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Post by jims on Jan 26, 2009 11:08:38 GMT -5
I thought that might draw your attention. Now with the disclaimers, that is in a .375 smokeless and before the project was completed through ignorance on my part I bulged a barrel.
It is no particular secret here that I have been working on a .375 smokeless. I did not want to post much until I could give some "workable" loads. That was a major mistake on my part, I should have been getting more information from those in the know on this board without trying things on my own.
I will share what I can to hopefully help others perhaps going down the path or wrong path on their own.
I have a .375 Krieger barrel with .366 lands. It is a 1 in 12 twist with the same contour as the Savage barrel it replaced. It was initially 24 inches long, now it is 22 inches long. It now uses the standard Savage breech plug. The barrel is threaded to accept a Vias muzzlebrake.
Here is the more vital information. Using MMP .36 caliber grey sabots, combined with 125 grain Hornady SP spire point 8mm bullets (.323), compacted powder of VV120 at 78 grains, with a Mike's cushion wad (1/2 inch) between the powder and the sabot and a CCImag primer the speeds were 3585 fps, 3569 and 3580 fps. Accuracy was lacking. The wad was tight enough that it filled the grooves so when one looked there was no light to be seen in the grooves as with the sabot alone. All this now to ask the pressure that may have been there. No shooting is being done at this time until I establish some new safe guidelines.
A "similar" load was the same combination as above except I used a 150 grain Sierra SP bullet and the speed was 3392 feet per second. Pressure thoughts.
I used a variety of saboted and non saboted bullets and powders. I will list them later so as not to overload anyone but generally the sabotless bullets were nearly twice as heavy and speeds were more in the 2400 to 2700 fps range except with a Hawk 200 grain sabotless that was near 3000 fps.
I do not recommend ANYONE try any of these at this time until I have more data. One damaged barrel and pride is enough.
I can supply powder column lengths later if needed as I will have to remeasure or find where I put that information as it got separated.
Keep in mind the barrel for future use is now 22 inches long and uses the standard Savage breechplug.
Accuracy was the best with my initial powder of IMR 4350 and 286 grain Noslers sabotless but the speed was only in the mid 2300s, no gain off the factory Savage except for a true center fire bullet. Also some of the sabotless bullets wanted to keyhole about 20% of the time so that did not instill any confidence in that combination either. Alot of information but I hope to give more if any interest and in the hope of ideas/future safe loads etc.
I will await to hear from this sage group.
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Post by rbinar on Jan 26, 2009 11:40:39 GMT -5
My first impulse is to lament that you gave up on the 286 grain bullet shooting 4350. At only 2350fps it is very likely you were shooting a pressure anemic load and that was why the bullet would keyhole.
With 4350 speeds of at least 2400 to 2500fps are possible and that would not be at a very high pressure though I can't tell you an exact load I think anything short of 80 grains is in the works and can be explored by starting at 70 to 72 grains and working from there.
Data for the 375 Holland shows that 80 grains of H4350 shoots to about 42,000cup with a 270 grain bullet. Though your bullet is a little heavier you could come near that at the same pressure. Speed for the Holland was 2600fps but the barrel was 2" longer than your original.
My thoughts on pressure for the other loads later after some thinking.
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Post by sw on Jan 26, 2009 14:31:55 GMT -5
Jim,
I haven't tried to calculate the CUP but think that VV-120 is extremely fast for the application.
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Post by edge on Jan 26, 2009 18:24:04 GMT -5
Jim, I haven't tried to calculate the CUP but think that VV-120 is extremely fast for the application. If I assume that the total payload was about 135 grains then Powley would suggest IMR3031 as a starting powder. What that 1/2 inch wad does under extreme pressure I have no idea! edge. |
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Post by jims on Jan 26, 2009 21:37:46 GMT -5
To RB and edge: The 1/2 inch wad I do not think I will use again. It was involved with the barrel failure. If I use it again I plan to cut it in half so it would be at best a 1/4 inch wad unless that is even too much if you believe.
