huntington's and Midway USA. I also measured the cases for pertinent dimensional tolerances. The Midway USA cases are clearly the premier casings, based on both weight and measurement tolerances.
For those with the interest, following is a tabular chart I created to illustrate the differences between the two sources of Norma 8x68S casings. Even though I weighed 50 Midway USA sourced cases, compared to 20 Huntington sourced cases, the Midway USA cases still had an extreme spread in case weights which was 60% less than the Huntington cases. Also note the difference in the outer diameter dimensions of the extractor grooves and rims. The OD of the case webs just forward of the case rims was exceptionally consistent on the 50 Midway USA cases. I measured a sampling of 20 case web diameters and all measured right at 0.5180" diameter, except one case, which measured 0.5175", on my Mitutoyo digital calipers, which read out down to 0.0005". The Huntington brass varied in the case web diameter dimension so much that I simply averaged them when I collected those measurements several months ago.
Never set out on a mission to critique the quality of the Norma cases from the two different sources, but it is what it is. And if we don't share these findings on a Forum such as this one, then we all end up less knowledgeable than necessary. No apologies here to either of my two sources of Norma 8x68S casings.
I purchased 20 Norma cases from Huntington Die Specialties around 4 months ago. They came in a 20Ct plain-Jane white cardboard container without any separation within the box. All cases were in direct contact with one another.
I purchased 50 casings from Midway USA about 1 1/2 months ago. They came in 25Ct fancy norma USA cardboard boxes, each case separated by individual cardboard slots and covered with a piece of foam to keep them from rattling and banging against one another during storage and shipment.
The Hungtington cases looked a bit rough to me. Additionally one of the 20 casings came with an oversized primer pocket which was so large that one could see the flaw with the naked eye. It was about 0.015" over-sized, which meant a primer would rattle around loose in the primer pocket. A defective primer pocket straight from the Norma factory. Huntington replaced that case sight unseen, so good on them.
The Midway USA cases looked highly uniform and polished in comparison. So I set about weighing all of the cases, both from Huntington's and Midway USA. I also measured the cases for pertinent dimensional tolerances. The Midway USA cases are clearly the premier casings, based on both weight and measurement tolerances.
For those with the interest, following is a tabular chart I created to illustrate the differences between the two sources of Norma 8x68S casings. Even though I weighed 50 Midway USA sourced cases, compared to 20 Huntington sourced cases, the Midway USA cases still had an extreme spread in case weights which was 60% less than the Huntington cases. Also note the difference in the outer diameter dimensions of the extractor grooves and rims. The OD of the case webs just forward of the case rims was exceptionally consistent on the 50 Midway USA cases. I measured a sampling of 20 case web diameters and all measured right at 0.5180" diameter, except one case, which measured 0.5175", on my Mitutoyo digital calipers, which read out down to 0.0005". The Huntington brass varied in the case web diameter dimension so much that I simply averaged them when I collected those measurements several months ago.
Never set out on a mission to critique the quality of the Norma cases from the two different sources, but it is what it is. And if we don't share these findings on a Forum such as this one, then we all end up less knowledgeable than necessary. No apologies here to either of my two sources of Norma 8x68S casings.
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jasent
Well-Known Member
Glad I bought 100 from midway
jasent
Well-Known Member
Left to right
375 ruger, 8x68s fire formed, ready to fire form 8x68s
For the record I ran the reamer deeper than standard by about .025"
Looking good. Well on your way with some better quality brass.
I received my 30-8x68S Imp chamber reamer from Dave Manson today. 6-7 weeks from date of my order. That was a pleasant surprise. Was told to expect a 12 week turnaround.
Now I need to select a gunsmith.
I received my 30-8x68S Imp chamber reamer from Dave Manson today. 6-7 weeks from date of my order. That was a pleasant surprise. Was told to expect a 12 week turnaround.
Now I need to select a gunsmith.
I am a novice wildcatter if even that. Currently loading for a 7mm-08 A.I.
I have really enjoyed this thread and have learned much. Really appreciate all of the knowledge on this great forum.
Thanks to all who have contributed to this thread and the link(s) to the others.
I have really enjoyed this thread and have learned much. Really appreciate all of the knowledge on this great forum.
Thanks to all who have contributed to this thread and the link(s) to the others.
