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Post by TGinPA on Jan 2, 2015 11:34:52 GMT -5
375cal Pressure traces: First attempts. We are up and running! I have a gage glued onto a .375cal 28in Krieger barrel generously loaned to me by jims. Shown below (FWIW) are a few “proof of concept” traces of sabotless “landrider” loads using RSI software and equipment, based on use of the I4064 load as a calibration load. If what was seen in the 45cal traces holds true, pressures (and velocities) predicted by QL for mosty bullet/powder combos will be significantly higher than shown in the traces. This is likely due in part to relative lack of pressure buildup normally associated with bullet engraving into the lands for cartridge loads. For both loads, primers were not distorted. The loads shown in the trace below seemed safe in this barrel under conditions present at the time of the test, but may not be under other conditions. More to follow.( as long as the tracing equipment behaves). TG 26J) K375 I4064 60gr 270sp 9.3mm .365 nurl veg d f209 12/31/14 27J) K375 H322 52gr 250 9.3mm nos accubond .365 nurl vwool 1/2/15
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Post by jims on Jan 2, 2015 11:50:31 GMT -5
You have had that barrel less than a week and already posting results. Excellent work and we will be interested in what you find between knurled smooth formed and full formed full diameter bullets.
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Post by edge on Jan 2, 2015 12:02:35 GMT -5
Very nice looking traces.
edge.
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Post by Deleted on Jan 2, 2015 12:49:48 GMT -5
Nice work TG! Thanks
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Post by Dave W on Jan 2, 2015 13:07:19 GMT -5
Thanks Jim and TG! Powder chamber? Hope to push like weight bullets in the 2600-2800fps range when mine is done. Will be watching with great interest!
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Post by rob67 on Jan 2, 2015 19:45:51 GMT -5
Thanks Jim and TG! Powder chamber? Hope to push like weight bullets in the 2600-2800fps range when mine is done. Will be watching with great interest! Yes Thanks Tg and Jims. This barrel does not have a powder chamber. This is exciting to get to shoot rifle bullets in ml. So much so I have started to build another .375.
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Post by Deleted on Jan 2, 2015 19:55:41 GMT -5
Sweet PTs! So when are the 3000 fps traces coming with Retumbo?
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Post by mcgowen45 on Jan 2, 2015 21:41:16 GMT -5
Thanks TG. Now At least i have something to go by. Carlos
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Post by Jon on Jan 3, 2015 7:34:18 GMT -5
Thank you good looking trace very impressive. Keep up the good work.
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Post by Dave W on Jan 3, 2015 9:40:45 GMT -5
Will the .375 traces have their own section?
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Post by TGinPA on Jan 3, 2015 12:22:57 GMT -5
They can go wherever you want to put them. Before that happened, a few are being posted for comment/critique. Here are a few more: 28J) K375 I4350 75gr 270speer 9.3mm .365 nurl vwool 1/3/15 29J) K375 4759/I4350 10/65gr 270 Speer 9.3mm .365 nurl vwool 1/3/15 30J) K375 BlueDot/I4350 5/70gr 270speer 9.3mm .365 nurl vwool 1/3/15 The loads traced above seemed safe in this barrel under conditions present at the time, but may not be under other conditions. TG
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Post by Deleted on Jan 3, 2015 12:43:20 GMT -5
The booster really brings that smooth form to life! Thanks for all your work, are you shooting groups at all or just getting the trace work out of the way?
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Post by TGinPA on Jan 3, 2015 12:50:05 GMT -5
Just the traces.
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Post by Dave W on Jan 3, 2015 12:51:37 GMT -5
Looks like I am going to have to look at a slower burning powder to get where I want to go. Thanks again!
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Post by jims on Jan 3, 2015 23:00:25 GMT -5
I am impressed on how much information you have been able to give already. I know we will have a great deal of useful info between the 9.3 smooth form and the .375 full forms. I hope you find an extremely accurate load as you get further down the road, I am going to speculate that the boattails will not be the ones to deliver it however. You have been pretty consistent on the pressures also with new/ experimental loads too.
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Post by Deleted on Jan 3, 2015 23:50:09 GMT -5
Thanks for your work as always. Can't wait to see what the FF does when you get to that stage.
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Post by rob67 on Jan 4, 2015 8:51:54 GMT -5
Great work and thanks. My results with a ff 235g speer and 80g of I4350 3 shot group averaged 2613 fps. with a 10/70 duplex of 4759 and I4350 3 shot group averaged 2904 fps. 10g of 4759 really brings this load to life, maybe too much. Ventliner wear increased a lot with the duplex from .031 to beyond .033 with 6 shots. I do not advise using this load. This load was shot 4 weeks before pressure traces.
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Post by fishhawk on Jan 4, 2015 9:25:13 GMT -5
Great work and thanks. My results with a ff 235g speer and 80g of I4350 3 shot group averaged 2613 fps. with a 10/70 duplex of 4759 and I4350 3 shot group averaged 2904 fps. 10g of 4759 really brings this load to life, maybe too much. Ventliner wear increased a lot with the duplex from .031 to beyond .033 with 6 shots. When I get a dry day to shoot some I'm going to try 4895 and 4198 a try as a booster You need a bushing!