RB, I did shoot with a series of IMR 4350. With 200 grain Hawk 9.3mm bullets sabotless and Mike's Cushion Wad I got 2766 fps with 60 grains of powder, 65 grains gave 2821 and 70 grains gave 2969 fps. With 70 grains and no Mikes wad but two overpowder wads I got 2975 fps.
With 125 grain Hornady SP spire points in 8 mm with the MMP .36 sabot and no wads with IMR 4350 I got 2797fps with 75 grains of powder, 79 grains said 2766 and 82 grains gave 2941 fps. I shot 78.1 grains with that bullet into lined up 1 gallon water filled milk jugs, the bullet stopped in the fourth jug, shed its jacket and had a retained weight of 105 grains, the lead expanded to .533. Later I shot the same load and had a squib load.
I shot IMR 4350 with the 150 grain Sierra Spitzer, MMP .36 caliber sabot and no wads. With 75 grains I got 2606 fps but the bullet keyholed. With 82 grains I got a squib load.
With the 286 grain Nosler sabotless Partition with IMR 4350 I got the first time out my best group of just over 1 inch with 80 grains of powder. Things went downhill from there. Wilth 75 grains of powder I got 2302 fps, 79 grains 2368. I tried with a 250 Nosler boattail but it keyholed. I got most of my keyholes with the boattails. This is a 9.3 mm bullet.
Edge: I did use some 3031. I got a 2 inch group with the 250 Nosler boattail in 9.3mm with 56 grains of powder with speeds of 2524, 2704, anad 2467fps. I used 4320 with the same bullet and got a 2 inch group with speeds of 2408,2454, and 2450 fps.
I have also tried VV140.
The absolute wrong powder I used and the source of the problem was too large of load of SR 4759 sabotless. I will not list that as it SHOULD not have been used. That is not everything I think I shot but is a fair representation. Again thoughts . I can stand the criticism I know I deserve on that last one.
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Post by ET on Jan 26, 2009 22:31:08 GMT -5
Jim
Far be it from me to criticize from one who fired a double load and bulged a barrel. When we go to uncharted loads that is a choice or making an error then the consequences are ours to bear. We learn from our mistakes that hopefully don’t result in a major loss and we usually become the wiser.
If anything I am enjoying the way you are now approaching your load development as an example to others. Good luck with your project and hope to see more results on a positive note.
Ed
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Post by rbinar on Jan 27, 2009 4:35:34 GMT -5
I have a .375 Krieger barrel with .366 lands. It is a 1 in 12 twist with the same contour as the Savage barrel it replaced. It was initially 24 inches long, now it is 22 inches long. It now uses the standard Savage breech plug. The barrel is threaded to accept a Vias muzzlebrake. Here is the more vital information. Using MMP .36 caliber grey sabots, combined with 125 grain Hornady SP spire point 8mm bullets (.323), compacted powder of VV120 at 78 grains, with a Mike's cushion wad (1/2 inch) between the powder and the sabot and a CCImag primer the speeds were 3585 fps, 3569 and 3580 fps. Accuracy was lacking. Pressure thoughts. For pressure estimates I had to make a few assumptions. For one the wad you used shortened the track of the bullet. That generally means more pressure for a given speed. However that could be partially offset if the wad compresses because that would be the equivilant of a larger case. I also had to guess the weight of the wad and sabot. I gave them a bit more than they probably weigh at 15 grains so the total weight of the 125 grain bullet load was 140 grains. Using the original barrel length and a bulk density of 1.04 for N120 the pressure estimates at no less than 54400cup or 66000psi. Without comment of where I'd go from there I'll just say that's pretty steep. |
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Post by jims on Jan 27, 2009 12:00:54 GMT -5
I can weigh the wad but I do not think it is necessary as it is way higher than I wanted to hear. I hate to even imagine what the 4759 charge pressure was.