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Post by fishhawk on Jan 4, 2015 9:42:50 GMT -5
I would think with the smaller bore that a slower booster would be better. I think slower powders should ignite fine in the more confined space. My guess is that 10gr of typical .45 boosters in a gun without a powder chamber are creating very high pressure. As TG ramps up this experiment, I expect to see the need for slower boosters and slower powders. The down side of this is as this happens the total weight of powder will go up creating very long powder columns. Earnhardt has shown the ability to shoot long columns in his .416's, but useable barrel length is lost. Rob67, I would be careful using the above duplex unless TG tries working towards something like that. I fear you might be getting way too much pressure. The velocity you posted is reasonable, but I think you might be getting it with very high pressure with 10gr of 4759.
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Post by TGinPA on Jan 5, 2015 16:07:09 GMT -5
Now we’re getting somewhere (IMO). Same load, smooth and full formed bullets being the variable. Note improved velocity at ? less pressure in the FF trace. Though both these loads are pressure starved, there is some room pressurewise in both for improvement with addition of booster. The problem is that it may not take much booster to get this main to light up a lot. So, it may be best to back way off on the primary, add a small booster and then work up to the high 40psi range with the addition of more H4831. Having pressure readings to facilitate this..Priceless! The loads shown in the traces below seemed safe in this barrel under conditions present at the time of the test, but may not be under other conditions. TG 31J) K375 H4831sc 90gr 270Hornady sp-rp .365 nurl vwool 1/5/15 32J) K375 H4831sc 90gr 270 Hornady sp-rp FF4.7 1/5/15
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Post by fishhawk on Jan 5, 2015 17:46:49 GMT -5
I'm seeing what i expected after playing with my .416. It takes lots of slower powders to make speed with lower pressures. Only issue is, in a .375 bore, 90gr and more of powder make a long column of powder. Earnhardt has proven that long columns can be burned, but lots of useable barrel length is lost. When a powder chamber is added to shorten the column, then the burn rates and pressures are effected which means adjustments in powder type and or volume. You headed in the right direction Ralph, keep up the good work and thank you!
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Post by jims on Jan 5, 2015 19:47:35 GMT -5
Nice comparisons between bullets of similar weight but full formed versus smooth. I actually always felt a little better with a thin veggie wad even full formed. You might consider that in a test of FF and FF with wad. You have enough bullets to try that you will have excellent information for the .375 guys. Pressures some lower also. Any sign of excessive vent liner wear? It is so nice to have some data line to compare versus guessing. Is the 28 inch barrel giving full burn even with the long powder column in your estimation?
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Post by yule on Jan 5, 2015 22:16:12 GMT -5
So, when will we see a 375 sabot with an 8mm bullet... Ha Ha
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Post by fishhawk on Jan 5, 2015 22:30:27 GMT -5
Ralph, What plug is being used in Jim's barrel? Is it a ventliner instead of a bushing. As I've seen with big charges of slow powder in my .416, venliners will not last but a few shots. If you need bushings, a plug modified, or a bushing plug, let me know and I'll help where I can.
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Post by jims on Jan 6, 2015 11:47:57 GMT -5
Unless he switched out the plug it was a factory plug with a vent liner.
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Post by fishhawk on Jan 6, 2015 11:57:32 GMT -5
Unless he switched out the plug it was a factory plug with a vent liner. Thanks Jims! If that is what Ralph is using, the vents won't last. Also with slower powders in .416's, Earnhardt and I have found the need for enlarged flame channel combined with a .030-.035 bushing. The longer dwell time of the the small caliber with slow powders seem to increase primer damage with similar pressures compared to bigger bores. Ralph, I could send my Savage plug that has the flame channel opened some along with .030, and .035 bushings.
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Post by jims on Jan 6, 2015 12:59:26 GMT -5
I was aware of the rapid erosion at times so I also sent him a variety of different vent liners but they may not last long. My concern was not so much in changing the liners but the variance as the hole eroded quickly. That is a variable that a bushing could potentially avoid.
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Post by TGinPA on Jan 6, 2015 16:10:44 GMT -5
375cal: Adding booster to H4831 (270gr full formed .375cal bullet, 2 traces, without/with fiber wad): FWIW, I do not see much effect due to addition of a wad. The loads shown in the traces below seemed safe in this barrel under conditions present at the time of the test, but may not be under other conditions. With a 30in bbl, one might be able to exceed 2800fps with this bullet and powder combination. But pressures needed might be close to 60kpsi? Fishhawk: Thanks for your offer. But,I do have an assortment of tungsten bushings (thank you Earnhardt). Several traces ago, (same bullet, slightly smaller charge of h4831) I saw significant primer distortion when I tried a .031 bushing with a plug having 10/32in flame channel. That caused me to go back to Jim’s ventliner plug which I have used for most .375 traces up until today. Today, for these 2 traces, I swapped in a bushing plug with a larger flame channel (flame channel = 7/32in.) using the same .031in bushing. This seemed to work well with no damage to the primer. TG 33J) K375 4759/H4831sc 10/75gr 270 .375cal Hornady sp-rp FF4.7 nowad 1/6/15 34J) K375 4759/H4831sc 10/75gr 270 .375cal Hornady sp-rp FF4.7 veg 1/6/15
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Post by fishhawk on Jan 6, 2015 17:23:06 GMT -5
How about H4198 as the booster in duplex loads? I would also like to see more H4831 in a single powder, but I know slow and steady, we'll get there..
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Post by jims on Jan 6, 2015 17:46:01 GMT -5
I like the progress and combos you have been trying. I got the barrel at 32 inches but cut it down for the die etc. I did not want it to long for use but for testing perhaps it would have been better but did not know it would be a test barrel. Keep it coming.
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