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Post by edge on Jan 27, 2009 14:44:41 GMT -5
 Powley generally keeps you around 45,000 psi! Personally I would tend to use the suggested powder OR slower and add a bit of duplex to tune the speed. Without a case you can't gage bolt lift or case stretching! edge. |
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Post by edge on Jan 27, 2009 15:27:36 GMT -5
SNIP Edge: I did use some 3031. I got a 2 inch group with the 250 Nosler boattail in 9.3mm with 56 grains of powder with speeds of 2524, 2704, anad 2467fps. SNIP With no wad powley would suggest imr-4064 NOT 3031 edge. |
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Post by jims on Jan 27, 2009 17:01:28 GMT -5
ET, RB, edge and sw: I appreciate the information. Keep it coming. I will feel a lot better when I restart again. I have some Norma 9.3mm in 232 grains coming and some Barnes 9.3mm in 250 grain Triple-Shocks coming and a Lee Resizer die in .365. Hopefully a combination there can be found, I think that will work. The most help I can get I think at this time is with the powders and amounts. A good safe starting load and I can work up safely from there. Thanks again.
I had cut some of the sabots petals off and just used the flat base between the powder and bullet (sabotless), I do not know if that has any disadvantages or just use the fiber or felt wads?
I also compact the powder with a 7/16 dowel, again problems. The powder column is so long I wanted to firm it up, I do not stand on it with pressure. I also use a long drop tube in putting the powder in so it does not hang up on the barrel.
The barrel is extremely slick, almost like a mirror. Would that cause trouble with sabots?
I actually would rather shoot with sabots and the 8mm bullets versus the 9.3mm sabotless. Whatever shoots best, at least I have two options potentially. Thanks. I will have more questions so stay in touch.
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Post by dougedwards on Jan 27, 2009 20:36:14 GMT -5
So Jim.......you actually ordered the 38/55 caliber barrel from Krieger correct? Not the 9.3mm?
Doug
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Post by dave d. on Jan 27, 2009 20:51:37 GMT -5
:)jim i don't think the slick barrel is a problem when shooting sabots i think it is a benefit.i've been watching your progress and sorry i couldn't help out but i think the big 3 will get you shooting bugholes with that slick caliber you are shooting.best of luck
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Post by jims on Jan 27, 2009 22:45:50 GMT -5
To dougedwards: The barrel is a .375 Krieger (groove size). It is what you would call a .375 if it was a centerfire rifle. The lands are .366. If it were centerfire you would shoot .375 bullets out of it. In a muzzleloader you cannot, I can barely get .366 (9.3mm) bullets down the barrel without chilling them. I just ordered a Lee resizer today in .365 to slightly reduce the .366 to a more manageable size. If they get undersize I will try to knurl them back up.
Lee could not guarantee me a .3655 size, the best they guarantee is .001 tolerance. I asked them to try for a .3655 and they said they will try but the best they can say is plus or minus .001 so I could get a .364 or a .366. I was going to order two sizes at once but they recommended against that. We shall see but it could be 6 to 8 weeks. It is a slow process but I am in no hurry this time. I have a .50 that shoots extremely well so it is always there plus I have an SMI barrel in a .50 on the Savage action. That is the gun my daughter got her first deer.
I have a different scope in trade coming for that, she got to like the higher powered scopes except for the recoil to the eye. We will work on that.
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Post by dougedwards on Jan 28, 2009 6:16:21 GMT -5
OK I understand now. I was thinking that you had ordered the 9.3mm but the land to land is actually 9.3mm and a .375 groove diameter. Thanks for clearing that up.
Doug
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lc
Forkhorn
Posts: 72
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Post by lc on Jan 28, 2009 14:51:33 GMT -5
jims did I help stimulate some of these questions by pm you with my 375-06 loads last week?
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Post by jims on Jan 28, 2009 15:09:17 GMT -5
lc: Yes, thanks
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Post by jims on Jan 28, 2009 19:30:56 GMT -5
Is there any application of VV140 with the saboted or sabotless loads. I saw a 9.3mm use it once. With where it is in the powder charts any feasible use with the .375?
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Post by edge on Jan 29, 2009 6:43:07 GMT -5
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